TY - JOUR
T1 - Inhibitory effects of a shock load of Fe(II)-mediated persulfate oxidation on waste activated sludge anaerobic digestion
AU - Zhen, Guangyin
AU - Lu, Xueqin
AU - Niu, Jing
AU - Su, Lianghu
AU - Chai, Xiaoli
AU - Zhao, Youcai
AU - Li, Yu You
AU - Song, Yu
AU - Niu, Dongjie
N1 - Funding Information:
The authors wish to thank Science and Technology Commission of Shanghai Municipality (Nos. 08 DZ 1202802 and 09 DZ 1204105 ), National Natural Science Foundation of China (No. 51278350 ), China Scholarship Council (CSC) and Fundamental Research Funds for the Central Universities (No. 0400219152 ) for the partial support of this study.
PY - 2013
Y1 - 2013
N2 - The activated sludge process of wastewater leads to the production of a substantial amount of excess activated sludge. The increasing interest of Fe(II)-mediated persulfate (S2O82-) oxidation in improving sludge dewatering highlights a need to understand their environmental impacts on subsequent treatment, but the potential effects on sludge anaerobic digestion remains unknown. In this study, the response of waste activated sludge anaerobic digestion to a shock load of Fe(II)/S2O82- oxidation were investigated. It was observed that total suspended solids (TSS) and volatile suspended solids (VSS) removals were considerably lowered when Fe(II) and S2O82- dosages were greater than 0.8 and 1.0mmol/g VSS, respectively, while 34.6-60.5% drop in hydrogen sulfide (H2S) took place. Degradation of extracellular polymeric substances (EPS) of sludge induced by Fe(II)/S2O82- oxidation resulted in their deteriorating protective role on the microorganisms, which may cause the inhibitory effects on the microbial activity, and subsequently reduce digestion efficiency and H2S generation. Then, sludge dewaterability during digestion process was investigated. It was found that dewaterability of sludge, firstly improved by Fe(II)S2O82- pretreatment, was gradually worsened during subsequent digestion because of slightly increased EPS. The visualization of EPS with three-dimensional excitation-emission matrix (3D-EEM) fluorescence spectroscopy further revealed that the discernable rise in tyrosine and tryptophan protein-like substances together contributed to poorer dewaterability.
AB - The activated sludge process of wastewater leads to the production of a substantial amount of excess activated sludge. The increasing interest of Fe(II)-mediated persulfate (S2O82-) oxidation in improving sludge dewatering highlights a need to understand their environmental impacts on subsequent treatment, but the potential effects on sludge anaerobic digestion remains unknown. In this study, the response of waste activated sludge anaerobic digestion to a shock load of Fe(II)/S2O82- oxidation were investigated. It was observed that total suspended solids (TSS) and volatile suspended solids (VSS) removals were considerably lowered when Fe(II) and S2O82- dosages were greater than 0.8 and 1.0mmol/g VSS, respectively, while 34.6-60.5% drop in hydrogen sulfide (H2S) took place. Degradation of extracellular polymeric substances (EPS) of sludge induced by Fe(II)/S2O82- oxidation resulted in their deteriorating protective role on the microorganisms, which may cause the inhibitory effects on the microbial activity, and subsequently reduce digestion efficiency and H2S generation. Then, sludge dewaterability during digestion process was investigated. It was found that dewaterability of sludge, firstly improved by Fe(II)S2O82- pretreatment, was gradually worsened during subsequent digestion because of slightly increased EPS. The visualization of EPS with three-dimensional excitation-emission matrix (3D-EEM) fluorescence spectroscopy further revealed that the discernable rise in tyrosine and tryptophan protein-like substances together contributed to poorer dewaterability.
KW - Anaerobic digestion
KW - Dewaterability
KW - Extracellular polymeric substances (EPS)
KW - Fe(II)-mediated persulfate (S2O82-) oxidation
KW - Waste activated sludge
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U2 - 10.1016/j.cej.2013.08.038
DO - 10.1016/j.cej.2013.08.038
M3 - Article
AN - SCOPUS:84883751982
SN - 1385-8947
VL - 233
SP - 274
EP - 281
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
ER -