Synthesis and Characterization of Promising Economic Biopolymer Composite as a Clarifying Agent for Sugar Industry

Three biopolymer composites (1), (2) and (3) based on chitosan and carboxymethyl cellulose were synthesized, characterized and applied as nontoxic cationic color precipitant and flocculating agents for mixed cane juice (MCJ) and raw syrup refining process. The chemical structure of the obtained composites was elucidated by different techniques, FT-IR, XRD and SEM. They were investigated as a decolorizing agent of colorant matters of MCJ and raw syrup. The composite (1) was chosen and tested for further procedures due to its stability and economically purposes. Composite (1) showed a color removal efficiency of MCJ and raw syrup by 15.8 and 40.7%, respectively, at 200 ppm dosages, compared to the traditional clarification method. All the analyses of MCJ and raw syrup were conducted in the pilot plant to compare between the obtained clarification efficiency in presence of bioclarifying agent and that with the currently used phosphatation process. Also, the obtained results showed that the composite (1) can act as flocculating agent where 50% reduction is in the dosage of anionic flocculant. Moreover, the total cost of chemical aids and maintenance will be decreased by about 2.4 million LE in case of incorporating composite (1) in the clarification process of sugar cane juice.


Introduction
In Egypt, the sugar industry is considered strategic division of the food industries that has economic, environmental and social importance. However, this industry faces many of challenges. The most of them is removing of coloring matters from juice to obtain white sugar. In sugar making process, there are two sources of color matters. First is the naturally occurring plant pigments, and these pigments are basically phenolics and flavonoids (Bourzutschky 2005). The phenolic compounds are in general colorless, but due to the oxidation reaction or their reaction with amine or iron present in raw juice it is converted into colorants during the process. The flavonoids are polyphenol occurrence in the cane plant, and they suffer from enzymatic browning reactions. Secondly, melanins, melanoidins, caramels, and alkaline degradation products produce during processing (Chai et al. 2016). Clarification and decoloration treatment in sugar factories is very important process to obtain high-quality white sugar. Three traditional methods, phosphatation, sulfitation and carbonation, are utilized for the clarification of cane and beet mixed juice (Bennett 1982). Phosphatation process is used for producing raw sugar, whereas sulfitation and carbonation processes are used for producing white sugar. Carbonation method has low production cost, but it has some disadvantages from which the sediment resulting from this way is not suitable for agricultural with Egyptian soil and causes soil erosion in the long run. Additionally, the sulfitation method has undesired effect on the equipment; thus, it causes corrosion from using of sulfur and leads to enhancing the cost of maintenance in sugar factories. Therefore, it is important to discover novel safety and cheap methods for the clarification processes in sugar factories. In the literature several methods are used in decolorization technology such as ozone decolorization (De Souza Sartori et al. 2017), ion exchange (Susanto et al. 2016), membrane separation, ultrafiltration (Nene et al. 2002) and adsorption processes (Mudoga et al. 2008). Ion exchange methods are the most common mechanism using in decolorization processes. There are three mechanisms through that polymer's flocculation could occur (Tripathy and De 2006;Rasteiro et al. 2011): electrostatic patch, charge neutralization and bridging mechanism. Recently, many studies are developed to obtain high effective clarifying agents are eco-friendly and possess adsorption properties. Cationic polymers have many applications in different fields such as water treatment (Dardeer et al. 2022a, b) and food industries (Davis 2001). Chitosan (Chs) is natural cationic polymers especially when it solvated under acidic conditions (Izvozchikova et al. 2003;Pinotti et al. 2001). The amino group in this condition becomes protonated and carries a quaternary ammonium moiety per monomeric unit, which is an effective role in the removal of the colorant matters (Liu et al. 2018(Liu et al. , 2021. Chitosan considers one of the unique renewable polymeric material results from the deacetylation process of chitin and characterized as biodegradable renewable and nontoxic nature (Cheng et al. 2010). The chemical composition of chitosan contains amino and hydroxyl groups in presence of large number of hydrogen bonding. The pKa value ~ 6, therefore, is positively charged and has a high charge density (Gajda and Bogacki 2012;Radwan et al. 2021). Carboxymethyl cellulose (CMC) is one example of anionic flocculants and is the most biopolymers that can be prepared from sugarcane bagasse. CMC is an anionic highly viscous polysaccharide, nontoxic, nonallergenic and biodegradable (Chandel et al. 2012;Nie et al. 2004). It has several hydroxyl and carboxyl groups that enhance its ability to bind and absorb water (Tongdeesoontorn et al. 2011). It can prepare by a simple and cheap method via etherification of the hydroxyl groups in cellulose under alkaline conditions (Pushpamalar et al. 2006;Thenapakiam et al. 2013). CMC is widely used in different fields such as food, paper, paint, textile, pharmaceutical, cosmetics and detergent industries (Methacanon et al. 2003). Currently, enormous quantities of plant wastes are produced globally (Mandal and Chakrabarty 2011;Shaikh et al. 2009). The conversion of plant wastes into valuable materials can be helpful in saving of the environmental problems (Pushpamalar et al. 2006). Sugarcane bagasse is a residue produced in large quantities every year by the sugar industries in many countries (The standard laboratory manual for Egyptian Sugar  & Integrated Industries Company The standard laboratory  manual for Egyptian Sugar Integrated Industries Company, 1991), and most of this amount is used as a raw material for industrial applications such as electricity generation, pulp for paper production. In treatment processes of mixed cane juice, phosphatation process is not an efficient method to produce white sugar. From this point, the main objective of this study is to raise the efficiency of phosphatation process for producing white consumption sugar in an effective, safe and economical way by incorporating novel biopolymers composites based on Chs and CMC prepared from waste sugarcane bagasse.

