建筑垃圾对雨水径流中Cu的吸附特性

Adsorption characteristics of construction wastes to Cu from urban stormwater runoff

以砖混建筑垃圾为研究对象,采用人工模拟雨水,通过静态和动态吸附实验研究了不同粒径粒级建筑垃圾对雨水径流中Cu的吸附效果。结果表明,准二级动力学模型比准一级动力学模型能更好地描述建筑垃圾对Cu的吸附过程;Freundlich等温模型能较好地拟合其等温吸附过程;不同粒径粒级建筑垃圾均对雨水径流中的Cu具有较好的净化效果,去除率均超过90%,粒径粒级越小,对Cu的净化效果越好,但其渗透性能越差;建筑垃圾的粒径粒级对Cu的吸附平衡时间、吸附速率和吸附量具有重要影响,粒径粒级2.36~4.75 mm的建筑垃圾对Cu的平衡吸附速率和平衡吸附量最大,分别为4.1μg/min和12.4μg/g。

Using construction wastes as the adsorbents,static and dynamic adsorption experiments were carried out to investigate the adsorption of Cu to construction wastes with different particle size fraction in simulated stormwater runoff system. The experimental results showed that the pseudo-second-order kinetics model could better characterize the adsorption processes of Cu than the pseudo-first-order kinetics model. The Freundlich isotherm model was successfully used to fit the equilibrium data. The construction wastes with four particle size fraction could greatly remove Cu from stormwater runoff and their average removal rate was more than 90%,and the construction wastes with small particle size fraction could better remove Cu but with worse permeability. The particle size fraction of construction wastes greatly influenced the equilibrium time,rate and the capacity of Cu adsorption. The equilibrium adsorption rate and capacity( i. e.,4. 1 μg / min and 12. 4 μg / g,respectively) were greatest for the construction wastes with the size of 2. 36 ~ 4. 75 mm among the four particle size fraction.