Assessing Marine Ecotoxicity Potential Impacts of Industrial Wastewater Discharge from the Secondary Battery Industry: A Life Cycle Impact Assessment Approach

This study aims to develop a quantitative methodology for assessing the marine ecotoxicity of wastewater from the secondary battery industry and to establish discharge limits based on this assessment. To achieve this, two key objectives were pursued. First, the ecotoxicity impact of wastewater discharge on the marine environment was quantified using the Life Cycle Impact Assessment (LCIA) method. Second, a Local Marine Ecotoxicity Impact Limit (Local MEIL) was derived from the LCIA results, and the corresponding allowable discharge flow rates and contaminant concentrations were determined.To support this analysis, characterization factors for Cu, Co, Ni, and Mn in the Korea Peninsula & Japan marine region were calculated using fate, exposure, and effect factors provided by LC-Impact. Additionally, the characterization factor for salinity was adopted from Roibas-Rozas et al. (2022). The expected marine ecotoxicity was then estimated by multiplying the characterization factors of each substance by the corresponding wastewater discharge amounts. The Local MEIL was determined by integrating wastewater discharge limits with characterization factors.The results indicate that under expected wastewater discharge conditions in the Saemangeum watershed, Gunsan (100,000m3/day, with current known concentrations of Cu, Co, Ni, Mn, and salinity), the projected marine ecotoxicity is 3.16E+07 [PAF·m3·day], significantly exceeding the allowable Local MEIL of 1.22E+07 [PAF·m3·day]. Notably, salinity emerged as the dominant contributor to marine ecotoxicity, accounting for 94.8% of the total impact. To reduce ecotoxicity to an acceptable level, the salinity discharge concentration would need to be lowered from the expected 120,000mg/L to 41,000mg/L, or the wastewater discharge volume would need to be reduced to 38,500m3/day or less. These findings highlight the importance of appropriate wastewater discharge management in mitigating marine ecotoxicity impacts.