The boom of tanneries in north India has converted the river Ganga into a waste dumping stream. The tanneries discharge their heavy metal-rich effluents into the river. Tissues of two-year-old tree saplings of Dalbergia sissoo, soil sediments and river water samples were collected from three sites along the river Ganga at Jajmau, Kanpur. Site-1 was located 1 km upstream from the point of discharge of the effluents of the tanneries, Site-2 was close to the source point, and Site-3 was about 1 km downstream from the source point. Accumulation of Cu, Cr and Ni in leaves, bark, wood growth rings, soil sediments and water samples was estimated using an atomic absorption spectrophotometer. The tissues of the two-year-old wood growth rings of D. sissoo accumulated large amounts of Cr, Cu and Ni. The Cr concentration in leaves, bark and wood rings had a strong, positive and linear correlation (r2) with the Cr concentration in soil sediments. The bio-concentration factors (BCFs) of Cr, Cu and Ni were higher than 1 in the wood, bark and leaves at all three selected sites, indicating the strong phytoremediating ability of the tree. The uptake of Cr and Ni was consistent in the bark and wood growth rings of two successive years. Owing to the strong uptake and accumulating abilities of Cr, Cu and Ni as evident from high BCF values and high biomass, we propose D. sissoo as a suitable species for phytoremediation throughout its range of distribution in Africa, Asia and the Americas.
Phytofiltration, phytoextraction, phytostabilization and phytovolatilization are being considered as effective means of phytoremediation [1,2,3]. The extent of uptake and accumulation of pollutants vary from plant to plant . The careful selection of a phytoremediating species is of utmost importance, especially for highly polluted soil . The phytoremediating species must be highly tolerant of the pollutants . The preference is given to an indigenous and naturalized species of the locality, adapted to local climate conditions . It is also best to select a fast growing and high biomass plant with high capacity for uptake of heavy metals . Dalbergia sissoo (Indian Rosewood; Fabaceae) has all these attributes (e.g., high biomass, rapid growth, climate tolerance, economic value, etc.). Dalbergia sissoo is the most commonly used timber tree in India, Afghanistan, Bangladesh, Iran, Iraq, Myanmar, Nepal and Pakistan, with additional advantages of easy propagation, deep root system, wide adaptability and a minimal role in the human and animal food chain . Dalbergia sissoo shows healthy growth in metal-contaminated soil making this tree a suitable candidate for phytoremediation . The heavy metals localized in the wood may get locked for a longer duration if used in furniture, doors and windows. Thus, the costs involved in harvesting and processing for recovery of metals may also be minimized. Dalbergia sissoo is native to the Indian sub-continent and widely distributed in Africa, Asia and Americas .
The river Ganga is the largest river in India and considered sacred by the majority of the Hindu community. It flows from Gangotri glaciers in upper Himalayas passing through several states of India and enters Bay of Bengal . During the past several decades, large numbers of industries have come up along the Ganga river mainly in the state of Uttar Pradesh . The Ganges basin is world’s most heavily populated with a density of about 1000 inhabitants per square mile . Inefficiently treated municipal wastes and effluents of the industries along the river are discharged in the water stream directly . Kanpur (26°26′N and 80°24′E) is a major industrial city of Uttar Pradesh, India situated on the bank of river Ganga (14). Large numbers of tanneries clustered in the Jajmau area of Kanpur city (Fig. 1) discharge their effluents into the river Ganga after inadequate treatment and containing several toxic metals and organic substances [9, 14,15,16,17,18]. These toxins affect the aquatic organisms of almost all tropic levels . All these metals are usually in soluble form and bio-available at low pH . The concentration of these metals in the river consistently decreases with increasing distance from the point of discharge . These heavy metals can also get absorbed and accumulated in aquatic organisms .
