Effects Of Adding Plant Carbon Source On N&P Removal Capacity Of Multiple-stage Integrated Vertical Flow Constructed Wetland

With the rapid development of Chinese rural economy in recent years, the rural non-point source pollution (NPS pollution) gradually becomes a serious threat to the receiving water bodies. In Poyang Lake region in Jiangxi, the harm to the lake water quality which caused by the rural NPS pollution is against the ecological&economic development strategy in Poyang Lake region. The constructed wetland technology is effective means of controlling the rural NPS pollution in Poyang Lake region. In constructed wetlands, regularity the lake of carbon source restrains the ability of removal contaminates. To saving operating costs, a best carbon source is chose from the cheap and easy, environmentally friendly plant (water bamboo and reeds) straws. The best carbon source is added to the multi integrated vertical flow constructed wetland (MIVFCW) to improve its capacity of removal contaminates. This study has two parts, a choosing of plant carbon source and the effect on the ability of removal contaminates to the MIVFCW. These results are got:(1)The water bamboo straws C and N take18.09%and0.339%respectively in weight. The reeds straws C and N take33.13%and1.311%respectively in weight. And the C in these two straws can be released and used as availability carbon source in constructed wetland.(2)In the plant straws static release experimental for80days, we find that the C release curve of the reeds straws is relatively flat. And the reeds straws should be the better permanence plant carbon source materials.(3)By the comparison in small constructed wetlands, the better kind and adding weight are confirmed, that is the reeds straws at1.0kg/m2adding weight.(4)After adding the reeds straws at1.0kg/m2adding weight to the MIVFCW, we can find those:①COD of the effluent water from the MIVFCW is stable, and the removal rate of COD is maintained at about90%.②It improves the removal rate of NO3--N from76.67%to94.7%. It advances the microorganism's denitrification reaction, and enhances the capacity of removal N from MIVFCW radically.③It has less effect on the capacity of removal NH3-N from MIVFCW, only improves the removal rate of NH3-N from81%to85.5%.④It can remission accumulation of NO2--N, and enhances the capacity of removal N from MIVFCW radically too.⑤It has a positive role in promoting P removal capacity of the system. Because the carbon source amount promotes the growth of microorganisms, the absorption and transformation of the microorganisms of P is improved, then the release of PH3is promoted.