title: Electricity assisted anaerobic treatment of salinity wastewater and its effects on microbial communities.
abstract: High salinity wastewater is often difficult to treat using common anaerobic technologies. Considering that high conductivity of salinity wastewater may enhance electrodes reaction to accelerate the decomposition of volatile fatty acids produced in anaerobic digestion, a pair of electrodes was packed into an anaerobic reactor (R1) with the aim to enhance the treatment of salinity wastewater. With increasing the salt concentration (NaCl) gradually from 0 to 50 g/L in 137 days' operation, COD removal in this reactor under the voltage for the electrodes of 1.2 V was well maintained at 93%, while the COD removal in a reference anaerobic reactor without electrodes (R2) decreased to 53%. When the voltage for R1 was cut off, about 10% COD removal was declined, which was still 30 percentage points higher than that in R2. The electrodes enhanced the biodegradation of volatile fatty acids, especially propionate. Fluorescence in situ hybridization analysis confirmed that the relative abundance of propionate-utilizing bacteria in R1 was significantly higher than that in R2. PCR-DGGE analysis of bacteria and archaea domains indicated that the electric field stimulation effectively enriched salt-adapted microorganisms during the treatment.
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, No. 794, Huanghe Road, Dalian 116024, China.
authors.forename: Jingxin
authors.initials: J
authors.lastname: Zhang
authors.forename: Yaobin
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xie
authors.initials: X
authors.lastname: Quan
mesh_terms: D000693:Anaerobiosis; D001105:Archaea / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology*; D004553:Electric Conductivity; D004558:Electric Stimulation; D004560:Electricity; D004566:Electrodes; D004867:Equipment Design; D005232:Fatty Acids, Volatile / Q000737:chemistry / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D017404:In Situ Hybridization, Fluorescence; D011422:Propionates / Q000378:metabolism; D054712:Salinity; D012722:Sewage / Q000382:microbiology*; D012965:Sodium Chloride; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*
chemical_list: D005232:Fatty Acids, Volatile; D011422:Propionates; D012722:Sewage; D012965:Sodium Chloride