Uji Toksisitas Limbah Cair Industri Tepung Tapioka Sebelum dan Sesudah Dilakukan Pengolahan Menggunakan Metode Ozonasi Terhadap Ikan Nila (Oreochromis niloticus)

Abstract

Tapioca flour industry produces waste water containing toxic compounds in the form of cyanide (CN). Tapioca flour industrial waste water which is discharged directly into water bodies can cause damage to water bodies and disrupt the survival of the ecosystem. The purpose of this study was to determine the quality of tapioca flour industrial wastewater and the toxicity of tapioca flour industrial wastewater to Lethal Concentration 50% (LC50) bioindicator, before and after being processed by the ozonation method. Waste was taken from the tapioca flour industry in Gumelar Village, Gumelar District, Banyumas Regency. The research phase included: 1) pre-treatment toxicity test which consisted of: a) acclimatization stage for 7 days, b) preliminary test with concentration of tapioca industrial wastewater 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100%, c) real tests with concentrations of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10%; 2) determine the optimal time with variations of time 30, 60, 90, and 120 minutes and processing using the ozonation method with processing time of 30 minutes; 3) post-treatment toxicity test consisting of: a) acclimatization stage for 7 days, b) preliminary test with concentrations of 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100%, c) actual test with concentrations of 41, 42, 43, 44, 45, 46, 47, 48, 49 and 50%; 4) analysis of research data using probit analysis and linear regression. Based on the processing data, the optimal ozonation time (below the quality standard according to the Central Java Provincial Regulation Number 5 of 2012) is 30 minutes with a decrease of 82.5%. The 96-hour LC50 value of the actual test on tapioca flour industrial wastewater before it was oozed was 3.531% with treatment concentrations of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10%. whereas the 96-hour LC50 value of the actual test for industrial wastewater from tapioca flour after oozonation was 45.821% with treatment concentrations 41, 42, 43, 44, 45, 46, 47, 48, 49 and 50%. The percentage increase in the quality of industrial wastewater of tapioca flour against bioindicators based on LC50 is 87.95% - 92.29%.