Research On Landfill Groundwater Pollution Process Identification Technology Based On The Sensitive Factor Index Method

The municipal landfill leachate pollution to the surrounding environment like water, soil has been increasingly serious.It has become a worldwide environmental problem. Landfill leachates may be characterized as water composed of dissolved organic matter, inorganic macrocomponents, heavy metals and xenobiotic organic compounds, most of which are toxic and harmful,this poses a great threat to the safe use of groundwater.In an aquifer with a continous leachate relaease, redox zones will be developed. On the basis of thermodynamic principle and biogeochemical effects,a methanogenic zone elvolves close to the landfill, with and downgradient from which are in sequence of sulfate reduction zone, iron reduction zone, maganese reduction zone, nitrate reduction zone and oxygen reduction zone. These zones are significant to the study that is to predict polluted groundwater, to control and remediate pollution. Therefore,it’s very necessary to further study the research of landfill groundwater pollution process identification technology as well as landfill redox characteristic zones identification method on the issues of groundwater pollution control and restoration.According to the foreign and domestic research situation,on the basis of biogeochemical process of leachate pollutants degradation and redox zones in the groundwater environment, this paper described a landfill groundwater pollution process identification technology based on the sensitive factor index method and will be applied to the actual pollution sites. It can identify the landfill redox characteristic zones by determining sensitive factors, setting up the quantitative method based on characteristic area representation, calculating the sensitive factor weight value and each value of characteristic areas. Among them,the value of sensitive factors weights in various redox characteristic zones is an important part in the whole system. On the basis of the previous research, three kinds of weight calculation methods were applied to the sensitive factor index method, and the results were obtained combined with the actual landfill in this paper. Finally construct one kind of landfill groundwater pollution process identification technology based on the sensitive factor index method.The results showed that five redox characteristic zones appeared in pollution plume, i.e. methanogenic zone, sulfate reduction zone, iron reduction zone, nitrate reduction zone and oxygen reduction zone;combination weighting method can evaluate the weight of each factor more scientific, objectively and exactly, as well as more suitable for the sensitive factor index method;the distribution of every characteristic zone in the study area is not completely in accordance with the ability of microbial lined,it may be due to its special hydrogeological conditions or peripheral environment influence and some other reasons lead to the actual distribution compared with theory.On the whole, the recognition result is relatively scientific and reasonable,also the distribution of each characteristic zone is quite consistent with the actual situation.