Performance of trembesi seed (Samanea saman) on tempeh wastewater treatment (a case study in Semanan Tempeh Industry), West Jakarta

Abstract

Tempeh wastewater contains organic matter, TSS, and high turbidity, which negatively impact if discharged directly into water bodies. The use of biocoagulant from trembesi seeds to treat wastewater is considered more environmentally friendly, easy to find, and affordable. The purpose of this research is to determine how effective trembesi seeds are as a coagulant in removing turbidity, Total Suspended Solid (TSS), Biochemical Oxygen Demand (BOD), and Chemical Oxygen Demand (COD) from tempeh wastewater in a batch-stirred reactor. Jar test with dose variations of 10-700 mg/L, finding the optimum stirring duration for coagulation at 200 rpm with time intervals of 1-3 minutes and for flocculation at 80 rpm with time intervals of 15, 30, and 45 minutes. The findings show that using a coagulant concentration of 500 mg/L resulted in a 63% reduction in turbidity. The optimum coagulation duration is 2 minutes and flocculation is 30 minutes. BOD initially at 1,245 mg/L decreased by 78% to 273 mg/L. COD initially at 6,400 mg/L decreased by 40% to 3,840 mg/L. TSS initially at 609 mg/L decreased by 66% to 205 mg/L. The percentage of allowance for BOD, COD, TSS, and turbidity using a reactor is 68%, 35%, 58%, and 70%. From these results it can be said that trembesi seed coagulant is effective in removing BOD, COD, TSS, and turbidity in tempeh wastewater.