Pollution Research Paper

TREATMENT OF TOFU WASTEWATER USING CONSTRUCTED WETLAND IN INDONESIA

KURNIADIE D., WIJAYA D., WIDAYAT D., UMIYATI U. AND ISKANDAR

Abstract

Tofu factory wastewater belongs to one of the main contributor to the eutrophication of surface waters in Indonesia. The sources of wastewater in tofu factory coming from washing process,soaking and stripping soy and whey from clotting process. Wastewater normally discharged directly into the surface water without treatment processes causing pollution and are harmful to the surface water. A constructed wetland to treat wastewater from tofu factory has been built in Tofu factory in Sumedang Regency, Indonesia, in December 2015. Water samples from both influent and effluent were taken every nine days and analysed for COD, BOD5, DO and total settleable solids. The objective of this study was to find out whether combination of pre-treatment and constructed wetland planted with Phragmites karka can meet the discharge requirements corresponding to 150 mg L-1 biochemical oxygen demand (BOD5), 300 mg L-1 chemical oxygen demand (COD), 100 mg L-1 according to Indonesian standard for tofu industry. The results of this experiment showed that the average of treatment efficiencies during the period from July 2016 to March 2017 for BOD5, COD and total settleable solids were 99.07%, 98.99% and 92.54% respectively, whereas the concentration in effluent was 17 mg L-1 for BOD5, COD was 22 mg L-1 and total settleable solids was 51 mg L-1. The overall results show that BOD5 and COD concentration in effluent were already lower than the Indonesian standard for tofu factory wastewater.