Photocatalytic degradation of microcystins-LR in source water using TiO2 nanotubes
DENG Yi-rong1,2,3,4, ZHAO Lu5, SU Ya-ling3, ZHONG Yin1, PENG Ping-an1, XIAO Rong-bo2
1. State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China;
2. Guangdong Key Laboratory of Contaminated Environmental Management and Remediation, Guangdong Provincial Academy of Environmental Science, Guangzhou 510045, China;
3. State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China;
4. University of Chinese Academy of Sciences, Beijing 100049, China;
5. Guangzhou Research Institute of Environmental Protection, Guangzhou 510620, China
In this work, TiO2 nanotubes was fabricated using anodization method with oxalic acid and NH4F solution. TiO2 nanotubes were used to photocatalytic degradation of microsytins-LR. The results showed that the morphology was the most highly ordered under the optimum anodic voltage of 20V, electrolyte composition of 1/12mol/L H2C2O4·2H2O+0.5wt%NH4F and anodization time of 1~2h. The pore size of nanotubes was around 50nm, and the length was 250~600nm. After annealing at the temperature of 500~600℃, TiO2 nanotubes showed a high photocatalytic ability for MC-LR under pH 3.5and 8. The photocatalytic reactions of MC-LR fit well with the pseudo-first order kinetics. We infer the possible degradation pathways of MC-LR involve not only the attack by hydroxyl radicals for the conjugated double bond and methoxy group in the Adda chain, as well as the conjugated system in the Mdha amino acid, but also the hydrolysis of peptide bonds.
Francis G. Poisonous australian lake[J]. Nature, 1878,18(444):11-12.
[2]
Ma J G, Feng Y Y, Jiang S Y, et al. Altered cellular metabolism of HepG2 cells caused by microcystin-LR[J]. Environmental Pollution, 2017,225:610-619.
[3]
Zhang H, Wang L H, Song S, et al. Toxic effects of microcystin-LR on the development of prostate in mice[J]. Toxicology, 2017, 380:50-61.
[4]
Wang L, Hou J, Guo H H, et al. Dualistic immunomodulation of sub-chronic microcystin-LR exposure on the innate-immune defense system in male zebrafish[J]. Chemosphere, 2017,183:315-322.
[5]
Soheila R, Esmaili S, Abbas B, et al. Tissue distribution and bioaccumulation of microcystin LR in the phytoplanktivorous and carnivorous fish in Anzali wetland, with potential health risks to humans[J]. Science of The Total Environment, 2017,575:1130-1138.
[6]
Xu H Z, Pei H Y, Jin Y, et al. Characteristics of water obtained by dewatering cyanobacteria-containing sludge formed during drinking water treatment, including C-, N-disinfection byproduct formation[J]. Water Research, 2017,111:382-392.
[7]
T S W, Zheng D J, Jiang W W, et al. Combined Exposure to 3-Chloro-4-dichloromethyl-5-hydroxy-2(5H)-furanone and Microsytin-LR Increases Genotoxicity in Chinese Hamster Ovary Cells through Oxidative Stress[J]. Environmental Science & Technology, 2013,47(3):1678-1687.
[8]
Botes D P. Configuration assignments of the amino acid residues and the presence of N-methyl dehydroalanine intoxins from the blue-green alga Microcystis aeruginosa[J]. Journal of the Chemical Society Perkin Transactions, 1982,1:2747-2748.
[9]
Zhang X, Hu H Y, Men Y J, et al. The effect of Poterioochromonas abundance on production of intra-and extracellular microcystin-LR concentration[J]. Hydrobiologia, 2010,652(1):237-246.
Kim M S, Lee H H, Lee K M, et al. Oxidation of microcystin-LR by ferrous-tetrapolyphosphate in the presence of oxygen and hydrogen peroxide[J]. Water Research, 2017,114:277-285.
[13]
Park J A, Park Y B, Choi C, et al. Oxidation of microcystin-LR by the Fenton process:Kinetics, degradation intermediates, water quality and toxicity assessment[J]. Chemical Engineering Journal, 2017,309:339-348.
