title: Simultaneous photocatalytic and microbial degradation of dye-containing wastewater by a novel g-C3N4-P25/photosynthetic bacteria composite.
abstract: Azo dyes are very resistant to light-induced fading and biodegradation. Existing advanced oxidative pre-treatment methods based on the generation of non-selective radicals cannot efficiently remove these dyes from wastewater streams, and post-treatment oxidative dye removal is problematic because it may leave many byproducts with unknown toxicity profiles in the outgoing water, or cause expensive complete mineralization. These problems could potentially be overcome by combining photocatalysis and biodegradation. A novel visible-light-responsive hybrid dye removal agent featuring both photocatalysts (g-C3N4-P25) and photosynthetic bacteria encapsulated in calcium alginate beads was prepared by self-assembly. This system achieved a removal efficiency of 94% for the dye reactive brilliant red X-3b and also reduced the COD of synthetic wastewater samples by 84.7%, successfully decolorized synthetic dye-contaminated wastewater and reduced its COD, demonstrating the advantages of combining photocatalysis and biocatalysis for wastewater purification. The composite apparently degrades X-3b by initially converting the dye into aniline and phenol derivatives whose aryl moieties are then attacked by free radicals to form alkyl derivatives, preventing the accumulation of aromatic hydrocarbons that might suppress microbial activity. These alkyl intermediates are finally degraded by the photosynthetic bacteria.
authors.affiliation: College of Environment and Resources, Fuzhou University, Fuzhou, Fujian, PR China.|Research Institute of Photocatalysis, State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, Fuzhou, China.
authors.forename: Xinying
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Environment and Resources, Fuzhou University, Fuzhou, Fujian, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wu
authors.affiliation: College of Environment and Resources, Fuzhou University, Fuzhou, Fujian, PR China.
authors.forename: Gao
authors.initials: G
authors.lastname: Xiao
authors.affiliation: College of Environment and Resources, Fuzhou University, Fuzhou, Fujian, PR China.
authors.forename: Zhenping
authors.initials: Z
authors.lastname: Tang
authors.affiliation: College of Environment and Resources, Fuzhou University, Fuzhou, Fujian, PR China.
authors.forename: Meiyin
authors.initials: M
authors.lastname: Wang
authors.affiliation: College of Environment and Resources, Fuzhou University, Fuzhou, Fujian, PR China.
authors.forename: Fuchang
authors.initials: F
authors.lastname: Liu
authors.affiliation: Section Sanitary Engineering, Department of Water Management, Faculty of Civil Engineering and GeoSciences, Delft University of Technology, Delft, Netherlands.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Zhu
mesh_terms: D018407:Bacterial Physiological Phenomena; D001673:Biodegradation, Environmental; D002384:Catalysis; D004396:Coloring Agents / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D010788:Photosynthesis; D062065:Wastewater / Q000382:microbiology*
chemical_list: D004396:Coloring Agents; D062065:Wastewater