Improvement of methane production from waste activated sludge by on-site photocatalytic pretreatment in a photocatalytic anaerobic fermenter.
This paper reports a new technology that using on-site TiO2-photocatalytic pretreatment in the anaerobic digestion of waste activated sludge (WAS) can enhance WAS degradation and methane production in a novel photocatalytic anaerobic fermenter. The fermenter consists of a photocatalytic unit and a digestion unit. The photocatalytic unit can constantly supply soluble organics and has less negative effect on the activity of methanogens at the optimal photocatalytic time of 4h per day. After anaerobic digestion for 35days, 1266.7ml/l-sludge of methane, 67.4% of volatile solid (VS) reduction and 60.5% of total chemical oxygen demand (TCOD) removal were achieved in the photocatalytic anaerobic fermenter, compared with 923.2ml/l-sludge of methane, 48.9% of VS reduction and 43.5% TCOD removal in the control fermenter. The results indicate that timely utilization of solubilized organics by methanogens could avoid further mineralization by TiO2-photocatalysis, which not only improves methane production but also enhances WAS degradation.
Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
Chunguang
C
Liu
Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
Wansheng
W
Shi
Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
Huifang
H
Li
Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
Zhongfang
Z
Lei
Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
Leilei
L
He
Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan. Electronic address: zhang.zhenya.fu@u.tsukuba.ac.jp.
Zhenya
Z
Zhang
D001421:Bacteria, Anaerobic / Q000378:metabolism*; D057919:Biological Oxygen Demand Analysis; D002384:Catalysis; D005285:Fermentation; D008697:Methane / Q000096:biosynthesis*; D008956:Models, Chemical; D055668:Photochemical Processes; D012722:Sewage / Q000382:microbiology*; D014025:Titanium / Q000378:metabolism*; D014865:Waste Disposal, Fluid / Q000379:methods*
D012722:Sewage; C009495:titanium dioxide; D014025:Titanium; D008697:Methane
Activated sludge; Anaerobic fermenter; Methane fermentation; On-site pretreatment; TiO(2) photocatalysis