Simultaneous removal of COD and ammonium from landfill leachate using an anaerobic-aerobic moving-bed biofilm reactor system.
The performance of a moving-bed biofilm reactor (MBBR) system with an anaerobic-aerobic arrangement was investigated to treat landfill leachate for simultaneous removal of COD and ammonium. It was found that the anaerobic MBBR played a major role in COD removal due to methanogenesis, and the aerobic MBBR acted as COD-polishing and ammonium removal step. The contribution of the anaerobic MBBR to total COD removal efficiency reached 91% at an organic loading rate (OLR) of 4.08 kgCOD/(m3d), and gradually decreased to 86% when feed OLR was increased to 15.70 kgCOD/(m3d). Because of the complementary function of the aerobic reactor, the total COD removal efficiency of the system had a slight decrease from 94% to 92% even though the feed OLR was increased from 4.08 to 15.70 kgCOD/(m3d). Hydraulic retention time (HRT) had a significant effect on NH+4-N removal; more than 97% of the total NH+4-N removal efficiency could be achieved when the HRT of the aerobic MBBR was more than 1.25 days. The anaerobic-aerobic system had a strong tolerance to shock loading. A decrease in COD removal efficiency of only 7% was observed when the OLR was increased by four times and shock duration was 24 h, and the system could recover the original removal efficiency in 3 days. The average sludge yield of the anaerobic reactor was estimated to be 0.0538 gVSS/gCOD rem.
Chen
Sheng
S
School of Municipal and Environmental Engineering, 2nd Campus, Harbin Institute of Technology, No. 202, Haihe Road, Harbin 150090, China. hitchensheng@126.com
Sun
Dezhi
D
Chung
Jong-Shik
JS
D000332:Aerobiosis; D000693:Anaerobiosis; D019149:Bioreactors; D002244:Carbon / Q000737:chemistry; D003077:Coke; D049329:Nanostructures / Q000737:chemistry; D020959:Polyethylene / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*; D012037:Refuse Disposal; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D017641:Zeolites / Q000737:chemistry
D003077:Coke; D000644:Quaternary Ammonium Compounds; D014874:Water Pollutants, Chemical; D017641:Zeolites; D002244:Carbon; D020959:Polyethylene