Research The Law Of Surface Transport By Simulated Rainfall

In order to study rainfall-runoff rain water flows through the underlying surface, the discipline of underlying surface reduce on contaminants of runoff. The data monitoring through the outdoor results are based on, in the indoor the conditions of artificial simulation of runoff,rainfall, underlying surface study on the pollutant transport. The results are as follows:The results showed that:(1) The flower collecting efficiency of the underlying surface, the lower reduction of pollutants, the role of the stronger, recovered to the initial value of the longer, but after a run-off needs to be restored to its original state after the recovery period required for the more long; The greater efficiency of underlying surface, the smaller impaction of environmental; The higher efficiency of the underlying surface and in the longer time interval, the greater intensity of its initial erosion, in another words, the greater increase in the amount of pollutants of initial lmin; Comprehensive consideration of collecting efficiency and reduction on pollution of underlying surface, Cement-soil is suitable as collecting material of garden-style. Followed by the lime earth, the original soil compaction, concrete, plastic film.(2) The higher the concentration of pollutants in raw rainwater, the more reduction to runoff pollutants CODcr by the concrete underlying surface and the NH4+-N in runoff pollutants as well, but the instability of the runoff water quality change correspondingly increase; On the condition of fixed quality of runoff, the greater flow rate,the more obvious effects of underlying surface on reducing to CODcr, the more gently TP trends, the less reduce to the TP' in pollutants of runoff; the reduction to the NH4 +-N and TP by the concrete underlying surface is an inhaled-precipitated process, the change of flow rate have a large impact on the capacity of reduction of the concrete underlying surface, with the flow rate increases, the maximum reduction rate is also increased; when the NH4 +-N and TP in pollutants of runoff flow through the underlying surface of concrete, there has a competition between NH4 +-N and TP in inhalation and precipitation. When the concentration in the raw water is high, the more inhalated NH4 +-N than the TP's. when concentration is low in the raw water, the more inhalated TP than in the NH4 +-N's, and the reduction of surface to UV254 is kind of infiltration process. The study show that the impact of change of the concentration in the raw water on reduction to UV254 far greater than the impact of flow rate changes.(3) The greater rainfall intensity, the smaller pollution CODMn, NH4 +-N, and UV254 when the rainwater flow though the concrete underlying surface during the initial 5 mins, and the maximum reduction rate of them is also greater and the rate of reduction to the TP as well. When the rainwater flow though the brick underlying surface during the initial 5 mins, the greater rainfall intensity have,the less pollution NH4 +-N and UV254,but the pollution to CODMn is greater and the rate of reduction to the TP as well. As to tile surface, the greater rainfall intensity, the smaller pollution CODMn, NH4 +-N and UV254, and the maximum reduction rate is also higher.(4) The effect of reduction of underlying surface to the CODMn determine by the holes in the underlying surface material and pore size and numbers; to the NH4+-N and TP,by the underlying surface penetration; to the rainwater turbidity, by the underlying surface roughness; to the UV254,by the storage performance of the underlying surface.(5) The results showed that the effect of reduction of underlying surface to the CODMn and NH4+-N is in the order of tile>brick>concrete. To the UV254 is in the order of brick >cement>tile. To the TP is in the order of cement>brick>tile. Consider the collection efficiency and reduction efficiency of underlying surface; tile is the optimal underlying surface in three kinds of underlying surface.