Materials
CMC formed as described below from bleached bagasse pulp supplied from Quos sugar factory, Qena, Egypt. All solvents and reagents were of analytical grade and were used as purchased. Sodium hydroxide, methanol, isopropanol, monochloroacetic acid, glacial acetic acid and chitosan (DA degree = 85%) were purchased from Alfa Aesar GmbH, Co KG. All chemicals and reagents were used as received without any additional purification.

Synthesis of Carboxymethyl Cellulose Sodium Salt (CMC) from Cellulose of Sugarcane Bagasse
CMC was synthesized from sugarcane bagasse waste from Quos sugar factory in upper Egypt as follows: In a beaker, 30 ml of sodium hydroxide (NaOH 30%) was added into 9 g of cellulose (produced from the same factory), and then, 300 ml isopropanol 99.9% was added to the mixture with vigorous stirring for 1 h. After that, 11 g monochloroacetic acid was added to the mixture with continuous stirring for another 2 h at room temperature and then kept for 3 h at 60 °C. The solid residue was soaked in 200 ml of methanol and neutralized with acetic acid to pH 7, then filtered off, and washed three times by methanol 70% to remove undesirable by-products. The obtained CMC was dried at 60 °C to constant weight and kept in a dry place. The degree of substitution of produced CMC was determined according to the ASTM D1439-03 T standard method and was found to be 0.81.

Purification of CMC
Approximately, 5 g of the synthesized CMC was dissolved in 100 ml of 80 ºC distilled water at constant stirring for 10 min. Then, it was centrifuged using an Eppendorf 5430 centrifuges for 1 min at 4000 rpm. The dissolved CMC was re-precipitated in 100 ml of acetone. Recovered CMC was filtered and dried in a 60 ºC oven until constant weight and was kept in desiccator for characterization process.

Synthesis of the Biopolymer Composites
Synthesis of Chs/CMC (1:1) (1) Briefly, 1 g of chitosan (DA degree = 85%) was dissolved in 150 ml distilled water containing 0.15% glacial acetic acid at 60 °C. Then, 1 g of CMC was dissolved in 100 ml distilled water and then added to the chitosan solution with stirring for 24 h with 550 rpm to obtain the off white gel.

