Efficacy of Chitosan Derived from Tahong (Perna viridis) Shells in Treating Swine Biogas Digester Effluent
Abstract
Chitosan, a natural linear biopolyaminosaccharide, is a non-toxic and environmentally friendly coagulant derived through the deacetylation of chitin, a major component of Tahong (Perna viridis) shells. This study evaluates the efficacy of chitosan in modifying the physicochemical properties of treated swine biogas digester effluent under varying chitosan dosages (8 g/L and 10 g/L) and agitation speeds (30 rpm and 50 rpm). The extracted chitosan powder exhibited high deacetylation, quantified at 74.65%. The untreated swine biogas digester effluent displayed the following properties: pH 7.34, COD 704 mg/L, BOD 338 mg/L, phosphate 81.54 mg/L, nitrate 138.75 mg/L, TDS 2027 mg/L, and TSS 2355 mg/L. Optimal treatment conditions were observed at a dosage of 8 g/L and an agitation speed of 30 rpm, yielding effluent properties of pH 8.30, COD 1499.00 mg/L, BOD 348.33 mg/L, phosphate 2.28 mg/L, nitrate 64.93 mg/L, TDS 2950.67 mg/L, and TSS 25.33 mg/L. Comparative analysis against the Department of Environment and Natural Resources (DENR) Class C water standards revealed significant improvements in BOD, phosphate, and nitrate levels, with p-values of 0.000. Conversely, the differences in pH and TSS were not statistically significant, with p-values of 0.141 and 0.199, respectively.
References
Abddulkarim, A., 2014. “Extraction and characterization of chitin and chitosan for Chromium (VI) ion removal from wastewater”, Master’s Thesis, Ahmadu Bello University, Zaria.
Cheng and Liu, 2002. “Swine wastewater treatment in anaerobic digester with floating medium.” ASAE. 45(3), 799-805. https://doi.org/10.13031/2013.8842
Coleman, C. K., Oza, H. H., Bailey, E. S., & Sobsey, M. D., 2024. “A review of chitosan as a coagulant of health-related microorganisms in water and wastewater”. Environ. 11(10), 211. https://doi.org/10.3390/environments11100211
Dimatulac, A & Delgado, M., 2005. “Formulation of anti-inflammatory ointment using chitosan form crab shells”.
DENR Administrative Order No. 34 Series of 1990 (Sgd) (RP)
Ferreira, de Lucas Jr., do Amaral, 2003. “Partial characterization of the polluting load of swine wastewater treated with an integrated biodigestion system”, Bioresour. Technol., 90, 101-108. https://doi.org/10.1016/S0960-8524(03)00127-5
Garcia, M & Moreno, L., 2012. “Removal of nitrogen and carbonic matter by chitosan and aluminum sulphate”, Water Supply, 12(1), 1-10 https://doi.org/10.2166/ws.2011.111
Lapus, Z., 2009. “Swine Production in the Philippines (1/2)” 24 March, viewed 08 September 2015.
Mehta, A., Sain M. Y., Ni and D Morneau, 2004. “Chemical additive optimization program: Short-cycle clarification of deinking mill alkaline-water loop”, Pulp and Paper Canada, 105(3), 43-46.
MohdZin, N, Abdul Aziz H, MohdAdlan N, Ariffin A, and Yusoff M 2009. “Understanding the use of chemical and natural coagulants in the coagulation process: A review”, Casp. J. Appl. Sci. Res., 2(9), 300-308.
Musico, Y., 2007. “The potential of calcium carbonate for Philippine green mussel shells as extender in the manufacture of flat latex paints.” TIP-QC Research Journal, 4(1).
Pontius F., 2016. “Chitosan as a Drinking Water Treatment Coagulant”, Am. J. Civ. Eng., 4(5), 205. https://doi.org/10.11648/j.ajce.20160405.11
Rockson-Itiveh, D., Ozioko, F., & Keke, M., 2023. “The Use of Chitosan as A Coagulant in Wastewater Treatment”. IJEP., 7(1), 27–36.
Sinardi, Prayatni S., and Suprihato N., 2013. “The Chemical Characteristics of Chitosan Extracted from Green Mussels Shells (Mytilus viridis linneaus) and Its Potential Application as a Natural Coagulant.” The Second International Conference on Sustainable Infrastructure and Built Environment- Bandung 19-20 November 2013.
Solidum, J. N., 2010. “An exploratory study on possible preparations that may be formulated from Tahong Shells collected from Cavite City, Philippines.” IJCEE., 1(2), 102-107.
Tokhun N., 2009. “Piggery farm wastewater: Alternative solution for agriculture and soil fertility.” IJERD., 1 (2), 58-61.
Zaman, H. G., Baloo, L., Aziz, F., Kutty, S. R., & Ashraf, A., 2022. “COD adsorption and optimization from produced water using chitosan–ZnO nanocomposite,” Appl. Nanosci., 12(6), 1885–1898. https://doi.org/10.1007/s13204-022-02392-y.
Copyright (c) 2025 ASEAN Journal of Chemical Engineering

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
Copyright holder for articles is ASEAN Journal of Chemical Engineering. Articles published in ASEAN J. Chem. Eng. are distributed under a Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) license.
Authors agree to transfer all copyright rights in and to the above work to the ASEAN Journal of Chemical Engineering Editorial Board so that the Editorial Board shall have the right to publish the work for non-profit use in any media or form. In return, authors retain: (1) all proprietary rights other than copyright; (2) re-use of all or part of the above paper in their other work; (3) right to reproduce or authorize others to reproduce the above paper for authors’ personal use or for company use if the source and the journal copyright notice is indicated, and if the reproduction is not made for the purpose of sale.