In the present study, we investigated the heavy metal extraction capacity of D. sissoo and its ability to compartmentalize heavy metals in tissues of three aboveground plant organs. We determined the extent of accumulation and bio-concentration factor (BCF) of Cr, Cu and Ni in wood, bark and leaves. Our objectives were to determine (a) the concentrations of these metals likely to be locked in the wood for a longer period if used in building material and furniture making, (b) the concentrations of these metals partitioned in the bark and leaves where it can be harvested annually via natural defoliation so that the targeted toxic metals can be recovered without damaging the tree and (c) the BCF of Cr, Cu and Ni in aboveground plant organs to document the tree’s capacity for phytoremediation.
Location of sites and sampling
Accumulation of Cr, Cu and Ni was estimated in varying parts of D. sissoo using an atomic absorption spectrophotometer (GBC Scientific Equipment, Dandenong, Australia). The plant tissue, water and soil samples were collected from three sites along the Ganga river bank. Site-1 is located on the right bank of the Ganga at Jajmau, Kanpur about 1 km before the major point of discharge of effluents of tanneries into the river. Site-2 is located at the point of the discharge of effluents of tanneries into the river and Site-3, about 1 km downstream from Site-2 (Fig. 1). Five samples of soil (over 1 kg of fresh soil sediments) were collected from 50–60 cm inland of the river stream bank, and an additional five soil samples were collected from top 20 cm layer of soil about 3–4 m inland of the river bank (close to the saplings of D. sissoo). Soil samples were dried in an oven at 80 °C for 72 h. The dried soil samples from each collection site were mixed to make one composite sample of each site for estimation of selected heavy metal in soil.
The trees of D. sissoo are widely distributed along the river banks of Ganga at Jajmau, Kanpur. Two-year-old saplings of growing about 3–4 m away from the river bank were collected in triplicate in the first week of November (before the beginning of defoliation) for estimation of Cr, Cu and Ni in the aboveground plant organs (leaves, bark and wood). The leaves of each tree sapling were separated and dried at 80 °C for 72 h and ground to a fine powder. About 10 cm pieces of the main trunk, including bark, were separated from 30 cm above the ground and kept in the oven (80 °C) for partial drying. The bark samples were separated and chopped off with a sharp knife into thin, small pieces. The secondary xylem (wood) rings of both years in each wood block were separated using a sharp knife following guidelines of Ghouse et al. [23, 24]. The wood chips of each growth ring were also chopped off into smaller pieces. The chopped bark and wood rings were re-dried at 80 °C for 48 to 72 h or until complete drying and ground to a fine powder. The powder of leaves, bark and wood rings of each tree saplings was sieved and acid digested for heavy metal analysis.
The powdered plant samples were digested following the method of Parkinson and Allen . 0.3 g of the powdered plant samples and soil sediment samples were weighed and transferred to conical flasks. Nitric acid (69%) of the analytical grade was added and kept on a hot plate for digestion until the brown fume evolving from the conical flask turned white. The digest was allowed to cool, diluted with DDW and filtered with Whatman’s filter paper 42, leaving a whitish residue. The volume of the filtrate was made to 25 ml with double distilled water and analyzed for heavy metal using the AAS (GBC Scientific Equipment, Dandenong, Australia). The AAS results were converted to actual concentration of metal in the sample using the following equation:
where calibration reading is obtained from the AAS with pre-installed Avanta Software Package, version 2.02. Extract volume is the final volume of the digest used for spectrometric analysis.
Bio-concentration factor (BCF)
Bio-concentration factor (BCF) or transfer factor (TF) is defined as the ratio of total metal concentration in the harvested tissues (barks, leaves and wood rings in the present study) and metal concentration in the soil . In previous studies, BCF has been used to estimate the ability of plants to accumulate certain heavy metals absorbed from soil [27, 28]. BCF was calculated using the following equation:
where C harvested tissue = concentration of heavy metal in harvested tissues and C soil = concentration of heavy metal in soil.
The data were analyzed using SPSS Version 17.0 for Windows .
