Green Treatment Strategies for Tannery Wastewater Employing Natural Polymers

The leather tanning industry is one of the most water-intensive industrial sectors and generates highly polluted wastewater containing organic matter, inorganic salts, sulfides, chromium, and recalcitrant compounds. Conventional treatment methods rely heavily on chemical coagulants, which often produce non-biodegradable sludge and pose potential environmental and health risks. The present study investigates an eco-friendly and sustainable approach for tannery effluent treatment using a natural polysaccharide extracted from Strychnos potatorum L. seeds. The extracted polysaccharide was instrumentally confirmed using Fourier Transform Infrared (FTIR) spectroscopy, which revealed the presence of hydroxyl, carboxyl, and amine functional groups responsible for coagulation activity and SEM analysis of raw polysaccharide and treated sludge for the confirmation of coagulation process..Physicochemical characteristics of untreated tannery wastewater were analyzed and compared with treated samples following coagulation–flocculation using varying doses of the extracted polysaccharide. Process optimization studies identified an optimum coagulant dosage of 30 mg/L, rapid mixing at 120 rpm for 2 min, slow mixing at 40 rpm for 20 min, and a settling time of 30 min for maximum treatment efficiency. Significant reductions in turbidity, total suspended solids, chemical oxygen demand, and biological oxygen demand were observed, with maximum removals of 78% color, 62.5% total dissolved solids, 70% COD, and substantial reduction in suspended solids and BOD at the optimized dosage, demonstrating effective pollutant removal. The results highlight the potential of Strychnos potatorum seed polysaccharide as a biodegradable, low-cost alternative to conventional chemical coagulants. This green treatment strategy offers a promising pathway for sustainable tannery wastewater management and supports the transition toward environmentally responsible industrial practices.

Department of Biotechnology, Mother Teresa Women’s University, Kodaikanal, TamilNadu, India-624101

1. 1 Ahmad, A. L., Wong, S. S., Teng, T. T., and Zuhairi, A., “Improvement of alum and PACl coagulation by natural coagulant aids,” Chemical Engineering Journal, vol. 137, pp. 510–517, 2007. [Google Scholar] [Crossref]

2. Ake, A. H. J., et al., “Natural polymers for wastewater remediation,” Environmental Science and Pollution Research, vol. 29, pp. 66542–66555, 2022. [Google Scholar] [Crossref]

3. Alam, M. Z., Ahmad, S., Malik, A., and Ahmad, M., “Treatment of tannery wastewater using hybrid processes,” Journal of Environmental Management, vol. 262, 110336, 2020. [Google Scholar] [Crossref]

4. Alazaiza, M. Y. D., et al., “Application of natural polymers in wastewater treatment,” Journal of Environmental Chemical Engineering, vol. 10, 107255, 2022. [Google Scholar] [Crossref]

5. Ali, M. F., and Naher, U. H., “Characteristics of tannery wastewater and its environmental impacts,” Environmental Monitoring and Assessment, vol. 187, 410, 2015. [Google Scholar] [Crossref]

6. Al-Jlil, S. A., and Alsewailem, F. D., “Tannery wastewater treatment using eco-friendly natural coagulants,” Environmental Technology, vol. 37, pp. 1–9, 2016. [Google Scholar] [Crossref]

7. Ang, W. L., and Mohammad, A. W., “State of the art and sustainability of chemical coagulants,” Journal of Water Process Engineering, vol. 33, 101035, 2020. [Google Scholar] [Crossref]

8. Ashraf, S., et al., “Human health risks of heavy metals in industrial wastewater,” Ecological Engineering, vol. 148, 105789, 2020. [Google Scholar] [Crossref]

9. Beltrán-Heredia, J., and Sánchez-Martín, J., “Removal of sodium lauryl sulfate by coagulation with natural coagulants,” Industrial & Engineering Chemistry Research, vol. 48, pp. 5085–5092, 2009. [Google Scholar] [Crossref]

10. Bernet, N., and Béline, F., “Challenges in sludge management,” Environmental Science & Technology, vol. 43, pp. 807–813, 2009. [Google Scholar] [Crossref]

11. Bhatia, S., Othman, Z., and Ahmad, A. L., “Bio-based coagulants for wastewater treatment: A review,” Journal of Environmental Chemical Engineering, vol. 6, pp. 5122–5130, 2018. [Google Scholar] [Crossref]

12. Bhardwaj, A., et al., “Economic importance of leather industries,” Environmental Science and Pollution Research, vol. 30, pp. 15421–15435, 2023. [Google Scholar] [Crossref]

13. Boshoff, G., et al., “Industrial effluent management practices,” Water Research, vol. 38, pp. 389–396, 2004. [Google Scholar] [Crossref]

14. Bratby, J., Coagulation and Flocculation in Water and Wastewater Treatment, IWA Publishing, 2016. [Google Scholar] [Crossref]

