南水北调中线工程通水后, 将有部分结余水量用于补给潮白河地下水调蓄区。由于南方地表水( 以下简称南 水) 与北京当地地下水的水质存在一定差异, 回灌过程中很有可能发生水岩相互作用。研究以潮白河地下水回灌区 为例, 通过静态摇瓶实验和水文地球化学模拟等研究方法, 对南水补给北京深层地下水过程中产生的水岩作用过程 和水质影响程度进行分析评价。研究结果表明: 南水回灌过程中, 地下水的主要离子成分会受到硝化作用、阳离子 交换作用及包气带矿物质溶解等作用的综合影响。两种水混合过程中, 土壤矿物相中的方解石和白云石不断溶解, Ca2+ 、Mg2+ 浓度逐渐升高, 反应过程中还伴随强烈的阳离子交换作用, 主要为Na+ 与Ca2+ 、M g2+ 的交换。南水比 例越大, 溶解氧促进硝化作用越明显; 在硝化作用和碳酸平衡的共同影响下, 地下水的pH 值呈现先降低后升高的 趋势。

In t he process o f T he South2 to2Nor th Water Transfers, some of the w ater w ill be used t o supplement the g ro undwater of Chaobai Riv er basin. Due to the differences of Danjiangko u reserv oir w ater and Beijing gr oundw ater, w ater2r ock interaction may occur. Taking the ex ample of Chao ba i Riv er basin, w e analyzed the water2ro ck inter act ion and chang es of w ater during re2 charg e by batch ex per iments and hy drog eochemistry simulat ion. T he results show ed that: dur ing the r echarg e, the water w as af2 fected by nitr ificatio n, cation ex change and solution of minerals.With t he incr ease of pr opor tion o f so uthern water , calcite and do lomite disso lv e and concent ratio ns of calcium and mag nesium wer e elevated coupled wit h catio n ex change w hich mainly is so2 dium w ith calcium and/ or mag nesium. The higher pr oport ion o f south wat er , the st rong er o f nitr ificatio n is fo und. Affected by nitrificatio n and car bo nate balance, pH of g roundw ater w as reduced at early stage then elevated at lat e stag e.

国家水体污染控制与治理科技重大专项/ 海河流域水资源调蓄区水质保障及生态修复关键技术研究与示范0 ( 2014ZX07203010)