Abstract
The working conditions during the preparation and extraction of solvents from various plant parts significantly improved plant-based coagulants used in water treatment. The study reviews the performance of plant-based coagulants in reducing turbidity, total hardness, heavy metals, and microorganisms, emphasizing dosage variations across different plant types. Utilizing specific keywords for searching plant-based coagulants status and organizing data into descriptive analysis were applied. The preparation process results of plant-based coagulants involved particle size, mixing speeds, drying temperature and time were presented. Again, performance results of the plant-based coagulants indicated the average turbidity removal performance ranged between 78 and 87.3%, heavy metal removal ranged from 59 to 98%, hardness reduction ranged from 15.45 to 43.3%, and microbial elimination ranged from 91 to 92% using solid dosage levels ranged from 0.5 to 10.3 g/L and liquid dosage level ranged from 2 to 54 mL/L, respectively. The actionable suggestions for implementing plant-based coagulants for up scaled in water treatment systems were presented. Therefore, the findings would support the optimization of dosage level from various plants for commercialization in water treatment applications.
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1 Introduction
Water treatment minimized the presence of contaminants in the polluted water to reach the minimum level for consumption in social and economic activities [1]. The organic coagulants are mixed with contaminated water to get optimal pH values, clear up suspended colloidal, and lessen turbidity, hardness, heavy metals, and microbes. In a chemical reactor, the process generally involves polluted or influent water entering a basin, where it is combined with organic coagulants using a mechanical mixer before moving on toa settling basin for filtration [2]. Organic coagulants effectively neutralized negatively charged contaminants in water, causing them to aggregate and settle at the bottom of treatment basins, thereby clarifying the water above [2, 3].
Organic coagulants are obtained from plant-based, animals and microorganisms [4]. Plant-based coagulants are derived from various plant parts, such as seeds, leaves, roots, bark, flowers, cones, buds, and fruits, and are increasingly utilized for water treatment. A notable example is Moringa oleifera, which employs seeds, leaves, roots, and bark [5, 6]. Cactus used leaves part [5], while Moringa stenopetala used leave and root parts, orange used peels part, Luffa fruit mucilage [7, 8], and Calotropis procera used flowers part [9] to purify polluted water. Examples of animal coagulants are chitosan and crustacea, while microorganism coagulants include bacteria, algae, and fungi [10]. Plant-based coagulants offered advantages over animal and microorganism-derived coagulants due to their non-toxic [11], biodegradable nature [12], and environmental sustainability, making them safer for human consumption in water treatment processes [13]. Additionally, sources of plant-based coagulants are available locally and demonstrated effectiveness across a range of water quality [14], unlike animal and microbial coagulants, which have more limited applications [15, 16] and pose health risks due to potential contamination [17].
Plant-based coagulants are rich in bioactive compounds that play a vital role in water treatment by promoting the removal of impurities. Bioactive compounds are classified into several chemical groups, including glycosides, phenolic, proteins, alkaloids, tannins, mono-, di-, and sesquiterpenoids, phenylpropanoids, lignans, resins, furocoumarins, naphthodianthrones, and peptides [18]. The specific bioactive components and their effectiveness depended on the plant species, part of the plant used, extraction methods employed and geographical location [19]. Conventional extraction methods such as maceration, soxhlet, and hydrodistillation are employed during the extraction of bioactive compounds from plants [20]. However, other non-conventional extraction methods, including enzyme, pulse electric field, supercritical fluid, ultrasound, microwave, and pressured liquid extraction, gained attention with high efficiency and reduction of the environmental impact compared to conventional extraction methods [21].
The water quality parameters include turbidity, total hardness, heavy metals, and microbes [22]. For instance, Moringa oleifera used dosages of 200 mg/L to 0.2 mg/L for turbidity removal [23, 24], dosages of 150 mg/L to 0.1 mg/L for hardness removal [25, 26], dosages of 60 g/L to 0.05 mg/L for heavy metal removal [27], while dosages of 200 mg/L to 50 mg/L for microbial removal [28, 29]. However, local sourcing of plant materials reduced costs and promoted sustainable practices [30]. Determining the optimal pH is crucial for the effective functioning of plant-based coagulants, as the medium’s acidity or alkalinity significantly affects coagulant efficiency by altering its surface charge or causing contamination, with Moringa oleifera demonstrated the best performance at pH 2, achieved turbidity of 81% [31]. Aloe vera was obtained at pH 12 turbidity of 99.13% [32]. Dolichos lablab seeds reduced turbidity by 74% at pH 9 [33]. Theobroma cacao at pH 4.5 removed 90% of Lead metal [34]. Banana pith at pH 4 eliminated Copper 100% [35]. Moringa oleifera removed Coliform 97.50% [36]. Banana peels and pith were used to remove turbidity by 99.1% at a temperature of 26 °C [37]. Moringa olifera and Moringa stenopetala, as a coagulant with 0 to 40 °C temperature, removed Cadmium metal by 70.7% reduction, compared to only 82.7% at 0 to 60 °C [38]. The maximum turbidity reduction was 66.20% and 76.06% for temperatures 10 °C and 18 °C, respectively, at the pH range of 6 to 9 [39].
Natural variability factors such as plant species, growth conditions, harvest times, and environmental conditions affected their coagulation efficiency [40]. However, the presence of bioactive components in plants fluctuated due to soil types, water quality, and seasonal changes, which impacted their concentration [19]. The advantages of plant-based coagulants over other inorganic or chemical forms are that they are cheaper, locally accessible, environmentally friendly, produce less sludge, and are mainly used as a disinfectant [41, 42]. The disadvantages of using plant-based coagulants largely depend on plant source availability, storage duration, and release of organic content into the treated effluent, which increases chemical oxygen demand, biochemical oxygen demand, and total organic carbon concentrations [43]. Again, plant-based coagulants are mainly affected by several parameters such as temperature, effects of polymer molecular weight and price density, consequences of mixing situations, pH level, ionic strength type, and dosage level [44]. This paper addresses the common consideration factors during preparation and extraction of solvents from different parts of plants. Researchers also review the performance of various amounts of plant-based coagulants to clean water, like turbidity, total hardness, heavy metals, and microorganisms, against the dosage amount from different plant types for scale-up consideration.
2 Methodology
2.1 Sources of information and search strategy
The keywords such as “plant-based coagulants”, “natural coagulant”, and “Organic coagulants” for “water treatment” were used to search the research articles, reviews, and reports under Google Engine/Google Scholar and ScienceDirect databases. Using Bibtex in Google Scholar with Jabref software to convert reference format style.
2.2 Review criteria consideration
The performance parameters such as turbidity removal efficiency, optimal dosage, pH, settling time, and other numerical preparation process indicators were presented in quantitative data. Quantitative research is based on previous research to provide proper knowledge that would be logically formulated into the theory and behavioral patterns of an interested field [45]. In addition, this study used descriptive data grouped into tables and flowcharts. Criteria conditions used in this review article were chosen related to the factors shown in Table 1.
2.3 Topology of the plant-based coagulants
The structure of plant-based coagulants is based on understanding how plants are converted into coagulants and their role in water purification. The topology of the plant-based coagulants included knowledge of the basic properties of plants, extraction techniques of the coagulants, and processes used to purify water. Figure 1 gives a complete overview of the preparation and use of plant-based coagulants based on insights from 15 reviewed articles on this topic. The reviewed articles also presented plant science to bench-scale practical applications in water purification [23, 46,47,48,49,50].
3 Experimental procedures of plant-based coagulant
3.1 Preparation processes
Plant-based coagulants play a vital role in treating polluted water. The most common stages of preparation and processing of plant-based coagulants include primary, secondary and tertiary stage, which comprises the selection of usable plant, washing, drying, grinding, sieving, extraction, filtration, and purification [59, 60], and flowchart is described in Yin [23]. These processing stages exist because most plant-based coagulants are not readily available and require some preparation steps to be a usable product in water treatment [61]. The primary stage of different plant-based coagulants is illustrated in Table 2. This summary shows typical particle sizes for different plant-based coagulants ranging from 0.075 to 2.5 mm. In the secondary processing stage (extraction) in plant-based coagulation, different solvents have been used in the process of extraction of active components to enhance the coagulation processes, which are distilled water, potassium chloride (KCl), sodium chloride (NaCl), potassium nitrate (KNO3), sodium nitrate (NaNO3), barium chloride, sodium hydroxide, and ammonium chloride [51].
Table 3 shows plants with various extraction solvents with turbidity removal efficiency. Different days were applied for drying the plant-based parts; they ranged from 4 weeks to half a day, either directed by the sun energy for a longer duration or an electric oven with a temperature between 35 and 105 °C for a shorter duration. The grinding process was conducted, followed by sieving analysis to reach particle sizes ranging from 1 to 0.15 mm. The tertiary processing stage includes techniques like lyophilization, ion exchange, and dialysis. These methods are costly and not often used with plant-based coagulants. However, they yield pure bioactive compounds when used, reducing the amount of plant-based coagulants needed for water purification. This stage requires intricate procedures and advanced facilities [62].
The solvent used in the extraction methods (Table 4) depends on the polarity of the target compound, the molecular affinity between the solvent and solute, mass transfer, environmental safety, human toxicity, and financial feasibility [20]. Tannins are typically extracted through solvent extraction (using ethanol or methanol), microwave-assisted extraction, or ultrasonic extraction; Terpenoids are extracted using steam distillation, solvent extraction, or supercritical fluid extraction [90, 91]; Plant-based proteins from seeds, nuts, and legumes extracted using water extraction, enzyme-assisted extraction, or ultrasonic extraction; Phenolic and glycosides compounds found in fruits, leaves, and whole grains, extracted using solvent extraction, ultrasound-assisted extraction, and microwave-assisted extraction [92]. Lastly, polysaccharides from plants like aloe vera are extracted using hot water extraction, enzyme-assisted extraction, and ultrasonic extraction [91]. Flavonoids found in fruits and leaves are obtained via solvent extraction, ultrasound-assisted extraction, and supercritical fluid extraction [18, 91]. Various bioactive compounds are found in different plants, each extracted using specific methods suitable for water treatment.
