某城市生活垃圾填埋场地下水“三氮”及溶解性有机质特征研究

Study on the characteristics of groundwater“three nitrogen”and dissolved organic matter in a municipal solid waste landfill

采用三维荧光光谱及紫外可见光谱技术,对豫北某规范建设的城市生活垃圾填埋场内5个监测井的水样进行"三氮"、溶解性有机质等含量特征的测定及源解析,这对于评价垃圾填埋场对地下水的影响及进行环境风险评价具有重要的意义。结果表明:该垃圾填埋场地下水属弱碱性水,2号(污染扩散监控井)、4号(污染监控井)、5号(污染扩散监控井)监测井的氨氮浓度超标;3号井(污染监控井)中具有芳香结构的有机物浓度相对较高,而2号、4号、5号井中溶解性有机质(DOM)以小分子有机物为主;只有2号井出现了类蛋白荧光峰,可能与场区附近农田、垃圾渗滤液调节池以及污水处理站的直接输入有关,也与水中微生物活动产生类蛋白有关;FI反映5个监控井的DOM均以微生物源为主,且与BIX结果具有较好的溯源一致性。

Three-dimensional fluorescence spectroscopy and ultraviolet-visible spectroscopy were used to the content characteristics of"three nitrogen"and dissolved organic matter in water samples from five monitoring wells in a municipal solid waste landfill in north Henan province.It was of great significance to evaluate the impact of waste landfills on groundwater and conduct environmental risk assessment.The results showed that:The groundwater of the waste landfill was weak alkaline water,and the ammonia nitrogen concentration in No.2(contamination diffusion well),No.4(contamination monitoring well)and No.5(contamination diffusion well)monitoring wells exceeded the standard.The concentration of organic matter with aromatic structure in No.3(contamination monitoring well)was relatively high,while the DOM in No.2,No.4 and No.5 wells was mainly small molecular organic matter.Only protein-like fluorescence occurred in No.2 well,which might be related to the direct input of farmland,landfill leachate regulating tank and sewage treatment station near the field,and also related to the production of protein-like by microbial activity in water.The FI reflected that the DOM of the five monitoring wells were mainly biological sources,and it had good traceability consistency with BIX results.