Experimental Study On Resource Utilization And Environmental Effects Of Agricultural Ecological Wetland

Agricultural non-point source pollution is the main source of water pollution. Constructed wetland technology is regarded as an important mean of agricultural non-point source pollution control. Efficient resource utilization of constructed wetland is the key to ensure the sustainable development of agricultural non-point source polluti-on control. This experiment was conducted in Changsha agricultural environment observation and research station, Chinese Academy of Sciences. Using Myriophyllum aquaticum ecological wetland and small ponds which were constructed for small wat-ershed agricultural non-point source pollution control projects to carry out the Chines-e Mitten Crab(Eriocheir sinensis) and eel (Monopterus albus) artificial breeding exp-eriment. In order to explore the comprehensive utilization of Myriophyllum aquaticum artificial wetland ecological technology and environmental and economic benefits. The main results were as following:The Myriophyllum aquaticum wetland can significantly reduce the water content of N, P. In addition to COD, TN, other indicators have reached the surface water environment quality standards of the III class standards, and COD did not exceed the standard too much. In the late experiment period, TN, TP, NH4+-N and NO3--N conc-entration with respect to the initial values were decreased by 58.3%,2% and 86.1%, 73.3%. In the culture of monopterus albus in Myriophyllum aquaticum wetland exper-iment, In addition to TN, COD did not reach the standard, the other water quality indicators have reached the standard of fishery water quality or surface water enviro-nmental quality standards. The removal rates of NH4+-N were 53.9%,42.7%,46.6% and the removal rates of N03--N were 75.1%,3.3%,78.6% in Myriophyll-um aquatic-um group, Alternanthera philoxeroides and Ipomoea aqutica group.The economic benefit of the culture of Eriocheir sinesis and in Myriophyllum el-atinoides wetland was 67 thousand per hectare which is significantly higher than the economic benefits of rice planting. The final single crab weighing up to 166g, the average weight is 105g. In the culture of monopterus albus in Myriophyllum elatinoi-des wetland experiment, the economic benefit of Myriophyllum aquaticum group and Ipomoea aqutica group were 207 thousand and 186 thousand per hectare.Myriophyllum aquaticum ecological wetland crab model is feasible, does not inc-rease the water load, in the vast rural areas has broad application prospects. Myriop-hyllum aquaticum ecological wetland, Ipomoea aqutica wetland raising eel model in a certain extent can reduce pollution and produce great economic benefit. It is worth to promote.