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Rychtowski P, Paszkiewicz O, Markowska-Szczupak A, Leniec G, Tryba B. Sulphated TiO 2 Reduced by Ammonia and Hydrogen as an Excellent Photocatalyst for Bacteria Inactivation. MATERIALS (BASEL, SWITZERLAND) 2023; 17:66. [PMID: 38203920 PMCID: PMC10779939 DOI: 10.3390/ma17010066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 12/13/2023] [Accepted: 12/16/2023] [Indexed: 01/12/2024]
Abstract
This study presents a relatively low-cost method for modifying TiO2-based materials for photocatalytic bacterial inactivation. The photocatalytic inactivation of Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus epidermidis) bacteria using modified sulphated TiO2 was studied. The modification focused on the reduction of TiO2 by ammonia agents and hydrogen at 400-450 °C. The results showed a high impact of sulphate species on the inactivation of E. coli. The presence of these species generated acid sites on TiO2, which shifted the pH of the reacted titania slurry solution to lower values, around 4.6. At such a low pH, TiO2 was positively charged. The ammonia solution caused the removal of sulphate species from TiO2. On the other hand, hydrogen and ammonia molecules accelerated the removal of sulphur species from TiO2, as did heating it to 450 °C. Total inactivation of E. coli was obtained within 30 min of simulated solar light irradiation on TiO2 heat-treated at 400 °C in an atmosphere of Ar or NH3. The S. epidermidis strain was more resistant to photocatalytic oxidation. The contact of these bacteria with the active titania surface is important, but a higher oxidation force is necessary to destroy their cell membrane walls because of their thicker cell wall than E. coli. Therefore, the ability of a photocatalyst to produce ROS (reactive oxidative species) will determine its ability to inactivate S. epidermidis. An additional advantage of the studies presented is the inactivation of bacteria after a relatively short irradiation time (30 min), which does not often happen with photocatalysts not modified with noble metals. The modification methods presented represent a robust and inexpensive alternative to photocatalytic inactivation of bacteria.
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Affiliation(s)
- Piotr Rychtowski
- Department of Catalytic and Sorbent Materials Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Pułaskiego 10, 70-322 Szczecin, Poland;
| | - Oliwia Paszkiewicz
- Department of Chemical and Process Engineering, West Pomeranian University of Technology in Szczecin, Piastów 42, 71-065 Szczecin, Poland; (O.P.); (A.M.-S.)
| | - Agata Markowska-Szczupak
- Department of Chemical and Process Engineering, West Pomeranian University of Technology in Szczecin, Piastów 42, 71-065 Szczecin, Poland; (O.P.); (A.M.-S.)
| | - Grzegorz Leniec
- Department of Nanomaterials Physicochemistry, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Piastów 42, 71-065 Szczecin, Poland;
| | - Beata Tryba
- Department of Catalytic and Sorbent Materials Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Pułaskiego 10, 70-322 Szczecin, Poland;
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Nawaz R, Haider S, Anjum M, Oad VK, Haider A, Khan R, Aqif M, Hanif T, Khan N. Optimized photodegradation of palm oil agroindustry waste effluent using multivalent manganese-modified black titanium dioxide. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023:10.1007/s11356-023-27831-3. [PMID: 37266783 DOI: 10.1007/s11356-023-27831-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 05/18/2023] [Indexed: 06/03/2023]
Abstract
This article presents a methodological approach to use manganese (Mn3+Mn7+)-modified black titanium dioxide (Mn/BTiO2) as a photocatalyst to optimize and improve visible-light-driven photodegradation of treated agro-industrial effluent (TPOME). A modified wet chemical process was used to prepare BTiO2. The BTiO2 was then wet impregnated with Mn and calcined at 300 °C for 1 h to produce Mn/BTiO2. The activity of Mn/BTiO2 was investigated in terms of photo-assisted elimination of chemical oxygen demand (COD), phenolic compounds (PCs), color, and total organic carbon (TOC). Using the design of experiments (DOE), the conditions of the photocatalytic process, including photocatalyst loading, Mn concentration, hydrogen peroxide (H2O2) dose, and irradiation time, were optimized. Under the optimum conditions (0.85 g/L photocatalyst loading, 0.048 mol/L H2O2 dose, 0.301 wt.% Mn concentration, and 204 min irradiation time) COD, PCs, color, and TOC removal efficiencies of 88.87%, 86.04%, 62.8%, and 84.66%, respectively, were obtained. Statistical analysis showed that the response variable's removal from TPOME estimation had high R2 and low RMSE, MSE, MAD, MAE, and MAPE values, indicating high reliability. This study demonstrated the significant potential of the developed photocatalytic system for the treatment of waste effluent generated by the palm oil industry and other agro-industries, with the ability to simultaneously reduce a number of organic pollution indicators (OPIs).
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Affiliation(s)
- Rab Nawaz
- Institute of Soil and Environmental Sciences, Pir Mehr Ali Shah Arid Agriculture University Shamsabad, Murree Rd, Rawalpindi, 46300, Pakistan.
| | - Sajjad Haider
- Chemical Engineering Department, College of Engineering, King Saud University, P.O. Box 800, Riyadh, 11421, Saudi Arabia
| | - Muzammil Anjum
- Institute of Soil and Environmental Sciences, Pir Mehr Ali Shah Arid Agriculture University Shamsabad, Murree Rd, Rawalpindi, 46300, Pakistan
| | - Vipin Kumar Oad
- Faculty of Civil and Environmental Engineering, Gdansk University of Technology, 80-233, Gdansk, Poland
| | - Adnan Haider
- Department of Biological Sciences, National University of Medical Sciences, Rawalpindi, Pakistan
| | - Rawaiz Khan
- Restorative Dental Sciences Department, College of Dentistry, King Saud University, Riyadh, 11545, Saudi Arabia
| | - Muhammad Aqif
- Faculty of Materials and Chemical Engineering, Department of Chemical Engineering, Ghulam Ishaq Khan Institute, Topi, Khyber Pakhtunkhwa, 23460, Pakistan
| | - Tahir Hanif
- Civil and Environmental Engineering Department, The University of Alabama in Huntsville, Huntsville, AL, 35899, USA
| | - Nasruulah Khan
- Department of Botany, University of Malakand, District Dir Lower, Chakdara, Khyber Pakhtunkhwa, 18800, Pakistan
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