Study On The Effect Of Removing Contaminants From Yellow River Water By Riverbank Filtration Project

With increasingly contamination of drinking water sources,traditional drinking water purification process has been difficult to achieve the country's new drinking water health standards.Therefore,it is necessary to search an economic and highly efficient drinking water treatment technology,in order to guarantee the safety of drinking water,which has become the hot point.Soil filtration technology,which is of low cost and high efficiency,is paied much attention to.Riverbank filtration technology is a process that is discussed and established widely in the world.People diged the drawing wells on riverbeach or flood where groundwater and fiver water have closely hydraulic contact,and extracted the groundwater instead of pumping riverwater,which was turned into clean water through riverbank lateral seepage.Nowadays,it is still in the starting period that take riverbank filtration project as the pre-treatment process.Choosing "jiu wu" beach as the experimental site,study the effect of river bank filtration project on the removal of ammonia,UV₂₅₄,microcystins and other pollutants from Yellow River,in order to offer the scientific basis for government making decisions.experimental site:In this study,select six monitoring wells according to different distances from drawing wells to Yellow River in "Jiu Wu" beach.These wells are NO.39 well (50m),NO.41well(100m),NO.22well(300m),NO.21 well(1500m),NO.2Weil (2000m),NO.9Well(3000m),water inputing plant,water out of plant and yellow river water.From April to November in 2008,have 8-month continuously analysis of water quality testing.Materials and methods:1.Total Phosphours(TP) by Potassium Persulfate—malachite green ammonium molybdate spectrophotometry method;2.UV₂₅₄ by ultraviolet-visible absorbance at 254 nm; 3.Ammonia-nitrogen(NH₃-N) by ammonium—Nesster's reagent colorimetric method;4.Chemical oxygen demand(COD_Mn) by acidic Potassium Pemranganate method;5.Algae cell density(ACD) by blood cell counter;6.Microcystins(MCs) by ELISA method;7.Chlorophyll-a(Chla) by spectrophotometric method;Results:1.The removal rates of"jiuwu" beach riverbank filtration project are account for total removal rates of the combined process of 96.10%,93.31%,60.83%,52.84%for COD_Mn,UV₂₅₄,TP,NH₃-N,respectively.The removal rates of ACD are more than 90%in different times and account for total removal rates of the combined process of 94.61%～97.90%2.Correlation coefficients r which to COD_Mn,UV₂₅₄,NH₃-N and TP elimination rates and the travel distance are 0.449,0.576,0.444,0.594,respectively.There is no statiscally significant(P＞0.05).3.The removal rates of No.21well,No.2 well are both 100%for microcystins;The removal rate of No.9well is 78.3%～100%;The removal rate of No.22 well is 73.9%～100%;The average removal rate of No.41 well is 6.1%～15.0%.Conclusion:1.The "jiuwu" beach riverbank filtration project in zhengzhou is removal of the main unit for COD_Mn,UV₂₅₄,ACD,MCs in the combined water purification process, however,it has well removal effect on TP and lower removal effect on NH₃-N.2.The correlation between removal rates for NH₃-N,COD_MN,TP,UV₂₅₄ and travel distance required for further study.3.The "jiuwu" beach riverbank filtration project could be considered as an excellent water pre-treatment process,it can guarantee the drinking water safety.