알루미늄 가공 공장 배출 방류수의 독성 원인물질 탐색

Application of Toxicity Identification Evaluation Procedures for Toxic Effluents from the Aluminum Rolling Industry

Objectives: The objective of this study is to identify toxicants causing acute toxicity in effluents from the aluminum rolling industry that violate the discharge limits in Korea. Methods: Whole effluent toxicity tests (WET) were conducted on effluent discharged from the aluminum rolling industry following the US EPA WET test methods. We collected effluent samples three times and evaluated acute toxicity by using Daphnia magna. We employed toxicity identification evaluation (TIE) procedures to identify toxicants causing toxicity in the effluent. Results: No specific chemical groups were identified in the seven different manipulations applied to the of wastewater effluent samples showing 1.3 toxic units (TU) according to the TIE phase I procedures. Water quality parameters for water hardness, electric conductivity and heavy metals (Mn) were 4,322 mg/l as CaCO 3 , 11.39 mS/cm, and 5,551 µg/l, respectively. Considering water hardness and reference toxicity, high concentrations of Mn can be disqualified from the causative toxicants. Consequently, high ionic concentrations of Na (1,428 mg/l) and SO 4 (7,472 mg/l) were identified to be causative toxicants. Water hardness and electric conductivity exceed the EC 50 value obtained by biological toxicity tests using Daphnia magna. Conclusion: According to TIE procedures, high salt concentration is determined to be a major toxicant in the effluent of agro-industrial wastewater treatment plants receiving wastewater from the aluminum rolling industry.