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Kanchanatip E, Kiattisaksiri P, Neramittagapong A. Photocatalytic treatment of real liquid effluent from hydrothermal carbonization of agricultural waste using metal doped TiO 2/UV system. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2023; 58:246-255. [PMID: 36855964 DOI: 10.1080/10934529.2023.2184156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 02/15/2023] [Accepted: 02/15/2023] [Indexed: 06/18/2023]
Abstract
This study investigated treatment of real liquid effluent generated from hydrothermal carbonization (HTC) of macadamia nut shell by employing transition metals Cu, Ni, and Fe doped titanium dioxide (TiO2) photocatalysts. The anatase TiO2 based photocatalysts were prepared via sol-gel method, and calcined at 400 °C. The modification with metal dopants was performed via ultrasonic assisted incipient wetness impregnation method. The prepared photocatalysts were characterized using XRD, UV-Vis DRS, SEM-EDX, and N2 physisorption. The influence of metal dopants, types of TiO2 support, and initial pH of the wastewater on the photocatalytic degradation performance of total organic carbon (TOC) and chemical oxygen demand (COD) in the wastewater were investigated. The results revealed that Fe doped TiO2 exhibited the highest photocatalytic activity followed by Cu and Ni, respectively. Among all, Fe doped anatase TiO2 were the most promising catalyst as it performed the highest removal of 75.1% for TOC and 94.1% for COD after 1 h irradiation at pH 4, achieving the lowest TOC and COD concentration of 405.62 mg/L and 91.26 mg/L, respectively. The findings suggested that photocatalytic degradation of HTC liquid effluent could be a potential treatment before releasing the wastewater to the environment.
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Affiliation(s)
- Ekkachai Kanchanatip
- Department of Chemical Engineering, Faculty of Engineering, Khon Kaen University, Khon Kaen, Thailand
- Faculty of Science and Engineering, Kasetsart University, Sakon Nakhon, Thailand
| | - Pradabduang Kiattisaksiri
- Faculty of Public Health, Thammasat University (Lampang Campus), Lampang, Thailand
- Center of Excellence in Environmental Catalysis and Adsorption, Faculty of Engineering, Thammasat University, Pathumthani, Thailand
| | - Arthit Neramittagapong
- Department of Chemical Engineering, Faculty of Engineering, Khon Kaen University, Khon Kaen, Thailand
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Juwar VA, Rathod AP. Catalytic ozonation of real food wastewater using catalyst synthesized from waste. ENVIRONMENTAL TECHNOLOGY 2023; 44:12-21. [PMID: 34319854 DOI: 10.1080/09593330.2021.1961873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 07/18/2021] [Indexed: 06/13/2023]
Abstract
ABSTRACTIn the present study, complex wastewater from the food industry was used to study the effect of ozonation and catalysed ozonation for chemical oxygen demand (COD) removal. The catalysts used were synthesized from agro-waste, activated carbon (AC) and plastic waste, multiwalled carbon nanotubes (MWCNTs)(MWCNT). The effect of various operating parameters, like ozone dosage, catalyst dosage, pH, on COD removal of food industry wastewater was investigated. The maximum COD removal was observed at ozone dose of 2gm/hr. MWCNTs(MWCNT) catalysed ozonation removes 85% COD and 48% total organic carbon (TOC) removal within 180 min at pH 9 and 74% COD and 36% TOC removal was observed for activated carbon catalysed ozonation for the same experimental conditions. A significant inhibition of COD removal was observed in the presence of tertiary-butyl alcohol. Using para-chlorobenzoic acid (p-CBA) as a probe compound, the hydroxyl radical exposure was determined for AC and MWCNT catalysed ozonation. The hydroxyl radical exposure was measured to understand the mechanism of catalytic ozonation and compare the performance of two different catalysts in terms of hydroxyl radical generation. It was found that hydroxyl radical exposure increases with increasing catalyst dose, which confirms the hydroxyl radical (OH.) pathway for COD reduction. The kinetic studies showed a 5.5time increment in rate for MWCNT catalysed ozonation and a 4 time increment for activated carbon catalysed ozonation when compared with standalone ozonation. The synergistic factor for MWCNTs and ozone was found to be 1.83 and for activated carbon and ozone, 1.5.Highlights Catalysts used were synthesized from waste.Application of activated carbon and multiwalled carbon nanotubes for catalytic ozonation of real food wastewater was investigated.Effectiveness of standalone ozonation and catalytic ozonation was identified and compared.A multiwalled carbon nanotube presents higher catalytic performance than activated carbon for ozonation of real food wastewater.Hydroxyl radical mechanism of catalytic ozonation was confirmed by using p-CBA as a probe compound.
