Pengaruh pemakaian biofilter struktur sarang tawon pada pengolah limbah organik sistem kombinasi anaerobik-aerobik: studi kasus: limbah tahu dan tempe

Abstract

The objective of this study are to assess the influence of honeycomb biofilter application in degrading organic pollutant at combined anaerobic and aerobic system, and also to assess the possibility for applicating this technology in tofu and fermented soybean cake industry. This study was carried out in tofu and fermented soybean industry at Semanan, west Jakarta, that have around 800 small industries which has been operated since 1992. The total amount of wastewater produced from that area is about 846 m3/day, and is collected in wastewater lagoon nearby. Wastewater treatment of a combined anaerobic-aerobic system is a secondary wastewater treatment after physical treatment. Basically this wastewater treatment relies on bacteria in degrading pollutants. The use of honeycomb biofilter is to increase specific surface of media for attachment of bacteria. The Biofilter is made of plastic, 28 cm x 25 cm x 30 cm, very light and easy to clean. The system consist of two reactors that is made of 8 mm glass, and the volume of each reactor is 140 liter (so total volume of reactors is 280 liter). The reactor is equipped with two circulating pump and blower in the aerobic zone. It takes 14 - 25 days for seeding. The reactors run in four different resident times, namely 7 days, 5 days, 3 days and 1 day. The raw water used in this experiment is wastewater from tofu and fermented soybean cake industries that have 8005 around 300 - 500 mg/I. The water for physical and chemical analysis is sampled weekly. It took from raw water and each colum of reactor. Bacteria analysis was also carried out to investigate the presence of bacteria using carbohydrate and protein as main component of wastewater. Bacterial population decreased significantly at the end of the proses. The results from 1,872 physical and chemical parameters from 144 water samples showed that the reactors using biofilters have better performance than the reactors without biofilters. The Efficiency process in decreasing 8005 value is up to 90.24%, COD 74.43%, ammonia 98,68%, nitrite 87.64%, nitrate 94.76%, sulfide 100%, and total phosphate 97 .60%. Besides such a good relatively high efficiency, the hydraulic loading is around 0,48 - 3,33 m3/m2 of surface biofilter media each day and BOD loading is around 0, 20 - 0,43 kg BO05 / m3 of biofilter media each day. Economic assessment of small industry that used 100 kg soybean as raw material, need investment Rp. 5 562 000,- and operation cost Rp. 68 440,- every month or equivalent with Rp. 463,-/m3 wastewater.