The effectiveness of plant-based coagulants in water treatment is closely tied to their bioactive compounds (like tannins, flavonoids, saponins, and proteins) and their functional groups (such as hydroxyl, carboxyl, amino, phenolic, and sulfhydryl), which aid in neutralizing contaminants and forming flocs, making them a sustainable alternative to chemical coagulants [99]. The Fourier Transform Infrared Spectroscopy (FTIR) is crucial for identifying functional groups in coagulants, revealing molecular structures that contributed to coagulation [100], such as amines and carboxylic acids found in Moringa oleifera extracts [101]. Scanning Electron Microscopy (SEM) provided high-resolution images of the coagulants surface morphology and particle size, showing porous structures that enhance floc formation and adsorption capacity [102]. Studies have shown that the morphology of plant-based coagulants, such as those derived from Tamarindus indica and Moringa oleifera, reveals a porous structure that enhances floc formation [52]. Coupled with Energy-Dispersive X-ray Spectroscopy (EDX), which analyzed the elemental composition, such as the presence of metal ions and other elements, like calcium and magnesium [103]. Furthermore, EDX helped to identify any impurities in the coagulants, which may influence their performance and suitability for water treatment applications [52]. FTIR, SEM, and EDX offered valuable insights into plant-based coagulants’ chemical, physical, and elemental properties, aiding in their optimization for sustainable water treatment solutions [104].
3.2 Factors affecting plant-based preparation
Dehusking is essential for increasing the purity of the coagulant by removing the outer layers. Drying improves the stability shelf-life of coagulants and enhances the solubility of active components [105]. Grinding enhanced the small particle sizes of plant parts to increase interaction with contaminants. In contrast, larger particles tended to reduce surface area and slower settling rates, which impeded the coagulation process [106]. Sieving ensured the uniform particle size [50]. Different contents of the bioactive components in the plants enhanced different extraction solvents, preferably salt and distilled water. Salt and alcohol solvents achieved a 5% increase in turbidity removal than water solvents [105]. Other plant-based coagulants had varied charges to destabilize particles with factors such as size and charge of suspended particles, dosage or concentration, turbidity, temperature, mixing speeds and pH level.
The size and charge of suspended particles affect how easily they can be destabilized and aggregated. Particles larger than 1micron are generally easier to remove through coagulation [107]. The optimal dosage for plant-based coagulants depended on the specific plant extracts and water characteristics [32]. As too little dosage may not effectively remove impurities, too much leads to excess sludge and introduces other contaminants. Sufficient time is necessary for particle aggregation; too little time is allowed for proper settling [108]. Low initial turbidity resulted in fewer collisions between the coagulant and pollutants due to the lower number of pollutant particles or vice versa. Low turbidity produced smaller flocs, slowing the sedimentation process and extending the time required for sedimentation [43].
Moreover, temperature impacted coagulation kinetics, and cold water required more coagulants and longer mixing times; lower temperatures reduced the movement of particles and solubility of coagulants, while warmer temperatures improved particle collision rates [109]. The initial rapid mixing speed should occur between 100 and 150 rpm for about 1–3 min, followed by slower mixing at around 20 to 30 rpm for 10–20 min to allow flocs formation and settling. Improper mixing speeds led to incomplete coagulant dispersion or breaking up of formed flocs, resulting in poor performance [110]. The optimal pH range is typically between 6.5 and 8.5; too low or too high pH reduces coagulation efficiency [111].
3.3 Experimental procedures
The experimental procedure involved measuring the polluted water and coagulant dose in the Jar test apparatus. The Jar test apparatus included various components essential for testing water samples in a treatment experiment, as shown in Fig. 2. Water containers or beakers (1) hold the water samples, each containing different dosages of coagulants to evaluate their effectiveness. A mixing paddle (2) agitated the samples to simulate mixing conditions in the water containers, ensuring even distribution of the coagulants. The control panel allowed the operator to adjust settings such as the mixing speed button (4) The time settings (5) helped control different phases of the experiment, while a general switch (7) turned the device on or off, powering the stirring mechanism and related instruments. Additionally, lighting (3) with light switch (6) is provided for visual observation of floc formation and settling, aiding in assessing treatment effectiveness. The jar test is vital for obtaining the optimal coagulant dose to clean a specific volume of polluted water [113]. The other controlled parameters included revolution per minute and mixing time until all contaminants settled down. Table 5 summarizes different types of plant species, the time taken, and the revolution per minute required to acquire clean water. The lowest dose of coagulant that provides satisfactory settling is used to treat the polluted water [114]. The Jar test experiment required the rotational speed for slow mixing, which ranged from 20 to 60 rpm; rapid mixing ranged from 80 to 300 rpm, and the time taken to complete one batch ranged from 38 to 392 min.
Schematic diagram of jar test apparatus Modified from Kumar et al. [112]
3.4 Optimization of plant-based coagulants
Process optimization refers to adjusting a process to optimize a specified set of parameters without violating constraints to reduce operating costs while increasing throughput or efficiency [125]. There are various techniques employed for optimizing the parameters of the plant-based coagulants in water treatment, such as Response Surface Methodology (RSM) [31], and Genetic Algorithms (GA), which mimic natural selection to find optimal solutions through mutation and crossover [126]; Artificial Neural Networks (ANN), which model complex systems to predict coagulant performance [127]; Taguchi Method, which uses orthogonal arrays for efficient experimentation [104]; and hybrid models that integrate various techniques, such as GA with ANN or RSM, enhanced prediction accuracy [127].
The RSM is the most common helpful tool used for optimization. The RSM comprises experimental design, analysis, and modeling of the observed variables through partial regression fighting. The most common designs used by RSM are central composite design (CCD) and Box–Behnken Design (BBD) [128]. Also, experimental data obtained from the CCD model experiments can be stated in the forms expressed in Khettaf et al. [129]. The BBD depended on the number of experimental runs required, while the CCD depended on the factorial design to build a second-order (quadratic) model for the response variable [130].
In the RSM technique, the most common controlled factors/parameters in plant-based coagulants are input variables such as dosage, temperature, mixing speed, pH, and mixing time. The output results are response variables such as turbidity, hardness and colour removal [131]. Compared with the traditional method, the merits of RSM require many experiments, allow studying any variables simultaneously, and make it possible to study the interactions between the variables precisely within a short time [132]. Studies reported that several preliminary experiments were conducted to screen the appropriate parameters and determine the experimental domain [129].
Owoicho et al. [133] used banana stem juice coagulant with the employed RSM to optimize the raw water process by conducting an initial test using design expert version 10 by consideration of three, using the Box Behnken design, which determines the influential factors, level, and range of the input values for the RSM. Also, the quadratic function was identified to have the best response function for experimental data of response variable for turbidity removal with achieved turbidity removal of 58.07% at pH 6.5 after 60 min retention time with a dosage of 7.5 mL/L. Obiora-Okafo and Onukwuli et al. [134] studied the optimization colour removal efficiency of plant-basedcoagulants for Vigna unguiculata, Telfaria occidentalis, Brachystegia eurycoma, Vigna subterranean, Moringa oleifera and obtained maximum values of 90.74%, 99.73%, 99.44%, 89.92%, and 98.92%, respectively. Also, the optimal conditions for optimum efficiencies were established using the RSM approach. Some plant-based coagulants derived from Hibiscus esculentus, okra, sweet dater, and cocoyam using Box–Behnken Design indicated the optimum removal of turbidity ranged between 60 and 92.6% at pH range 2–4, dosage 100–200 mg/L, settling time of 30 min [135]. Usefi and Asadi-Ghalhari [136] and Li et al. [137] employed RSM to optimize the coagulation process using different natural coagulants such as Moringa oleifera and rice starch, whereby optimum operating conditions were generated for each coagulant, and lower the turbidity and increased colour removal efficiency. The optimization techniques built a robust prediction accuracy framework for enhancing the effectiveness of plant-based coagulants and improving sustainable water treatment practices.
4 Performance characteristics of plant-based coagulants
4.1 Turbidity removal/reduction efficiency
All plant-based coagulants have a highly effective capacity to remove turbidity, with few having the capacity to achieve up to 99% comparable with the performance of the chemical coagulants [23]. Table6 shows over 40 plants that reduce turbidity based on different dosage levels. Since then, Moringa Oleifera has been used as a plant-based coagulant to treat water using seeds, roots, leaves, flowers, and bark [138]. The kernel from seeds of Moringa Oleifera naturally dried for medium and high turbidity with the optimum dosage of 50 mg/L and 100 mg/L has the efficiency of turbidity removal of 90.46% and 88.57%, respectively, due to adsorption between coagulation bioactive components in Moringa oleifera and particles of suspension to permit inter-particle bridging [139].
4.2 Hardness removal efficiency
The quantity of divalent ions such as calcium and magnesium in water, which is derived from bearing rock types rich in calcium and magnesium, is used to define the level of total hardness (TH) [159]. The water hardness problem is reported in various places worldwide [160]. Table 7 illustrates the dosage level and removal efficiency from more than 15 different types of plants. The use of Moringa Oleifera seeds in coagulation gave hardness removal from 0 to 15% with an optimal dosage of 125 mg/L [40] or removal efficiency of about 23% to 34% [161, 162].
