Study On Growth Characteristics And Phosphate Accumulating Performance Of PAOX

The key factor caused eutrophication is phosphorus, phosphorus removal is the key to control eutrophication. And, biological dephosphorization is the most effective and economical technology.The core of biological dephosphorization is phosphate-accumulating organism. So,it is very significant and valuable to develop out efficient phosphate-accumulating organism and understand their growth characteristics for improving the effect of biological dephosphorization. The objective of this study is to afford the basis of theory and Support of technology for the application of phosphate-accumulating organism on biological dephosphorization process. Work introduced mainly: phosphate-accumulating organisms domestication ,isolation and purification, screening and identifying, growth and dephosphorization characteristics. Meanwhile ,I verified its effect of phosphorus removal in simulation SBR device.A efficient phosphate-accumulating organism was domesticated ,isolated and screened from wastewater and soil polluted by phosphorus,it was named PAOX. In terms of its physiological and biochemical testing and 16SrDNA analysis, PAOX belonged to genus Klebsiella. In order to understand the growth and dephosphorization characteristics,the PAOX was pure cultured in aerobic synthetic wastewater. The result showed, the growth and the dephosphorization effect of PAOX is the highest when the time was 32 hours, the initial pH was 7.0, the temperature was 29℃, the volume of liquid was 50ml and the volume of inoculation was 2%.And its dephosphorization rate reached 83%.Dyeing poly-P and PHB at the end of anaerobic stage and aerobic stage when PAOX was continuously cultured in simulation SBR device. Meanwhile, monitoring the concentration of phosphorus in solution in various time slots.The result of Dyeing showed the poly-P at the end of aerobic stage was more than anaerobic stage, but the PHB was just the opposite. PAOX had the characteristics of a typical phosphate-accumulating organism. Concentration of phosphorus in solution was 38mgL-1 at the end of anaerobic stage and 1.4mgL-1 at the end of subsequent aerobic stage.PAOX showed the characteristics of a typical phosphate-accumulating organism as it displayed apparent phosphorus accumulation and release. Futhermore, PAOX had a higher rate of phosphate removal in a simulation SBR device than aerobic pure culture.