Graduation program in Geosciences and Environmental Science, Geosciences and Exact Sciences Institute (IGCE), São Paulo State University (UNESP), 24-A avenue, 1515, Bela Vista, Rio Claro, São Paulo State, 13506-900, Brazil.
Geology Department (DG), Geosciences and Exact Sciences Institute (IGCE), São Paulo State University (UNESP), 24-A avenue, 1515, Bela Vista, Rio Claro, São Paulo State, 13506-900, Brazil.
Environ Monit Assess. 2020 Mar 24;192(4):249. doi: 10.1007/s10661-020-8206-5.
Sanitary landfills are a well-planned engineering work for final disposal of municipal solid waste in order to minimize the environmental impacts in soil and groundwater. Therefore, several control systems are installed such as liners and leachate and biogas collectors. However, the establishment of landfill in vulnerable areas, the inadequate operations, and failures in collectors and liner systems can cause subsurface contamination. The discovery of eventual leachate leakage usually is based on chemical analyses of groundwater using monitoring wells; which may not be representative in spatial terms. This work involves a geophysical monitoring of the leachate percolation in a landfill waste cell closed in 2014, in which geomembrane boreholes and aquifer contamination have been proved. The DC resistivity method was applied by means of electrical resistivity tomography (ERT) in order to detect eventual contrasts in electrical properties. Twelve ERT lines have been carried out in a steady mesh during three years of study (2016, 2017, and 2018). The results of 2016 allowed a clear contrast between zones of leachate percolation into the aquifer and the natural environment. The comparative analyses of the three-year monitoring results reveal a gradual increase in resistivity values in the areas of leachate percolation. The absence of replacement of biodegradable organic matter after 2014 conditions the gradual decrease of leachate salinity. In this sense, the increase in resistivity is an indicator of the tendency for chemical stabilization of the organic waste and existence of natural attenuation processes.
卫生垃圾填埋场是为了最小化对土壤和地下水的环境影响而对城市固体废物进行最终处置的精心规划的工程工作。因此，安装了几个控制系统，如衬垫、渗滤液和沼气收集器。然而，在脆弱地区建立垃圾填埋场、运营不当以及收集器和衬垫系统故障可能会导致地下污染。最终发现渗滤液泄漏通常是基于使用监测井对地下水进行化学分析；这在空间上可能不具有代表性。这项工作涉及对 2014 年关闭的垃圾填埋废物单元中的渗滤液渗透进行地球物理监测，其中已经证明了防渗膜钻孔和含水层污染。直流电阻率法通过电阻率层析成像（ERT）应用于检测可能存在的电性能对比。在三年的研究期间（2016 年、2017 年和 2018 年）进行了 12 条 ERT 线的稳定网格测量。2016 年的结果可以清楚地对比出渗滤液进入含水层和自然环境的区域。对三年监测结果的比较分析显示，渗滤液渗透区域的电阻率值逐渐增加。2014 年以后，可生物降解有机物的替代物减少，渗滤液盐度逐渐降低。从这个意义上说，电阻率的增加是有机废物化学稳定和存在自然衰减过程的趋势的指标。
