Comparison of Optimum Dosages of Biocoagulant and Commercial Coagulant Alum in the Coagulation-Flocculation Process of Tofu Wastewater

Abstract

The tofu industry is an agro-industrial sector that produces wastewater with high organic content of organic matter, suspended solids, and nitrogen compounds that have the potential to pollute the environment. The coagulation-flocculation process is one of the effective methods to reduce these pollutants, with the selection of coagulants as a determining factor in success. This study aims to compare the effectiveness of natural coagulants in the form of maggot shell biocoagulants and moringa seeds with commercial alum coagulants in treating tofu wastewater. The research methods include the preparation of biocoagulants, determining the optimum dosage through a jar test, and analyzing the parameters of pH, Total Suspended Solids (TSS), turbidity, and color. The results showed that all coagulants were able to reduce turbidity, TSS, and color of tofu wastewater, although their effectiveness varied for each parameter. Alum coagulant showed the highest performance in turbidity removal of 86.67% (dose 250 mg/L), TSS removal of 98.66% (dose 250 mg/L), and color removal of 96.17% (dose 250 mg/L). Meanwhile, moringa seed biocoagulant was able to remove turbidity of 86.67% (dose 150 mg/L), TSS of 98.66% (dose 150 mg/L), and color of 96.17% (dose 150 mg/L). Meanwhile, maggot shell biocoagulant was able to remove turbidity of 74.96% (dose 150 mg/L), TSS of 83.89% (dose 150 mg/L), and color of 77.48% (dose 150 mg/L). This study recommends the use of biocoagulants as an environmentally friendly alternative with performance close to that of the commercial coagulant alum.