Low strength wastewater treatment under low temperature conditions by a novel sulfur redox action process.
The objective of this research is to make a novel wastewater treatment process activated by a sulfur-redox cycle action of microbes in low temperature conditions. This action is carried out by sulfate-reducing bacteria (SRB) and sulfur-oxidizing bacteria (SOB). The process was comprised of a UASB reactor as pre-treatment and an aerobic downflow hanging sponge (DHS) reactor as post-treatment. As the results of reactor operation, the whole process achieved that over 90% of CODcr removal efficiency, less than 30 mgCODcr/L (less than 15 mgBOD/L) of final effluent, at 12 h of HRT and at 8 degrees C of UASB reactor temperature. Acetobacterium sp. was detected as the predominant species by PCR-DGGE method targeting 16SrDNA with band excision and sequence analysis. In the UASB reactor, various species of sulfate-reducing bacterium, Desulfobulbus sp., Desulfovibrio sp., and Desulfomicrobium sp., were found by cloning analysis. In the DHS reactor, Tetracoccus sp. presented as dominant. The proposed sulfur-redox action process was considered as an applicable process for low strength wastewater treatment in low temperature conditions.
Yamaguchi
T
T
Dept. of Civil Engineering, Kure College of Technology, 2-2-11, Aga-minami, Kure, Hiroshima, Japan. yamaguti@kure-nct.ac.jp
Bungo
Y
Y
Takahashi
M
M
Sumino
H
H
Nagano
A
A
Araki
N
N
Imai
T
T
Yamazaki
S
S
Harada
H
H
D019149:Bioreactors; D003080:Cold Temperature; D003901:Desulfovibrio / Q000235:genetics; D010084:Oxidation-Reduction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012722:Sewage; D013455:Sulfur / Q000737:chemistry*; D016999:Sulfur-Reducing Bacteria / Q000235:genetics* / Q000378:metabolism; D013696:Temperature; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods*
D012336:RNA, Ribosomal, 16S; D012722:Sewage; D013455:Sulfur