Synthesis of Chs/CMC (2:1) (2)
Briefly, 1 g of chitosan was dissolved in 150 ml distilled water containing 0.15% glacial acetic acid at 60 °C. Then 0.5 g of CMC was dissolved in 100 ml distilled water and then added to the chitosan solution with stirring for 24 h with 550 rpm to obtain the white gel.

Synthesis of Chs/CMC (4:1) (3)
Briefly, 1 g of chitosan was dissolved in 150 ml distilled water containing 0.15% glacial acetic acid at 60 °C. Then 0.25 g of CMC was dissolved in 100 ml distilled water and then added to the chitosan solution with stirring for 24 h with 550 rpm to obtain white gel. The synthetic route for the synthesis of Chs/CMC composites in shown in Scheme 1 and Fig. 1.

Semi-Industrial Experiments Using Chs/CMC Composites (1), (2) and (3) on Mixed Cane Juice (MCJ) The Effect of Incorporating Chs, CMC and Chs/ CMC (1) Polymers in Mixed Cane Juice Clarification Compared with Traditional Phosphatation Method
Mixed cane juice sample was obtained from pilot scale experiments of Quos sugar factory. The comparison was taken according to the following: 60 L of mixed cane juice divided to two equal quantities. The first tank (control) contains 30 L of mixed cane juice, at 73 °C. The pH, purity and calcium content were determined. Phosphoric acid "5% w/v" was added until 300 ppm P 2 O 5 content in juice. Then the lime (Ca(OH) 2 ) was added to pH 7.3, allowing retention time of 8 min for complete reaction between phosphate and calcium hydroxide; the temperature of the reaction mixture was raised to 103 °C, flashing of juice and adding 4 ppm of anionic flocculant. The suspension is settling through 1. was treated at the same conditions with incorporating Chs/ CMC (1) composite after addition of lime. The same experiments were done in case of pure Chs and CMC polymers. Assessment of pure polymers and composite treated juice compared with the control was investigated by analyzing brix, color removal, turbidity, conductivity ash, CaO and pH using standard analytical tests (The standard laboratory manual for Australian sugar mills 1984; ICUMSA method GS1/3/4/7/8-13 1994) Table 6.

The Effect of the Prepared Composites Chs/CMC (1), (2) and (3) on Mixed Cane Juice Clarification
In this experiment different formulations of Chs/CMC composites were carried out by taking about 100 ppm from each one of the three composites (1), (2) and (3), then adding into mixed cane juice before the clarification process Table 7.

The Effect of the Different Dosages of Chs/CMC (1) on Mixed Cane Juice
Chs/CMC (1) was incorporating with different dosages after liming as shown in Table 8, three replicates were done in pilot scale, and the average was calculated.

Application of the Chs/CMC Composite (1) on Clarification of Raw Sugar Syrup The Effect of Different Chs/CMC Dosages (1) on Raw Sugar Syrup Treatment
According to the results that are obtained from remediation of cane juice, we carried out several remediations on raw sugar syrup treatment using Chs/CMC (1) to investigate the efficiency of clarification of raw sugar syrup in talodura using phosphatation flotation process during syrup refining. In phospho flotation process of raw sugar syrup in pilot scale 80 L of syrup at 82 °C was divided into four tanks. At the first tank, 300 ppm P 2 O 5 as H 3 PO 4 5% was added and stirred, then addition of lime (Ca(OH) 2 ) tell 7.4 pH and aeration using air pump to 30 s., after that 10 ppm anionic flocculant was added, and allowing retention time 30-40 min., for complete flotation of suspended matters and adsorbed nonsugars on the surface of mud. The clear sample of clarified syrup was pulled from the bottom for analyzing of brix, color, turbidity, cond. ash. In the 2 nd , 3 rd and 4 th tanks, the samples were treated with the same steps with incorporating (50, 100, 200 ppm dosage.) of Chs/CMC (1), respectively, on syrup after liming, Table 10.

Effect of Treatment pH's on Chs/CMC (1) Efficiency During Syrup Clarification
The effect of change in the pH of clarification on the efficiency of composites on color removal present was studied via conducting the experiments in the same manner with changing the pH of clarification from 6.5 till 7.3, Table 11.