4.3 Heavy metals removal
Often, heavy metals are in ionic form when present in water and usually do not degrade quickly, leading to accumulation in human systems and causing disease due to their toxicity even at low concentrations [168]. Primary sources of heavy metals are derived from different industries such as dying, textiles, leather, mining, pesticides, plastic, wood, and pharmaceuticals [169]. Most heavy metals found in water are Chromium (Cr), Cadmium (Cd), Mercury (Hg), Arsenic (As), Zinc (Zn), Copper (Cu), Iron (Fe), Aluminum (Al), Barium (Ba), Lead (Pb), Manganese (Mn), Silver (Ag) and Selenium (Se). The main mechanisms of heavy metal removal by coagulation are adsorption, co-precipitation, and complexation [170]. Table 8 shows more than 12 different types of plants used to remove heavy metals in the polluted water. Tamarindus indica and Moringa Oleifera coagulants are treated with heavy metal with the optimal dosage of 0.1 g/L for each plant coagulant. They achieved the removal of efficiency for Cr is 62%, Cd is 73%, Zn is 70%, and Cr is 58%, Cd is 70%, Zn is 65%, respectively [26]. Shan et al. [171], using Moringa Oleifera as a coagulant, the performance results based on removing Fe, Cu, and Cd were 92%, 98%, and 98%, respectively.
4.4 Microbial removal efficiency
Plants are rich in a wide variety of secondary metabolites, such as tannins, terpenoids, alkaloids, flavonoids, and so forth, which have been found to have antimicrobial properties in vitro [179]. Table 9 illustrates different types of plants used for microbial reduction during water treatment with other performances. Flavonoids are produced by plants in response to microbial infection [180]. Flavonoids are active in directly destroying the cell walls of gram-negative and gram-positive bacteria and acting toward specific molecular targets essential for the survival of the microorganisms [181]. Tannins are found in almost every plant part: bark, wood, leaves, fruits, and roots [182]. Tannins showed antiviral, antibacterial and antiparasitic effects; their antimicrobial action may be related to their ability to inactivate microbial adhesions, enzymes, and cell envelope transport proteins [183].
Alkaloids have microbiocidal effects against Giardia and Entamoeba species. The mechanism of action of highly aromatic planar quaternary alkaloids such as berberine and harmane is attributed to their ability to combine with bacteria DNA [187]. Terpenoids are active against bacteria, fungi, viruses, and protozoa [188]. The mode of action of the terpenoid compounds is not fully known but is thought to contain lipophilic compounds for membrane disruption of bacteria [189]. Different percentages of crude alkaloids, phenols, tannins, flavonoids, and saponins on medicinal plants were presented by Edeoga et al. [190]. Using Neem oil with a minimum dosage of 2.13 g/L had an efficiency of E. coli removal that was more significant than 99%. Different efficiency removal was observed when the dosage was altered [184]. Only a limited number of studies have reported that the removal of microbial cyanobacteria was greater or equal to 70% using all types of plant-based coagulants [55].
4.5 General performance of plant-based coagulants
Using data in “Turbidity removal/reduction efficiency”, “Hardness removal efficiency”, “Heavy metals removal”, “Microbial removal efficiency” sections, Fig. 3 shows the general performance of the plant-based coagulants toward turbidity, heavy metals, total hardness, and microbes removal based on the solid dosage. This study collected 38 plants that used an average dosage level of 0.5 g/L to reduce turbidity with an average performance efficiency of about 78%, followed by 18 plants used average dosage level of 6.14 g/L to reduce total hardness with the average performance of 43.3%; 16 plants used average dosage level of 10.3 g/L to reduce heavy metals with the average performance of 59%, and lastly, 8 plants used average dosage level of 1.7 g/L to remove microbes with the average performance of 91%. Again, using liquid dosage, Fig. 4 shows the general performance of the plant-based coagulants toward turbidity, heavy metals, total hardness, and microbes removal. About 13 plants used an average dosage level of 13.4 mL/L to reduce turbidity with an average performance efficiency of about 87.3%, followed by 3 plants used average dosage level of 5.4 mL/L to remove microbes with the average performance of 92%; 1 plant used average dosage level of 2 mL/L to reduce total hardness with the average performance of 15.45%, and 1 plant used average dosage level of 54 mL/L to reduce heavy metals with the average performance of 98%. Different plant species that remove heavy metal and total hardness with advanced techniques would be encouraged to improve performance efficiency. Liquid coagulants absorb quickly and act faster, while solid coagulants take longer to absorb because they must dissolve first.
The general performance of the plant-based coagulants toward turbidity, heavy metals, total hardness, and microbes removal using solid dosage
The general performance of the plant-based coagulants toward turbidity, heavy metals, total hardness, and microbes removal using solid dosage
4.6 Practicability of the plant-based coagulants
Research on plant-based coagulants has progressed significantly. However, process development beyond lab scale remains in its early stages with several tests at all levels, including bench, pilot, and semi/full process scales [49]. Plant-based coagulants exhibited impressive coagulation capacity towards turbid particles and microbes, with some effects observed on water quality parameters [85]. Concerning softening hard water, Moringa oleifera seed extracts were effective at the expense of relatively high dose applications [191]. From bench-scale trials, extracts of Moringa oleifera, Strychnos potatorum, Plantago ovate, and Trigonella faenumgraecum were proposed as suitable plant-based coagulants [85]. Pilot-scale coagulation trials with Moringa oleifera seed reduced turbidity and counts of total coliforms, fecal coliforms, and fecal streptococci in treatment plants [49]. Semi and full process scale coagulation plants using Moringa oleifera seed extracts provided robust performance, was comparatively cheap to install, and were modular for removing turbidity and microbial [192, 193].
Commercialization of organic coagulants is hindered by two main challenges: the practicality and feasibility of real field applications, which have overlooked technical, environmental, economic, and social aspects [62]. The acceptance of natural coagulants in water treatment plants is low due to several critical challenges that impede commercialization. Key issues include a lack of industrial confidence regarding their cost-effectiveness and performance consistency, as plant-based coagulants require larger doses due to their weaker coagulation capability [194]. Additionally, the cost-effective preparation of organic coagulants is problematic; crude preparations introduced unwanted carbon loads into treated water, promoting microbial growth and leading to bio-fouling in treatment systems [52]. However, other factors constrained the commercialization of plant-based coagulants, including financial support, market awareness, up-scale technologies, and regulatory approval [52].
Furthermore, insufficient toxicological studies on their purified fractions hinder their transition from laboratory bench level to practical applications [49]. Also, the practicality and feasibility of actual application as the capability of organic coagulants in bracing the real application challenges such as fluctuating feed water quality, steady supply of organic coagulants with consistent quality, and storage and handling of organic coagulants have not been confirmed. The sustainability of organic coagulants lacked a continuous supply of sufficient amounts of organic coagulants with desired properties without being affected by differences in extraction and water purification [62].
Yet, preparation and extraction methods of plant-based coagulants would be realistically applied in rural settings due to the simplicity of methods and local resources. The plant-based coagulants’ performance might vary according to the sources and extraction approaches. All plant-based coagulants, including Moringa, are extracted and purified from three stages [23]. The first stage involves pre-processing the sample, which is cleaned and converted into fine powder suitable for the second stage. In the second stage, the compounds possessing coagulation activity are extracted using water, salt solution, or appropriate solvent. The third stage is purification, where only the compounds genuinely contributing to the coagulation process are purified. Improving extraction approaches influences the quality and performance of natural coagulants in treating water. Plant-based coagulants that can be locally sourced and easily extracted could greatly benefit communities without clean water, particularly in rural or financially constrained regions. By enabling water treatment, plant-based coagulants can improve public health and ultimately enhance living conditions for rural populations [62]. Generally, the plant-based alternatives have significantly lower environmental impact compared to the inorganic coagulants due to the low level of ecological footprint [19], minimal toxicity, eco-friendly options [52], and ease of adaptation in rural areas [104].
Plant-based coagulants are an economical option for industries due to their non-toxicity, biodegradability, and reduced cost [195, 196]. For instance, they were replacing alum with Moringa oleifera as a coagulant aid for treating 1.74 million m3 of water saved USD 2370 in production costs [49]. Similarly, the cost of harvesting microalgae for the plant-based coagulant was lower at USD 0.037 per metric ton, compared to alum at USD 0.28 per metric ton and chitosan at USD 9.02 per metric ton [197]. An alternative approach utilizing plant-based materials involves using plant-based adsorbents for adsorption [198]. Current research is concentrated on developing plant-based adsorbents to replace chemical alternatives [199]. Plant-based adsorbents offer significant economic advantages due to their low cost and high efficiency in removing highly toxic pollutants [200]. Various plant-based adsorbents have been explored for this purpose; for example, the use of banana peel, compost, bark, wheat husk, wheat bran, sugar beet pulp, and pomegranate peel for ammonium adsorption, with pomegranate peel powder achieving a remarkable 97% removal rate [201]. Palm kernel shells are also converted into biochar to remove heavy metals such as Pb2⁺, Cr⁶⁺, Cd2⁺, and Zn2⁺ from contaminated water [202]. Future research in plant-based coagulants will likely focus on optimizing extraction methods, enhancing the efficiency of bioactive compounds, and exploring new plant sources [195, 203]. Genetic engineering and biotechnology advances also play a role in developing more effective and sustainable coagulants [204].
5 Discussions
Mostly active coagulant components extracted from natural coagulants are protein polymers, carbohydrates, polysaccharides, and phenolic compounds, which promote the mechanisms of adsorption, polymer bridging, and charge neutralization during the coagulation process. Among the plants studied, Moringa oleifera seed, Psidium guava, Jatropha curcas, and maize had a high efficiency of about 99% in turbidity removal due to the extraction methods used [148, 151]. Moringa oleifera contains high polyphenol, flavonoid, and protein content and exhibits effective coagulating properties due to dimeric cationic proteins with a molecular mass of 6.5–14 kDa [49] and an isoelectric point of 10–11.Moringa oleifera also contained an organic polyelectrolyte (~ 3.0 kDa), and its coagulation was enhanced by bivalent cations such as Ca2+ and Mg2+ [205]. Similarly, the high coagulation ability of cactus is attributed to its mucilage, which is rich in carbohydrates like l-arabinose and galacturonic acid, which aid in colloidal particle adsorption. Jatropha curcas seeds contain soluble cationic proteins that act as coagulants [206] whereas Psidium guajava leaves exhibit antimicrobial properties due to bioactive compounds like b-Caryophyllene and Alpha-bisabolol [207], and its cell composition includes polygalacturonase inhibitory proteins that make it suitable for water purification [208].
