| The accumulation of Phosphorus in the water always cause eutrophication, pollutions caused by Phosphorus have seriously threatened human beings'life and the balance of ecosystem.The study on the theory and technology of Phosphorus removal in wastewater treatment has been generally concerned in environmental science and the field of engineering. Phosphorus remove by united technology combine the advantages of chemical and biological technology, but it makes the process complication, and also increase the costs of operation. So we need to study ecnomic, efficient techniques and processes that are suitable for the national circumstances for Phosphorus removal.In this paper, we choice aluminum sulfate as a reagent at the stage of chemical phosphorus removal, the results showed that, the reaction volume of material ratio for Al3 + and PO43- is 4:1, that is to say the Al3 +amount involved in response is the total of aluminum1/4; Many factors affect the biological phosphorus removal. This paper based on aerobic - anaerobic alternating cycle process , discuss the factors about different types of COD, pH, DO, temperature, COD concentration, phosphorus sludge age of micro-organisms; it Shows that use the mixed matrix of glucose and sodium acetate (COD ratio is 1:20-1:40), the effect domestication of activated sludge excelled than other mixed matrix, the COD, NH4 +-N, PO43- reachs good removal, when in operation parameters: pH of 7-8 (7.5), the temperature is 20-30℃, DO anaerobic stage for less (equivalent) 0.16 mg/L, DO aerobic stage for 2-4 mg/L, COD between 300-500 mg/L, sludge age of 15 days , the phosphorus removal reach the best.Aluminum and oxygen bring stress of the phosphorus removal system. The results showed that the anaerobic system (commonly nitrogen), the microbes can maintain normal anaerobic metabolism, the system has not been damage, here O2·-≦ 0.0249mmol/g, MDA≦ 31.25 nmol/g , The removal rate of COD, NH4 +-N, PO43- is 96.5%, 97.4%, 92% in effluent; when the oxygen stress increase, vacuum for more than 6 min, the microbes can not maintain anaerobic metabolism normally, the system has been damnified, the O2·- more than 0.0249 mmol/g, MDA is greater than 31.25 nmol/g, and the more the concentration of O2·-and MDA is, the more serious damnify, The removal rate of COD and NH4 +-N dropped by nearly half, and PO43- decline in more and more, the minimum value of 0.10, reach the peak more than 0.80. Al3 + concentration affect COD on biological phosphorus removal system is not obvious, when the the Al3 + water level lower than 5 mg/L; with the increase in Al3 + concentration, COD removal rate increase, the biggest addition may be about 2 percent, when the concentration of Al3 + more than this value, COD removal followed decline, but remained at about 90%; Al3 + affect the removal of PO43- evidenttly than COD, when the Al3 + less than 15 mg/L, with the Al3 + increase, the removal of PO43- increased slightly, the largest addition about 1 percent, but when Al3 + concentration greater than 15 mg/L, with the Al3 + increase, the removal of PO43-obviously decline, the peak reached 56% , above all when Al3 + concentration less than 15 mg/L, MDA is about 31.25 nmol/g, when Al3 + concentration excess 15 mg/L, MDA increase, the system has been damnified, the removal rate of PO43- has lower too.From the experiment, we can see that MDA and O2·-can accurate and timely reflect the system running, as SOD and MDA and O2·- are intrinsically linked counterparts, so we can use SOD as biological markers, through detected the online determine of SOD in system, we can manage the entire system of phosphorus removal.The chemical sludge from water treatment plant contain much aluminum when using aluminum-based coagulation . Its comprehensive utilization can not only economize resource but also avoid secondary pollution.The key factor of extracting aluminum from the chemical sludge is pH value. Commonly, when pH<1.7 (acid concentration>0.02mol/L),the aluminum in sludge will be dissolved,and when acid concentration increase at 4.0mol/L.extraction can reach the largest amount.The eaction can reach balance rapidly in acidic circumstance in 4 minutes.Stir and temperatures elevation can also enhance the dissolution rate of aluminum.Different functional groups of small molecular organic matters in sludge,that is an important intensification condition.especially organic matters contains-OH and-NH2, can solubilize above 10%.Moreover,it also can extent the upper boundary of pH from 1.7 to about 3.0.
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