Results and discussion
Soil and water
The concentrations of Cr, Cu and Ni were higher in the soil sediments at the Site-2 close to source point than either at Site-1 (1 km upstream) or Site-3 (1 km downstream). The concentration of all three heavy metals in the soil sediments were in the order as Site-2 > Site-3 > Site-1. The presence of Cr, Cu and Ni at Site-1 may largely be due to the addition of these heavy metals through the effluents of several other sources of Kanpur city rather than tanneries at Jajmau area alone (Table 1). This result is in agreement with the findings of Bhatnagar et al. . The Cr concentration in water samples was relatively higher at source point (Site-2) than in the water samples of Site-1 (1 km upstream) and Site-3 (1 km downstream). The presence of high quantities of Cr in the water and soil sediments at Site-2 as compared to other sites indicates that the tannery effluents consist of higher quantities of Cr and it is readily retained at the site of confluence of the major drainage system of the effluents of tanneries and the river Ganga. In a similar study, it was reported that during the tanning process, large amounts of un-reacted Cr remain in water . But, Cu and Ni concentrations in water samples of Site-2 (at source point of the tannery effluents) were comparatively less than those in the water samples of Site-1 and Site-3 (Table 1). The concentration of Cu was very high in water samples of Site-1 followed by Site-3 and Site-2, respectively (Table 1). The sedimentation of Cr, Cu and Ni was reduced at Site-3 (1 km distance from source point). The sedimentation of Cr and Ni was relatively higher at 1 km downstream from the source point (Site-3) than that of Cu (Table 1). There are no specific studies to our knowledge investigating the rate of sedimentation of these metals; therefore, we are unable to compare our results to other published studies. In our findings (Table 1), relatively larger quantities of Cr were recorded in the soil sediments at Site-2 (source point) than at 1 km downstream (Site-3). The Ni sedimented in larger quantities at 1 km (Site-3) away from the source point (Site-2). This indicates that the Cr sedimented quickly near the source point, while Ni sedimentation was highest at 1 km from the point of discharge. Further studies based on sampling from the point of discharge (Site-2) to downstream at regular intervals are needed to examine various factors that may contribute to the patterns of sedimentation of various metals (Table 1).
The concentration of Cr in the leaves of D. sissoo varied from 21 to 23% and in the bark from 24.7 to 26.3% at all three sites (Fig. 2). In a similar study, high quantity of Cr, Cu and Ni, besides some other heavy metals, accumulated in the bark and the leaves of the Juglans regia growing in contaminated soil . The concentration of Cr in the wood (rings 1 and 2 together) varied from 50 to 52% at all three sites (Fig. 2). In our study, the Cu concentration is higher in the leaf samples rather than in the bark samples at all sites (Table 1). The defoliated and green leaves may differ in accumulated quantities of these metals. Rafati et al.  reported that the accumulation of Cd and Cr was relatively higher in defoliated leaves than in the green leaves of Populus alba. High concentration of Cu has also been reported in leaves of an oak species growing at a contaminated site . In the present study, the Cu concentration in the wood rings 1 and 2 varied from 38 to 41% (Fig. 2) at all three sites. The partitioning of Cu and Ni was relatively higher in the leaves than in the bark at Site-1 and Site-3 than at the point of discharge of tannery effluents (Table 1). The quantity of Ni has also been reported higher in the defoliated leaves of Morus alba . The overall trend of accumulation of Cr was wood rings (1 + 2) > bark > leaves and that of Cu and Ni was wood > leaves > bark (Fig. 2 and 3). Further, there are differences in the levels of metal accumulation in different tissues. For examples, leaves and stem of Salix sp. growing in metal-contaminated soil accumulated high quantities of Cd and Zn compared to other parts of the plant . Zhao et al.  found high phytoextracting potentials for Cd, Cu, Pb and Zn in 18 woody species of China. Among these trees, Broussonetia papyrifera had the highest multi-metal phytoremediating ability. In contrast to our results, the partitioning of metal from trunks to leaves consistently increased in the order of trunks < branches < leaves . Many D. sissoo germinate under metal-contaminated soil and grow to maturity along the Ganga river banks. Plants that are fast growing, able to tolerate heavy metals, accumulate and translocate high quantities of metals to aboveground tissues and easy to harvest make ideal candidates for phytoremediation . Dalbergia sissoo satisfies all these criteria and therefore makes an ideal candidate for the remediation and recovery of metals. In our study, accumulation of Cr, Cu and Ni in the wood of D. sissoo was relatively higher than in the other plant parts (Fig. 3). The partitioning of these toxic heavy metals in the dead wood may possibly be a defensive strategy to avoid toxicities to more physiologically active organs and tissues.
