Environmental Science Center, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan.
Water Sci Technol. 2010;62(9):2044-50. doi: 10.2166/wst.2010.517.
This study was aimed at comparing the Zn and Cu binding parameters with dissolved organic matter (DOM) in road runoff, wastewater treatment plant (WWTP) effluent and influent. Conditional stability constant (K') and binding site concentration ([L]) are important to predict free or labile metal concentration and toxicity in the water environment. The values of K' and [L] of three DOMs were determined by metal titration and Scatchard linearization. The Zn and Cu titration data for DOMs in WWTP effluent and influent fitted to a two-ligand model, while DOM in road runoff fitted to a single-ligand model. The order of the values of K' was WWTP influent > WWTP effluent > road runoff both for Zn and Cu. Total ambient binding site concentration ([L(T)]) was lower in DOM of road runoff (1.4-1.5 μM) than those in DOM of WWTP effluent (1.6-2.3 μM) and influent (17-18 μM), suggesting lower metal complexation capacity in DOM of road runoff. DOM in WWTP influent was expected to bind to both Zn and Cu more strongly than that of the effluent DOM.
本研究旨在比较道路径流、污水处理厂（WWTP）出水和进水的锌和铜与溶解有机物（DOM）的结合参数。条件稳定常数（K'）和结合位浓度([L])对于预测水环境中游离或可利用金属的浓度和毒性非常重要。通过金属滴定和 Scatchard 线性化确定了三种 DOM 的 K'和[L]值。WWTP 出水中 DOM 的 Zn 和 Cu 滴定数据符合双配体模型，而道路径流中的 DOM 则符合单配体模型。对于 Zn 和 Cu，K'值的顺序均为 WWTP 进水>WWTP 出水>道路径流。道路径流中 DOM 的总环境结合位浓度([L(T)])（1.4-1.5 μM）低于 WWTP 出水中 DOM 的浓度（1.6-2.3 μM）和进水 DOM 的浓度（17-18 μM），表明道路径流中 DOM 的金属络合能力较低。WWTP 进水 DOM 预计比出水中 DOM 更能与 Zn 和 Cu 结合。
