渗滤池砂样对回灌水中污染物去除的研究

Laboratory Sand Column studies on Characteristics of Aquifer Clogging and Water Quality Changes during Artificial Recharge

采用室内砂柱实验研究了渗滤池回灌过程中的渗滤层堵塞特征和水质变化规律,通过测定渗透系数定量分析了砂柱的堵塞程度并在回灌过程中测定砂柱不同位置水样的悬浮物浓度、TOC、高锰酸盐指数、总氮、无机阴离子等的变化。结果表明,回灌水中的悬浮物颗粒充填含水介质空隙引起的机械堵塞为砂柱堵塞的主要原因,砂柱对回灌水具有明显的去除作用,但对回灌水中的有机物、还原性污染物去除作用有限,当回灌水的污染物浓度较高时,地下水将被持续污染。

Laboratory sand column experiments were used to investigate the aquifer clogging and water quality changes during artificial recharge. The experiments analyzed the aquifer clogging quantitatively according to the hydraulic conductivity changes of the aquifer, meanwhile, some important water quality parameters of water samples at different sampling places were measured at regular intervals during artificial recharge. The result shows： the main cause of aquifer clogging in this experiment is physical clogging, passed by 40 hours continuous recharging, the decline of the aquifer permeability was evident, the hydraulic conductivity of the upper column（0--10 cm） decreased from 10.6 m/d to 8.5 m/d, while the lower column decreased from 10.6 m/d to 9.2 m/d; the aquifer has significant self-purification on some water quality parameters, including suspended matter, TOC, permanganate index, copper, total nitrogen, etc. The self-purification of the upper column is stronger and the clogging of that is more severe. However, passed by a certain time recharging, the hydraulic conductivity of the aquifer tended to be stable,the value of the water quality parameters like suspended matter, TOC, permanganate index, total nitrogen of water samples at the same sampling place increased gradually and tended to be stable finally.