Effects of nitrobenzene concentration and hydraulic retention time on the treatment of nitrobenzene in sequential anaerobic baffled reactor (ABR)/continuously stirred tank reactor (CSTR) system.
The effects of increasing nitrobenzene (NB) concentrations and hydraulic retention times (HRT) on the treatment of NB were investigated in a sequential anaerobic baffled reactor (ABR)/aerobic completely stirred tank reactor (CSTR) system. In the first step of the study, the maximum COD removal efficiencies were found as 88% and 92% at NB concentrations varying between 30 mg L(-1) and 210 mg L(-1) in ABR. The minimum COD removal efficiency was 79% at a NB concentration of 700 mg L(-1). The removal efficiency of NB was nearly 100% for all NB concentrations in the ABR reactor. The methane gas production and the methane gas percentage remained stable (1500 mL day(-1) and 48-50%, respectively) as the NB concentration was increased from 30 to 210 mg L(-1). In the second step of the study it was found that as the HRT decreased from 10.38 days to 2.5 days the COD removal efficiencies decreased slightly from 94% to 92% in the ABR. For maximum COD and NB removal efficiencies the optimum HRT was found as 2.5 days in the ABR. The total COD removal efficiency was 95% in sequential anaerobic (ABR)/aerobic (CSTR) reactor system at a minimum HRT of 1 day. When the HRT was decreased from 10.38 days to 1 day, the methane percentage decreased from 42% to 29% in an ABR reactor treating 100 mg L(-1) NB. Nitrobenzene was reduced to aniline under anaerobic conditions while aniline was mineralized to catechol with meta cleavage under aerobic conditions.
Kuscu
Ozlem Selcuk
OS
Department of Environmental Engineering, Engineering and Architecture Faculty, Süleyman Demirel University, Isparta, Turkey.
Sponza
Delia Teresa
DT
D000693:Anaerobiosis / Q000187:drug effects; D000814:Aniline Compounds / Q000302:isolation & purification; D001673:Biodegradation, Environmental / Q000187:drug effects; D019149:Bioreactors; D005740:Gases; D008697:Methane / Q000378:metabolism; D009578:Nitrobenzenes / Q000302:isolation & purification* / Q000494:pharmacology*; D010084:Oxidation-Reduction / Q000187:drug effects; D010100:Oxygen / Q000302:isolation & purification; D013997:Time Factors
D000814:Aniline Compounds; D005740:Gases; D009578:Nitrobenzenes; C036077:nitrobenzene; D008697:Methane; D010100:Oxygen; C023650:aniline