| For the wastewater treatment and afforestation in the fragile ecological area of Xinjiang desert,this project takes the Pishan County constructed wetland as the main research object.Sewage treatment in desert areas has the characteristics of relatively small amount of water,relatively simple pollutants,low quality of management personnel,and unacceptable sewage treatment process with high treatment cost.According to the specific conditions in desert areas in Xinjiang,the use of constructed wetlands to solve the problems of greening the desert and improving the ecological environment in the desert.Taking the Pishan County constructed wetland sewage treatment system as an example,based on the operational effects of the Pishan County constructed wetland,suggestions and parameters for using the constructed wetland to treat the sewage in the desert areas of Xinjiang are provided.The use of constructed wetlands,an efficient,low-cost,simple-to-use sewage treatment process for desert greening,is of great significance for the restoration of desert ecologically fragile areas.According to the 8-year operation effect of the Pishan County constructed wetland.From the water quality,effects of sewage irrigation plants,and animal and plant changes in desert ecosystem restoration,the types,substrates,plants,and operation and maintenance methods for the wastewater treatment of the constructed wetland system in desert areas were analyzed.The research and engineering practices are as follows:(1)A surface-flow constructed wetland was used in the Pishan County constructed wetland,and the plant was a native plant reed.The Gobi gravel was used as the substrate.According to the water quality data,the constructed wetland can guarantee the long-term stability of the secondary water discharge standard of the "Emission Standard of Pollutants for Urban Wastewater Treatment Plants"(GB18918-2002).The Pishan County constructed wetland used the purified sewage to carry out desert greening and restored the environment in the desert ecologically fragile area.(2)Based on the operating experience of the Pishan County constructed wetland,it is recommended to use a composite constructed wetland for the design of constructed wetlands in the desert areas of Xinjiang,and to use the native plant reeds and broadleaf cattails that are cold-tolerant,drought-tolerant,and saline-alkali as the plants for the constructed wetlands.The slag obtained nearby can be used as a matrix.The wastewater treatment technology for constructed wetlands is of great significance to the improvement of the environment in the entire desert area for the greening and ecological restoration of desert areas.Constructed wetland can be used as the main sewage treatment process in the desert region of Xinjiang in the future.(3)According to the actual project case of a constructed wetland in a township and a city,the wastewater treatment system of the constructed wetland in Pishan County was compared,and the treatment of the constructed wetland for different conditions was analyzed.It can be confirmed that the constructed wetland can reach the sewage treatment effect above Class I B,and it can be confirmed that the constructed wetland can combine the waterscape and greening to form the landscape.Constructed wetlands can adopt various water forms and tortuous riverbanks,and increase the amount of aeration in the form of water distribution in stages and adjust the flow rate of water through flooding.These landscape and sewage treatment methods combined with each other will be artificial.Wetlands merge into the urban landscape and give different meanings to the urban landscape.In summary,according to the actual situation in the desert areas of Xinjiang,artificial wetlands can be used as a sewage treatment process for sewage treatment,green deserts,land environment and water environment improvement.Therefore,constructed wetlands can achieve more wastewater treatment goals in Xinjiang and similar desert regions. |
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