Effect of Feeding Point on Chs/CMC (1) Efficiency During Raw Sugar Syrup Clarification
The effect of addition of Chs/CMC (1) on feeding point was investigated before and after treatment, Table 12.

Effect of Retention Time on Chs/CMC Efficiency During Raw Sugar Syrup Clarification
The retention time effect was studied at 30, 50 and 110 min, Table 13.

Characterization
The chemical structures of the synthesized derivatives were examined by FT-IR spectroscopy using infrared spectrometer (Jasco Model 4100-Japan) at room temperature in the wavenumber range of 4000-400 cm −1 . The crystalline structure of each material and the composite was determined by powder X-ray diffraction (XRD), and patterns were recorded using Philips's diffractometer (Model PW 2103, λ = 1.5418 A°, 35kv and 20 mA) and were employed to obtain the crystal structures of the material in the 2θ region at 10° to 80°. Scanning electron microscope SEM (JEOL SEM model JSM -5500-Japan) was used to observe the morphological structures of the obtained biopolymer composites with accelerated voltage 10 kV. presence of the bands due to hydroxyl groups (νOH) at 3576 cm −1 , (νCH-aliphatic) at 2827 cm −1 , (νCOO) at 1603 cm −1 . Chs spectrum shows many characteristic bands due to hydroxyl groups (νOH, NH) at 3440 cm −1 , (νCHaliphatic) at 2930 cm −1 , (νC = O) at 1654 cm −1 . The broad band in chitosan spectrum at ∼ 3440 cm −1 is due to stretching vibrations of (-OH, -NH, -N H 2 ) functional groups and intermolecular hydrogen bonding between chitosan chains. In Chs/CMC polymer spectrum has some spectral changes like an energy shifting toward the large wavenumber approximately, at 3449 cm −1 , and became broadening and less in intensity. Such changes are due to the consumption of some amino groups of chitosan in the formation of hydrogen bonds of carboxylic and hydroxyl groups of carboxymethyl cellulose. Also, the FT-IR spectrum of Chs/CMC (1) presented the presence asymmetric stretching vibration of C H 2 groups appeared as a peak at 2930 cm −1 in chitosan spectrum (Dardeer et al. 2022a, b). Such band was shifted toward low energy 2923 cm −1 .  (1) Chs/CMC (1), this band undergoes an energy shifting to 1668 cm −1 and enhancing in its intensity. such variations are owing to merging the vibrations of amide groups with hydroxyl groups in CMC, confirming the proper chemical synthesis composite. In addition, the observed peak at ∼ 1598 cm −1 of -NH bending vibrations of chitosan was noticeably moved to be centered at low energy position of 1565 cm −1 . The results in (Table 1) Table 2 displays the change in the absorption bands of pure CMC and Chs/CMC (1). The results show appearance of variation in the absorption bands of the functional groups of CMC after formation of the Chs/CMC (1). The absorption band of hydroxyl groups, aliphatic protons glycosidic groups in Chs/CMC was shifted to lower frequencies with high intensity compared to those in pure CMC. On the other hand, the [COO] and [C-O] groups were shifted to high frequencies. These changes (increasing and decreasing in the intensity) indicate the strong interaction (electrostatic attractions) between the functional groups in the chitosan and CMC. These changes give good evidence for the synthesis of the composite (1). The reducing and increasing in frequencies are due to the formation of the hydrogen bonding and electrostatic bonds in addition to the charge neutralization between the carboxyl groups of CMC and positive charge on the quaternary amine of Chs. Figure 3 shows the FT-IR spectra of Chs/ CMC (1), Chs/CMC (2) and Chs/ CMC (3). Table 3 illustrates the difference in the frequencies of the active groups in the three composites (1), (2) and (3) due to the modification in the CMC ratio. The CMC to Chs ratio in the composite has large effect on the intensity and the shifting of the FT-IR peaks. The FT-IR spectrum of Chs/   CMC (1) shows the presence asymmetric stretching vibration of OH, NH, NH 2 groups appeared as a broad peak at 3449 with high intensity; such band was shifted toward low energy 3436 and 3428 cm −1 in the two other composites (2) and (3). This variation is due to the decreasing of CMC ratio in the biopolymer composite. In addition to the absorption band for glycosidic bond of Chs/CMC (1) was decreasing from 1058 to 1040, 1034 cm −1 , respectively. These changes are due to decreasing of the number of hydrogen bonds forming by decreasing the amount of CMC in composite.

