The Reaserch Of PRB Recovery Technology Application In Landfill Groundwater Pollution

For municipal landfill pollution of groundwater, the proposed active percolation wall (lm-prb) repair technology to execute repair management of groundwater environment in jobsite, the first by early hydrogeology investigation and groundwater environmental quality investigation, detailed describe landfill numerical simulation environment hydrogeological conditions; Secondly, through the laboratory simulation lm-prb technology screening to determine lm-prb filling medium; Finally, in view of the landfill groundwater pollution lm-prb preliminary design, making late monitoring plan. Research results can provide lm-prb technology specific investment project in China, provide certain theoretical support for the handling of the garbage leachate pollution of groundwater by in situ effective way to explore and research.The understandings are as follow:(?) The landfill site is located in the shallow tectonic denudation ridges location of low mountain valley. According to the size and location, the simulation research area is identified. Its groundwater flows roughly in the north-south direction, water flows from both sides of west and east flow according to the height of terrain to form a confluence at the valley bottom and eventually flows along the north-south direction to the downstream plain area.(?)The standard exceeding pollutants of this landfill site is mainly ammonia nitrogen compound, the main pollution source is the garbage heap leachate. The maximum pollution concentration is 5 mg/L by simulation prediction that has been far beyond the limiting value of III class standard for more than 24 times according to the groundwater quality index classification.(?) It proves that the application of PRB recovery technology in landfill site underground pollution abatement is feasible. The experiment of PRB technologysimulation in laboratory has got an active medium with a well remove effect of the target ammonia nitrogen pollutants called zeolite. Meanwhile, the zeolite's adsorption of ammonia nitrogen compound conforms the form of the secondary dynamic curve. Its correlation coefficient is 0.98998 and the degradation constant is 3.94646 h-'.(IV)The permeability coefficient ratio of increased PRB filling layer and aquifer is acquired through its technology simulation by Feflow softare. However, it also reduces the average residence time. With the increase of the permeability coefficient ratio, the rising extent of captured area reduces gradually.(V)As for the study of this landfill site, the selected PRB's structure type is diaphragm wall its filling medium is zeolite particle, the permeability coefficient is 10 times of the permeability coefficient of aquifer around, the wall thickness is 3 meters, the wall height is 9.2 m and the buried depth is 5.4 meters. It is installated at the linear distance along the groundwater flow direction and garbage heap of 330 meters in 32°.