The Design Of The Integrated Vertical Flow Constructed Wetland And Study On The Effect Of Pollutant Removal

Constructed wetland is a kind of sewage treatment technology that emerged in the 1970s.It has become more and more widely used,and has gradually become one of the commonly used technologies for water pollution control.Integrated vertical flow constructed wetland?IVCW?is a new type of sewage treatment method.It has low infrastructure investment,simple operation modes,and it has a significant removal effect of pollutants such as organic matter and nutrients nitrogen and phosphorus.However it has many problems such as matrix clogging,surface area water,and single water flow in actually operation.In order to improve the effect of the integrated vertical flow constructed wetland,this study optimized and improved the traditional integrated vertical flow constructed wetland,and designed a new integrated vertical flow artificial wetland simulation device,through experiments to explore the best hydraulic load and the best water flow method of the device,and on this basis to conduct research on the operation effect of the integrated vertical flow constructed wetland.The research results can provide technical support for the improvement and application of the integrated vertical flow constructed wetland,so it has certain practical significance.The integrated vertical flow constructed wetland simulation device is optimized and designed based on the existing research and experiment of constructed wetlands.By changing the position of the inlet and outlet holes of the device,the surface flow and subsurface flow constructed wetlands can be changed or combined,and the vertical down flow and vertical up flow can be changed and superimposed flexibly.It also can effectively reduce investments and save costs.Experimental research shows that the best hydraulic load of the integrated vertical flow constructed wetland simulation device is 0.36 m³·?m²·d?^-1,and the best water flow method is UVCW?vertical ascending type?,which has a good operation effect.Under different plant combinations and under different influent pollution loads,they have a better ability to remove pollutants in sewage.During the experiment,the simulation device showed no problems such as matrix blockage and serious surface area water.When the constructed wetland has a hydraulic load of 0.36 m³·?m²·d?^-11 and the water flow mode is UVCW?vertical ascending?,the combined of different plants has different effects on the removal effect of pollutants in the constructed wetland.When the concentration of TN,TP,NH₃-N,and COD in the influent is 15 mg/L,0.5 mg/L,5 mg/L,and 50 mg/L,respectively,the constructed wetland with the combination of emergent water,floating water and submerged plants has the removal rate of COD,TP and NH₃-N of 87.7%?80.0%?77.4%,respectively,and the TN removal rate of constructed wetland With the combination of emergent plants,emergent plants and floating plants is higher,which can reach 85.7%;under the same hydraulic conditions,when the COD?NH₃-N?TN?TP concentrations of the wetland influent were 100 mg/L?10 mg/L?30 mg/L?1 mg/L,the removal rates of the four pollutants were the highest,reaching 82.5%?73.0%?80.3%?74.0%,respectively.The COD and TP concentrations of the effluent are lower than the limits of Class-III and Class-?water quality standards in the Surface Water Environmental Quality Standards?GB3838-2002?,respectively.The concentration of NH₃-N in the effluent was close to the Class-?standard.