TY - JOUR
T1 - Intimately coupling of photolysis accelerates nitrobenzene biodegradation, but sequential coupling slows biodegradation
AU - Yang, Lihui
AU - Zhang, Yongming
AU - Bai, Qi
AU - Yan, Ning
AU - Xu, Hua
AU - Rittmann, Bruce
N1 - Funding Information:
The authors acknowledge the financial support of the National Natural Science Foundation of China ( 50978164 ), Key project of basic research in Shanghai ( 11JC1409100 ), the Special Foundation of Chinese Colleges and Universities Doctoral Discipline ( 20113127110002 ), Special Fund of State Key Joint Laboratory of Environment Simulation and Pollution Control ( 13K09ESPCT ), and the United States National Science Foundation ( 0651794 ).
Publisher Copyright:
© 2015 Elsevier B.V.
PY - 2015/4/8
Y1 - 2015/4/8
N2 - Photo(cata)lysis coupled with biodegradation is superior to photo(cata)lysis or biodegradation alone for removal of recalcitrant organic compounds. The two steps can be carried out sequentially or simultaneously via intimate coupling. We studied nitrobenzene (NB) removal and mineralization to evaluate why intimate coupling of photolysis with biodegradation was superior to sequential coupling. Employing an internal circulation baffled biofilm reactor, we compared direct biodegradation (B), biodegradation after photolysis (P. +. B), simultaneous photolysis and biodegradation (P&B), and biodegradation with nitrophenol (NP) and oxalic acid (OA) added individually and simultaneously (B. +. NP, B. +. OA, and B. +. NP. +. OA); NP and OA were NB's main UV-photolysis products. Compared with B, the biodegradation rate P. +. B was lower by 13-29%, but intimately coupling (P&B) had a removal rate that was 10-13% higher; mineralization showed similar trends. B. +. OA gave results similar to P&B, B. +. NP gave results similar to P. +. B, and B. +. OA. +. NP gave results between P. +. B and P&B, depending on the amount of OA and NP added. The photolysis product OA accelerated NB biodegradation through a co-substrate effect, but NP was inhibitory. Although decreasing the UV photolysis time could minimize the inhibition impact of NP in P. +. B, P&B gave the fastest removal of NB by accentuating the co-substrate effect of OA.
AB - Photo(cata)lysis coupled with biodegradation is superior to photo(cata)lysis or biodegradation alone for removal of recalcitrant organic compounds. The two steps can be carried out sequentially or simultaneously via intimate coupling. We studied nitrobenzene (NB) removal and mineralization to evaluate why intimate coupling of photolysis with biodegradation was superior to sequential coupling. Employing an internal circulation baffled biofilm reactor, we compared direct biodegradation (B), biodegradation after photolysis (P. +. B), simultaneous photolysis and biodegradation (P&B), and biodegradation with nitrophenol (NP) and oxalic acid (OA) added individually and simultaneously (B. +. NP, B. +. OA, and B. +. NP. +. OA); NP and OA were NB's main UV-photolysis products. Compared with B, the biodegradation rate P. +. B was lower by 13-29%, but intimately coupling (P&B) had a removal rate that was 10-13% higher; mineralization showed similar trends. B. +. OA gave results similar to P&B, B. +. NP gave results similar to P. +. B, and B. +. OA. +. NP gave results between P. +. B and P&B, depending on the amount of OA and NP added. The photolysis product OA accelerated NB biodegradation through a co-substrate effect, but NP was inhibitory. Although decreasing the UV photolysis time could minimize the inhibition impact of NP in P. +. B, P&B gave the fastest removal of NB by accentuating the co-substrate effect of OA.
KW - Biodegradation
KW - Co-substrate
KW - Intimate coupling
KW - Nitrobenzene
KW - Photolysis
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U2 - 10.1016/j.jhazmat.2015.01.055
DO - 10.1016/j.jhazmat.2015.01.055
M3 - Article
C2 - 25661172
AN - SCOPUS:84922254693
SN - 0304-3894
VL - 287
SP - 252
EP - 258
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
ER -