| The eutrophication of water environment is recognized as "water cancer" in the world, which attracts much attention of scholars. This paper took a strain of Rhodophseudomonas palustris as the main object, studied its basic rules of assimilating to nitrogen and phosphorus in the culture medium of different concentrations, different xenobiotics and natural water condition. Also, the reasonable medium of photosynthetic bacteria is optimized. Specific results were as follows:It had a high amount of nitrogen and phosphorus assimilation in a high concentration of water. After 6 days of adding the photosynthetic bacteria into the medium, the final residue of TN and TP contents reached 245.23mg/L and 382.05mg/L when the initial concentration of TN,TP in the medium were 314.04mg/L,402.73mg/L. In addition, corresponding to the amount of nitrogen and phosphorus assimilation was 68.81mg/L,20.68mg/L; It had the highest rates of nitrogen and phosphorus assimilation in a middle concentration of water. After 2 days of adding the photosynthetic bacteria into the medium, its assimilation rate of nitrogen and phosphorus was respectively 65.23% and 10.22% when the concentration of TN,TP were llmg/L and 22.71mg/L in the medium; Photosynthetic bacteria had a reduction of efficiency of nitrogen assimilation in a low concentration of water, and assimilation also decreased. When the concentration of TN was in a range of 3.5 to 6.5mg/L in the medium, the residual one of TN can be reduced to 2.6-2.8mg/L. It was basically the same amount of phosphorus assimilation in 0.5mg/L when the concentration of TP was 4-10mg/L.It had a promoting efficiency of growth and nitrogen, phosphorus assimilation of photosynthetic bacteria after adding amount of FeCl3 and MgSO4-7H2O. The nitrogen assimilation of photosynthetic bacteria rate was 26.75% when the concentration of FeCl3 was 0.015g/L, higher than the control group. TN assimilation increased 30.01mg/L compared with the control one. The maximum assimilation rate of TN,TP could reach 22.39% and 6.66%, which increased by 5.38% and 4.65% compared with the control group when MgSO4·7H2O was 5mg/L;Different concentrations of GA could significantly increase the efficiency of assimilation of TN of photosynthetic bacterial. When the concentration of GA was 0.5mg/L, nitrogen assimilation rate of photosynthetic bacteria was 23.92%, which increased 9.04% compared with the control group; When Rhodophseudomonas palustris and Rhodopseudomonas faecalis mixed with a ratio of 1:0.25, its highest rate of nitrogen assimilation was 81.84%, which increased by 19.89% compared with the control group.Through investment in natural water sprinkling of photosynthetic bacteria, the concentration of 105CFU/mL in the water analysis found that photosynthetic bacteria can reduce the natural water bodies of the NH4-N, SOP, and the concentration of TN, especially for the SOP which has the strongest assimilation, assimilation rate of 89.94%.The results showed that KH2PO4 was the most significant factor affecting the efficiency of nitrogen assimilation by single factor and orthogonal experimental. To ensure of the fermentation of biomass, medium optimization palustris formula:NaCl 2.0g NH4Cl 0.05g yeast extract 1.0g MgSO4·7H2O 0.2g CH3COONa·3H2O 3.0g NaHCO3 2.0g KH2PO4 1.40g H2O 1000mL. The medium can significantly increase efficiency of nitrogen and phosphorus of the photosynthetic bacteria and reduce nitrogen and phosphorus content of the residual medium. |
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