Bio-concentration factor (BCF)
Bio-concentration factors of Cr, Cu and Ni in D. sissoo are shown in Table 2. The values of BCF were determined in the leaves, bark and wood (Ring 1 and Ring 2) (Table 2). The bio-concentration factors of Cr, Cu and Ni in all the harvested tissues of D. sissoo were above 1 at all three selected sites. Maximum BCF of Cr (2.9) was recorded in the wood at Site-1. In a similar study, Algreen et al.  found that BCF values of Zn > Cu > Cd > Ni were highest in the wood of willow and poplar trees. In our study, the highest BCF values of Cu (5.5) and Ni (11.8) were found in leaves at Site-3 and Site-1, respectively. Native plant species are the best option for phytoremediation in any region of the world even if they have a lower ability for metal accumulation, instead of non-native plant species with higher ability for heavy metal uptake and remediation .
The correlation coefficients (r2) were determined between the concentration of Cr, Cu and Ni in leaves, bark and wood rings of D. sissoo and water as well as sediments (Table 3). There were weak correlations of heavy metals concentration between water samples and Cr in the leaves, bark and wood rings (Table 3). The Cr concentration in leaves, bark and wood and Cu concentrations in the bark was strongly correlated with their respective concentrations in the soil sediments (Table 3). The Ni accumulation in plant tissues had weak correlations with Ni concentrations in water or sediments (Table 3). The strong correlation of Cr in plant tissues with respect to sediments (Table 3) indicates concentration-dependent uptake. The weak correlation between Cu and Ni concentration in tissues and their corresponding concentration in water and sediments appears concentration independent.
We observed compartmentalization of Cr, Cu and Ni in leaves, bark and growth rings of wood in D. sissoo. A significant amount of absorbed heavy metals is locked into the wood growth rings, where the metals can be retained for long without reentering the soil through decomposition. The heavy metals may also be recovered annually (via phytomining) by collecting and processing the defoliated leaves and barks. In India, the timber of this tree is very commonly used in making furniture, doors and other building material, and thus, the significant amounts of Cr, Cu, and Ni localized in the annual wood rings can become locked in for a long period of time. These features, in addition to the wide distribution and high biomass, make D. sissoo an ideal candidate for the phytoremediation of Cr and Ni.
