| Artificial wetland technology as a commonly used sewage treatment technology,with a simple process,easy operation,low operating costs,water quality is good,improve the ecological environment and other advantages.It is of great practical significance to study the effect of artificial wetland construction,management and water purification in the winter conditions in winter,especially for the artificial wetland which has been built and successfully operated in China.By analyzing the emission reduction of pollutants in constructed wetlands,Under the conditions of artificial wetland emission reduction performance level,will help optimize the winter wetland operating parameters,improve the management of wetland management level,improve the wetland emission performance management,and winter under the conditions of other artificial wetlands to provide guidance.In this paper,three artificial wetlands in Shandong Province were selected for field investigation and follow-up monitoring.The effects of three wetlands on water quality and water quality were analyzed.The performance of artificial wetland under winter conditions was evaluated.Optimization Countermeasures and Suggestions.This paper mainly carried out the following aspects:(1)Based on the monitoring and analysis of winter D artificial wetland,M artificial wetland and X constructed wetland,the results showed that the removal rate of pollutants in artificial wetlands was higher than that in national surface water III Water quality standards,which is mainly due to water quality can not meet the wetland design of water quality requirements.The average removal rates of COD,ammonia nitrogen,total nitrogen and total phosphorus were 77.59%,85.53%,52.19% and 72.93% respectively.The average removal rates of COD,ammonia nitrogen,total nitrogen and total phosphorus were 47.17%,47.83%,75.66% and 73.68% respectively.The average removal rates of COD,ammonia nitrogen,total nitrogen and total phosphorus in artificial wetland were 55.78%,81.55%,55.17% and 34.43%respectively.Based on the analysis of wetland water quality,it was found that the removal efficiency of COD,NH3-N and TN in the subsurface flowering wetland was better than that in the surface wetland under winter conditions,and the concentration of pollutant in the backflowwetland was stable and increased slightly,The main reason is the existence of a large number of plant rot,resulting in unstable concentration of pollutants.(2)This paper constructs the evaluation framework of emission reduction performance in winter,including target layer A,criterion layer B and index layer C,and determines the performance evaluation index of artificial wetland under winter conditions.Wetland construction,wetland management and winter water quality purification effect,The economic and social characteristics of the four criteria to reflect the overall target system,and to determine the "TN removal rate,TP removal rate,NH3-N removal rate,COD removal rate,effluent index compliance rate,pool design,filler status,Winter plant management and insulation,tons of water operating costs,the average winter temperature,plant conditions,line management system,the power of residence time,tons of water operating costs,siltation " 15 indicators.The index weight is calculated by the analytic hierarchy process(AHP),the relative importance degree of each index is determined by the expert scoring method,the performance evaluation standard of the constructed wetland emission reduction is determined,and the evaluation index system of the comprehensive index of the wetland emission reduction performance is put forward.(3)Through the comprehensive evaluation model,the three artificial wetlands were evaluated for winter emission reduction,and the comprehensive evaluation score of artificial wetland in winter was 73.55,and the results were good.M artificial wetland winter comprehensive performance assessment score 64.94,the assessment results are in the.X artificial wetland winter emission reduction performance comprehensive assessment score68.85,the evaluation results for the medium.The countermeasures and suggestions were put forward for the stability of water quality of constructed wetland,the operation of negative management system,plant management,siltation and winter insulation. |
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