15. Can, O. T., et al., “Chromium toxicity and environmental risk assessment,” Journal of Hazardous Materials, vol. 372, pp. 117–125, 2019. [Google Scholar] [Crossref]

16. Cassano, A., Drioli, E., Galaverna, G., and Cagnasso, P., “Treatment of aqueous effluents of the leather industry by membrane processes,” Desalination, vol. 141, pp. 157–165, 2001. [Google Scholar] [Crossref]

17. Chowdhury, M., Mostafa, M. G., Biswas, T. K., Mandal, A., and Saha, A. K., “Characterization of the effluents from leather processing industries,” Journal of Cleaner Production, vol. 87, pp. 701–708, 2015. [Google Scholar] [Crossref]

18. Choy, S. Y., Prasad, K. M. N., Wu, T. Y., Raghunandan, M. E., and Ramanan, R. N., “Utilization of plant-based natural coagulants as future alternatives,” Journal of Environmental Sciences, vol. 26, pp. 2178–2189, 2014. [Google Scholar] [Crossref]

19. Dehghani, M. H., Alimohammadi, M., and McKay, G., “Removal of COD from industrial wastewater using natural coagulants,” Desalination and Water Treatment, vol. 57, pp. 1–10, 2016. [Google Scholar] [Crossref]

20. Devipriya, S., et al., “Functional characterization of natural polysaccharides,” International Journal of Biological Macromolecules, vol. 148, pp. 853–863, 2020. [Google Scholar] [Crossref]

21. Feng, J. W., et al., “Adsorption of pollutants using natural materials,” Journal of Hazardous Materials, vol. 146, pp. 280–286, 2007. [Google Scholar] [Crossref]

22. Fersi, C., et al., “Coagulation–flocculation treatment of industrial wastewater,” Separation and Purification Technology, vol. 201, pp. 427–436, 2018. [Google Scholar] [Crossref]

23. Freitas, T. K. F. S., et al., “Sludge generation and management in wastewater treatment,” Chemical Engineering Journal, vol. 268, pp. 1–10, 2015. [Google Scholar] [Crossref]

24. Freitas, T. K. F. S., Almeida, C. A., et al., “Review of natural coagulants in water treatment,” Environmental Technology Reviews, vol. 7, pp. 1–16, 2018. [Google Scholar] [Crossref]

25. Gautam, S., and Saini, G., “Natural coagulants: Sustainable materials for water purification,” Journal of Cleaner Production, vol. 272, 122628, 2020. [Google Scholar] [Crossref]

26. Ghernaout, D., and Ghernaout, B., “From chemical disinfection to electrocoagulation,” Desalination, vol. 297, pp. 1–8, 2012. [Google Scholar] [Crossref]

27. Ghernaout, D., “Natural organic polymers for water and wastewater treatment: A review,” Applied Water Science, vol. 10, pp. 1–12, 2020. [Google Scholar] [Crossref]

28. Hameed, Y. T., Idris, A., and Hussain, S. A., “A review on natural coagulants for wastewater treatment,” Journal of Environmental Management, vol. 175, pp. 117–127, 2016. [Google Scholar] [Crossref]

29. Ho, Y. S., and McKay, G., “Pseudo-second order kinetic model for adsorption processes,” Process Biochemistry, vol. 34, pp. 451–465, 1999. [Google Scholar] [Crossref]

30. Kabir, M., et al., “Emerging green coagulants for wastewater treatment,” Journal of Molecular Liquids, vol. 369, 120927, 2023. [Google Scholar] [Crossref]

31. Katal, R., and Pahlavanzadeh, H., “Influence of parameters on coagulation–flocculation using plant-based materials,” Iranian Journal of Environmental Health Science & Engineering, vol. 8, pp. 1–8, 2011. [Google Scholar] [Crossref]

32. Lee, C. S., Robinson, J., and Chong, M. F., “Application of plant-based coagulants in wastewater treatment,” Process Safety and Environmental Protection, vol. 92, pp. 489–508, 2014. [Google Scholar] [Crossref]

33. Lejri, R., and Younes, S., “Environmental risks of tannery effluents and treatment strategies,” Environmental Science and Pollution Research, vol. 29, pp. 11245–11260, 2022. [Google Scholar] [Crossref]

34. Malik, Q., “Environmental impacts of tannery wastewater,” Environmental Monitoring and Assessment, vol. 186, pp. 423–432, 2014. [Google Scholar] [Crossref]

35. Manahan, S. E., Environmental Chemistry, CRC Press, 2010. [Google Scholar] [Crossref]

36. Matilainen, A., Vepsäläinen, M., and Sillanpää, M., “Natural organic matter removal by coagulation,” Advances in Colloid and Interface Science, vol. 159, pp. 189–197, 2010. [Google Scholar] [Crossref]

