[Nitrogen removal by enhanced endogenous denitrification with excess activated sludge reduction technology].
In order to increase the efficiency of nitrogen removal by endogenous denitrification, and to realize the excess activated sludge reduction in the traditional wastewater treatment process, this investigation proposes a hydrolysis/anoxic/oxic (H/A/O) process utilizing nitrogen removal with excess activated sludge reduction. The experimental equipment for continuous treatment of domestic wastewater was set up and the pilot experiment was conducted. The results showed that, without adding external carbon sources and alkalinity, the removal efficiency of COD, NH4+-N and TN were higher than 90%, 95% and 75%, respectively, under the condition that the hydraulic retention time was 10 h and the backflow ratio of nitrification liquor was 300%, the COD of influent between 220-410 mg/L, the NH4+-N of influent between 36-58 mg/L. When the carbon source was not the limiting condition of the denitrification, with the increasing of the return nitrification liquor, the nitrogen removal efficiency increased. On the contrary, with the increasing of the return nitrification liquor, the nitrogen removal efficiency decreased. It has been tested that the reduction rate of excess activated sludge in the system reached 56.2%. The nitrogen removal efficiency was improved greatly by the wastewater and excess activated sludge hydrolysis. It's proved that using hydrolysis as pre-treatment of wastewater and excess activated sludge is feasible, thas it not only improved the biodegaradability of wastewater and the nutrient removal efficiency, but also enhanced the stability for the operation of the wastewater treatment system, and then the wastewater and excess activated sludge were treatment simultaneously.
Wang
Jian-Long
JL
School of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100022, China. wjl-xt@163.com
Peng
Yong-Zhen
YZ
Gao
Yong-Qing
YQ
Wang
Shu-Ying
SY
Gao
Chun-Di
CD
D000641:Ammonia / Q000737:chemistry; D019149:Bioreactors; D009573:Nitrites / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry* / Q000302:isolation & purification; D015203:Reproducibility of Results; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*
D009573:Nitrites; D012722:Sewage; D000641:Ammonia; D009584:Nitrogen