The Research On Artificial Wetland Processing Mode In Mixed Sewage Control

At present, with the domestic sewage pollution being gradually controlled, the control of urban rainstorm runoff pollution and agricultural non-point source pollution has been paid more and more attention. Compared with other wastewater treatment technologoes, as a new type of ecological treatment technology, constructed wetlands have several advantages of stable effluent quality,high hydraulic loadings, simple operation, low cost of construction and operation, good pollutant removal effect and possessing aesthetic value.This paper analyzed the regional characteristics and artificial wetland treatment of mixed wastewater mixed sewage related cases, and then to bamboo lake wetlands engineering as an example, discussed the urban life pollution treatment, non-point source pollution control and comprehensive functions such as early rainstorm runoff filtering mode of artificial wetlands, and analyzes the running effect of patterns. The main results of the thesis as follow:(1) To treat the mixed sewage from urban or rural area which including stormwater runoff,agricultural runoff,livestock wastewater,sewage,catering sewage by constructed wetland system,there are a series of measure to improve system hydraulic loading efficiently and to ensure that operation can be long-term and stable in system,including pre-treatment (such as grid, regulating ponds, anaerobic ponds, oxidation ponds, biological septic tanks, etc.),spilling, multi-level combination surface flow constructed wetland with subsurface flow construced wetland, ultilizing composite matrix filler and functional plant configuration.(2)According to the star and moon reservoir’s environmental characteristics in Qingzhu lake, this project uses the "surface flow wetland (A)-subsurface flow wetland (B)" water landscape(C) three series pattern, and construct landscape artificial wetland system with comprehensive function that consisting of Water storage, flood discharge, agricultural non-point source pollution control, urban sewage treatment and early storm runoff filtering, the total areais 10410m2, mixed sewage treatment 6000 m3/d, the rainstorm runoff processing capacity 20000m3/d, discharge capacity 250000 m3/d. The whole system is divided into three functional areas consisting of Qingzhu wetland, moon pool, and seven star reservoir and wetland, in order to purify star and moon reservoir’s water quality with the combination of artificial wetland and enhance the function of water storage and discharge; the project is took star, month, water, bamboo, living environment and wetland ecological system as the basic elements of landscape design to show the theme of harmony between man and nature.(3)Based on the analysis of water quality after Qingzhu lake artificial wetland system operating, the number of plant root rhizosphere microbial each unit, plant and landscape effect, result shows:the content of COD、TN、TP、NH3-N in water have treated during November 2013 and July 2014 reach the Ⅲ water quality from environment quality standard for surface water GB3838-2002, the effluent water quality is stable; in November the water indicators were higher than in July, but higher root microorganism, the pollutant removal efficiency is higher each unit. The plants in artificial wetland grow and bloom well, with luxuriant foliage and beautiful shape, and format a wonderful scenery line.