FT-IR Studies
On the other hand, the intensity CH aliphatic and glycosidic bonds decrease. This feature gives good indication for the formation of three composites (1), (2) and (3).

XRD Analysis
The phase structure, crystallinity and amorphous percentage of Chs, Chs/CMC (1), Chs/CMC (2) and Chs/CMC (3) composites were figured out by using XRD analysis (Fig. 4, Table 4). XRD spectra were recorded at room temperature in the range 5°-80°. Semi-crystalline Chs exhibits diffraction peaks at 10.6° and 19.86° for (101), (002), respectively. These peaks appear when the powder polysaccharide was reacted with chitosan (Najaflou et al. 2021), and the diffraction peaks of the CMC powder are more amorphous also intensely changed when it reacts with Chs (Dardeer et al. 2022a, b). The characteristic diffraction peaks of chitosan were observed at 2θ = 10.6° and 19.86° (Liu et al. 2018) and were shifted due to the formation of Chs/CMC polymer composites. These biopolymer composites were confirmed by the change in the crystalline nature of the pure chitosan as showed by the increasing and decreasing of the peak at 10.6°. Also, there is slight shift and broadening of the peak at 19.86° and the appearance of a peaks at 20.27°, 19.68° and 20.25° for the three composites (1), (2) and (3), respectively. The XRD pattern demonstrates that the amorphousness increased with increasing the CMC percentage. Also, the number of hydrogen bonding increased by increasing the ratio of CMC. The peak at 10.6° in Chs polymer nearly disappeared and shifted toward the lower diffraction angles to be at ~ 10.2°, 10.0° and 9.5° in the biopolymer composites, with a clear reduction in its intensity. A possible explanation for these modifications depends on the ratio of Chs to CMC in composites, the electrostatic attractions and the intermolecular interactions among Chs and CMC. So, the amorphous nature of Chs/CMC biocomposites increases in the composite.
The crystallinity values of pure chitosan, Chs/CMC (1), Chs/CMC (2) and Chs/CMC (3) were found to be 58.5, 41.3, 46.2 and 49.8, respectively. These values show a significant decrease in crystallinity of Chs/CMC polymers compared to chitosan, which is correlated with the formation of hydrogen bonding and strong bending between Chs and CMC (Mokhtari et al. 2021). The XRD pattern of Chs/CMC polymers indicates some increasing in the crystallinity of Chs/CMC (2) (46.2%), Chs/CMC (3) (49.8%), compared to the Chs/CMC (1) (41.3%) as decreasing the percentage of CMC. The change in XRD spectra of chitosan polymers supported the synthesis of these polymers.

SEM Analysis
The SEM analysis reveals some features about the surface and morphology of the pure Chs, CMC polymers, also, the prepared Chs/CMC (1), Chs/CMC (2) and Chs/CMC (3) polymer composites, and there are different surfaces and morphology for every image, as given in Fig. 5. The morphology structure of Chs and CMC was changed after formation of the Chs /CMC composites (1), (2) and (3). The microstructure of CMC that prepared from the sugarcane bagasse appears as fibers tubes with dimension around from 61 to 64.5 μm. On the other hand, the morphological structure of Chs appears as fibrous matrix with dimension around from 105 to 262 μm. The morphology structure of the obtained composite Chs/ CMC (1) is completely different look like rugged particles with appearance of large pores with dimension around 15 to 52 μm. These dimensions of pores aid the biopolymer composite to be act as a good trape for the colloidal suspended particles from juice. The structural morphology of Chs/CMC (2) was appeared as smooth slides; with appearance of small pores, their dimension is around from 9 to 13.6 μm. In addition, the SEM image of Chs/CMC (3) composite showed rugged composite matrix with appearance of holes their dimension around from 12.5 to 24 μm. The presence of pores and holes inside the matrix of the prepared composites confirmed their high efficiency to capture the colorant materials inside it and, also, give additional elucidation for the synthesis of these composites.

