Effects Of Carbon Sources And Their Combination With Plants On The Purification Of Nitrogen And Phosphorus In Constructed Wetlands

The effects of different carbon sources and adding ratios on the purification of nitrogen were studied.In the early stage,the purification efficiency of the four substrates of pebble,Zeolite,vermiculite and gravel was studied,and the best material suitable for artificial wetland was selected,by adding Straw and corn as additional carbon sources separately,the ratio of 0.5,1,2 kg·m-2 was added to the column,Compare its purification efficiency and screen out the appropriate proportion of carbon sources,the results of the first two experiments were used to study the purification efficiency of nitrogen and phosphorus in artificial wetlands with different plants and different carbon sources by adding 1 and 2 kg·m-2 of Straw and maize as wetland plants,through the above research,a set of high efficient ammonium removal technology for Guangxi's climate is selected,which makes the effluent index meet the standard a of the first level of the"standards for the discharge of pollutants from urban Sewage Treatment"(GB189198-2002).The conclusion from the experiment:(1)Different kinds of substrates have different purifying effects on artificial wetlands,when the ratio of carbon to nitrogen reaches 5:1 in the influent water,without adding the carbon source,the nitrogen purification efficiency of four substrates are pebble<gravel<Zeolite<vermiculite;phosphorus purification efficiency is pebble<vermiculite<Zeolite;The removal efficiency of COD is the pebble<gravel<vermiculite<zeolite.(2)When the ratio of carbon to nitrogen is about 2:1,the addition of rice straw and corn straw can increase the removal rates of N and P in domestic wastewater from constructed wetlands.The removal rate of added rice is better than that of added corn,and the efficiency is highest when the ratio is 1 kg·m-2.(3)The combination of different plants and carbon sources affected the removal rates of nitrogen,phosphorus and other elements in wetlands..The purification effect of Cyperus on wetlands is better than that of Canna.The straw added with 1 kg·m-2 of Cyperus has the best purification effect on wetlands.