Role of self-assembly coated Er(3+): YAlO3/TiO2 in intimate coupling of visible-light-responsive photocatalysis and biodegradation reactions.
Conventionally used ultraviolet light can result in dissolved organic carbon (DOC) increasing and biofilm damage in intimate coupling of photocatalysis and biodegradation (ICPB). Visible-light-responsive photocatalysis offers an alternative for achieving ICPB. In this study, composite-cubes were developed using self-assembly to coat a thin and even layer of visible-light-responsive photocatalyst (Er(3+): YAlO3/TiO2) on sponge-type carriers, followed by biofilm cultivation. The degradations of phenol (50 mg L(-1)) were compared for four protocols in circulating beds: adsorption (AD), visible-light-responsive photocatalysis (VPC), biodegradation (B), and intimately coupled visible-light-responsive photocatalysis and biodegradation (VPCB). The phenol and DOC removal efficiencies using VPCB in 16 h were 99.8% and 65.2%, respectively, i.e., higher than those achieved using VPC (71.6% and 50.0%) or B (99.4% and 58.2%). The phenol removal of 96.3% could be obtained even after 3 additional cycles. The 6.17-min intermediate detected by HPLC, continuously accumulated for VPC, appeared at 1-6 h and then was completely removed for VPCB in 10 h. ICPB was further illustrated in that most of the biofilm was protected in the carrier interiors, with less protection on the carrier exterior in VPCB. A self-regulation mechanism that helped photocatalyst exposure to visible-light irradiation was identified, promoting the combined photocatalysis and biodegradation.
Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China.
Shanshan
S
Dong
Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China. Electronic address: dongshuangshi@gmail.com.
Shuangshi
S
Dong
Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China.
Xiadi
X
Tian
Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China.
Zhengxue
Z
Xu
Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China.
Dongmei
D
Ma
Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China.
Bin
B
Cui
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin 150090, China. Electronic address: rnq@hit.edu.cn.
Nanqi
N
Ren
Swette Center for Environmetal Technology, Biodesign Institute at Arizona State University, Tempe, AZ, 85287-5701, USA.
Bruce E
BE
Rittmann
D000537:Aluminum Oxide / Q000737:chemistry; D001673:Biodegradation, Environmental; D002384:Catalysis; D004785:Environmental Pollutants / Q000737:chemistry*; D004871:Erbium / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D019800:Phenol / Q000737:chemistry*; D010782:Photolysis; D013050:Spectrometry, Fluorescence; D014025:Titanium / Q000737:chemistry; D014961:X-Ray Diffraction; D015019:Yttrium / Q000737:chemistry
D004785:Environmental Pollutants; C009495:titanium dioxide; D019800:Phenol; D015019:Yttrium; D004871:Erbium; D014025:Titanium; D000537:Aluminum Oxide
Intimate coupling; Phenol; Self-assembly; Self-regulation mechanism; Visible-light-responsive photocatalysis