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Affiliation(s)
- Vijay A Juwar
- Chemical Engineering Department, Visvesaraya National Institute of Technology, Nagpur, India
| | - Ajit P Rathod
- Chemical Engineering Department, Visvesaraya National Institute of Technology, Nagpur, India
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Saravanan A, Deivayanai VC, Kumar PS, Rangasamy G, Hemavathy RV, Harshana T, Gayathri N, Alagumalai K. A detailed review on advanced oxidation process in treatment of wastewater: Mechanism, challenges and future outlook. CHEMOSPHERE 2022; 308:136524. [PMID: 36165838 DOI: 10.1016/j.chemosphere.2022.136524] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 09/08/2022] [Accepted: 09/15/2022] [Indexed: 06/16/2023]
Abstract
The presence of several contaminants in waterbodies raises global pollution and creates major risks to mankind, wildlife, as well as other living organisms. Development of an effective, feasible, cost-effective and eco-friendly approach for treating wastewater that is discharged from various industries is important for bringing down the deposition of contaminants into environment. Advanced oxidation process is an efficient technique for treating wastewater owing to its advantages such as high oxidation efficacy and does not produce any secondary pollutants. Advanced oxidation process can be performed through various methods such as ozone, Fenton, electrochemical, photolysis, sonolysis, etc. These methods have been widely utilized for degradation of emerging pollutants that cannot be destroyed using conventional approaches. This review focuses on wastewater treatment using advanced oxidation process. A brief discussion on mechanism involved is provided. In addition, various types of advanced oxidation process and their mechanism are explained in detail. Challenges faced during wastewater treatment process using oxidation, electrochemical, Fenton, photocatalysis and sonolysis are discussed elaborately. Advanced oxidation process can be viewed as potential approach for treating wastewater with certain modifications and solving challenges.
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Affiliation(s)
- A Saravanan
- Department of Sustainable Engineering, Institute of Biotechnology, Saveetha School of Engineering, SIMATS, Chennai, 602105, India.
| | - V C Deivayanai
- Department of Sustainable Engineering, Institute of Biotechnology, Saveetha School of Engineering, SIMATS, Chennai, 602105, India
| | - P Senthil Kumar
- Department of Chemical Engineering, Sri Sivasubramaniya Nadar College of Engineering, Chennai, 603110, India; Centre of Excellence in Water Research (CEWAR), Sri Sivasubramaniya Nadar College of Engineering, Chennai, 603110, India.
| | - Gayathri Rangasamy
- University Centre for Research and Development & Department of Civil Engineering, Chandigarh University, Gharuan, Mohali, Punjab, 140413, India
| | - R V Hemavathy
- Department of Biotechnology, Rajalakshmi Engineering College, Chennai, 602105, India
| | - T Harshana
- Department of Biotechnology, Rajalakshmi Engineering College, Chennai, 602105, India
| | - N Gayathri
- Department of Biotechnology, Rajalakshmi Engineering College, Chennai, 602105, India
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Ganesh Kumar P, Kanmani S. Removal of persistent organic pollutants and disinfection of pathogens from secondary treated municipal wastewater using advanced oxidation processes. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2022; 86:1944-1957. [PMID: 36315087 DOI: 10.2166/wst.2022.308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
An affordable and sustainable tertiary treatment is imperative to solve the secondary contamination issues related to wastewater reuse. To decontaminate and disinfect the actual secondary treated wastewater, various types of advanced oxidation processes (AOPs) have been studied. The optimization of the oxidant and catalyst is carried out to identify the best-performing system. Under selected experimental conditions, UV/peroxymonosulfate (PMS), O3/PMS, UV/MnO2, O3/MnO2, UV/O3/H2O2, O3/MnO2/H2O2, UV/MnO2/H2O2, and UV/O3/MnO2 has been identified as an efficient treatment option for simultaneous decontamination (>90% COD removal) and disinfection (100% inactivation of the total viable count of bacteria). The techno-economic assessment revealed that UV/MnO2 (23.5 $ kg-1 of COD) UV/O3/MnO2 (37.4 $ kg-1 of COD), UV/H2O2/MnO2 (36.4 $ kg-1 of COD), and O3/MnO2/H2O2 (32.5 $ kg-1 of COD) are comparatively low-cost treatment processes. Overall, UV/MnO2, UV/H2O2/MnO2, and O3/MnO2/H2O2 are the three best treatments. Nevertheless, further investigation on by-product and catalyst toxicity/recovery is needed. The results showed that AOPs are a technologically feasible treatment for simultaneously removing persistent organic pollutants and pathogens from secondary treated wastewater.
