DOI: https://doi.org/10.55373/mjchem.v26i1.154

Keywords: Biopolymer; coagulant; cowpea seeds; fenugreek; effluent; treatment

Abstract

Water is vital to all living organisms. However, rapid urbanization has deteriorated the water ecosystem. Therefore, emerging treatments must be implemented to enhance water quality before consumption. Thus, it is important to improve the quality of effluent in wastewater treatment plants before being discharged into the water bodies. This study comprised the potential of fenugreek and cowpea seeds as natural coagulants in the tertiary treatment to reduce the effluent pollutants. A jar test experiment was conducted with variables ratio of green substances (fenugreek and cowpea seeds) in the effluent medium. The characteristics of the effluent before and after treatment were analyzed for biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), ammonia-nitrogen, nitrite-nitrogen, nitrate-nitrogen, and turbidity. The optimum concentration and pH for each bio-coagulant were evaluated. From the experimental results for the highest turbidity removal, 7.11 Nephelometric Turbidity unit (NTU) was determined for cowpea seeds of 0.2 mg/L concentration. Meanwhile, the optimum concentration for fenugreek was 0.6 mg/L, with turbidity removal rates of 7.93 NTU. Therefore, from the observation, the lowest turbidity removal was 20%, and the maximum was 41%. The Fourier Transform Infrared (FTIR) Spectroscopy indicated that the chemical structure of each polymer had changed (before and after treatment), which involved the production of C=O, O-H in fenugreek, cowpea seeds, with both coagulants and using aluminium sulfate, respectively. Moreover, isotherm analysis for the adsorption capacity of bio-coagulants has been determined. From the output evaluation, this natural coagulant can be an effective agent in the water treatment process. It can be compared with the efficiency values achieved using these green substances in contrast to the treatment of chemicals coagulant.