PEMANFAATAN BIJI ASAM JAWA (Tamarindus indica) SEBAGAI KOAGULAN ALTERNATIF DALAM PENGOLAHAN LIMBAH CAIR INDUSTRI TAHU

THE UTILIZATION OF TAMARIND (Tamarindus indica) SEEDS AS AN ALTERNATIVE COAGULANT IN THE TREATMENT OF LIQUID WASTE FROM A TOFU INDUSTRY (Fitri Puspasari, 2014, 46 pages, 13 tables, 16 pictures, 3 appendixes) Tamarind seeds are rarely used. Tamarind seeds contain of tanin and protein so it can be used as an alternative coagulant. The purpose of this research was to determine the optimum dose of alternative coagulant and stirring speed of liquid waste from a tofu industry on Turbidity, TSS, pH, COD, and BOD5. The variable of this research were the coagulant dosages (400, 800, 1200, 1600, and 2000 mg/L sample), and the difference of stirring speed in coagulation and flocculation, there were 20 and 5 rpm, 30 and 10 rpm, 40 and 15 rpm. The result showed that in coagulant dose of 2000 mg/L, the stirring speed of coagulation 20 rpm and flocculation 5 rpm was the optimum coagulant dose and stirring speed of these five parameters, which in turbidity, it decreased from 316 NTU to 167 NTU, TSS level decreased from 56,5 mg/L to 39,2 mg/L, pH level increased from 3,89 to 4,96, COD level decreased from 1223 mg/L to 107 mg/L and BOD5 level decreased from 399,5 mg/L to 33,5 mg/L. These parameters met the requirement of the quality standard of waste water for industry Keywords: Tamarind seeds, Tofu wastewater, Coagulation, Flocculatio