Screening And Characteristics Of Marine Polyphosphate Accumulating Organisms For Phosphorus Removal

Eutrophication mainly caused by the disposal of nutrients (N and P) is becoming one of worldwide environmental problems.Phosphorus removal is of great significance to avoid eutrophication. Nowadays using seawater can effectively ease water shortage crisis in coastal areas. but the following problem is that, the entery of seawater into the sewage treatment system can deteriorate the phosphorus removal ability because of high salinity.Use of salt-resistant microorganisms is an efficitive solution and it is necessary to screen marine phosphorus accumulating bacteria aimed to treating domestic sewage mixed with seawater.One strain with high phosphorus removal efficiency was screened from Jiaozhou Bay sediment by the qualitative and quantitative method of blue-white spot and phosphorus removal efficiency determination, this screened strain was entitled as Pseudoalteromonas sp.A3-10.Effects of factors including phosphorus concentration,salinity, initial pH, temperature and dissolved oxygen on the growth and phosphorus removal were studied by the shake-flask test method.Total phosphorus removal efficiency was achieved upper96%after24hours culturing,the phosphorus concentration of iffluent was10mg/L while the phosphorus content ratio in the body was high as12.46%(dry weight). The phosphorus removal efficiency was kept upper90%in treating synthetic wastewater with phosphorus concentration range from5to15mg/L. The salinity tolerance of strain ranged from0to100g/L, the optimum salinity for phosphorus removal and growth was30g/L, the phosphorus removal efficiency and growth were very low when the salinity higher than100g/L. The phosphorus removal efficiency was achieved upper80%with the temperature range from10to35℃, the optimum temperature was15℃with the phosphorus removal efficiency of96%.Phosphorus removal and growth were stagnated when lower than10℃.the strain can grow under the initial pH ranged from4.0to10.0.the phosphorus removal efficiency of upper95%peaked at pH7.0and high phosphorus removal efficiency was achieved even without anaerobic section that was different from the traditional phosphorus theory.Bioaugmentation with strain Pseudoalteromonas.A3-10was applied to accelerate the start-up of SBR with single-oxic stage process.and the influence of bioaugmentation was also investigated without anaerobic section. The phosphorus removal efficiency of reactor R1with Pseudoalteromonas sp.A3-10addition was achieved upper90%, improved by20%than R2without screened strain addition.Bioaugmentation of Pseudoalteromonas sp. A3-10is feasible that can shorten the startup of sewage phosphorus removal with salinity of10g/L.The sludge phosphorus components of reactor was analysed by SMT protocol and the results were that phosphorus components of reactor R1and R2sludge was mainly inorganic phosphorus (IP), with the proportion of total phosphorus (TP)71.93%,70.99%respectively; Organophosphate (OP) content was low, just34.53%,26.19%; And apatite inorganic phosphorus (NAIP) was the main form in inorganic phosphorus, with the proportion of44.55%,44.81%in the IP respectively. The sludge showed high potential of biological utilizability and phosphorus recovery.