潮白河受水区再生水入渗盐污染模拟柱试验

根据工程地质勘察及采样测试分析,选取北京市顺义潮白河再生水受水区3种典型代表性土壤介质(砾石含砂、细砂、粉质粘土)装柱,并采用受水区再生水进行淋溶模拟土柱试验。测试结果分析表明,在3种典型土壤介质中,阳离子交换吸附作用主要体现为K+与Ca2+之间的交换,且粉质粘土柱中阳离子的离子交换作用较砾石含砂柱和细砂柱更为显著。另外,试验结果还表明,随着土壤介质中粘粒含量、总有机碳含量、阳离子交换容量和粘土矿物总量的增加,典型介质淋溶模拟土柱试验中阳离子交换作用达到平衡时所需要的时间也就越长,分别为砾石含砂72 d、细砂80 d和粉质粘土86 d。定量结果计算也证明:粉质粘土介质的各阴、阳离子本底含量最高,单位质量粉质粘土介质硬度及溶解性总固体(TDS)的贡献量最大,分别为5 767 mg/g和6 952 mg/g。

Experimental Study on Salt Pollution for Groundwater Recharge with Reclaimed Water in Area of Chaobai River

According to engineering geologic investigation and sample test analysis, reclaimed water of Chaobai River in Shunyi, Beijing was selected to take three kinds of typical representative soil medium (sandy gravel, fine sand, silty clay) to install the soil column, and was used to carry on the leaching simulation test. The column test results show that the cation exchange adsorption mainly manifests the K~+and Ca~(2+) exchange in three kinds of typical soil medium, and the cation exchange function compares the sandy gravel column and the fine sand column is more remarkable in the silty clay column. Moreover, the column test results also indicated that, with increasing of clay content, total organic compounds (TOC)cation exchange capacity (CEC) and total amount of clay minerals, in the typical medium leaching simulation column experiment, the cation exchange functions equilibrium time is also longer, and is 72 days for the sandy gravel,80 days for the fine sand and 86 days for the silty clay, respectively. The quantificational results computation has also proven the above conclusion: the background value of various anions and cations concentration of the silty clay medium is highest;the contribution quantity of the hardness of the unit mass silty clay medium and the total dissolved solids (TDS) is biggest, and is 5,767 mg/g and 6,952 mg/g, respectively.