Sensory Quality Analysis And Improvement Technology Of River Water

River water in urban cities is an important embodiment of urban comprehensive strength,and closely related to the quality of people’s life.However,after solving the problem of black-odorous water,the sensory quality of urban river water is still not very good,which is far from people’s expectation.The influencing factors of river water sensory quality and how to improve the sensory quality with a low-carbon concept "well and economically" have become the current problems faced by many cities.In this paper,the Waicheng River in Suzhou Gusu district is taken as an example,seven sampling points were set up in the main tributaries of the Waicheng river.The spatio-temporal analysis of 7 sampling points in four seasonswas carried out,and the main factors affecting the sensory quality were analyzed.On this basis,the effect of Nanometer ferric oxide enhanced coagulation filter cloth technology is verified through the combination of simulation experiment and field experiment,and the removal effect of materials affecting the sensory quality of river water is investigated.The research results are as follows:(1)the sensory quality of Suzhou River water is generally normal in spring and winter,but poor in summer and autumn.The main reason for the poor water quality in summer and autumn is that the environmental factors and the ratio of nitrogen and phosphorus are very suitable,which leads to the rapid increase of phytoplankton,and then the content of chlorophyll a in the river water is significantly increased.The river water in the urban area of Gusu district is greatly affected by its upstream water quality,so the water quality of the seven sampling points is worse than that of the downstream.In addition,the water quality of sampling points close to residential areas is relatively poor,while those close to parks,wetlands and scenic spots are better.(2)There are mainly diatom,cyanobacteria and green algae in the river water of Gusu district.In spring,winter and early summer,diatom is the dominant population in the river water.The outbreak of cyanobacteria and green algae rich in chlorophyll a in summer and autumn is the real reason for the increase of chlorophyll a content in the river water.CDOM has obvious autogenous characteristics in the whole year,mainly from microbial activities,and the degree of humification is low.The content of CDOM increased significantly in August and September,mainly because the increase of phytoplankton led to the increase of organic matter content in the river water,which led to the increase of humic acid and fulvic acid content.(3)The main factors affecting the sensory quality of river water are suspended solid content,phytoplankton,chlorophyll a and CDOM,which are linearly correlated with turbidity and chroma.At the same time,the content of ammonia nitrogen has a significant linear correlation with color and turbidity.The distribution of turbidity and chromaticity is very similar to that of p H,temperature,redox potential,dissolved oxygen and other environmental factors.To improve the sensory quality of river water,it is necessary to remove suspended solids,phytoplankton,chlorophyll a and CDOM effectively to reduce turbidity and chroma.(4)Three kinds of coagulants and three kinds of coagulants all show better effect of improving water quality in the simulation experiment.Compared with the other two coagulants,PAC is the best coagulant because of its better treatment effect and settling speed,and it is easy to preserve,and it will not increase the color of river water.As a coagulant aid,nano-sized ferric oxide has the advantages of good treatment effect,fast settling speed and relatively low price,and it is the best coagulant aid.(5)A one month field experiment was carried out in Suzhou to verify the effectiveness of the equipment.The results show that the effluent of the device is stable and can effectively improve the sensory quality of river water.The removal rate of turbidity is 84.8% ～ 94.1%,the removal rate of chroma is 67.7%,the average removal rate of dissolved organic carbon is47.1%,the removal rate of chlorophyll a was 53.4%,and the removal rate of algae cells was 95.0% ～ 99.8% the removal rate of total nitrogen is27.5%,and the removal rate of CDOM is 30.2%.