Research On Water Quality Analysis, Evaluation, Prediction And Countermeasure For Artificial Landscape Water

With the development of economic and the improvement of living standard,more and more artificial landscape water appeared in our lives.However,water quality variation brought many environmental problems that can't be neglected when living environment was beautified.Eutrophication was one of these problems.If water quality of artificial landscape water was predicted precisely and water quality was restorated in time,Environmental deterioration would be played the percentages.In this paper,the park of Qujiang Pool site in Xi'an city was investigated,on one hand water quality was predicted and analysed by WASP water quality model,on the other hand supply water quantity monthly and the change of water quality were researched by analysis of dynamic water quantity ballance in artificial landscape water.Water quality was evaluated by scoring method,then strategies of water restoration were given.The results showed that:(1) Waters in the park of Qujiang Pool site in Xi'an city were divided into 299748 unites by GAMBIT.Then the flow field was simulated by FLUENT and water quality was simulated by WASP.The results showed that:flow rate of Number 3 was the lowest in these 8 spots of flow field,nutrient such as nitrogen,phosphorus would be accumulated easily,eutrophication would happened easily;Six parameters of water quality such as organic phosphorus,organic nitrogen,ammonia nitrogen,dissolved oxygen,CBOD,phytoplankton were simulated,then the results were analysed;Six parameters of the degree of fitting are 85.5%,86.7%,84.3%,88.2%,81.9%,83.5 %。(2) Dynamic water quantity ballance analysis of water in the park of Qujiang Pool site showed that:the park of Qujiang Pool site needed to water supplement annually except September and October.Supplementary water capacity was the largest in March, April,May and June,the supplementary water capacity monthly were 42300 m~3,34400 m~3,44100 m~3,39800 m~3 respectively,which account for 67.85%of total supplementary water capacity.Meanwhile COD,TN,TP which could reflected eutrophication were calculated by the calculation results,the results showed that:①The concentrations of COD were high in March,April,May,June and July which were 17.68 mg/L,17.39 mg/L,17.74 mg/L,17.59 mg/L,17.23 mg/L respectively.the concentration of COD was the lowest in September which was 15.63 mg/L;②The concentrations of TN were high in March,April,May,June and July which were 0.43 mg/L,0.42 mg/L,0.43 mg/L, 0.43 mg/L,0.42 mg/L respectively.The concentration of TN was the lowest in September which was 0.38 mg/L;②The concentrations of TP were high in March, April,May,June and July which were 0.043 mg/L,0.042 mg/L,0.043 mg/L,0.043 mg/L,0.042 mg/L respectively.The concentration of TP was the lowest in September which was 0.039 mg/L.(3) Water quality of the park of Qujiang Pool site was evaluated by scoring method,the results showed that:nutrient grades of 8 spots were above Middle-nutrient grade which were middle eutrophic.(4) The restoration strategy which was "artificial wetland+ filter with modified media" was brought in this paper according to the water quality characteristics of the park of Qujiang Pool site.Their technical parameters were brought respectively,part of water was drawed forth downstream area which was heavily polluted,then reflux the upstream area which was heavily polluted after treatment by optimal process,whole water quality would be keeped,Eutrophication and supplementary water capacity would be controlled and reduced by this alternative circulation.