37. Murugesan, A. G., and Rajakumari, C., “Environmental issues of tannery clusters,” Indian Journal of Environmental Protection, vol. 25, pp. 873–878, 2005. [Google Scholar] [Crossref]

38. Okuda, T., Baes, A. U., Nishijima, W., and Okada, M., “Coagulation mechanism of natural coagulants,” Water Research, vol. 35, pp. 830–836, 2001. [Google Scholar] [Crossref]

39. Parveen, S., et al., “Leather industry and environmental sustainability,” Applied Water Science, vol. 7, pp. 2099–2110, 2017. [Google Scholar] [Crossref]

40. Roussy, J., Van Vooren, M., Dempsey, B. A., and Guibal, E., “Influence of chitosan characteristics on coagulation,” Water Research, vol. 39, pp. 3247–3258, 2005. [Google Scholar] [Crossref]

41. Sabur, M. A., et al., “Pollution potential of tannery wastewater and its impacts,” Journal of Environmental Management, vol. 130, pp. 82–89, 2013. [Google Scholar] [Crossref]

42. Song, Z., and Williams, C. J., “Application of coagulation–flocculation in industrial wastewater treatment,” Water Research, vol. 37, pp. 3871–3878, 2003. [Google Scholar] [Crossref]

43. Vijayaraghavan, K., Ahmad, D., and Ezani, E., “Bioflocculants: Recent advances and applications,” Biotechnology Advances, vol. 40, 107500, 2020. [Google Scholar] [Crossref]

44. Wang, J., Chen, C., and Wang, X., “Removal of pollutants from industrial effluents by coagulation processes,” Water Research, vol. 88, pp. 329–338, 2016. [Google Scholar] [Crossref]

45. Yin, C. Y., “Emerging usage of plant-based coagulants,” Process Biochemistry, vol. 45, pp. 1437–1444, 2010. [Google Scholar] [Crossref]

46. Zhao, X., et al., “Advanced treatment of tannery wastewater,” Journal of Environmental Management, vol. 304, 114289, 2022. [Google Scholar] [Crossref]

47. Zungolo, F., et al., “Sustainable materials for wastewater remediation,” Journal of Cleaner Production, vol. 389, 136086, 2023. [Google Scholar] [Crossref]

48. Renault, F., Sancey, B., Badot, P. M., and Crini, G., “Chitosan for coagulation/flocculation processes – An eco-friendly approach,” European Polymer Journal, vol. 45, pp. 1337–1348, 2009. [Google Scholar] [Crossref]

49. Ndabigengesere, A., Narasiah, K. S., and Talbot, B. G., “Active agents and mechanism of coagulation using Moringa oleifera,” Water Research, vol. 29, pp. 703–710, 1995. [Google Scholar] [Crossref]

50. Miller, S. M., et al., “Efficacy of Moringa oleifera in water treatment,” Environmental Science & Technology, vol. 42, pp. 4274–4279, 2008. [Google Scholar] [Crossref]

51. Diaz, A., et al., “Evaluation of turbidity removal by natural coagulants,” Process Biochemistry, vol. 35, pp. 391–395, 1999. [Google Scholar] [Crossref]

52. Vijayaraghavan, K., and Yun, Y. S., “Bacterial biosorbents and biosorption,” Biotechnology Advances, vol. 26, pp. 266–291, 2008. [Google Scholar] [Crossref]

53. Bolto, B., and Gregory, J., “Organic polyelectrolytes in water treatment,” Water Research, vol. 41, pp. 2301–2324, 2007. [Google Scholar] [Crossref]

54. Gregory, J., Particles in Water: Properties and Processes, CRC Press, 2006. [Google Scholar] [Crossref]

55. Matilainen, A., et al., “Overview of NOM removal by coagulation,” Chemosphere, vol. 83, pp. 1431–1442, 2011. [Google Scholar] [Crossref]

56. Sharma, P., and Kaur, H., “Role of natural coagulants in water purification,” International Journal of Environmental Science and Technology, vol. 15, pp. 123–134, 2018. [Google Scholar] [Crossref]

57. Teh, C. Y., Wu, T. Y., and Juan, J. C., “Optimization of agro-based natural coagulants,” Industrial Crops and Products, vol. 89, pp. 166–173, 2016. [Google Scholar] [Crossref]

58. Tripathy, T., and De, B. R., “Flocculation: A new way to treat wastewater,” Journal of Physical Sciences, vol. 10, pp. 93–127, 2006. [Google Scholar] [Crossref]

59. Mohan, D., and Pittman, C. U., “Adsorbents for chromium removal from water,” Journal of Hazardous Materials, vol. 137, pp. 762–811, 2006. [Google Scholar] [Crossref]

60. Sharma, V., and Kumar, R., “Application of natural coagulants for wastewater treatment,” Journal of Water Process Engineering, vol. 45, 102567, 2022. [Google Scholar] [Crossref]

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