| Nowadays,environmental protection has become the focus of all the countries of the world,our country-a developing country is included,too.With the rapid development of our economy and the increasing of population,especially,the increasing number of many middle-small companies,as a result,a great deal of wastewater is released,which leads the serious environmental problem,so we must control and dispose this problem of discharge of the wastewater well. We must study new approaches and new processes to dispose wastewater to purify the water environment gradually,and give a prefect and the orginal well space which we live by.The earliest biological treatment technology of wastewater is mainly used to the organism and suspended solid removal. Nitrogen and phosphorus is not needed to remove to the standard when is discharged,until 70 and 80 decade 20th century,because of the more and more serious problem of water eutrophication,nitrogen and phosporus in wastewater must be disposed to reach standard before draining. In a word,nowadays,the primary treatment object of wastewater treatment factory of cities include mainly to dispose organic(COD,BOD5) ,suspended solid(SS) and nitrogen,phosphorus,etc. The following is the outline of the principle and processes of nitrogen and phosphorus removal,the conflict and solution of nitrogen and phosphorus removal and result of experimental research.First,wastewater biological nitrogen removal treatmentWastewater biolgical nitrogen removal accords to nature microorganism transfer nitrogen theory,it is a man-made measure,which purpose is to transfer organic-nitrogen or ammonia-nitrogen to nitrogen.The principle of biological nitrogen removal makes ammonia-nitrogen became nitrate-nitrogen and nitrite-nitrogen by nitrifying and denitrifying bacteria,in the aerobic condition then make nitrate-nitrogen and nitrite-niteogen transfer nitrogen by denitrifying bacteria and lastly reach the purpose of nitrogen removal from wastewater.There are some methods from NH3 to N2:conventional nitrfication-dentrification,short-cut nitrfication-dentrification,simultaneous nitrfication-dentrification(SND) and anaerobic ammonia oxidation(ANAMMOX),etc.There are many biological nitrogen removal processes:such as conventional processï¼›A/O(anearobic/oxic) processï¼›SBR(sequencing batch reator) processï¼›A2/O(anaerobic/anoxic/oxic)processï¼›Simultaneous nitrfication-dentrification processï¼›Bardenpho processï¼›improved AB (absorpition-biodegradation) processï¼›Biofilm nitrogen removal processï¼›TETRA deep-bed nitrogen removal processï¼›Carrosel 2000 type aerobic ditch process,etc. These processes have their own characters,we should use smartly by according the feature and quality of wastwater.This experiment use SBR process, using principle of biological nitrogen removal to remove nitrogen.Second,wastewater biological phosphorus removal treatmentSo far,the principle of wastewater biological phosphorus removal treatment is also the main principle,it is mainly to make use of accumulation phosphorus bacteria releasing phosphorus to westewater in anaerobic condition,and in aerobic condition accumulate phosphate from wastewater,and then phosphorus removal from wastewater by discharging activated-sludge.There are many biological phosphorus removal process:A/O processï¼›A2/O processï¼› SBR processï¼›phostrip processï¼›Bardenpho processï¼›UCT processï¼›phoredox proscessï¼›AP processï¼›VIP processï¼›AB process ï¼›aerobic ditch processï¼›construeted wetland processï¼›trickling filterï¼›rotating biologic contactor,etc.It is needed to point out,in the course of wastewater biological treatment,in the most case ,me must not only remove nitrogen from wastewater,but also remove phosphorus,so,we often consider that we should make nitrogen and phosphorus removal in the same process,which is usually called BNR(biological nutrient removal) process in other countries,our country should strengthen study futher in the field.This experiment use SBR process, using principle of biol...
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