| Non-point source pollution caused by rain runoff had become an important source of urban pollution, where there were a large number of nutrients, especially phosphorus transported to lakes could cause eutrophication, and were easy to contaminate drinking water sources. How to control pollution caused by rainfall runoff was imminent. In this paper, on the basis of analyzing the characteristics of rainfall runoff, we found out the efficient phosphrous absorbents by static adsorption experiments. Then the optimized phosphrous absorbents were used for purification in artificial filtration column and pilot study.The main conclusions were as follows:1. The concentration of pollutants reduced with the rainfall duration, the changing process varied with characteristics of the rainfall. When the rainfall intensity was uniform, the runoff quality was less volatile; when it was great, the changes of water quality were larger, except NH4+-N. The runoff quality was different on different underlying surfaces and showed a weak alkaline on the whole. The concentration of TP (0.216 mg/L), COD (170 mg/L) and SS (710 mg/L) were higher on the road than any other underlying surfaces. The concentration of TN (7.5 mg/L) and NH4+-N (0.5 mg/L) showed an inrichment in the grassland. Fruthermore, the pollutions in the rainoff of Wuxi City was relatively serious and changed with the seasons.2. The properties of phosphrous removal by activated alumina, manganese sand and coal were investigated. The saturated adsorption of activated alumina could reach 4.72 mg/L under the optimized condition of adsorption time 17 h,30℃, pH 2 and mass ratio of Wf:Wp 200:1. The adsorptive capacity of manganese sand and coal were relative small, with a saturated adsorption of 2.01 mg/L and 1.49mg/L, respectively. Howerve, the influence of temperature on the adsorption process was not significant in the study. Finally, phosphorus adsorption onto activated alumina was found a chemical adsorption process, manganese sand and coal were physical processes by mechanism investigation of thermodynamic kinetic fit and SEM.3. In order to effectively remove phosphorus and nitrogen simultaneously, manganese sand, coal and quartz sand were encased into artificial filtration column to carry on the road runoff adsorption investigation in dynamic mode. Results showed that a fast adsorption process of 2 min could achieve the objective. Coal filtration column had the best efficiencies of TP removal of 73.89% and COD removal of 51.06% respectively at column depth of 25 cm. Quartz sand column had the best efficiencies of TN removal of 60.34% at column depth of 25 cm.The pollutions removal efficiencies of manganese sand filtration column were relative small, and all fitration columns have better capacity of purification at 75 cm depth. All filtration columns had anti hydraulic loading capacity, the system could remove the contaminants effectively when the hydraulic load was between 0.1911-0.3822 m3/(m2·h).4. Based on the base investigation, coal and quartz sand were chosen as medieas in artificial filtration system for pilot study. Results showed that system had better purification efficiency under low rain intensity with a TP removal rates of 96%-98% and NH4+-N Removal rates of 26%-28%. Furthermore, when drying day achieveed 3 days, functional groups of adsorption could be regenerate. Afer operation of 3 months, the artificial filtration system could keep the removal of TP, PP and PO43- more than 85%, and could control the concentration of phosphrous under 0.02 mg/L. In conclusion, artificial infiltration system applied for surface runoff control was feasible.
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