Again, the extraction of Moringa using sodium chloride yields a more coagulant agent [209], increasing the protein's solubility and improving coagulation activity [151]. Fahmi et al. [210] and Ribeiro et al. [211] on Moringa oleifera showed turbidity removal through the mechanism of adsorption and charged neutralization whereby adsorption occurred due to electrostatic interactions and hydrogen bonding effects and neutralized negatively charged colloids in water [212]. Sago had a high efficiency of about 97.67% in hardness removal compared to other plants studied [152]. Sago contained starch, which is a natural polymer [213], characterized as polyelectrolyte, and acted as a coagulant aid that is categorized according to the ionization traits, which are the anions, cations, and amphoteric with dual charges [214]. The cation polymer adsorbed negatively charged particles by attracting the particles through an electrostatic force [151, 215]. Vara [152] showed anion and non-ionized polymers cannot coagulate negatively charged particles.
Moringa Oleifera seed cake and banana pith had a high performance of about 98% up to 100% for Cu, Cd, and Fe removal compared to the other species reported [35, 171], due to the activation of the polyelectrolyte of Moringa Oleifera seed by removing the oil from the seed [216]. Increasing Moringa Oleifera seed cake concentration led to high efficiency in removing heavy metals [217]. The primary mechanism for heavy metal removal is adsorption, which is brought by the positive metal ions that form a bridge among the anionic polyelectrolyte and negatively charged protein functional groups on the colloid particle surface [218]. The banana powder contains many functional groups and potentially adsorbs many contaminants, including heavy metals [219], neem oil, and Solonum incunum had a high percentage of microbial removal of about 99% [184, 185]. Neem oil and other Neem components contain the bioactive compound called Azadirachtin [220], which disrupts the bacteria cell membrane [221]. Solonum incunum contains steroids and diosgenin, which are bioactive natural products with medicinal value and act as disinfectants [185]. The actionable suggestions for implementing plant-based coagulants in water treatment systems are stipulated below: (1) identification of suitable plants and parts (2) improve extraction techniques to maximize the bioactive components from the plants [19], (3) optimized solvent-based extraction and mechanical methods to enhance the coagulant efficacy [222], (4) standardized the coagulant dosage based on solvent characteristics [32], (5) adapt plant-based coagulant production and usage strategies to account for the natural variability in the plant chemical composition [55], (6) ensure the sustainable harvesting of plant resources to prevent overexploitation and maintaining an ecological balance [62], (7) implement field trials in diverse geographical and environmental conditions to ensure the scalability and effectiveness of plant-based coagulants, (8) conduct community training and awareness programs, (9) explore hybrid approaches by combining plant-based coagulants with conventional chemical coagulants (10) promote the use of plant-based coagulants in communities with limited access to chemical coagulants.
6 Conclusions
Water treatment using coagulation technology is among the affordable methods used in many countries to remove turbidity, total hardness, heavy metals, and microorganisms. Several studies have been conducted on organic coagulants, emphasizing the use of plant-based coagulants in water treatment. This review paper focused on the general overview for preparation, experimental setups, optimization of plant-based coagulants, and removal of turbidity, hardness, heavy metals, and microbes using different plant-based coagulants. The common guidelines/suggestions for choosing the best plant-based coagulants for water treatment based on local conditions are (i) plant species and parts, (ii) chemical/bioactive compounds concentration based on the soil, growth rate, climate, agricultural practices, (iii) extraction method (iv) solvent used (v) targeted performance parameters either for turbidity, heavy metal, total hardness, or microbes, (vi) dosage and toxicity levels.
The study revealed that Moringa oleifera seed, Psidium guava, Jatropha curcas, and maize had high performance in turbidity removal. Also, sago showed high performance in hardness removal compared to other studied plants. Besides that, Moringa oleifera and banana pith increased performance in heavy metal reduction. Moreover, neem oil and Solonum incunum performed better in microbial reduction. Therefore, the sustainable water purification method using plant-based coagulants should focus on critical factors such as particle size, the choice of extraction solvents, and the concentration of active components from various plant parts in the removal of turbidity, total hardness, heavy metals, and microbial from polluted water. Concurrently, dosage optimization from different plants is to be scaled up into commercialization for water treatment.
Data availability
No datasets were generated or analysed during the current study.
References
Pakharuddin NH, Fazly MN, Ahmad Sukari SH, Tho K, Zamri WFH. Water treatment process using conventional and advanced methods: a comparative study of Malaysia and selected countries. In: IOP conference series: earth and environmental science, vol. 880; 2021. p. 012017.
Hariz Amran A, Syamimi Zaidi N, Muda K, Wai Loan L. Effectiveness of natural coagulant in coagulation process: a review. Int J Eng Technol. 2018;7:34–7.
Jiang J-Q. The role of coagulation in water treatment. Curr Opin Chem Eng. 2015;8:36–44.
Saharudin NFA, Nithyanandam R. Wastewater treatment by using natural coagulant. 2nd Eureca. 2014;2014:2–3.
Tunggolou J, Payus C, et al. Moringa oleifera as coagulant used in water purification process for consumption. Earth Sci Pak. 2017;1:1–3.
Beyene HD, Hailegebrial TD, Dirersa WB, et al. Investigation of coagulation activity of cactus powder in water treatment. J Appl Chem. 2016;2016:1–9.
Metsopkeng CS, Nougang ME, Nana PA, Tamsa Arfao A, Ngo Bahebeck P, Lontsi Djimeli C, Eheth JS, Noah Ewoti OV, Moungang LM, Agbor GA, Perrière F, Sime-Ngando T, Nola M. Comparative study of Moringa stenopetala root and leaf extracts against the bacteria Staphyloccocus aureus strain from aquatic environment. Sci Afr. 2020;10(e00549):2020.
Al-Aubadi IM, Hashim LQ. Purification of turbid water using orange peel extract and luffa mucilage. Basrah J Agric Sci. 2022;35:259–70.
Premkumar R, Rajesh S, et al. Feasibility study on application of natural coagulants. J Phys Conf Ser. 2021;2070: 012186.
Kurniawan SB, et al. What compound inside biocoagulants/bioflocculants is contributing the most to the coagulation and flocculation processes? Sci Total Environ. 2022;806: 150902.
Fida Z, Tanoli MA, Mahmood Q, Alamgir MS, Sajjad D. Evaluation of plant-based natural extracts as coagulants for surface water treatment. Environ Eng Geosci. 2023.
Shukri AS, Baharudin F, Kassim J, Mohd Kamil NA, Hamzah N. Performance of plant-based coagulants in removing turbidity and chemical oxygen demand (COD) in industrial wastewater: a systematic review and meta-analysis. J Sustain Civil Eng Technol JSCET. 2023;2:91–103.
Abujazar MSS, Karaağaç SU, Abu Amr SS, Alazaiza MYD, Fatihah S, Bashir MJK. Recent advancements in plant-based natural coagulant application in the water and wastewater coagulation-flocculation process: challenges and future perspectives. Glob Nest J. 2022;24:685–705.
Knap-Bałdyga A, Żubrowska-Sudoł M. Natural organic matter removal in surface water treatment via coagulation—current issues, potential solutions, and new findings. Sustainability. 2023;15:13853.
Salazar-Gámez L, Luna-delRisco M, Narváez-Jojoa E, Salazar-Cano R, Rosales-Delgado D, Pinchao D, Santander-Yela EI, David J, Revelo MC, Delgado-Garcés S, Rocha-Meneses L. Turbidity removal performance of selected natural coagulants for water treatment in colombian rural areas. Civil Eng J. 2024. https://doi.org/10.28991/CEJ-2024-010-02-020.
Konkobo FA, Savadogo PW, Diao M, Dakuyo R, Dicko MH. Evaluation of the effectiveness of some local plant extracts in improving the quality of unsafe water consumed in developing countries. Front Environ Sci. 2023;11:1134984.
Kumar J, Choudhary M, Dikshit PK, Kumar S. Recent advancements in utilizing plant-based approaches for water and wastewater treatment technologies. Clean Water. 2024;2(100030):2024.
Bubalo MC, Vidović S, Redovniković IR, Jokić S. New perspective in extraction of plant biologically active compounds by green solvents. Food Bioprod Process. 2018;109:52–73.
Akhtar M, Amin M, Nazir M. Natural variability in plant-based coagulants and their impact on water treatment efficiency. J Environ Manag. 2021;280: 111684.
Azmir J, Zaidul ISM, Rahman MM, Sharif KM, Mohamed A, Sahena F, Jahurul MHA, Ghafoor K, Norulaini NAN, Omar AKM. Techniques for extraction of bioactive compounds from plant materials: a review. J Food Eng. 2013;117:426–36.
Subramanian P, Anandharamakrishnan C. Extraction of bioactive compounds. In: Industrial Application of Functional Foods, Ingredients and Nutraceuticals. Elsevier; 2023. p. 45–87.
Sanjeeva Rayudu E, Likhitha A, Sudhakar Reddy K, Nagesh KG. A study on dragon fruit foliage as natural coagulant and coagulant aid for water treatment. IOP Conf Ser Earth Environ Sci. 2022;982: 012040.
Yin C-Y. Emerging usage of plant-based coagulants for water and wastewater treatment. Process Biochem. 2010;45:1437–44.
Adekitan AA, Oyewumi JO, Dada VO, Layi-Adigun BO, Raheem I. Use of neem leaf, pawpaw seed and moringa seed as natural coagulants for surface water treatment. J Appl Sci Environ Manag. 2023;27:1347–52.
