河砂对径流污染物吸附效果试验研究

河砂是透水铺装、生物滞留池及树池等海绵城市建设用设施的主要原材料之一,对其吸附去除径流污染物的效果进行了试验研究。结果表明,随着污染物初始浓度的增加,河砂对COD、TN、TP、Cu的吸附量均呈现先增加后趋于平稳的趋势。当初始溶液浓度达到160 mg/L以上时,河砂对COD、TN、Cu的最大吸附量分别保持在1.83、1.19、1.22 mg/g左右,当初始溶液浓度达到80 mg/L以上时,河砂对TP的最大吸附量维持在0.50 mg/g左右。同时在去除率方面,河砂对小于20 mg/L的低浓度TN、TP的去除效果较好;当初始溶液浓度为100 mg/L时,河砂对COD的最高去除率为74%;不同初始溶液浓度下河砂对铜的去除率在77%~98%之间。结果表明,河砂对径流污染物均具有一定的吸附效果,尤其对重金属Cu的吸附去除效果最佳。这为进一步推广应用涉及以砂为原材料的海绵城市相关技术及设施提供了技术支持。

Experiment on the river sand for the adsorption effect of runoff contaminants

River sand is one of the main raw materials of the permeable pavement, bioretention and tree pool, which are facilities in constructing the sponge city. In this paper, the effect of river sand on the adsorption of runoff contaminants was studied. The results showed that the adsorption capacity for COD, TN, TP and Cu by the river sand increased firstly and then tended to be stable with the increase of the initial solution concentration of runoff contaminants. When the initial solution concentration reached and was over 160mg/L, the maximum adsorption capacity for COD, TN and Cu were up to 1.83 mg/g, 1.19 mg/g and 1.22mg/g respectively. And when the initial solution concentration was more than 80 mg/L, the maximum adsorption capacity for TP is about 0.50mg/g. At the same time, the removal effect of river sand on the low concentration(less than 20 mg/L) for TN and TP was better. When the initial solution concentration was 100 mg/L, the maximum removal rate for COD was 74%. And the removal rate for Cu was from 77% to 98% under the condition of different initial solution concentration. The results indicated that the river sand has good adsorption effect on the runoff contaminants, especially in the removal for heavy metal Cu. This also provided the technological support to further promote the relevant technology and facilities of the sponge city with river sand as raw material.