Results of Semi-Industrial Experiments The effect of Pure Chs, CMC and Chs/CMC (1) Composite on Mixed Cane Juice (MCJ) Clarification
In this study, a comparison between the efficiency of traditional phosphatation method of MCJ and that after incorporating of pure Chs, CMC and Chs/CMC (1) composite was made. Table 5 shows the composition of Egyptian mixed cane juice. Figure 6 indicates color removal percentage which increases from 7.0% using pure Chs to 14.5% by using Chs/ CMC (1) composite comparing to control (traditional phosphatation clarification). Moreover, color removal enhances from 0.2% in case of pure CMC to 14.5% in case of Chs/  1 3 CMC. This explained because of increasing the positive sites of amide or amine groups which possesses two active positive centers (quaternary amine) in case of Chs/CMC (1) composite. In addition, the nature of the morphological structure of Chs/CMC (1) has large number of holes and cavities. These cavities have high ability to capture and trapping the colorant matters inside them (Mokhtari et al. 2021;Liu et al. 2021) (Fig. 7). On the other hand, there is no significant difference in the efficiency of removing calcium, conductivity ash % Bx and D.S. sugar % bx in each case of clarification as shown in Table 6. Furthermore, the obtained results could be explained based on fundamentals of the cationic color precipitants in the following mechanism.

The effect of the Prepared Composites Chs/CMC (1), (2) and (3) on MCJ Clarification
The effect of prepared three composites as cationic clarifying agent on MCJ was investigated. Table 7 indicates a significant increasing in the color removal with each of the prepared composites compared with control. There is no significant increase in the color removal between Chs/CMC (1) (10.7%), Chs/CMC (2) (10.8%) and Chs/CMC (3) (11.5%). From the previous results, we choose Chs/CMC (1) to be underinvestigation as cationic color precipitant due to its stability during storage before experiment which was noticed visually. Table 8 indicates the enhancement in the color removal % by increasing the dosages from 50 to 300 ppm with nonsignificant change in the pH value during clarification. The pH value must be controlled by about 7.5 before adding Chs/CMC composite to improve the color removal without sharp decreasing in pH value which leads to sucrose inversion (Klasson et al. 2022;Enxian et al. 2009). The most effective dosage was 300 ppm with which 20.5% increase in color removal % was achieved (Fig. 8). This increase is described via increasing the positive sites (amino groups) in comparison with coloring matters with increasing dosage. Color removal % Fig. 6 The effect of Chs, CMC and Chs/CMC (1) on the color removal of MCJ   Fig. 7 The mechanism of the color removal based on the cationic color precipitant  Moreover, the rise of dosage facilitates additional surface area for adsorption of coloring matters and trapping suspended materials and thus decreases turbidity in case of using Chs/CMC composite.

Effect of Chs/CMC (1) Composite on Anionic Flocculant Dosages
In this experiment, after incorporating 200 ppm of Chs/ CMC (1) in phosphatation clarification process followed by addition of different dosages (4, 3, 2 ppm) of anionic flocculant. The results in (Table 9) indicate the quality parameters of resulted clear juice did not affect with decreasing the dosage of anionic flocculant from 4 to 2 ppm (by about 50%) (Fig. 9). This is good evidence for the flocculating power of Chs/CMC (1) via its morphological structure and thus can be used as a flocculating agent. This represents an additional advantage must be taken in consideration when Chs/CMC (1) is used in full-scale application. In addition, the active positive centers of quaternary amine have the ability to neutralize the negative charges of colorant. And thus, macroflocculated molecules of colorant-Chs/CMC (1) composite are ready to sediment under gravity.