Mangale Sapana M, Chonde Sonal G, Raut PD. Use of Moringa oleifera (drumstick) seed as natural absorbent and an antimicrobial agent for ground water treatment. Res J Recent Sci ISSN. 2012;2277:2502.
Maruti Prasad SV, Srinivasa Rao B. Influence of plant-based coagulants in waste water treatment. IJLTEMAS. 2016;5:45–8.
Oluwasanya GO, Odjegba EE, Sadiq AY, Bankole AO, Awokola OS. Turbid water treatment with Kenaf (Hibiscus cannabinus) fibers and Moringa seeds (Moringa oleifera): an application of nature-based solutions. J Meteorol Clim Sci. 2023;22:149–75.
Unnisa SA, Deepthi P, Mukkanti K. Efficiency studies with Dolichos lablab and solar disinfection for treating turbid waters. J Environ Protect Sci. 2010;4:8–12.
Choubey S, Rajput SK, Bapat KN. Comparison of efficiency of some natural coagulants-bioremediation. Int J Emerg Technol Adv Eng. 2012;2:429–34.
Patchaiyappan A, Devipriya SP. Chapter 5—application of plant-based natural coagulants in water treatment. In: Kathi S, Devipriya S, Thamaraiselvi K, editors. Cost effective technologies for solid waste and wastewater treatment. London: Elsevier; 2022. p. 51–8.
Redha ZM. Multi-response optimization of the coagulation process of real textile wastewater using a natural coagulant. Arab J Basic Appl Sci. 2020;27:406–22.
Benalia A, et al. Application of plant-based coagulants and their mechanisms in water treatment: a review. J Renew Mater. 2024;12:667–98.
Daverey A, Tiwari N, Dutta K. Utilization of extracts of Musa paradisica (banana) peels and Dolichos lablab (Indian bean) seeds as low-cost natural coagulants for turbidity removal from water. Environ Sci Pollut Res. 2019;26:34177–83.
Lavado-Meza C, et al. Arabica-coffee and teobroma-cocoa agro-industrial waste biosorbents, for Pb (II) removal in aqueous solutions. Environ Sci Pollut Res. 2023;30:2991–3001.
Kakoi B, Kaluli JW, Ndiba P, Thiong’o G. Banana pith as a natural coagulant for polluted river water. Ecol Eng. 2016;95:699–705.
Ugwu SN, Umuokoro AF, Echiegu EA, Ugwuishiwu BO, Enweremadu CC. Comparative study of the use of natural and artificial coagulants for the treatment of sullage (domestic wastewater). Cogent Eng. 2017;4:1365676.
Rayer EJ, Muhamad MS, Apandi NM, Sunar NM, Ali R. Combined effects of banana peels and pith as dual natural plant-based coagulants for turbidity removal. J Adv Res Appl Mech. 2024;116:75–87.
Masamba WRL, Mataka LM, Mwatseteza JF, Sajidu SMI. Cadmium sorption by Moringa stemopetala and Moringa oleifera seed powders: batch, time, temperature, pH and adsorption isotherm studies; 2010.
Guan Di, Zhang Z, Li X, Liu H. Effect of pH and temperature on coagulation efficiency in a North-China water treatment plant. Adv Mater Res. 2011;243:4835–8.
Nkurunziza T, Nduwayezu JB, Banadda EN, Nhapi I. The effect of turbidity levels and Moringa oleifera concentration on the effectiveness of coagulation in water treatment. Water Sci Technol. 2009;59:1551–8.
Kalibbala HM, Olupot PW, Ambani OM. Synthesis and efficacy of cactus-banana peels composite as a natural coagulant for water treatment. Results Eng. 2023;17: 100945.
Megersa M, Beyene A, Ambelu A, Woldeab B. The use of indigenous plant species for drinking water treatment in developing countries: a review. J Biodiv Environ Sci. 2014;53:269–81.
Bahrodin MB, et al. Recent advances on coagulation-based treatment of wastewater: Transition from chemical to natural coagulant. Curr Pollut Rep. 2021;7:379–91.
Saxena K, Brighu U, Choudhary A. Parameters affecting enhanced coagulation: a review. Environ Technol Rev. 2018;7:156–76.
Olivera CAC, Cavero YR, Torres RJC. Bibliometric analysis on the use of natural coagulants in the treatment of water for human use. In: 22nd LACCEI international multi-conference for engineering, education, and technology: sustainable engineering for a diverse, equitable, and inclusive future at the service of education, research, and industry for a society 5.0 Hybrid Event, San Jose - Costa Rica, July 17–19, 2024; 2024.
Nimesha S, et al. Effectiveness of natural coagulants in water and wastewater treatment. Glob J Environ Sci Manag. 2022;8:101–16.
Okoro BU, Sharifi S, Jesson MA, Bridgeman J. Natural organic matter (NOM) and turbidity removal by plant-based coagulants: a review. J Environ Chem Eng. 2021;9: 106588.
Paigude R, Patil R. Review on comparative analysis of natural and chemical coagulants. Int Res J Eng Technol. 2019;6:299.
Saleem M, Bachmann RT. A contemporary review on plant-based coagulants for applications in water treatment. J Ind Eng Chem. 2019;72:281–97.
Usman IMT, et al. Evaluation of annona diversifolia seed extract as a natural coagulant for water treatment. Sustainability. 2023;15:6324.
Benalia A, Derbal K, Khalfaoui A, Bouchareb R, Panico A, Gisonni C, Crispino G, Pirozzi F, Pizzi A. Use of Aloe vera as an organic coagulant for improving drinking water quality. Water. 2021;13:2024.
Koul B, Bhat N, Abubakar M, Mishra M, Arukha AP, Yadav D. Application of natural coagulants in water treatment: a sustainable alternative to chemicals. Water. 2022;14:3751.
Aarø SS. A review of selected natural coagulants in water and wastewater treatment. Water Environ Technol; 2020.
Choy SY, Prasad KMN, Wu TY, Ramanan RN. A review on common vegetables and legumes as promising plant-based natural coagulants in water clarification. Int J Environ Sci Technol. 2015;12:367–90.
El Bouaidi W, Libralato G, Douma M, Ounas A, Yaacoubi A, Lofrano G, Albarano L, Guida M, Loudiki M. A review of plant-based coagulants for turbidity and cyanobacteria blooms removal. Environ Sci Pollut Res. 2022;29:42601–15.
Jayalakshmi G, Saritha V, Dwarapureddi BK. A review on native plant based coagulants for water purification. Int J Appl Environ Scie. 2017;12:469–87.
Dwarapureddi BK, Saritha V. Plant based coagulants for point of use water treatment–a review. Curr Environ Eng. 2016;3:61–76.
Kumar U, Thakur AS. Sustainable treatment of water and wastewater using natural plant-based coagulants: a review. Int J Eng Res Technol. 2022;11:650–6.
Al-Samawi AA, Shokralla EM. An investigation into an indigenous natural coagulant. J Environ Sci Health Part A. 1996;31:1881–97.
Ang TH, Kiatkittipong K, Kiatkittipong W, Chua SC, Lim JW, Show PL, Bashir MJ, Ho YC. Insight on extraction and characterisation of biopolymers as the green coagulants for microalgae harvesting. Water. 2020;12:1388.
Diver D, Nhapi I, Ruziwa WR. The potential and constraints of replacing conventional chemical coagulants with natural plant extracts in water and wastewater treatment. Environ Adv. 2023;13: 100421.
Wei Lun Ang and Abdul Wahab Mohammad. State of the art and sustainability of natural coagulants in water and wastewater treatment. J Clean Prod. 2020;262: 121267.
Varkey AJ. Purification of river water using Moringa Oleifera seed and copper for point-of-use household application. Sci Afr. 2020;8: e00364.
Kisakye V. A bucket sand filter and Moringa Oleifera drinking water treatment hybrid system for rural households. Sci Afr. 2023;20: e01689.
Valverde KC, Coldebella PF, Salcedo Vieira AM, Nishi L, Bongiovani MC, Baptista AT, et al. Preparations of Moringa oleifera seeds as coagulant in water treatment. Environ Eng Manag J. 2018;17:1123–9.
Amagloh FK, Benang A. Effectiveness of Moringa oleifera seed as coagulant for water purification. Afr J Agric Res. 2009;4(1):119–23.
Pandey P, Khan F, Ahmad V, Singh A, Shamshad T, Mishra R. Combined efficacy of Azadirachta indica and Moringa oleifera leaves extract as a potential coagulant in ground water treatment. SN Applied Sciences. 2020;2:1–8.
Ahmed T, Kanwal R, Hassan M, Ayub N, Scholz M, McMinn W. Coagulation and disinfection in water treatment using Moringa. Proc Inst Civil Eng Water Manag. 2010;163:381–8.
Saif MMS, Siva Kumar N, Prasad MNV. Binding of cadmium to Strychnos potatorum seed proteins in aqueous solution: adsorption kinetics and relevance to water purification. Colloids Surf B Biointerfaces. 2012;94:73–9.
Packialakshmi N, Guru V. Study of Strychnos potatorum against water borne pathogens. Int J Biol Pharm Allied Sci. 2013;2:1890.
Ben Rebah F, Siddeeg SM. Cactus an eco-friendly material for wastewater treatment: a review. J Mater Environ Sci. 2017;8:1770–82.
Nigussie Z, Habtu NG. Performance evaluation of biocoagulant for the effective removal of turbidity and microbial pathogens from drinking water. J Water Health. 2023;21:1158–76.
Kenea D, et al. Investigation on surface water treatment using blended Moringa oleifera seed and Aloe vera plants as natural coagulants. South Afr J Chem Eng. 2023;45:294–304.
Hussain S, Ghouri AS, Ahmad A. Pine cone extract as natural coagulant for purification of turbid water. Heliyon. 2019;5: e01420.
Samuel F, Oloboh S, Omale SO. Application of watermelon seed cake for turbidity removal and treatment of microoganism from waste water. Cambridge Res Publ. 2020;19:2329–7309.
