title: Enhancement of anaerobic acidogenesis by integrating an electrochemical system into an acidogenic reactor: effect of hydraulic retention times (HRT) and role of bacteria and acidophilic methanogenic Archaea.
abstract: In this study, an acidogenic reactor packed with a pair of Fe-carbon electrodes (R1) was developed to enhance anaerobic acidogenesis of organic wastewater at short hydraulic retention times. The results indicated that the acidogenic efficiency was improved by settling a bio-electrochemical system. When hydraulic retention times decreased from 12 to 3h, R1 showed 18.9% more chemical oxygen demand removal and 13.8% more acidification efficiency. After cutting off the voltage of R1, the COD removal decreased by about 5%. Coupling of Fe(2+) leaching and electric field accelerated the hydrolysis of polysaccharide, relieving its accumulation in the sludge phase. Several acidophilic methanogenic Archaea such as Methanosarcina sp. were enriched in R1, which was favorable for consuming organic acids and preventing excessive pH decline. Thus, the developed acidogenic reactor with Fe-carbon electrodes is expected to be potentially effective and useful for wastewater treatment.
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China; NUS Environmental Research Institute, National University of Singapore, 1 Create Way, Create Tower #15-02, Singapore 138602, Singapore.
authors.forename: Jingxin
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China. Electronic address: zhangyb@dlut.edu.cn.
authors.forename: Yaobin
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
authors.forename: Xie
authors.initials: X
authors.lastname: Quan
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
authors.forename: Shuo
authors.initials: S
authors.lastname: Chen
mesh_terms: D000143:Acids / Q000737:chemistry; D000693:Anaerobiosis; D001105:Archaea / Q000378:metabolism*; D001419:Bacteria / Q000378:metabolism*; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology*; D016000:Cluster Analysis; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D005232:Fatty Acids, Volatile / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000032:analysis; D008697:Methane / Q000378:metabolism*; D011134:Polysaccharides / Q000032:analysis; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D012722:Sewage / Q000382:microbiology; D013997:Time Factors; D014865:Waste Disposal, Fluid
chemical_list: D000143:Acids; D005232:Fatty Acids, Volatile; D011134:Polysaccharides; D012722:Sewage; D007501:Iron; D008697:Methane
keywords: Acidification; Anaerobic; Bio-electrochemical enhancement; Hydrolysis; Microbial community