Partial nitrification in a sequencing batch reactor treating acrylic fiber wastewater.
A sequencing batch reactor was employed to treat the acrylic fiber wastewater. The dissolved oxygen and mixed liquor suspended solids were 2-3 and 3,500-4,000 mg/L, respectively. The results showed ammonium oxidizing bacteria (AOB) had superior growth rate at high temperature than nitrite oxidizing bacteria (NOB). Partial nitrification could be obtained with the temperature of 28 °C. When the pH value was 8.5, the nitrite-N accumulation efficiency was 82 %. The combined inhibitions of high pH and free ammonium to NOB devoted to the nitrite-N buildup. Hydraulic retention time (HRT) was a key factor in partial nitrification control, and the optimal HRT was 20 h for nitrite-N buildup in acrylic fiber wastewater treatment. The ammonium oxidation was almost complete and the transformation from nitrite to nitrate could be avoided. AOB and NOB accounted for 2.9 and 4.7 %, respectively, corresponding to the pH of 7.0. When the pH was 8.5, they were 6.7 and 0.9 %, respectively. AOB dominated nitrifying bacteria, and NOB was actually washed out from the system.
School of Chemical and Environmental Engineering, Qingdao University, Qingdao, People's Republic of China. ljin0532@126.com
Jin
J
Li
Deshuang
D
Yu
Peiyu
P
Zhang
D001483:Base Sequence; D001673:Biodegradation, Environmental; D019149:Bioreactors; D017931:DNA Primers; D006863:Hydrogen-Ion Concentration; D017404:In Situ Hybridization, Fluorescence; D058465:Nitrification; D013696:Temperature; D062065:Wastewater
D017931:DNA Primers; D062065:Wastewater