Domestication And Screening Of Denitrifying Phosph Ate Accumulating Bacteria And Its Efficiency Of Nitrogen And Phosphorus Removal

In this study,strains with denitrification and phosphorus removal were screened and acclimated from the activated sludge of domestic sewage treatment plant.The optimal growth conditions of the strains were explored by changing the efficiency of denitrification and phosphorus removal of carbon source,pH and temperature environmental factors.Two groups of SBR reactors were constructed,named No.1and No.2,respectively.J3 was added to Reactor No.2,and reactor No.1 was used as the control group to explore the effect of Strain J3 on biological strengthening of Reactor No.2 SBR.In the experiment,6 strains with denitrification and dephosphorization effects were isolated and purified from activated sludge of domestic sewage treatment plant by gradient dilution and streaking method,respectively named J1-J6.,and using phosphorus absorption experiment,nitrate also from gas test,gram staining,metachromatic granules dyeing experiments on denitrifying phosphorus accumulating strain identification experiment,J3 strains of phosphorus removal effect can reach37.1%,gram staining results for positive,metachromatic granules cell body with black phosphorus accumulating material dyeing results,so choose phosphorus removal effect is the best denitrifying phosphorus accumulating bacteria strains J3 further research of optimal growth conditions.The results showed that the phosphorus removal efficiency and nitrogen removal efficiency of J3 strain were 69% and 75% respectively when sodium acetate was used as carbon source and other environmental factors were unchanged.When the pH value of 7,other environmental factor at constant parameters,phosphorus removal efficiency was 67%,the nitrogen removal efficiency is 85%,when the temperature condition control is 30 ?,other environmental factor at constant parameters,phosphorus removal efficiency was 61%,the nitrogen removal efficiency is 74%,so the preliminary mastered the optimal growth conditions for denitrifying phosphorus accumulating bacteria when the pH of 7,with sodium acetate as carbon source,under the condition of 30 ?,more suitable for the growth of strains.Using artificial simulated wastewater in SBR reactor inlet,and the J3 strains cast to the SBR reactor 2,no.1 reactor as the control group,on a regular basis to the reactor inlet and outlet of chemical oxygen demand(COD),ammonia nitrogen,total nitrogen and total phosphorus indicators monitoring,after adding the denitrifyingphosphorus accumulating bacteria on the COD removal rate increased by 5%,ammonia nitrogen removal rate increased by 10%,and TP removal rate increased by6%,TN removal rate increased by 8%,the results show that enhanced the biochemical system after biological treatment efficiency is slightly higher than did not strengthen the biochemical system,but the effect is not obvious,This may be due to the high efficiency denitrifying phosphorus accumulating bacteria can not adapt to SBR system conditions,resulting in only a small number of strains survived,the impact factors of biofortification post-treatment efficiency remain to be studied.