Mineralization Process Of Organic Phosphorus And Influential Factors In Urban Lake Sediment

Mineralization of phosphorus (P) in sediment-water of urban lakes in Beijing was investigated with the physical and chemical properties of water and sediment in Bayi Lake, Kunming Lake, Houhai Lake, Taoranting Lake and Lianhuachi Lake by field monitoring. A case study on simulated experiments of organic phosphorus (OP) mineralizing from sediment at different pH and aerobic/anaerobic conditions was carried out in Bayi Lake.Beijing urban water quality was varying in the same season. The worst water quality appeared in Lianhuachi Lake where total phosphorus (TP) concentration of 0.083 mg/L and Chlorophyll a content was 74.37μg/L in autumn. The concentration of TP in Bayi Lake was 0.035 mg/L that lower than other lakes and the concentration of Chlorophyll a was 11.75μg/L. The water quality status of Bayi Lake in summer was poorer than in spring and autumn, the contents of P in sediments did not show distinct disparity in three seasons.Simulated experiments of phosphorus releasing from sediment at different pH and aerobic/anaerobic conditions showed that the concentrations of TP and Total dissolved phosphorus (TDP) in overlying water were fluctuating with increasing. Where as the percentage of OP in sediments were fluctuating with decreasing. It suggested that releasing of phosphorus in sediment was happened when non-external pollution sources. Percentages of OP in sediment at different pH did not appear disparity and had different trends at different phases in experiment. The adsorption and releasing of P were more active in sediment at anaerobic condition.New methods what extracting and exterminating phytate and nucleic acid (DNA) from sediment had been tried. The method of DNA extracted from sediments was used to analyze the organic phosphorus in nucleic acid form and the result was satisfactory. The methods of extracting and determining phytate were compared and detected the reference material of phytate by HPLC that achieved Chromatogram and Mass spectrogram of phytate.Simulated experiments were set to understand the mineralization process in sediment at different pH and aerobic/anaerobic conditions. The content of DNA-P in sediment was lower when pH near to 7. The variation of DNA-P in sediment was higher at anaerobic condition difference with TP that showed microbial activity promoting mineralization of OP in sediment.