Open AccessNitrifying Treatment of Wastewater from Fertilizer Production in a Three‐Phase Flow Airlift Loop Bioreactor
Author(s) -
Jianping W.,
Lei P.,
Xiaojing X.,
Zhiyong Z.
Publication year - 2003
Publication title -
engineering in life sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.547
H-Index - 57
eISSN - 1618-2863
pISSN - 1618-0240
DOI - 10.1002/elsc.
Subject(s) - airlift , effluent , fertilizer , bioreactor , wastewater , hydraulic retention time , ammonia , environmental engineering , chemistry , residence time (fluid dynamics) , pulp and paper industry , sewage treatment , nitrification , environmental science , nitrogen , geotechnical engineering , organic chemistry , engineering
A 12‐L gas‐liquid‐solid three‐phase flow airlift loop bioreactor, in which biological membranes replace the activated sludge, was used in the nitrifying treatment of a real effluent in a Nanjing chemical fertilizer plant. The influences of temperature, pH, air flow rate and HRT on ammonia nitrogen reduction were investigated and discussed. The optimum operating conditions, such as temperature of 30–35 °C, pH value of 7–8, air influx of 0.3 m 3 /h, and hydraulic residence time (HRT) of 8 hours, were found. Under optimum operating conditions, the average removal efficiencies of COD and NH 4 ‐N are higher than 95 % and 99 %, corresponding to the effluent COD < 50 mg/L and NH 4 ‐N < 5 mg/L, which is far below the primary discharge standard for the chemical fertilizer industry of P.R. China – COD < 150 mg/L and NH 4 ‐N < 60 mg/L (GWPB4–1999). In addition, the radial and axial positions have little influence on the local profiles of COD and NH 4 ‐N.