| Nowadays, frequent traffic activities, burning of fossil fuels in the running process of motor vehicles discharged waste gas and a large number of hydrocarbons, vehicle tyre wear and braking frequently formed a large number of rubber particles and metal particles. Most of these pollutants will be migrated to a natural water body as the precipitation, damage the water quality of receiving waters and the ecological environment, which formed the road surface runoff pollution, this pollution is a kind of non-point source pollution which has a high load and be difficult to control, it is imperative to find a way to control road surface runoff pollution.Using certain materials and building or modifying some structure within the scope of road land, so that the material and structure can control road surface runoff pollution by osmosis, filtering, slowing down the flow and purifying.According to the test results of runoff, the pollutant concentration is out of limits, and the pollution is very serious. Early Analysising the significance of first flush effect, it is concluded that the initial rainwater is the key of road surface runoff pollution treatment. According to the test results, chemical reagent is used to simulate the runoff rainwater in laboratory.By comparing ceramsite layer, zeolite layer and ceramsite-zeolite double-layer ecological percolation layer structure, the result of decontamination ability is:ceramsite-zeolite double-layer> zeolite> ceramsite. The initial removal rate of double-layer filter for material for SS is more than 70%, and more than 90% for zinc and lead, the removal rate of COD and TP also reached more than 50% as the inflow continuous, besides, and the decontamination ability of ecological percolation layer structure layer tend to stable in the process of using outdoor place. Through optimizing the layer structure of ecological percolation by slowing down the flow, the removal efficiency of TN and NH3-N can be strengthened.By analysising the pore blockage effect and the decay rule of the decontamination ability of porous asphalt mixture, the results show that:the permeable coefficient of porous asphalt mixture(PAC) decreased with the increase of pollution load, and the greater the void fraction is, the more significant the trend is. Smaller void fraction PAC mixture has better initial pollutants removal effect for SS, COD, zinc and lead, decontamination effect of larger void fraction PAC mixture is vulnerable to the influence of the pollutant load.By study decontamination ability of permeable concrete adding zeolite powder, the removal rate of NH3-N increased with the increase of the zeolite powder content, when zeolite powder content reaches 50%, the removal rate of NH3-N reached 45%. Zeolite powder content in permeable concrete is 30% based on removal rate and the intensity. Analyzing the water storage-seepage mechanism of permeable concrete and water storage-seepage model of permeable concrete is established, therefore, the height of internal water of permeable concrete can be calculated based on the model.Based on the field application of road surface runoff pollution treatment measures, the design process and application method in road engineering of ecological percolation layer structure are put forward, the optimized plan for the edge drainage system of porous asphalt pavement and the application of permeable concrete in road slope project are put forward. And the application effect of road surface runoff pollution treatment measures is analyzed according to the formation and migration process of road surface runoff pollution. |
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