洛阳市区包气带中污染物自净规律初步研究

包气带是地下水补给和地下水污染的主要通道，因此包气带的性质直接控制了地下水的污染化速度和程度。以洛阳市区洛河河床岩性（以砂砾石为主）以及由亚粘土、亚砂土、中细砂等介质构成的包气带为研究对象，来分析河床和包气带对污染物的自净能力，并对其天然的自净机制进行了简要的分析，结论如下：洛河河床岩性对各种污染物（NO3-除外）的净化能力均达到90％以上；亚粘土、亚砂土、中细砂等包气带介质层对重金属（Cu^2＋、Pb^2＋等）有很强的净化能力，而对Cl、Cr^6＋净化能力则较弱，在短时间内介质中就达到饱和而失去净化能力；在环境条件相近及水文地质条件基本相同的条件下，包气带厚度与地下水的污染程度呈负相关关系；污水经过包气带发生较强的过滤、吸附、离子交换、生物化学降解等作用，能有效地去除污水中的有害物质，防止地下水污染。

Primary Research on the self-purification of Contamination in unsaturated zone

The unsaturated-zone is main channels for recharge and contamination of groundwater, therefore the character of unsaturated-zone will control the velocity and degree of groundwater contamination directly. The paper takes the lithology of riverbed of LuoHe, that is main made of grit, and unsaturated-zone, that is made of sub-clay, sub-sand soil, medium and thin sand, in Luo-Yang city as the research object to analyze the serf-purification capacity of riverbed and unsaturated-zone, and make simple analysis on natural serf-purification mechanism, the results as follows： the purification capacity on many contamination of river lithology can exceed 90%, besides NO3-. sub-clay, subsand soil, medium and thin sand, can have the strong capacity to purify the some high metal such as Cu2 ＋,Pb2 =, but have infirm capacity to purify Cl and Cr6 ＋, because the capacity disappears in the short time for saturation. The contamination degree and thickness of unsaturated-zone exists obvious negative correlativity when the environment and hydro-geology condition is close or same. The contamination will happen filtration, adsorption, ion-change , biology and chemistry degradation in unsaturated -zone, it can wipe off some contamination effectively and prevent the groundwater form being polluted.