토양 공극수 내 Cu의 존재형태가 terrestrial biotic ligand model을 이용한 보리의 급성독성 예측에 미치는 영향

Abstract

In this study, the predictive toxicity of barley Hordeum vulgare was estimated using a modified terrestrial biotic ligand model (TBLM) to account for the toxic effects of CuOH+ and CuCO3(aq) generated at pH 7 or higher, and this was compared to that from the original TBLM. At pH values higher than 7, the difference in EA50{Cu2+} (half maximal effective activity of Cu2+) between the two models increased with increasing pH. As Mg concentration increased from 8.24 to 148 mg/L in the pH range of 5.5 to 8.5, the difference in EA50{Cu2+} increased, and it reached its maximum at pH 8. The difference in EC50[Cu]T (half maximal effective concentration of Cu) between the two models increased as dissolved organic carbon (DOC) concentration increased when pH was above 7. Thus, for soils with alkaline pH, the toxic effect of CuOH+ and CuCO3(aq) are greater at higher salt and DOC concentrations. The acceptable Cu concentration in soil porewater can be estimated by the modified TBLM through deterministic method at pH levels higher than 7, while combination of TBLM and species sensitivity distribution through the probabilistic method could be utilized at pH levels lower than 7.