地下污水管线泄漏原位自动监测模拟实验研究

地下污水管线的泄漏将会对土壤、地下水环境产生严重的影响.本研究建立一套基于高密度电阻率测量的地下污水管线泄漏原位自动监测装置,通过室内模拟实验,验证该装置在不同地下水水位条件下对地下污水管线泄漏进行实时监测的可行性.结果表明,当泄漏管线位于包气带中时,能够迅速监测到管线发生的小流量泄漏;当管线位于地下水水位附近,也能迅速监测到管线发生的小流量泄漏,而且通过管线以上土层电阻率的梯度变化,还可推测污染物泄漏的程度;当管线位于地下水位以下时,由于污染物在地下水中迅速的混合并扩散,只有当泄漏达到一定浓度,使电阻率产生能够观测到的变化,才能监测到泄漏发生.本研究所使用的装置能够对位于不同地下水位和埋深条件下的污水管线泄漏进行实时自动监测.

Experimental Research on In-Situ Auto-Monitoring for Underground Sewage Pipeline Leakage

The leakage of underground sewage pipes may seriously affect the soil and the environment of groundwater. In this paper, an in-situ automatic monitoring device on basis of multi-electrode resistivity method was developed for the leakage of underground sewage pipelines, and it was validated by a simulated experiment in laboratory that the feasibility of the new device is feasible for real-time monitoring the leakage of underground sewage pipelines at many different groundwater levels. The experimental results indicated that small leakage of sewage pipelines could be rapidly detected by the developed monitoring device when the pipeline was located in the vadose zone. The leakage could also be monitored in a prompt manner when the pipeline was located near the groundwater level, and the extent of pollutant leakage could be speculated with the gradient change in resistivity of the soil layer above the pipeline. When the pipeline was located below the groundwater level, the device could only monitor the leakage if it reached a certain concentration to produce notable changes in resistivity, because of the rapid mixing and diffusion of the pollutant in groundwater. The device set up in this paper was found capable of real-time automatic monitoring the leakage of underground sewage pipelines buried in different depths and groundwater levels.