Godhani PJ, Adiyecha RP, Vir MM, Joshi JB. A new promising technique using plant extracts for purification of polluted water. Life Sci Leaflets. 2014;49:44.
Rudram C, Reddy P. Fluoride removal from aqueous solution using custard apple (Annona Squamosa) leaves. In: Proceedings of the international conference on advances in chemical engineering (AdChE); 2020. p. 17.
Mohan S, Vidhya K, Sivakumar CT, Sugnathi M, Shanmugavadivu V, Devi M. Textile waste water treatment by using natural coagulant (Neem-Azadirachta India). Int Res J Multidiscip Technovation. 2019;1:636–42.
Singh Thakur S, Choubey S. Use of tannin based natural coagulants for water treatment: an alternative to inorganic chemicals. Int J ChemTech Res. 2014;6:3628–34.
Patale V, Pandya J. Mucilage extract of Coccinia indica fruit as coagulant-flocculent for turbid water treatment. Asian J Plant Sci Res. 2012;2:442–5.
Tometin LAS, et al. Use of natural coagulants in removing organic matter, turbidity and fecal bacteria from hospital wastewater by coagulation-flocculation process. J Water Resour Protect. 2022;14:719–30.
Ramesh S, Sudarsan JS, Jothilingam M, et al. Low cost natural adsorbent technology for water treatment. Rasayan J Chem. 2016;9:325–30.
Bouchareb R, Derbal K, Benalia A. Optimization of active coagulant agent extraction method from Moringa Oleifera seeds for municipal wastewater treatment. Water Sci Technol. 2021;84:393–403.
Rodrigues KC, de Morais LSR, de Paula HM. Green/sustainable treatment of washing machine greywater for reuse in the built environment. Clean Eng Technol. 2022;6: 100410.
Sánchez-Martin J, Beltrán-Heredia J, Peres JA. Improvement of the flocculation process in water treatment by using Moringa oleifera seeds extract. Braz J Chem Eng. 2012;29:495–502.
Kristianto H, Tanuarto MY, Prasetyo S, Sugih AK. Magnetically assisted coagulation using iron oxide nanoparticles-Leucaena leucocephala seeds’ extract to treat synthetic Congo red wastewater. Int J Environ Sci Technol. 2020;17:3561–70.
Abidin ZZ, Ismail N, Yunus R, Ahamad IS, Idris A. A preliminary study on Jatropha curcas as coagulant in wastewater treatment. Environ Technol. 2011;32:971–7.
El-Sayed EM, Nour El-Den AA, Elkady MF, Zaatout AA. Comparison of coagulation performance using natural coagulants against traditional ones. Separ Sci Technol. 2021;56:1779–87.
DePaolis M, De Respino S, Samineni L, Brighton S, Kumar M. Cottonseed extract as a coagulant for water treatment. Environ Sci Adv. 2023;2:227–34.
Haruna A, Yahaya SM. Recent advances in the chemistry of bioactive compounds from plants and soil microbes: a review. Chem Afr. 2021;4:231–48.
Yolci Omeroglu P, Acoglu B, Özdal T, Tamer CE, Çopur ÖU. Extraction techniques for plant-based bio-active compounds. Natural bio-active compounds: volume 2: chemistry, pharmacology and health care practices; 2019. p. 465–92.
Yusoff IM, Taher ZM, Rahmat Z, Chua LS. A review of ultrasound-assisted extraction for plant bioactive compounds: phenolics, flavonoids, thymols, saponins and proteins. Food Res Int. 2022;157: 111268.
Zhang J, Wen C, Zhang H, Duan Y, Ma H. Recent advances in the extraction of bioactive compounds with subcritical water: a review. Trends Food Sci Technol. 2020;95:183–95.
Awad AM, et al. Green extraction of bioactive compounds from plant biomass and their application in meat as natural antioxidant. Antioxidants. 2021;10:1465.
Marobhe NJ, Dalhammar G, Gunaratna KR. Simple and rapid methods for purification and characterization of active coagulants from the seeds of Vigna unguiculata and Parkinsonia aculeata. Environ Technol. 2007;28:671–81.
Ross KA, Beta T, Arntfield SD. A comparative study on the phenolic acids identified and quantified in dry beans using HPLC as affected by different extraction and hydrolysis methods. Food Chem. 2009;113:336–44.
Jha AK, Sit N. Extraction of bioactive compounds from plant materials using combination of various novel methods: a review. Trends Food Sci Technol. 2022;119:579–91.
Sharififar F, Dehghn-Nudeh G, Mirtajaldini M. Major flavonoids with antioxidant activity from Teucrium polium L. Food Chem. 2009;112:885–8.
Alnawajha MM, Kurniawan SB, Imron MF, Abdullah SR, Hasan HA, Othman AR. Plant-based coagulants/flocculants: characteristics, mechanisms, and possible utilization in treating aquaculture effluent and benefiting from the recovered nutrients. Environ Sci Pollut Res. 2022;29:58430–53.
Khan SA, et al. Fourier transform infrared spectroscopy: fundamentals and application in functional groups and nanomaterials characterization. In: Handbook of materials characterization. Springer; 2018. p. 317–44.
Syabanah N, Yulianti E, Istighfarini VN, Lutfia FNL. Characterization and effectiveness of Moringa Oleifera seeds extract as a phosphate coagulant. Jurnal Neutrino J Fisika dan Aplikasinya. 2020;12:57–64.
Akhtar K, Khan SA, Khan SB, Asiri AM. Scanning electron microscopy: Principle and applications in nanomaterials characterization. Springer; 2018.
Shirley B, Jarochowska E. Chemical characterisation is rough: the impact of topography and measurement parameters on energy-dispersive X-ray spectroscopy in biominerals. Facies. 2022;68:7.
Usman IMT, et al. Comprehensive review of modification, optimisation, and characterisation methods applied to plant-based natural coagulants (PBNCs) for water and wastewater treatment. Sustainability. 2023;15:4484.
Kurniawan SB, Ahmad A, Said NS, Gustinasari K, Abdullah SR, Imron MF. The influence of preparation and pretreatment on the physicochemical properties and performance of plant-based biocoagulants in treating wastewater. Environ Adv. 2023;14: 100441.
Shah A, Manning G, Zakharova J, Arjuna A, Batool M, Hawkins AJ. Particle size effect of Moringa oleifera Lam. seeds on the turbidity removal and antibacterial activity for drinking water treatment. Environ Chem Ecotoxicol. 2024;6:370–9.
Sun H, Jiao R, Hui Xu, An G, Wang D. The influence of particle size and concentration combined with pH on coagulation mechanisms. J Environ Sci. 2019;82:39–46.
Kurniawan SB, et al. Challenges and opportunities of biocoagulant/bioflocculant application for drinking water and wastewater treatment and its potential for sludge recovery. Int J Environ Res Public Health. 2020;17:9312.
Dayarathne HNP, Angove MJ, Aryal R, Abuel-Naga H, Mainali B. Removal of natural organic matter from source water: review on coagulants, dual coagulation, alternative coagulants, and mechanisms. J Water Process Eng. 2021;40: 101820.
Alnawajha MM, Abdullah SR, Hasan HA, Othman AR, Kurniawan SB. Effectiveness of using water-extracted Leucaena leucocephala seeds as a coagulant for turbid water treatment: effects of dosage, pH, mixing speed, mixing time, and settling time. Biomass Convers Bioref. 2024;14:11203–16.
Feria-Diaz JJ, Rodino-Arguello JP, Gutierrez-Ribon GE. Behavior of turbidity, pH, alkalinity and color in Sinú River raw water treated by natural coagulants. Revista Facultad de Ingenierı́a Universidad de Antioquia. 2016;78:112–8.
Kumar L, Sharma J, Kaur R. Catalytic performance of cow-dung sludge in water treatment mitigation and conversion of ammonia nitrogen into nitrate. Sustainability. 2022;14(4):2183.
Chiavola A, Di Marcantonio C, D’Agostini M, Leoni S, Lazzazzara M. A combined experimental-modeling approach for turbidity removal optimization in a coagulation–flocculation unit of a drinking water treatment plant. J Process Control. 2023;130: 103068.
Pivokonsky M, Novotna K, Čermáková L, Petricek R. Jar tests for water treatment optimization: how to perform jar tests–a handbook. IWA Publishing; 2022.
Janna H, et al. Effectiveness of using natural materials as a coagulant for reduction of water turbidity in water treatment. World J Eng Technol. 2016;4:505.
Asrafuzzaman M, Fakhruddin AN, Hossain MA. Reduction of turbidity of water using locally available natural coagulants. Int Scholarly Res Notices. 2011;2011: 632189.
Kingue B, Njila R, Ndongo B. Assessment of groundnut (Arachis hypogaea) as a natural coagulant for water treatment. Water Pract Technol. 2023;18:2057–67.
Shamsuri MISM, Pa NFC. The potential of dendrocalamus asper (Betong Bamboo) leaves as natural coagulant for wastewater treatment agent. Progr Eng Appl Technol. 2023;4:74–83.
Dollah Z, et al. Citrus fruit peel waste as a source of natural coagulant for water turbidity removal. J Phys Conf Ser. 2019;1349: 012011.
Muhamad NAN, Juhari NF, Mohamad IN. Efficiency of natural plant-based coagulants for water treatment. IOP Conf Ser Earth Environ Sci. 2020;616: 012075.
Ali AH, Abaas ST. Testing of conventional and natural coagulants in single and binary systems to treat turbid water. J Eng Sustain Dev JEASD. 2020;24:1–8.
Gandiwa BI, et al. Optimisation of using a blend of plant based natural and synthetic coagulants for water treatment:(Moringa Oleifera-Cactus Opuntia-alum blend). S Afr J Chem Eng. 2020;34:158–64.
