Study On Imitation Ecological Restoration Technology Scheme Of Black-odor Water In The River Network-intensive City

With the accelerating urbanization process,the increase of domestic sewage,industrial sewage and runoff pollutants has led to the emergence of urban black and odorous water.Due to the complexity and change of the causes,pollution degree and environmental conditions of the black-smelting water in the river network-intensive city,the treatment plan only focuses on the short-term effect and the application of single technology,ignoring the long-term maintenance of water quality and the restoration of water ecology,black and odorous water can not be completely cured.Therefore,the systematic treatment of river-intensity black and odorous water is of great significance for the treatment of black and odorous water.This paper takes the river network intensive city X as the research object.Firstly,it analyzes the pollution characteristics and water quality status of the black and odorous water in the city,and uses the Nemero index method to quantitatively analyze the black and odorous water in the city.Based on the analysis of the applicability of the black odor water treatment technology,the analytic hierarchy process is used to optimize the black odor water treatment technology.Combined with the characteristics of the black odor water in the river network-intensive city,the transparency enhancement,aeration aeration and water ecology are proposed.The core ecological imitation technology system was repaired,and the treatment efficiency of fine filtration equipment,aeration equipment and submerged plants on pollutants was studied in depth.A demonstration project of imitation ecological restoration technology was established,and the imitation ecological restoration technology was verified.Feasibility.The specific research contents and conclusions are as follows:(1)The black-smelling water in the river-dense-intensive city has the characteristics of slow flow rate,serious organic pollution,outstanding runoff pollution problem and degraded water ecology.In the black odor water monitoring index,the dissolved oxygen DO and NH3-N accounted for a large weight of the black odor monitoring index,and most black odor water were in a mild black odor state.(2)The priority ranking of black and odor water treatment technology based on analytic hierarchy process is:artificial reinforcement>ecological restoration>endogenous treatment>point source control>non-point source treatment,combined with the characteristics of black odor water pollution in river network-intensive cities Ecological restoration techniques and construction principles.(3)The removal efficiency of pollutants by various treatment units in the imitation ecological restoration technology was studied.The intercept rate of SS by the fine filtration equipment was 66%.The removal rates of NH3-N,TP and CODcr for high-efficiency aeration equipment were 56%,33.8%and 76%,respectively.The highest removal rates of NH3-N,TP and CODcr in submered plants were ceratophyllum demersum and Elodea nuttallii.vallisneria natans.(4)Through the demonstration project construction based on the ecological restoration technology scheme,the black odor river DO recovered to about 6mg/L,and the removal rates of NH3-N,CODcr and TP were 83.3%,55.6%and 64.7%,respectively.The water quality meets the surface V water standard.