물벼룩(Daphnia magna)과 발광박테레아(Aliivibrio fischeri)를 이용한 리튬, 황산염, 니켈의 복합독성 연구

Abstract

Worldwide, demand for lithium has increased in various industries, increasing by 170% in 2022 compared to 2015. Lithium’s annual growth rate is expected to be the highest among metals by 2025 due to the rapid growth of the electric vehicle battery. Wastewater generated in the secondary battery production process contains lithium and high sulfate concentrationsAs the demand for high Ni-based precursors is rapidly increasing, the discharge of nickel wastewater is also a concern. In addition, lithium and sulfate are not currently included in the permissible limit for water pollutants, and are not treated in existing wastewater treatment facilities. If lithium and sulfate are discharged without treatment, adverse environmental effects are expected to be significant. Therefore, for the safe management of secondary battery discharge water, including lithium, sulfate, and nickel, we will conduct a mixture substance ecotoxicity study on these materials and finally prepare a plan to establish a secondary battery discharge water management system. In this study, the toxicity of lithium and sulfate, which are major contaminants contained in discharge water from the secondary battery production process, and nickel, a material of concern for discharge, were evaluated using Daphnia magna and Aliivibrio fischeri. In the case of Daphnia magna, the toxicity difference according to the exposure time was also evaluated after adding a reaction time of 48 hours in addition to 24 hours according to the water pollution standards method. As a result of the single material toxicity evaluation, lithium EC5018.2mg/L, EC5014.3mg/L, sulfate EC50 4,597.2mg/L, EC504,345.0mg/L, nickel EC507.5mg/L, EC505.1mg/L for 24h and 48h were found to be different in ecotoxicity according to the reaction time. Aliivibrio fischeri 30min lithium EC503,025.8mg/L, sulfate EC5067,010.3mg/L and nickel EC506.8mg/L confirming a difference in sensitivity between Daphnia magna and Aliivibrio fischeri species to lithium and sulfate. As a result of predicting mixture toxicity (CA, IA) of mixture substances, antagonistic, additive, and synergistic effects were found depending on the mixing ratio of single substances, but most showed antagonistic effects. Therefore, a systematic ecotoxicity management system for secondary battery effluent considering the exposure time, test species, and mixed toxicity according to the target substance is required.