Toxicity test of tempe industrial wastewater on cyperus rotundus and scirpus grossus

Tempe industrial wastewater usually discharged directly to water bodies without any treatment. This can cause water pollution caused by high concentration of organic material in wastewater. Average concentration of BOD, COD, TSS, and pH of tempe wastewater were 20000mg/L, 30000mg/L, 1000mg/L and 4. Wastewater sample was taken from tempe home industry area in Rungkut district, Surabaya. Wastewater was taken from several stages of tempe production which were boiling and marinating processes and also mixed of them. Scirpus grossus and Cyperus rotundus were two species known to have good ability in processing organic wastewater. In this study, the ability of Scirpus grossus and Cyperus rotundus tolerating tempe wastewater was tested by toxicity test using Range Finding Test (RFT) method. Toxicity test carried out for 7 days in reactors contain 0%, 10%, 25%, 50%, 75% and 100% of tempe wastewater (v/v diluted by tap water). Cyperus rotundus’s lethal concentration of boiling waste was 25%, marinade waste was 25% and mixed waste was 25% on 6 days of research period. Scirpus grossus’s lethal concentration of boiling waste was 25%, marinade waste was 25% and mixed waste was 50% on 7 days of research period. Based on physical observations, Cyperus rotundus was more tolerant to tempe wastewater. Physical change observed to be occurred on Scirpus grossus by 2 days of exposure while on Cyperus rotundus by 3 days of exposure.