径流溶解性有机物对生物滞留介质去除Cu2+和Pb2+的影响

分别以惰性介质（土、砂）和强化介质（给水厂污泥、铁锰复合氧化物）为研究对象，考察道路径流溶解性有机物（DOM）存在对生物滞留介质吸附去除Cu²⁺和Pb²⁺过程的影响，并揭示其主要响应组分及作用机制.结果表明，径流DOM、DOM各分子量组分和各化学组分均可抑制惰性生物滞留介质对Cu²⁺和Pb²⁺的吸附去除，促进强化生物滞留介质对两者的吸附去除；其中，径流DOM中<1kDa分子量组分和亲水性组分对惰性介质吸附去除Cu²⁺和Pb²⁺的抑制作用最明显、对强化介质吸附去除Cu²⁺和Pb²⁺的促进作用也最明显，是影响生物滞留介质对Cu²⁺和Pb²⁺吸附过程的关键DOM组分.<1kDa分子量组分存在使砂介质对Cu²⁺和Pb²⁺的吸附量减少了62.96%和83.70%，使铁锰复合氧化物介质对Cu²⁺和Pb²⁺吸附量增加了81.16%和4.67%；亲水性组分存在使土介质对Cu²⁺和Pb²⁺的吸附量最高减少了41.43%和69.12%，使给水厂污泥介质对Cu²⁺和Pb²⁺的吸附量最高增加了32.35%和39.06%.

Effect of dissolved organic matter in runoff on the removal of Cu2+ and Pb2+ by bioretention medium

The effect of dissolved organic matter (DOM) in the road runoff on the removal of Cu²⁺ and Pb²⁺ by inert medium (soil and sand) and enhanced medium (sludge from drink water purification plant, iron-manganese binary oxides) were investigated respectively, and the major response DOM fractions and mechanisms were also detected. The results showed that runoff DOM, different DOM molecular weight fractions and chemical fractions could inhibit the removal of Cu²⁺ and Pb²⁺ by inert medium and promote the adsorption of them by enhanced medium. The DOM fractions with <1kDa molecular weight and hydrophilic fractions had the most obvious inhibitory effect or promotion effect on the adsorption of Cu²⁺ and Pb²⁺ by inert medium or enhanced medium, respectively, indicating these two DOM fractions were the key componentsaffecting the adsorption of Cu²⁺ and Pb²⁺ by bioretention medium. The existence of DOM fractions with <1kDa molecular weight reduced the adsorption capacity of Cu²⁺ and Pb²⁺ by sand medium by 62.96% and 83.70%, and increased the adsorption capacity of Cu²⁺ and Pb²⁺by iron-manganese binary oxides medium by maximum 81.16% and 4.67%, respectively. The existence of hydrophilic fractions reduced the adsorption capacity of Cu²⁺ and Pb²⁺by soil medium by 41.43% and 69.12%, and increased the adsorption capacity of Cu²⁺ and Pb²⁺by sludge from drink water purification plant by maximum 32.35% and 39.06%, respectively.