title: A novel method developed for estimating mineralization efficiencies and its application in PC and PEC degradations of large molecule biological compounds with unknown chemical formula.
abstract: A new method to estimate the photocatalytic (PC) and photoelectrocatalytic (PEC) mineralization efficiencies of large molecule biological compounds with unknown chemical formula in water was firstly developed and experimentally validated. The method employed chemical oxidation under the standard dichromate chemical oxygen demand (COD) conditions to obtain QCOD values of model compounds with unknown chemical formula. The measured QCOD values were used as the reference to replace QCOD values of model compounds for calculation of the mineralization efficiencies (in %) by assuming the obtained QCOD values are the measure of the theoretical charge required for the complete mineralization of organic pollutants. Total organic carbon (TOC) was also employed as a reference to confirm the mineralization capacity of dichromate chemical oxidation. The developed method was applied to determine the degradation extent of model compounds, such as bovine serum albumin (BSA), lecithin and bacterial DNA, by PC and PEC. Incomplete PC mineralization of all large molecule biological compounds was observed, especially for BSA. But the introduction of electrochemical technique into a PC oxidation process could profoundly improve the mineralization efficiencies of model compounds. PEC mineralization efficiencies of bacterial DNA was the highest, while that of lecithin was the lowest. Overall, PEC degradation method was found to be much effective than PC method for all large molecule biological compounds investigated, with PEC/PC mineralization ratios followed an order of BSA > lecithin > DNA.
authors.affiliation: Institute of Environmental Health and Pollution Control, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China; Centre for Clean Environment and Energy, Gold Coast Campus, Griffith University, Queensland, 4222, Australia.
authors.forename: Guiying
authors.initials: G
authors.lastname: Li
authors.affiliation: Centre for Clean Environment and Energy, Gold Coast Campus, Griffith University, Queensland, 4222, Australia; State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.
authors.forename: Xiaolu
authors.initials: X
authors.lastname: Liu
authors.affiliation: Institute of Environmental Health and Pollution Control, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China; State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China. Electronic address: antc99@gdut.edu.cn.
authors.forename: Taicheng
authors.initials: T
authors.lastname: An
authors.affiliation: School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR, China.
authors.forename: Po Keung
authors.initials: PK
authors.lastname: Wong
authors.affiliation: Centre for Clean Environment and Energy, Gold Coast Campus, Griffith University, Queensland, 4222, Australia. Electronic address: h.zhao@griffith.edu.au.
authors.forename: Huijun
authors.initials: H
authors.lastname: Zhao
mesh_terms: D057919:Biological Oxygen Demand Analysis; D002384:Catalysis; D010084:Oxidation-Reduction; D014025:Titanium / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry
chemical_list: D014874:Water Pollutants, Chemical; D014025:Titanium
keywords: Large molecule biological compounds; Method developing; PC and PEC mineralization; Unknown chemical formula