Simulating Experimental Study Of Polluted River Water Purified By Vertical Flow Constructed Wetlands

Currently, the river water pollution problem of our country is very serious, the effective management of the polluted river water has become an urgent problem needed to be solved. Constructed wetlands as a kind of ecological treatment technology of wastewater, it has the characteristics of low investment, low consumption, low processing cost and with the removal function of nitrogen and phosphorus, nowadays, it is widely used in treatment of domestic sewage, industrial wastewater, agricultural point source and non-point pollution and governing the aspect of water entrophication, building the constructed wetlands in the side of the river is an effective method of purifying the river water.This study take the simulate experiment device of the vertical flow constructed wetlands as platform, taking the Qinghe River water of Beijing as the processing object, high spot view the effect of nitrogen, phosphorus and organism treated by constructed wetlands under the different conditions, selecting the proper control conditions and determining the process parameter of treatment, for the purpose of providing the theory reference for the future research and engineering application. According to the study conducted nearly one-year experiment, the results are as follows:(1)Through review the factors such as plants, series, hydraulic load and operation method influencing on purification effect of pollutants, and under the condition of hydraulic load was0.27m3/(m2·d) and took the intermittent operation mode, the planted three stages system had the superior removal effect of pollutants, the average removal efficiency of CODMn、TN、NH3-N、NO3--N、TP、DIP were57.83%、93.10%、88.48%、97.31%、73.41%、72.29%.(2)In the whole operation stage, the plants had a superior influence on constructed wetlands, the all planted systems had a better removal effect of pollutants. (3)There was no correlation between dehydrogenase activity on substrate and removal efficiency, it was the same between urease activity on substrate and TN removal efficiency, the enzymatic activity of planted systems was higher than unplanted systems, and enzymatic activity had the vertical distribution characteristics of surface (0-10cm)>middle level (45cm)>bottom (90cm).(4)The nitrogen and phosphorus of plant absorption is very limited, in the whole experimental process, the TN and TP of plant absorption was8.02percent and1.18percent of TN and TP of influent of planted systems.