Muda K, Ali NSA, Abdullah UN, Sahir AB. Potential use of fruit seeds and plant leaves as coagulation agent in water treatment. J Environ Treat Tech. 2020;8:971–7.
Lek BL, Peter AP, Chong KH, Ragu P, Sethu V, Selvarajoo A, Arumugasamy SK. Treatment of palm oil mill effluent (POME) using chickpea (Cicer arietinum) as a natural coagulant and flocculant: evaluation, process optimization and characterization of chickpea powder. J Environ Chem Eng. 2018;6:6243–55.
Getahun M, Asaithambi P, Befekadu A, Alemayehu E. Optimization of indigenous natural coagulants process for nitrate and phosphate removal from wet coffee processing wastewater using response surface methodology: In the case of Jimma Zone Mana district. Case Stud Chem Environ Eng. 2023;8: 100370.
Isa FM, Ariffin WNM, Jusoh MS, Putri EP. A review of genetic algorithm: operations and applications. J Adv Res Appl Sci Eng Technol. 2024;40:1–34.
Piuleac CG, Curteanu S, Rodrigo MA, Sáez C, Fernández FJ. Optimization methodology based on neural networks and genetic algorithms applied to electro-coagulation processes. Cent Eur J Chem. 2013;11:1213–24.
Humbird D, Fei Q. Scale-up considerations for biofuels. In: Biotechnology for biofuel production and optimization. Elsevier; 2016. p. 513–37.
Khettaf S, et al. Optimization of coagulation–flocculation process in the treatment of surface water for a maximum dissolved organic matter removal using RSM approach. Water Supply. 2021;21:3042–56.
Achite M, Samadianfard S, Elshaboury N, Sharafi M. Modeling and optimization of coagulant dosage in water treatment plants using hybridized random forest model with genetic algorithm optimization. Environ Dev Sustain. 2023;25:11189–207.
Myers RH, Montgomery DC, Anderson-Cook CM. Response surface methodology: process and product optimization using designed experiments. John Wiley & Sons; 2016.
Khouni I, Marrot B, Moulin P, Amar RB. Decolourization of the reconstituted textile effluent by different process treatments: enzymatic catalysis, coagulation/flocculation and nanofiltration processes. Desalination. 2011;268:27–37.
Owoicho A, Sani IM, et al. Optimization of coagulation efficacy of banana stem juice in water treatment. FUDMA J Sci. 2021;5:130–41.
Obiora-Okafo IA, Onukwuli OD. Optimization of coagulation-flocculation process for colour removal from azo dye using natural polymers: response surface methodological approach. Niger J Technol. 2017;36:482–95.
Okolo BI, et al. Coagulation kinetic study and optimization using response surface methodology for effective removal of turbidity from paint wastewater using natural coagulants. Sci Afr. 2021;14: e00959.
Usefi S, Asadi-Ghalhari M. Modeling and optimization of the coagulation–flocculation process in turbidity removal from aqueous solutions using rice starch. Pollution. 2019;5:623–36.
Li Na, Yi Hu, Yong-Ze Lu, Zeng RJ, Sheng G-P. Multiple response optimization of the coagulation process for upgrading the quality of effluent from municipal wastewater treatment plant. Sci Rep. 2016;6:26115.
Brilhante RSN, et al. Research advances on the multiple uses of Moringa oleifera: a sustainable alternative for socially neglected population. Asian Pac J Trop Med. 2017;10:621–30.
Gaikwad VT, Munavalli GR. Turbidity removal by conventional and ballasted coagulation with natural coagulants. Appl Water Sci. 2019;9:130.
Babu R, Chaudhuri M. Home water treatment by direct filtration with natural coagulant. J Water Health. 2005;3:27–30.
Marobhe NJ, Sabai SM. Treatment of drinking water for rural households using Moringa seed and solar disinfection. J Water Sanitation Hyg Dev. 2021;11:579–90.
Ng MH, Elshikh MS. Utilization of Moringa oleifera as natural coagulant for water purification. Ind Domestic Waste Manag. 2021;1:1–11.
Wambui Mumbi A, Fengting L, Karanja A. Sustainable treatment of drinking water using natural coagulants in developing countries: a case of informal settlements in Kenya. Water Util J. 2018;18:1–11.
Muhammad IM, Abdulsalam S, Abdulkarim A, Bello AA. Water melon seed as a potential coagulant for water treatment. Glob J Res Eng. 2015;15:1–9.
Ernest E, Onyeka O, David N, Blessing O. Effects of pH, dosage, temperature and mixing speed on the efficiency of water melon seed in removing the turbidity and colour of Atabong River, Awka-Ibom State, Nigeria. Int J Adv Eng Manag Sci. 2017;3: 239833.
Rekha B, Sumithra S. Natural plant seeds as an alternative coagulant in the treatment of mining effluent. Rekha Sumithra. 2020;6:15–23.
Akuboh DO, Saidu M, Abdulkareem AS, Busari AO. Assessing the potentials of a plant-based coagulant (Cyperus Esculentus Pulp) as alternative to alum in conventional water treatment process. Arid Zone J Eng Technol Environ. 2022;18:387–402.
Chivatá LDE, Celis ZCA, Pombo LM, Rodriguez AOE. The coagulant activity of the seeds of Psidium guajava L. and the Episperm of Persea americana Mill. in samples of water from the Bogotá River (Chocontá-Villapinzón). Indian J Sci Technol. 2018;11:21.
Marobhe NJ, Renman G. Purification of Charco dam water by coagulation using purified proteins from Parkinsonia aculeata seed. Int J Environ Sci. 2013;3:1749–61.
Mbogo SA. A novel technology to improve drinking water quality using natural treatment methods in rural Tanzania. J Environ Health. 2008;70:46–50.
Abidin ZZ, Shamsudin NSM, Madehi N, Sobri S. Optimisation of a method to extract the active coagulant agent from Jatropha curcas seeds for use in turbidity removal. Ind Crops Prod. 2013;41:319–23.
Vara S. Screening and evaluation of innate coagulants for water treatment: a sustainable approach. Int J Energy Environ Eng. 2012;3:1–11.
Seghosime A, Awudza JAM, Buamah R, Ebeigbe AB, Kwarteng SO. Effect of locally available fruit waste on treatment of water turbidity. Civil Environ Res. 2017;9:7–15.
de Oliveira C, Trevisan V, Skoronski E. Application of tannin-based coagulant for high-range turbidity surface water clarification. J Water Sanitation Hyg Dev. 2022;12:803–15.
Soumya Kiran P, Reddy Suda VB. Reduction of turbidity by adding bio coagulant-A sustainable approach. IOP Conf Ser Earth Environ Sci. 2022;982: 012039.
Shilpaa B, Akankshaa K, Girish P. Evaluation of cactus and hyacinth bean peels as natural coagulants. Int J Chem Environ Eng. 2012. https://doi.org/10.13140/RG.2.2.31066.98247.
Kazi T, Virupakshi A, Scholar M. Treatment of tannery wastewater using natural coagulants. Development. 2013;2:4061–8.
Nougbodé YAEI, et al. Evaluation of the Opuntia dillenii as natural coagulant in water clarification: case of treatment of highly turbid surface water. J Water Resour Protect. 2013;5:1242.
Kundu A, Nag SK. Assessment of groundwater quality in Kashipur block, Purulia district, West Bengal. Appl Water Sci. 2018;8:1–18.
Rolence C, Machunda R, Njau K. Water hardness removal by coconut shell activated carbon. Int J Sci Technol Soc. 2014;2(5):97–102.
Kamath GM, Ramalinga Reddy Y, Narayana G. The use of Moringa olifera seeds and alum as a natural coagulant for domestic waste water treatment in summer, winter & rainy seasons. J Recent Adv Built Environ JRAE. vol. 3; 2023.
Sotheeswaran S, Nand V, Maata M, Koshy K. Moringa oleifera and other local seeds in water purification in developing countries. Res J Chem Environ. 2011;15:135–8.
Bhat ZH. Removal of hardness from ground water using natural coagulants. J Mech Civil Eng. 2019;16(3):67–70.
Adeniran KA, Akpenpuun TD, Akinyemi BA, Wasiu RA. Effectiveness of Moringa oleifera seed as a coagulant in domestic wastewater treatment. Afr J Sci Technol Innov Dev. 2017;9:323–8.
Pallar BM, Abram PH, Ningsih P. Analysis of hard water coagulation in water sources of Kawatuna using aloe vera plant. Jurnal Akademika Kimia. 2020;9:125–32.
Verma S, Mehraj I, Jain A, Ray AP. Application of Zia Mays, Cucorbita Pepo, Carica Papaya as natural coagulants for purification of river water. Int J Innov Sci Eng Technol. 2015;2:693–6.
Rajalakshmi BS, Thamaraiselvi C, Vasanthy M. Natural coagulants—an alternative for conventional chemical coagulants for potable water purification. In: Waste water recycling and management: 7th IconSWM— ISWMAW 2017, vol 3; 2019. p. 265–84.
Vargas-Solano SV, Rodriguez-Gonzalez F, Martinez-Velarde R, Morales-Garcia SS, Jonathan MP. Removal of heavy metals present in water from the Yautepec River Morelos México, using Opuntia ficus-indica mucilage. Environ Adv. 2022;7: 100160.
Amjad M, et al. The sources, toxicity, determination of heavy metals and their removal techniques from drinking water. World. 2020;5:34–40.
Alazaiza MYD et al. Role of natural coagulants in the removal of heavy metals from different wastewaters: principal mechanisms, applications, challenges, and prospects; 2022.
Shan TC, Matar MA, Makky EA, Ali EN. The use of Moringa oleifera seed as a natural coagulant for wastewater treatment and heavy metals removal. Appl Water Sci. 2017;7:1369–76.
Ghawi AH. Using natural coagulant to remove turbidity and heavy metal from surface water treatment plant in Iraq. Int J Eng Technol Sci Innov. 2017;2:1851–2456.
