In order to investigate the competition for carbon source between denitrification and phosphorus release processes,simultaneous phosphorus release and denitrification in sludge operated in anoxic,aerobic mode are inve...In order to investigate the competition for carbon source between denitrification and phosphorus release processes,simultaneous phosphorus release and denitrification in sludge operated in anoxic,aerobic mode are investigated by varying the ratio of influent COD to nitrogenous compound concentration under anoxic condition using a lab-scale sequencing batch reactor（SBR）.The results show that the nitrate reduction rate is nearly independent of the ratio of influent COD to nitrate under anoxic condition.More NOx^--N in the influent leads to less PO4^3--P release during the feeding period.However, PO4^3--P release proceeds at a low rate simultaneously with denitrification even when the influent NOx^--N concentration is as large as 20 mg·L^-1and its rate is increased obviously when NOx^--N is denitrified to a concentration lower than 0.5 mg·L^-1.The variation of pH during anoxic period gives some information about the biochemical reactions of denitrification and PO4^3--P release.When more nitrate is present in the influent,more acetate uptake in feeding period is used for direct microorganism growth.展开更多
A novel modified pilot scale anaerobic oxidation ditch with additional internal anoxic zones was operated experimentally, aiming to study the improvement of biological nitrogen and phosphorus removal and the effect of...A novel modified pilot scale anaerobic oxidation ditch with additional internal anoxic zones was operated experimentally, aiming to study the improvement of biological nitrogen and phosphorus removal and the effect of enhanced denitrifying phosphorus removal in the process. Under all experimental conditions, the anaero- bic-oxidation ditch with additional internal anoxic zones and an internal recycle ratio of 200% had the highest nutrient removal efficiency. The effluent NH4 -N, total nitrogen （TN）, PO3 -P and total phosphorus （TP） contents were 1.2 mg.L-1, 13 mg.L 1, 0.3 mg.L -1 and 0.4 mg.L-1, respectively, all met the discharge standards in China. The TN and TP removal efficiencies were remarkably improved from 37% and 50% to 65% and 88% with the presence of additional internal anoxic zones and internal recycle ratio of 200%. The results indicated that additional internal anoxic zones can optimize the utilization of available carbon source from the anaerobic outflow for denitrification. It was also found that phosphorus removal via the denitrification process was stimulated in the additional internal anoxic zones, which was beneficial for biological nitrogen and phosphorus removal when treating wastewater with a limited carbon source. However, an excess internal recycle would cause nitrite to accumulate in the system. This seems to be harmful to biological phosphorus removal.展开更多
In order to enhance efficiency of the nitrogen and phosphorus removal of sewage treatment plant, Taking Wu Long kou sewage treatment plant project in Zhengzhou as an example, this article introduces the structure, the...In order to enhance efficiency of the nitrogen and phosphorus removal of sewage treatment plant, Taking Wu Long kou sewage treatment plant project in Zhengzhou as an example, this article introduces the structure, the working principle, the craft character, as well as the problems existed in the practical application of the improved oxidation ditch, and raises some corresponding processing countermeasures. Looked from the running situation of Wu Long kou sewage treatment plant, the improved oxidation ditch have certain advantages in city sewage treatment, such as high organic removing efficiency, good removing effect of nitrogen and phosphorus, low investing expenses and operating cost and so on. It is a craft that is worth promoting in urban sewage treatment.展开更多
基金Supported by the Scientific Innovation Platform of Beijing Municipal Education Commission(PXM2008_014204_050843)State Key Laboratory of Urban Water Resource and Environment(HIT)(QAK200802)Environment and Water Industry(EWI)Development Scheme of Singapore-The Process Control and Enhanced Biological Nutrient Removal of CSTR Proc-ess(EDB S07/1-53974082)
文摘In order to investigate the competition for carbon source between denitrification and phosphorus release processes,simultaneous phosphorus release and denitrification in sludge operated in anoxic,aerobic mode are investigated by varying the ratio of influent COD to nitrogenous compound concentration under anoxic condition using a lab-scale sequencing batch reactor（SBR）.The results show that the nitrate reduction rate is nearly independent of the ratio of influent COD to nitrate under anoxic condition.More NOx^--N in the influent leads to less PO4^3--P release during the feeding period.However, PO4^3--P release proceeds at a low rate simultaneously with denitrification even when the influent NOx^--N concentration is as large as 20 mg·L^-1and its rate is increased obviously when NOx^--N is denitrified to a concentration lower than 0.5 mg·L^-1.The variation of pH during anoxic period gives some information about the biochemical reactions of denitrification and PO4^3--P release.When more nitrate is present in the influent,more acetate uptake in feeding period is used for direct microorganism growth.
基金Supported by Major Science and Technology Program for Water Pollution Control and Treatment(2008ZX07316)
文摘A novel modified pilot scale anaerobic oxidation ditch with additional internal anoxic zones was operated experimentally, aiming to study the improvement of biological nitrogen and phosphorus removal and the effect of enhanced denitrifying phosphorus removal in the process. Under all experimental conditions, the anaero- bic-oxidation ditch with additional internal anoxic zones and an internal recycle ratio of 200% had the highest nutrient removal efficiency. The effluent NH4 -N, total nitrogen （TN）, PO3 -P and total phosphorus （TP） contents were 1.2 mg.L-1, 13 mg.L 1, 0.3 mg.L -1 and 0.4 mg.L-1, respectively, all met the discharge standards in China. The TN and TP removal efficiencies were remarkably improved from 37% and 50% to 65% and 88% with the presence of additional internal anoxic zones and internal recycle ratio of 200%. The results indicated that additional internal anoxic zones can optimize the utilization of available carbon source from the anaerobic outflow for denitrification. It was also found that phosphorus removal via the denitrification process was stimulated in the additional internal anoxic zones, which was beneficial for biological nitrogen and phosphorus removal when treating wastewater with a limited carbon source. However, an excess internal recycle would cause nitrite to accumulate in the system. This seems to be harmful to biological phosphorus removal.
文摘In order to enhance efficiency of the nitrogen and phosphorus removal of sewage treatment plant, Taking Wu Long kou sewage treatment plant project in Zhengzhou as an example, this article introduces the structure, the working principle, the craft character, as well as the problems existed in the practical application of the improved oxidation ditch, and raises some corresponding processing countermeasures. Looked from the running situation of Wu Long kou sewage treatment plant, the improved oxidation ditch have certain advantages in city sewage treatment, such as high organic removing efficiency, good removing effect of nitrogen and phosphorus, low investing expenses and operating cost and so on. It is a craft that is worth promoting in urban sewage treatment.
