Research On Optimizing Combination Of Padding And Removal Efficiency Of Nitrogen And Phosphorus In Low Temperature

As a new-style technology arising for the past several decades in China,the constructed wetland appears some inherent problems,of which the three remarkable problems are as follow:First,the disposal load is ,in general,0.5-0.8 m~3/m~2·d ,which is so low that the occupied area is, therefore, very huge; Second,as the operation time in constructed wetland extends,with the physical,chemical and biological influence on it,the infiltration rate is gradually decreasing,which in turn lead to the soil clogging phenomena.Clogging will make wastewater difficult to flow through the soil,contributing to the dramastical decrease of the purified capability; Third,the removal efficiency is hardly stable. This experiment applied five varied poles,simulating the constructed wetland,filled with diversed padding to treat low concentration municipal sewage in low temperature,make a reaearch on the corresponding results,follow up the variation of the filtration coefficient under the different load ,and also discuss the removal efficiency of organic compound, Nitrogen and Phosphorus,as well the clogging influence on it,and in the end suggest the endurable padding depending on the different load. Under the high, middle and low hydraulic load, 2m~3/m~2·d, 1m~3/m~2·d, 0.3m~3/m~2·d respectively,the research of low concentration municipal sewage directly flowing into poles indicates these results:(1)without any prelimilary treatment,after 60 days with the load of 1m~3/m~2·d , the filtration coefficient on the top surface decreased most dramastically.With the high hydraulic load about 2m3/m2·d , the filtration coefficient continuelly decreased in each pole:the pole 1 is more resistable to clogging than the rest poles.(2)We suggest apply endurable materials with big pores to resist the potential clogging,and recommend that the pole 1 can be exerted to treat wastewater under high hydraulic load; while the pole 2 is suitable under middle hydraulic load; ih the end,the pole 4 and pole 5 showed perfect results under low hydraulic load.(3)The research on the high concentration experiments indicates:still,the pole 1 and the pole 2 retain the steady removal efficiency,while under the middle hydraulic load,the pole 4 and pole 5 boast the perfect removal efficiency.