Ozturk M, Ashraf M, Aksoy A, Ahmad MSA, Hakeem KR (eds) (2015) Plants, pollutants and remediation. Springer, Dordrecht, pp 1–404
Ansari AA, Gill SS, Gill R, Lanza GR, Newman L (2017) Phytoremediation: management of environmental contaminants. Springer, Cham
Razzaq R (2017) Phytoremediation: an environmental friendly technique—a review. J Environ Anal Chem 4:195
Christou A, Papadavid G, Dalias P, Fotopoulos V, Michael C, Bayona JM, Piña B, Fatta-Kassinos D (2019) Ranking of crop plants according to their potential to uptake and accumulate contaminants of emerging concern. Environ Res 170:422–432
Mahar A, Wang P, Ali A, Awasthi MK, Lahori AH, Wang Q, Li R, Zhang Z (2016) Challenges and opportunities in the phytoremediation of heavy metals contaminated soils: a review. Ecotoxicol Environ Saf 26:111–121
Singh S, Parihar P, Singh R, Singh VP, Prasad SM (2016) Heavy metal tolerance in plants: role of transcriptomics, proteomics, metabolomics, and ionomics. Front Plant Sci 6:1–36
Heckenroth A, Rabier J, Dutoit T, Torre F, Prudent P, Laffont-Schwob I (2016) Selection of native plants with phytoremediation potential for highly contaminated Mediterranean soil restoration: tools for a nondestructive and integrative approach. J Environ Manag 18:850–863
Pajević S, Borišev M, Nikolić N, Arsenov DD, Orlović S, Župunski M (2016) Phytoextraction of heavy metals by fast-growing trees: a review. In: Ansari A, Gill S, Gill R, Lanza G, Newman L (eds) Phytoremediation. Springer, Cham
CABI (2018) Dalbergia sissoo. In: Invasive species compendium. Wallingford, UK; CAB International. www.cabi.org/isc
Manikandan M, Kannan V, Mahalingam K, Vimala A, Chun S (2016) Phytoremediation potential of chromium containing tannery effluent-contaminated soil by native Indian timber-yielding tree species. Prep Biochem Biotechnol 46(1):100–108
Al-Snafi AE (2017) Chemical constituents and pharmacological effects of Dalbergia sissoo—a review. IOSR J Pharm 7(2):59–71
CPCB (Central Pollution Control Board) (2018) Pollution assessment: river Ganga, Ministry of Environment and Forests, Govt. of India
Tripathi PK, Prakash R (2017) Report on ground water pollution study at Jajmau, Kanpur. Central Ground Water Board, Ministry of water resources, River Development and Ganga Rejuvenation, Government of India
Kalam SU, Naushin F, Khan FA (2019) Comparative assessment of four toxic heavy metals occurring in the river beds of Ganga at three major cities of U.P. India J Biol Chem Res 36(1):86–91
Paul D (2017) Research on heavy metal pollution of river Ganga: a review. Ann Agrar Sci 15(2):278–286
Parvin S, Mazumder LT, Hasan S, Rabbani KA, Rahman ML (2017) What Should We Do With Our Solid Tannery Waste? IOSR J Environ Sci Toxicol Food Technol 11(4):82–89
Emmanuel B, Ibrahim A-Q (2017) Effectiveness of treatment plants and determination of heavy metal concentration in tannery effluents in Kano, Kano State, Nigeria. Int J Mod Chem 9(1):100–110
Asfaw TB, Tadesse TM, Ewnetie AM (2017) Determination of total chromium and chromium species in Kombolcha Tannery wastewater, surrounding soil, and lettuce plant samples, South Wollo, Ethiopia. Adv Chem 2017:1–7
Rajeshkumar S, Li X (2018) Bioaccumulation of heavy metals in fish species from the Meiliang Bay, Taihu Lake, China. Toxicol Rep 5:288–295
Rostern NT (2017) The effects of some metals in acidified waters on aquatic organisms. Oceanogr Fish 4(4):1–7
Usman K, Nisa ZU, Ijaz S, Gull S, Ahmad SR, Rehman HU, Pervaiz K, Malik IU, Ullah W, Akhtar MN (2018) Assessment of heavy metals in River Kunhar at Naran Khyber Pakhtunkhwa, Pakistan. J Biol Environ Sci 13(1):249–255
Sharifuzzaman SM, Chowdhury SR, Hossain MS, Rahman H, Ashekuzzaman SM and Islam MM (2016.) Heavy metals accumulation in coastal sediments, Environmental remediation technologies for metal-contaminated soils, pp 21–42
Ghouse AKM, Khan FA, Pasha MJ (1984) Effect of air pollution on wood formation in Dalbergia sissoo–a timber tree of Gangetic plain. J Tree Sci 3:140–142
