Screening And Optimization Of Phosphorus Removal Microorganism

The eutrophication and algae outbreak caused by water pollution events occur frequentlytoday.Phosphorus content exceeding the standard is one of the main factors of watereutrophication. Various methods of phosphorus removal have been studied and developed.Being low cost, efficient without second-time pollution, biological phosphorus removal iswidely used in wastewater treatment.The main aim of this study was to screen efficient phosphorus removal bacteria andstudy the factors which affect the cell growth and phosphorus removal as well as theapplication of phosphorus removal preparation in wastewater treatment; to improve cellconcentration by optimization fermentation conditions of both phosphorus removal bacteriapreparation and industrialization application. The main results were as follows. The bacterialstrain P10with better phosphorus removal performance was isolated from the excess sludgein a sedimentation basin of a laboratory scale A/O reactor with stable performance. It wasnamed Pseudomonas putida P10. The optimum pH for growth and initial phosphorusremoval for the bacterium were6.5and6.0respectively. The optimum temperature for bothare at30℃. Ferrous, manganese and copper ions can stimulate bacterial growth. Moreover,ferrous and manganese ions also promote the phosphorus removal. The effect of ferrous ionswas the best one, which increases the bacteria concentration by8.1%and the phosphorusremoval amount by46.0%. The highest removal rate (up to11.23mg/(g h)) of phosphoruswas in form of dipotassium hydrogen phosphate. Pseudomonas putida P10could removephosphorus effectively in actual wastewater. Through the experiment, according to theresults, fed-batch culture was used by feeding beef extract peptone medium intofermentation culture of Pseudomonas putida P10, and the optimal C/N was7. When theoptimal C/N for phosphorus remove was8in wastewater,the optimal pH for the culture ofPseudomonas putida P10in fermentation tank was8, and the highest bacteria concentrationreached8.72g/l. The addition of protecting agent into the fermentation broth could prolongits preservation time.