Study On The Coupling Of Urban Tailing Water By Ecological Floating Bed And Biofilm

A composite three-dimensional ecological floating bed with biological fillers media and aquatic plants was constructed in the present work.The domestic sewage with after treating by SBR technology was used as the city tailing water,and the pollutants were absorbed and degraded by aquatic plants and biological fillers media in the composite floating bed system,which led to the decrease of the amount of pollutants.The system is widely used for surface water such as reservoirs,rivers and lakes.However,it has not been applied in the urban domestic sewage,which may have certain innovativeness.Besides effective purification of water and removal of organic matter in water,the compound ecological floating bed also has a kind of appreciation value.Furthermore,it has good practical application value.In this paper,the composite ecological floating bed will be built,which is mainly based on the emission statues and features of the urban tail water.The best operational parameters were determined by experiments results.The composite floating bed is applied to static and dynamic test,and different aquatic plants(Lythrum salicaria L.and Iris pseudacorus L.),biological fillers media(combined filler,suspended filler and ceramsite),aquatic plants and biological fillers media used in the system.Through the analysis of removal effect of pollutants in the test water,the best combination of biological filler and ecological floating bed is studied.The investigated results were as follows:Treated by SBR technology,Lythrum salicaria L.and Iris pseudacorus L.have showed a better removal effect on CODCr,ammonia nitrogen,total nitrogen and total phosphorus in the city tailing water using the static test by secondary treatment.The removal rate of CODCr by Lythrum salicaria L.was 86.7%,higher than 83.3%by Iris pseudacorus L.The purification effect of Iris pseudacorus L.on nitrogen and phosphorus in city tailing water was best,which the removal rates of ammonia nitrogen,total nitrogen and phosphorus were 98.6%,86.7%and 86.0%.The root system of Iris pseudacorus L.'s average Shanon index was 6.3 5,higher than the chilies' 6.04.With high microbial population index,good microbial diversity and effective removal rate of pollutants in the test water,Iris pseudacorus L.was selected for comprehensive consideration.In this study,three packings,including combined filler,suspended filler and ceramsite,and blank experiments were selected to use the static test by secondary treatment.The treatment of the city tailing water of CODCr,NH4+-N,TN and TP was compared and analyzed.The results show that combined filler had better removal efficiency for CODcr,NH4+-N,TN and TP in the state of stable operation of the system in city tailing water.The removal rate were 85.26%,96.17%,87.51 and 87.51%,which was significantly higher than those of the other 3 groups.Based on the static test,the dynamic test was carried out.The effects on the purification ability of domestic wastewater with advanced treatment by the ecological floating bed were investigated.Iris pseudacorus L.and combined filler ecological floating bed had better removal efficiency for CODCr,NH4+-N,TN and TP when the advanced treatment by compound ecological floating bed was adopted in domestic wastewater.The removal rate was(56.45?69.63)%,(66.26?81.98)%,(53.10?76.06)%and(69.68?80.67)%respectively,which was obviously higher than the other three groups.The effluent after treatment by compound ecological floating bed of Iris pseudacorus L.and Combined filler could reach primary A standard of the?Pollutants Emission Standard of Urban Wastewater Treatment?(GB 18918-2002).