Study On The Rural Sewage Treatment Technology And Management Mode

The rural domestic sewage contains a large number of pathogenic microorgani-sms, nitrogen and phosphorus,which will cause water eutrophication and threat thesafety of drinking water without treatment, so it should be paid more and moreattention. However,the traditional wastewater treatment technologies (such as A2O,flocculation precipitation, oxidation ditch technology)are not suitable for applicationin rural area, because of large energy consumption, complex of operationmanagement, high cost of construction and operation. Sewage land treatmenttechnology has been widely used on wastewater treatment in foreign countries, andhas many advantages in technology, capital and management, so it would have avery broad application prospects in the rural areas in China. At present, operationmanagement of rural sewage treatment facilities in our country is wasteful andinefficient,so there is an important practical significance to make a research onoperating mechanism of rural sewage treatment facilities.Packing layer is the most important part of sewage land treatment system, whichwill directly affects the removal efficiency of the system. Zeolite has a strong capitalof ion exchange, which especially is used to adsorb ammonia nitrogen. And clayceramsite, anthracite and activated carbon have large specific surface area,Thereforethis study choose the four packings as the research object to discuss the adsorptionmechanism of ammonia nitrogen and phosphorus by four packings, and to study theimpact on removal efficiency of different packing layer loading sequence.In order to evaluate the packings performance in ammonia nitrogen andphosphorus adsorption, this study has carried on the isothermal adsorption test, thesolid-liquid ratio test and the adsorption dynamics test. Both the Langmuir andFreundlich model can well describe the isothermal adsorption results. Results showthat, activated carbon has the largest theoretical maximum adsorption capacity forphosphorus, with Qe1768mg Kg-1,but the least adsorption capacity, Qeis68.8mg Kg-1.The capacity sorting of four packing adsorpting ammonia nitrogen iszeolite (1768mg Kg-1)> activated carbon (1052mg Kg-1)> clay ceramsite (769mg Kg-1)> anthracite (542mg Kg-1),and that of phosphorus is Activated carbon(2543mg Kg-1)> clay ceramsite (494.25mg Kg-1)> anthracite (199mg Kg-1)>zeolite (68.77mg Kg-1).When the solid-liquid ratio of zeolite and clay ceramsite areboth200g L-1, the phosphorus removal rate are30.9%and45.6%respectively; Whenthe solid-liquid ratio of anthracite and activated carbon are both120g L-1, thephosphorus removal rate reach76.9%and76.9%respectively. The adsorptionkinetics experiment results show that the adsorption in24h can reach equilibrium.In order to study the performance of the four packing in pollutant removemal, aseries of single packing and combination packing experiments were designed. Theexperiment results are as follows. zeolite has a very good removal effect for NH3-N in single packing condition. The ammonia nitrogen removal effect by anthracite coal andclay ceramsite is poor. Activated carbon have a good removal effect for NH3-N, TPand organic compounds. After enhanced hanging film, there are improvement ofremoval efficiency in different degrees, and the average removal rate of CODCrincreases more than10%. The combined packing experimental results show thatactivated carbon-clay ceramsite-zeolite system has an effect on removal of ammonianitrogen, systemZeolite-clay ceramsite-activated carbon system removal effect ofphosphorus is good, and the removal efficiency of pollutants with completely mixedloading way is more balanced, which has a good removal effect of organic matter,NH3-N, TN and TP.The operation management quality of sewage treatment facilities is the mainfactor that influences the continuous and stable operation of the facilities, so it isimportant to be considered. At present, the problems of operating mechanism of ruralsewage treatment facilities mainly occurs in law, financing and operationmanagement system and so on. So we should take measures to strengthen theoperation mechanism of rural sewage treatment facilities, such as perfecting the legallaws and regulations, increasing publicity and education, establishing fund securitysystem and proceduring of operation and maintaining, etc.