Effect of dissolved organic matter in urban wastewater on heavy metal speciation and trophic transfer

城市污水处理厂出水中的溶解有机物对锌、铜的络合条件稳定常数高于天然腐殖质。在培养基中添加有机质导致绿藻对锌的吸收减少，藻细胞的营养有效锌也减少。因此，有机质降低了环境中锌对捕食者的毒性。生物降解和光解试验结果表明，有机物在河水环境中具有络合特性。

Dissolved organic matter in municipal wastewater treatment plant effluent had higher conditional stability constant of zinc and copper complexation than natural humic substance. Addition of the organic matter to culture media induced lower zinc uptake by green algae as well as less trophically available zinc in algal cells. Consequently, it is suggested that zinc toxicity to the predator in the environment is reduced by the organic matter. Result of biodegradation and photodegradation tests showed the stability of the organic matter under river water environment in terms of complexation characteristics.