Study On Screening Phosphorus-Accumulating Bacteria And Effction On Removing Phosphorus In Eutrophic Water

In recent years, the lake waters emerging eutrophication. The limiting factor caused eutrophication is phosphorus,phosphorus removal is the key to control eutrophication. And, compared with adsorptive dephosphorization and chemical precipition, bicological dephosphorization is the most effective technology. The core of biological dephosphorization is phosphate-accumulating organism. The objective of this study is to afford the basis of theory for controlling eutrophication in GuanZhen river of CaoHu lake. Mainly work inclued: phosphate-accumulating organisms isolation, purification, sceening and identifying, growth ang dephosphorization characteristics. Meanwhile, I verified its effect of phosphorus removal in natural water.Two efficient phosphate-accumulating organisms were domesticated, isolated and screened from soil polluted by phosphorus. They were named strain 33 and strain 35. Tn terms of its physiological and biochemical testing and 16SrDNA analysis, strain 33 was pseudomonas syringae, belonged to pseudonas; strain 35 was pseudomonas, belonged to pseudonas. In order to understand the growth characteristics.organisms were pure cultured in aerobic syntheic medium. The result showed:the growth time of strain 33 was 24h, the inital pH was 5-9; the growth time of strain 35 was 24h, the inital pH was 5-8.Using orthogonal experiment to study TP、pH、temperature on PAOs effect in this article. The result showed that the optimal phosphorus conditions of strain 33 are TP 2.0mg/l, pH 9.0, temperature is 15℃, the phosphorus removal rate of the strain 33 was 64.68%; and 35 are TP 2.0mg/l, pH 5.0, temperature is 15℃, tthe phosphorus removal rate of the strain 35 was 80.43%.In order to study the distribution of phosphorus in strains, analysis of the intracellular and extracellular strains phosphorus content. The TP in intracellular content is 82.15% of the total biological and TP in EPS content in bicological phosphorus removal accounted for 3.69%; TP intracellular content within strain 35 accounted for 72.12% of the total biological phosphorus removal, EPS TP content in biological phosphorus removal accounted for 5.53% of the total.Investigated strains 33 and 35 to apply to natural water, the results showed that their phosphorus removal rate were not high and were instabilitive on effection. This may be related the growth and reproduction and physiological activity of strains in natural water, the need for further study of its applicability in natural water.