[14]
Wang X X, Zhang J T, Sun W Z, et al. Anti-algal activity of palladium oxide-modified nitrogen-doped titanium oxide photocatalyst on Anabaena sp. PCC 7120 and its photocatalytic degradation on microcystin LR under visible light illumination[J]. Chemical Engineering Journal, 2015,264:437-444.
[15]
Zhang X, Li J, Yang J Y, et al. Chlorine/UV Process for decomposition and detoxification of microcystin-LR[J]. Environmental Science & Technology, 2016,50(14):7671-7678.
[16]
Jiang W J, Chen L, Batchu, S R, et al. Oxidation of microcystin-LR by ferrate(VI):Kinetics, degradation pathways, and toxicity assessments[J]. Environmental Science & Technology, 2014, 48(20):12164-12172.
Fraga L E, Anderson M A, Beatriz M L, et al. Evaluation of the photoelectrocatalytic method for oxidizing chloride and simultaneous removal of microcystin toxins in surface waters[J]. Electrochimica Acta, 2009,54(7):2069-2076.
[19]
Antoniou M G, Shoemaker J A, Cruz A A, et al. Unveiling new degradation intermediates/pathways from the photocatalytic degradation of microcystin-LR[J]. Environmental Science & Technology, 2008, 42(23):8877-8883.
[20]
Hu X H, Tang X J, Wen C, et al. Mechanisms underlying degradation pathways of microcystin-LR with doped TiO2 photocatalysis[J]. Chemical Engineering Journal, 2017,330:355-371.
Wang X, Utsumi M, Yang Y N, et al. Degradation of microcystin-LR by highly efficient AgBr/Ag3PO4/TiO2 heterojunction photocatalyst under simulated solar light irradiation[J]. Applied Surface Science, 2015,325:1-12.
[23]
Mohammad R E, Choi H, et al. Effect of UV-LED wavelengths on direct photolytic and TiO2 photocatalytic degradation of emerging contaminants in water[J]. Chemical Engineering Journal, 2016,300:414-422.
[24]
Lívia X, Pinho A, Joana M, et al. Oxidation of microcystin-LR and cylindrospermopsin by heterogeneous photocatalysis using a tubular photoreactor packed with different TiO2 coated supports[J]. Chemical Engineering Journal, 2015,266:100-111.
Lawton L A, Robertson P K J, et al. Processes influencing surface interaction and photocatalytic destruction of microcystins on titanium dioxide photocatalysts[J]. Journal of Catalysis, 2003, 213(1):109-113.
[28]
Fristachi A, Sinclair J L, Hall S, et al. Occurrence of cyanobacterial harmful algal blooms workgroup report[R]. Cyanobacterial Harmful Algal Blooms:State of the Science and Research Needs, 2008:45-103.
[29]
Mcmurray T A, Byrne J A, Dunlop P S M, et al. Intrinsic kinetics of photocatalytic oxidation of formic and oxalic acid on immobilised TiO2 films[J]. Applied Catalysis A General, 2004, 262(1):105-110.
[30]
Harada K, Tsuji K, Watanabe M F, et al. Stability of microcystins from cyanobacteria-Ⅲ:Effect of pH and temperature[J]. Phycologia, 1996, 35(6):83-88.
[31]
Westrick J A, Szlag D C, Southwell B J, et al. A review of cyanobacteria and cyanotoxins removal/inactivation in drinking water treatment[J]. Analytical and Bioanalytical Chemistry, 2010, 397(5):1705-1714.
[32]
Antoniou M G, Shoemaker J A, Cruz A A, et al. LC/MSMS structure elucidation of reaction intermediates formed during the TiO2 photocatalysis of microcystin-LR[J]. Toxicon, 2008,51(6):1103-1118.
[33]
Antoniou M G, Nambiar U, Dionysiou D D. Investigation of the photocatalytic degradation pathway of the urine metabolite, creatinine:the effect of pH[J]. Water research, 2009,43(16):3956-3963.
[34]
Antoniou M G, Nicolaou P A, Shoemaker J A, et al. Impact of the morphological properties of thin TiO2 photocatalytic films on the detoxification of water contaminated with the cyanotoxin, microcystin-LR[J]. Applied Catalysis B:Environmental, 2009, 91(1/2):165-173.