Ravikumar K, Sheeja AK. Heavy metal removal from water using Moringa oleifera seed coagulant and double filtration. Contrib Pap, vol. 9; 2013.
Al Kindi GY, Gomaa GF, Abd Ulkareem FA. Combined adsorbent best (chemical and natural) coagulation process for removing some heavy metals from wastewater. Int J Environ Sci Technol. 2020;17:3431–48.
Shende AP, Chidambaram R. Cocoyam powder extracted from Colocasia antiquorum as a novel plant-based bioflocculant for industrial wastewater treatment: Flocculation performance and mechanism. Heliyon. 2023;9: e15228.
Nand V, Maata M, Koshy K, Sotheeswaran S. Water purification using Moringa oleifera and other locally available seeds in Fiji for heavy metal removal. Int J Appl. 2012;2:125–9.
Hurairah SN, et al. Archidendron jiringa seed peel extract in the removal of lead from synthetic residual water using coagulation-flocculation process. ScienceAsia. 2023;49:94–100.
Tanko MA, Sanda BY, Bichi MH. Application of Moringa oleifera seed extract (Mose) in the removal of heavy metals from tannery wastewater. Niger J Technol Dev. 2020;17:70–8.
Jain C, Khatana S, Vijayvergia R. Bioactivity of secondary metabolites of various plants: a review. Int J Pharm Sci Res. 2019;10:494–504.
Cowan MM. Plant products as antimicrobial agents. Clin Microbiol Rev. 1999;12:564–82.
Donadio G, et al. Interactions with microbial proteins driving the antibacterial activity of flavonoids. Pharmaceutics. 2021;13:660.
Zhang L, et al. Determination of vegetable tannins from plants in China. Biofuels Bioprod Biorefin. 2023;17:592–601.
Maitera ON, Louis H, Oyebanji OO, Anumah AO. Investigation of tannin content in Diospyros mespiliformis extract using various extraction solvents. J Anal Pharm Res. 2018;7:55–9.
Matthews RL, Templeton MR, Tripathi SK, Bhattarai K. Disinfection of waterborne coliform bacteria by neem oil. Environ Eng Sci. 2009;26:1435–41.
Kihampa C, Mwegoha WJS, Kaseva ME, Marobhe N. Performance of Solanum incunum Linnaeus as natural coagulant and disinfectant for drinking water. Afr J Environ Sci Technol. 2011;5:867–72.
Egbuikwem PN, Sangodoyin AY. Coagulation efficacy of Moringa oleifera seed extract compared to alum for removal of turbidity and E. coli in three different water sources. Eur Int J Sci Technol. 2013;2:13–20.
Ghoshal S, Krishna Prasad BN, Lakshmi V. Antiamoebic activity of Piper longum fruits against Entamoeba histolytica in vitro and in vivo. J Ethnopharmacol. 1996;50:167–70.
Hong-Xi Xu, Zeng F-Q, Wan M, Sim K-Y. Anti-HIV triterpene acids from Geum japonicum. J Nat Prod. 1996;59:643–5.
Sirohi P, et al. Herbal product based remedies against microbial infections and resistance. Weekly Sci Res J. 2013;1:1–20.
Okwu Edeoga H, Okwu DE, Mbaebie BO. Phytochemical constituents of some Nigerian medicinal plants. Afr J Biotechnol. 2005;4:685–8.
Ramamurthy C, et al. Evaluation of eco-friendly coagulant from Trigonella foenum-graecum seed. Adv Biol Chem. 2012;2:58.
Yongabi KA, Lewis DM, Harris PL. Integrated phytodisinfectant-sand filter drum for household water treatment in subsaharan Africa. J Environ Sci Eng. 2011;5:947–54.
Garcia-Fayos B, Arnal JM, Ruiz V, Sancho M. Use of Moringa oleifera in drinking water treatment: study of storage conditions and performance of the coagulant extract. Desalin Water Treat. 2016;57:23365–71.
Hoa NT, Hue CT. Enhanced water treatment by Moringa oleifera seeds extract as the bio-coagulant: role of the extraction method. J Water Supply Res Technol AQUA. 2018;67:634–47.
Ahmad A, Kurniawan SB, Abdullah SRS, Othman AR, Hasan HA. Exploring the extraction methods for plant-based coagulants and their future approaches. Sci Total Environ. 2022;818: 151668.
Balbinoti JR, dos Santos Junior RE, de Sousa LB, de Jesus Bassetti F, Balbinoti TC, de Matos Jorge LM, Jorge RM. Plant-based coagulants for food industry wastewater treatment. J Water Process Eng. 2023;52: 103525.
Behera B, Balasubramanian P. Natural plant extracts as an economical and ecofriendly alternative for harvesting microalgae. Bioresour Technol. 2019;283:45–52.
Sukmana H, Bellahsen N, Pantoja F, Hodur C. Adsorption and coagulation in wastewater treatment–review. Prog Agric Eng Sci. 2021;17:49–68.
Martini S, Afroze S, Roni KA. Modified eucalyptus bark as a sorbent for simultaneous removal of COD, oil, and Cr (III) from industrial wastewater. Alexandria Eng J. 2020;59:1637–48.
Mathurasa L, Damrongsiri S. Low cost and easy rice husk modification to efficiently enhance ammonium and nitrate adsorption. Int J Recycling Org Waste Agric. 2018;7:143–51.
Bellahsen N, et al. Pomegranate peel as a new low-cost adsorbent for ammonium removal. Int J Environ Sci Technol. 2021;18:711–22.
Baby R, Saifullah B, Hussein MZ. Palm Kernel Shell as an effective adsorbent for the treatment of heavy metal contaminated water. Sci Rep. 2019;9:18955.
Salem AK, Almansoory AF, Al-Baldawi IA. Potential plant leaves as sustainable green coagulant for turbidity removal. Heliyon. 2023;9:e16278.
Barbinta-Patrascu M-E, Bita B, Negut I. From nature to technology: exploring the potential of plant-based materials and modified plants in biomimetics, bionics, and green innovations. Biomimetics. 2024;9:390.
Patil D, et al. Characterization of Moringa oleifera leaf and seed protein extract functionality in emulsion model system. Innov Food Sci Emerg Technol. 2022;75: 102903.
Choy SY, Prasad KMN, Wu TY, Raghunandan ME, Ramanan RN. Utilization of plant-based natural coagulants as future alternatives towards sustainable water clarification. J Environ Sci. 2014;26:2178–89.
El-Sesy ME, Mahran BNA. The antibacterial and coagulant activity of Psidium guajava leaves extracts in purification of wastewater. Biosci Biotechnol Res Asia. 2020;17:191–203.
Deo A, Shastri NV. Purification and characterization of polygalacturonase-inhibitory proteins from Psidium guajava Linn. (guava) fruit. Plant Sci. 2003;164:147–56.
Camacho FP, Sousa VS, Bergamasco R, Teixeira MR. The use of Moringa oleifera as a natural coagulant in surface water treatment. Chem Eng J. 2017;313:226–37.
Fahmi MR, Najib NWAZ, Ping PC, Hamidin N. Mechanism of turbidity and hardness removal in hard water sources by using Moringa oleifera. J Appl Sci. 2011;11:2947–53.
Ribeiro JVM, Andrade PV, dos Reis AG. Moringa oleifera seed as a natural coagulant to treat low-turbidity water by in-line filtration. Revista Ambiente & Água. 2019;14: e2442.
El Gaayda J, et al. Optimization of turbidity and dye removal from synthetic wastewater using response surface methodology: effectiveness of Moringa oleifera seed powder as a green coagulant. J Environ Chem Eng. 2022;10: 106988.
Kiing SC, Dzulkefly K, Yiu PH. Characterization of biodegradable polymer blends of acetylated and hydroxypropylated sago starch and natural rubber. J Polym Environ. 2013;21:995–1001.
Omar FM, Rahman NNNA, Ahmad A. COD reduction in semiconductor wastewater by natural and commercialized coagulants using response surface methodology. Water Air Soil Pollut. 2008;195:345–52.
Bratskaya S, Schwarz S, Liebert T, Heinze T. Starch derivatives of high degree of functionalization: 10. Flocculation of kaolin dispersions. Colloids Surf, A. 2005;254:75–80.
Al-Jadabi N, Laaouan M, El Hajjaji S, Mabrouk J, Benbouzid M, Dhiba D. The dual performance of Moringa oleifera seeds as eco-friendly natural coagulant and as an antimicrobial for wastewater treatment: a review. Sustainability. 2023;15:4280.
Ali EN, Seng HT. Heavy metals (Fe, Cu, and Cr) removal from wastewater by Moringa oleifera press cake. MATEC Web Conf. 2018;150:02008.
Dhagat A, Goyal B, Sailo L. Removal of Cr (VI) in aqueous solution using iron oxide coated sand (IOCS). Int J Sci Eng Res. 2013;4:1–4.
Vilardi G, Di Palma L, Verdone N. Heavy metals adsorption by banana peels micro-powder: Equilibrium modeling by non-linear models. Chin J Chem Eng. 2018;26:455–64.
Eid A, Jaradat N, Elmarzugi N. A Review of chemical constituents and traditional usage of Neem plant (Azadirachta indica). Palestinian Med Pharm J. 2017;2:3.
Atawodi SE, Atawodi JC. Azadirachta indica (neem): a plant of multiple biological and pharmacological activities. Phytochem Rev. 2009;8:601–20.
Bina B, Mehdinejad M, Nikaeen M, Movahedian Attar H. Effectiveness of chitosan as natural coagulant aid in treating turbid waters. J Environ Health Sci Eng. 2009;6:247–52.
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Lwasa, A., Mdee, O.J., Ntalikwa, J.W. et al. Performance analysis of plant-based coagulants in water purification: a review. Discov Water 4, 108 (2024). https://doi.org/10.1007/s43832-024-00171-0
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DOI: https://doi.org/10.1007/s43832-024-00171-0