An experimental study of remediation of nitrate-contaminated groundwater with microbial techniques

With the development of agriculture, overuse of fertilizers and pesticides has threatened the safety of groundwater resources. A large amount of nitrogenous fertilizer that is not absorbed by crops has caused NO~-_3 contamination in the unsaturated zone and the shallow groundwater after nitrification by microbial processes. The purpose of this paper is to introduce the effects of microbial techniques in laboratory on the remediation of nitrate-contaminated groundwater. Under the simulating static and flowing conditions of an aquifer in the laboratory, we use the selecting solvate of microbial groups and a fraction of a carbon resource to remedy the groundwater contaminated by NO~-_3. The effect is remarkable and constant, and the riding rate can be up to 90%～100%, and still remains 89.74% after 256 days in the experiment under the static condition. In the experiment under flowing condition, after 112 days, the riding rate is still 16.22% and 27.26% in the 3# and 4# at the lower reaches of the main hole. The results show that the technique is useful for the removal of nitrate from groundwater in situ.