title: Simultaneous removal of chromate and nitrate in a packed-bed bioreactor using biodegradable meal box as carbon source and biofilm carriers.
abstract: An up-flow packed-bed bioreactor was constructed to investigate the simultaneous removal of chromate and nitrate using biodegradable meal box as carbon source and biofilm carriers. The bioreactor was operated for 164days with varying influent Cr(VI) concentrations (2.0-50.0mg/L) and hydraulic retention times (HRT, 10-24h). It was shown that complete denitrification and Cr(VI) reduction could be achieved when influent Cr(VI) concentrations were lower than 20mg/L with a HRT of 17h. Shortening the HRT could significantly reduce the effluent CODcr. It was also observed that Cr(III) was mainly immobilized on the biofilm. Further investigation on Cr distribution in the biofilm compartments indicated that Cr(VI) reduction occurred in all compartments and the intercellular Cr was dominant. High-throughput sequencing analysis showed that Proteobacteria, Bacteroidetes and Firmicutes were the dominant phyla in the biofilm and Cr(VI) stress had a negative effect on the abundance of most bacteria.
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian, Liaoning 116024, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian, Liaoning 116024, China. Electronic address: jin_ruofei@163.com.
authors.forename: Ruofei
authors.initials: R
authors.lastname: Jin
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian, Liaoning 116024, China.
authors.forename: Guangfei
authors.initials: G
authors.lastname: Liu
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian, Liaoning 116024, China.
authors.forename: Tian
authors.initials: T
authors.lastname: Tian
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian, Liaoning 116024, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian, Liaoning 116024, China.
authors.forename: Jiti
authors.initials: J
authors.lastname: Zhou
mesh_terms: D001419:Bacteria / Q000187:drug effects / Q000378:metabolism; D001673:Biodegradation, Environmental / Q000187:drug effects; D018441:Biofilms / Q000187:drug effects*; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology*; D002244:Carbon / Q000494:pharmacology*; D002840:Chromates / Q000302:isolation & purification*; D058440:Denitrification / Q000187:drug effects; D009566:Nitrates / Q000302:isolation & purification*; D009573:Nitrites / Q000032:analysis; D014865:Waste Disposal, Fluid
chemical_list: D002840:Chromates; D009566:Nitrates; D009573:Nitrites; D002244:Carbon
keywords: Biodegradable meal box; Cr(VI) reduction; Denitrification; Distribution