Physical and Chemical Properties of Wastewater Discharged from Tofu Industries in Banda Aceh City, Indonesia

Tofu which is produced by grinding soy bean produces high amount of wastewater, and is considered as one of the most polluting food-industrial effluent due to its high values of organic pollutants. Prior to discharge into the environment, the organic pollutants in the tofu waste should be removed through waste treatment process. Knowledge about the properties of the wastewater is crucial in designing the waste treatment system. This paper investigates the physical and chemical properties of untreated wastewater discharged from tofu industries in Banda Aceh, Indonesia. The parameter of BOD, COD, MLSS, PO4-P NH3-N, Turbidity and pH were analyzed based on the standard method, approved by the EPA, for the examination of water and wastewater. The COD and BOD of wastewater from tofu processing facilities in Banda Aceh were ranging from 5000-8500 and 3500-4500 mg/L, respectively. The amount of other parameters such as MLVSS, ammonia, and turbidity were above the threshold that allowed by the government of Indonesia. Site investigation shows that in Banda Aceh city, the tofu waste has been disposed into the environment without any treatment, causing bad odours and pollution of the surface, ground water, and river. Anaerobic method can be used for tofu waste treatment because the method produces biogas and at the same time reducing organic content in waste.