Ghouse AKM, Khan FA, Salahuddin M, Rasheed MA (1984) Effect of air pollution on wood formation in Tectonagrandis. Ind J Bot 1:84–86
Parkinson JA, Allen SE (1975) A wet digestion procedure suitable for the determination of nitrogen and mineral nutrients in biological material. Commun Soil Sci Plant Anal 6:1–11
Sakizadeh M, Sharafabadi FM, Shayegan E, Ghorbani H (2016) Concentrations and soil-to-plant transfer factor of selenium in soil and plant species from an Arid area. Earth Environ Sci 44:1–7
Alahabadi A, Ehrampoush MH, Miri M, Aval HE, Yousefzadeh S, Ghaffari HR, Ahmadi E, Talebi P, Fathabadi ZA, Babai F, Nikoonahad A, Sharafi K, Hosseini-Bandegharaei A (2017) A comparative study on capability of different tree species in accumulating heavy metals from soil and ambient air. Chemosphere 172:459–467
Yun L, Jensen KB, Larson SR (2018) Accumulation of metals in native wheatgrasses and wildryes when grown on metal-contaminated soil from three mine sites in Montana. J Agric Sci Bot 2(1):19–24
IBM® USA (2009) SPSS statistics editions. IBM Corporation Software Group, United States of America
Bhatnagar MK, Singh R, Gupta S, Bhatnagar P (2013) Study of Tannery effluents and its effects on sediments of river Ganga in special reference to heavy metals at Jajmau, Kanpur, India. J Environ Res Dev 8(1):56–59
Islam Md, Rahaman A, Afrose A (2017) Heavy metals concentration in different processing operational waste water from tannery industry. Int Multidiscip Res J 7:18–22
Dogana Y, Unverb MC, Ugulua I, Calisb M, Durkan N (2014) Heavy metal accumulation in the bark and leaves of Juglans regia planted in Artvin City, Turkey. Biotechnol Biotechnol Equip 28(4):643–649
Rafati M, Khorasani N, Moattar F, Shirvany A, Moraghebi F, Hosseinzaden S (2011) Phytoremediation potential of Populas alba and Morus alba for cadmium, chromium and nickel absorption from polluted soil. Int J Environ Res 5:961–970
Zakrzewska M, Klimek B (2018) Trace element concentrations in tree leaves and lichen collected along a metal pollution gradient near Olkusz (Southern Poland). Bull Environ Contam Toxicol 100:245–249
French CJ, Dickinson NM, Putwain PD (2006) Woody biomass phytoremediation of contaminated brownfield land. Environ Pollut 141:387–395
Zhao X, Liu J, Xia X, Chu J, Wei Y, Shi S, Chang E, Yin W, Jiang Z (2013) The evaluation of heavy metal accumulation and application of comprehensive bio-concentration index for woody species on contaminated sites in Hunan, China. Environ Sci Pollut Res 21:5076–5085
Neilson S, Rajakaruna N (2014) Phytoremediation of agricultural soils: using plants to clean metal-contaminated arable land. In: Ansari AA, Gill SS, Lanza GR, Newman L (eds) Phytoremediation: management environmental contaminants. Springer, pp. 159–168
Algreen M, Trapp S, Rein A (2014) Phytoscreening and phytoextraction of heavy metals at Danish polluted sites using willow and poplar trees. Environ Sci Pollut Res 21:8992–9001
Mok HF, Majumder R, Laidlaw WS, Gregory D, Baker AJM, Arndt SK (2013) Native Australian species are effective in extracting multiple heavy metals from biosolids. Int J Phytorem 15(7):615–632
The first author is grateful to the Aligarh Muslim University for the award of university fellowship and chairperson, Department of Botany for providing necessary laboratory facilities. NR was funded by a South and Central Asia Regional Travel Grant, The United States-India Educational Foundation.
Financial support from the University Grants commission of India and Department of Botany, AMU for required laboratory supplies and facilities is gratefully acknowledged.
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Kalam, S.U., Naushin, F., Khan, F.A. et al. Long-term phytoremediating abilities of Dalbergia sissoo Roxb. (Fabaceae). SN Appl. Sci. 1, 501 (2019). https://doi.org/10.1007/s42452-019-0510-8
- Dalbergia sissoo
- Ganga river
- Tannery effluents
- Bio-concentration factor
- Heavy metals