Toxicity of Decolorized Batik Wastewater on Common Carp Using Combination of Chitosan and Spent Mushroom Substrate

Swastika Oktavia (Biology Departement, Mathla’ul Anwar University, Banten, Indonesia)
Nisa Haerunissa (Biology Departement, Mathla’ul Anwar University, Banten, Indonesia)
Cory Novi (Chemistry Departement, Mathla’ul Anwar University, Banten, Indonesia)

Gema Lingkungan Kesehatan
Vol. 23 No. 1 (2025): Gema Lingkungan Kesehatan

Decolorization is a key treatment process in batik industry wastewater management, aimed at reducing color intensity. This study evaluates a decolorizing combination of chitosan from Litopennaeus vannamei (CLV) and spent mushroom substrate from Pleurotus ostreatus (SMSPO), examining its effect on the 96-hour LC50 value and scale structure of common carp. Using a completely randomized design, common carp was exposed to decolorized wastewater at concentrations of 0%, 1.875%, 3.75%, 7.5%, 15%, and 30%. Results show that decolorized wastewater at 7.5% concentration remains lethal to fish, while concentrations of 3.75% and below are non-lethal. Microscopic changes in fish scales indicate particle adhesion from the wastewater. The 96-hour LC50 for untreated wastewater is 5.663%, compared to 4.788% after decolorization, reflecting a slight decrease in toxicity. These findings suggest that C-LV and SMS-PO combination could contribute to sustainable wastewater treatment practices by reducing toxicity in batik industry effluent.