Application of the Chs/CMC Composite (1) on Clarification of Raw Sugar Syrup The Effect of the Different Dosages of Chs/CMC (1) on Refinery Syrup Treatment
The results in (Table 10) showed the incorporating of Chs/ CMC (1) after liming of syrup leads to significant increase in color removal percent of raw syrup from 20% (control) to 28.1, 30.9 and 40.7% with increasing dosage from 50, 100 and 200 ppm, respectively, as shown in (Table 10). Depending on the color removal % and turbidity results, the most proper dosage added from Chs/CMC (1) to raw syrup was 200 ppm (Fig. 10).

Effect of Treatment pH's on Chs/CMC (1) Efficiency During Syrup Clarification
The effect of change in the pH of clarification on the efficiency of composites on color removal Table 11 was studied by conducting the experiments in the same manner with changing the pH of clarification from 6.5 till 7.3. The most proper pH is 6.8 with which the color removal % was 21.3 and the pH of resulted clear syrup was 6.58 with which we can avoid sucrose inversion to some extent. Moreover, the color level of raw treated syrup 5851 means that the added dosages must be increase with increase color of raw syrup.

Effect of Feeding Point on Chs/CMC (1) Efficiency During Syrup Clarification
The effect of addition of Chs/CMC (1) on feeding point was investigated before and after treatment. Results in (Table 12) revealed that there was nonsignificant effective in color removal % with changing of feeding point.

Effect of Retention Time on Chs/CMC (1) Efficiency During Syrup Clarification
The retention time effect was studied (

Economic Study
According to our studies, incorporating of the synthesized cationic color precipitant Chs/CMC (1) in phosphatation process leads to sulfur removal from treatment processes. The cost of chemical aid may calculate according to the new case (phosphatation + Chs/CMC (1)) compared with sulfitation method. Table 14 shows the dosage of each chemical aid % cane and the cost LE/ton of each matter were calculated. The consumption and total cost of chemical aid and maintenance per season in a factory have million-ton crushed cane as shown in (Table 15). The economic study indicates a significant decreasing in the total cost in case of applying the new case (phosphatation + Chs/CMC (1)), where  the chemical cost will be decreased from 10.120 m. LE to 7.72 m. LE (saving about 2.4 million LE). In addition to the pollution resulted from sulfitation process will be removed and sugar free from sulfur will be obtained.

The Challenges and Future Perspectives of the Synthesized Biopolymer Composites
The future will be a good competition between our biopolymer composites and the other commercial decolorizing agents, which are used nowadays in the sugar industrial technology. The prepared biopolymer composite (Chs/CMC) is based on cheap and sustainable sources such as plant waste. On contrast, the commercial decolorizing agents are expensive in Egypt and imported. So, the challenge of sugar industry in Egypt is to replace the synthetic commercial decolorizing agents with our biopolymer composite and this point needs more advanced research.

Conclusions
In this study, a novel cationic biopolymer composites based on chitosan (Chs) and carboxymethyl cellulose (CMC) were synthesized, characterized and applied as cationic color precipitant for the mixed cane juice and raw syrup refining process in the pilot plant in Quos sugar factory, Qena, Egypt. Composite Chs/CMC (1) was the best one that showed a color removal efficiency of mixed cane juice and raw syrup by 15.8 and 40.7%, respectively, at 200 ppm dosages compared to the traditional clarification method (phosphatation) without any disadvantage side effects. Also, the obtained results showed that the composite (1) can act as flocculating agent by reducing the dosage of anionic flocculant by about 50% without disadvantages in efficiency of clarification. The most proper conditions for using this composite in raw syrup clarification were adopted as 6.8 pH, 30-min retention time and feeding point before or after clarification. The results mean that phosphatation process along with Chs/CMC (1) composite can be used for white sugar production. Moreover, the sediment resulting from this process is suitable for using as natural fertilizer enriched with phosphate and organic matter that can be invested in maximizing the benefit of the waste for this process. Finally, this new method is saving about 2.4 million LE per season as reported in this study.