Research On Substance Of The Constructed Rapid Infiltration System At Highway Service Area

Constructed Rapid Infiltration System in the traditional RI system developed on the basis of a brand new sewage treatment system.In China, CRI system is still in its infancy, pending further study. Sewage rapid infiltration system (referred to RI system) has many advantages. These advantages include:easy operation and management, simple equipment, low running costs and infrastructure investment management, purification effect and handling and low power consumption. But it also has disadvantages, which includes large area, low hydraulic loading, and application by a number of restrictions. To overcome the shortcomings of RI system, combined with sewage treatment and rapid filtration system matrix Research, established by laboratory simulation of soil column, from laboratory experiments to a small test project for CRI system were studied in detail.Laboratory tests using ceramic, zeolite, slag, vermiculite, peat as the main infiltration media. As the research object to the septic tank effluent, which is at higher hydraulic loading a motorway service area in Chongqing, which focus on the effects of contaminants on the removal of CRI system and research on the systems of Substrate compositions and treatment process. First through the soil column simulation experiments, the five kinds of single matrix material tested. The integration of economic, practical, durability and other considerations, Select to peat soil, slag as the main composite matrix material, through the optimization of the design of the system architecture, the optimal mix design parameters. System small scale experiment is to test the ratio of CRI, the practical application of the matrix, providing examples for the engineering design basis.The results show that slag has a strong adsorption properties of the ion exchange, chemical and physical in CRI single matrix system, which maintain a high removal rate to COD, ammonia-nitrogen in wastewater. In both hydraulic loading0.8m/d effect, the rate of removal is stability, having reached the first grade of "Integrated Wastewater Discharge Standard"(GB8978-1996). The ratio of the matrix system, by the ratio of peat and soil show that the content of soil from30%to70%, the removal efficiency decreased by10%to30%.When the ratio of peat and soil, strong salt balance, chelating ion exchange capacity and adsorption capacity have will be reduced. Watering three weeks after, decontamination effect to the first grade of "Integrated Wastewater Discharge Standard"(GB8978-1996).When the hydraulic load of0.8m/d to1.6m/d, the ratio of zeolite matrix by adding vermiculite removal and sewage are stable. Vermiculite has a good adsorption and the cation exchange characteristics and the zeolite has a fixed internal passage of uniform size, the adsorption of ions and molecules having a selective. These factors make the system of zeolite, vermiculite stable treatment effect when the volume of sewage changes. The system of small test project, join zeolite and vermiculite decontamination can not only improve efficiency, but also enhances the system impact resistance. After adding15%zeolite and vermiculite, efficiency is improved by10%to15%, that processing efficiency is stable. Vermiculite has a higher level of charge number, negatively charged surface, high specific surface area. Framework of the zeolite channels and cavities formed in a large amount, so that the system forms a matrix having a special structure strong stability, decontamination effect to the first grade of "Integrated Wastewater Discharge Standard"(GB8978-1996).Laboratory simulation of soil column experiments and small scale experimental results show that CRI system to overcome the disadvantages of traditional RI system of low hydraulic loading, retaining its advantages of simple equipment, low investment, low energy consumption and good water quality. So it has broad prospects for development.