|
With the advance of urbanization in China, the rapid development of economy and population, increasingly prominent contradiction between water supply and demand, coupled with urban stormwater runoff pollution water environment, to achieve resource utilization of urban stormwater runoff pollution control both, but also alleviate the urban water pressure. This article relies Shaangu rainwater utilization demonstration project, the study of regional rainwater harvesting system has been improved quality characteristics of regional rainfall analysis for storm water runoff and rainwater resource utilization and other issues, proposed the use of artificial infiltration system for rainwater to disperse type processing, analysis of the infiltration system for the removal of pollutants and system response to hydraulic loading shocks. Main results are as follows: (1) by creating a new rainwater tanks and rainwater tanks in series parts, so that the plant effectively collect rainwater area 90000m 2 , in rainwater reaches 36169m 3 . Meet the needs of the whole plant green water, the annual water savings of about 12 million. (2) study area stormwater runoff pH value in the normal range, the other indicators are more than \The annual rainfall water quality changes in the larger, relatively good water quality wet season, dry season water quality is relatively poor. Integrated rainwater runoff COD was 76.85 ~ 278.53mg / L, SS is 96 ~ 417 mg / L, NH 3 -N was 2.68 ~ 5.64 mg / L, TP was 0.28 ~ 1.35 mg / L. (3) water quality characteristics for the region and topographical conditions, the design of two different flow regimes of percolation tanks, percolation tanks of the 2nd vertical flow percolation tanks, and its main parameters are: design flow: 2.6m 3 / h; hydraulic loading: 1.0m / d; Dimensions: L × B × H = 5 × 4 × 1.3; filter thickness: 1.0m; filter: natural river sand layered arrangement, bottom- were flat on the paving, gravel, coarse sand, fine sand. The 6th percolation tanks for the horizontal flow-based composite flow percolation tanks, the main parameters are: design flow: 4.0m 3 / h; hydraulic loading: 1.3m / d; Dimensions: L × B × H = 6 × 4 × 1.3; filter thickness: 1.0m; filter: natural river sand layer arrangement. Are used alternately wet to dry operation mode, wet dry ratio: 1:2 (8h: 16h). (4) Two different flow percolation tanks in the steady state before running certain adaptation period, stable water after handling effects are good, the 2nd filter effluent COD, SS, NH 3 < / sub>-N, TP average concentration of 13.26mg / L, 7.75 mg / L, 4.02 mg / L, 0.36 mg / L, corresponding to the average removal rate was 87.33%, 90.81%, 59.58%, 64.27%; VI filter tank effluent COD, SS, NH 3 -N, TP average concentration of 16.69mg / L, 8.75mg / L, 4.29mg / L, 0.37 mg / L, corresponding to the average removal rate was 83.47%, 89.53%, 56.13%, 61.97%. Enables reuse of rainwater resources and effectively control stormwater runoff pollutants adverse impact on the environment. (5) of two diffusion cell comparison, II diffusion cell (vertical flow) than the sixth diffusion cell (horizontal flow-based composite stream) to be slightly better treatment effect, and fillers may be due to the flow state, water quality, hydraulic load and other factors. Two kinds of filter hydraulic load can withstand greater impact, COD, SS, NH 3 -N in the hydraulic loading 1.5m / d or less removed better, TP at 2.0m / d less Removal better. Actual operation can return water consumption demand, adjust the hydraulic load and run a more flexible way.
|