Chen Ying-Chen

Lin Yao-Tung

Tzeng Jing-Hua

Weng Chih-Huang

Yen Li-Ting

English

University of Szeged

  Kinetic Model of Disinfection Using Novel Chitosan-N-Doped TiO2 Photocatalyst Derived from Fishery Waste  Li-Ting Yen1,4, Chih-Huang Weng2, Ying-Chen Chen1, Jing-Hua Tzeng1,3, Yao-Tung Lin1,* 1Department of Soil and Environmental Sciences, National Chung Hsing University,  Taichung, Taiwan 2 Department of Civil and Ecological Engineering, I-Shou University, Kaohsiung, Taiwan 3Department of Civil and Environmental Engineering, University of Delaware, DE, U.S.A. 4Department of Plants, Soils and Climate, Utah State University, UT, U.S.A  Disinfection applications of titanium dioxide (TiO2) have been widely explored. However, most TiO2 materials are restricted to the presence of UV-light only. Nitrogen-doped TiO2 (N-TiO2) synthesized by our research group show high disinfection performance under visible light. According to our previous results, N-TiO2 damages the external cell wall/membrane, degrades the cellular membrane and releases the essential intracellular component, leading to the death of bacteria. Chitosan (CTS) is a natural polymer found in insect exoskeletons, crustacean shells, and fungal cell walls, which is the second most abundant polysaccharide after cellulose. CTS has a wide range of applications and beneficial properties, including antifungal and antibacterial. Most of the literature measured the removal rate of pollutants via CTS or CS-TiO2 or adopted the simple agar- well diffusion technique to determine the disinfection performance. The aforementioned studies rarely discuss the impacts on the microorganism reacting with CTS-TiO2 under visible light and with the absence of the light source. Furthermore, there is little literature investigating the kinetic model of disinfection performance using CTS and CTS-N-TiO2. In this study, we assume that incorporating shrimp-shells-CTS onto the surface of N-TiO2 will enhance photo-disinfection capacity and show the disinfection effect in the dark. The CTS-N-TiO2 photocatalyst has been synthesized and the photo-disinfection kinetic model experiments carry out under various key parameters, i.e., bacteria species (Gram-positive bacteria, S. aureus and Gram-negative bacteria, E. coli), visible light intensity, dosage, and initial bacteria concentration. The photo-disinfection mechanism of bacteria was investigated via SEM for the morphology of bacterial cells in the photo-disinfection process. Disinfection experimental results show that CTS exhibited 99.9% of E. coli and S. aureus within 2 h. The novel CTS-N-TiO2 photocatalyst is equipped with excellent disinfection activity against both S. aureus and E. coli under visible light and also in the dark. The two kinetic models (one for CTS and the other one for CTS-N-TiO2), containing k1, k2 and k3 constants, can describe the different disinfection stages. The model was adopted to fit the disinfection results using both CTS and CTS-N-TiO2. CTS-N-TiO2 is advantageous for abating the problem of abundance fishery waste and the kinetic model results of CTS and CTS-N-TiO2 are benefiting for the further application. 86

Kinetic model of disinfection using novel Chitosan-N-Doped TiO2 photocatalyst derived from fishery waste

http://acta.bibl.u-szeged.hu/76837/1/npm_005_paot_006_086.pdf

Kinetic model of disinfection using novel Chitosan-N-Doped TiO2 photocatalyst derived from fishery waste

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University of Szeged