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Affiliation(s)
- P Ganesh Kumar
- Department of Civil Engineering, Centre for Environmental Studies, Anna University, Chennai 600025, India E-mail:
| | - S Kanmani
- Department of Civil Engineering, Centre for Environmental Studies, Anna University, Chennai 600025, India E-mail:
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Preparation and Real World Applications of Titania Composite Materials for Photocatalytic Surface, Air, and Water Purification: State of the Art. INORGANICS 2022. [DOI: 10.3390/inorganics10090139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The semiconducting transition metal oxide TiO2 is a rather cheap and non-toxic material with superior photocatalytic properties. TiO2 thin films and nanoparticles are known to have antibacterial, antiviral, antifungal, antialgal, self, water, and air-cleaning properties under UV or sun light irradiation. Based on these excellent qualities, titania holds great promises in various fields of applications. The vast majority of published field and pilot scale studies are dealing with the modification of building materials or generally focus on air purification. Based on the reviewed papers, for the coating of glass, walls, ceilings, streets, tunnels, and other large surfaces, titania is usually applied by spray-coating due to the scalibility and cost-efficiency of this method compared to alternative coating procedures. In contrast, commercialized applications of titania in medical fields or in water purification are rarely found. Moreover, in many realistic test scenarios it becomes evident that the photocatalytic activity is often significantly lower than in laboratory settings. In this review, we will give an overview on the most relevant real world applications and commonly applied preparation methods for these purposes. We will also look at the relevant bottlenecks such as visible light photocatalytic activity and long-term stability and will make suggestions to overcome these hurdles for a widespread usage of titania as photocalyst.
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The Benefits of Using Saccharose for Photocatalytic Water Disinfection. Int J Mol Sci 2022; 23:ijms23094719. [PMID: 35563110 PMCID: PMC9101646 DOI: 10.3390/ijms23094719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/16/2022] [Accepted: 04/22/2022] [Indexed: 12/04/2022] Open
Abstract
In this work, the characteristics of saccharose (sucrose)-modified TiO2 (C/TiO2) photocatalysts obtained using a hydrothermal method at low temperature (100 °C) are presented. The influence of C/TiO2 on survivability and enzyme activity (catalase and superoxide dismutase) of Gram-negative bacteria Escherichia coli (ATCC 29425) and Gram-positive bacteria Staphylococcus epidermidis (ATCC 49461) under UV-A and artificial solar light (ASL) were examined. The obtained TiO2-1%-S-100 photocatalysts were capable of total E. coli and S. epidermidis inactivation under ASL irradiation in less than 1 h. In addition, the impacts of sugars on the photocatalytic activity and disinfection performance are discussed.
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Abstract
Raw clays, extracted from Bana, west Cameroon, were modified with semiconductors (TiO2 and ZnO) in order to improve their depollution properties with the addition of photocatalytic properties. Cu2+ ions were also added to the clay by ionic exchange to increase the specific surface area. This insertion of Cu was confirmed by ICP-AES. The presence of TiO2 and ZnO was confirmed by the detection of anatase and wurzite, respectively, using X-ray diffraction. The composite clays showed increased specific surface areas. The adsorption property of the raw clays was evaluated on two pollutants, i.e., fluorescein (FL) and p-nitrophenol (PNP). The experiments showed that the raw clays can adsorb FL but are not efficient for PNP. To demonstrate the photocatalytic property given by the added semiconductors, photocatalytic experiments were performed under UVA light on PNP. These experiments showed degradation up to 90% after 8 h of exposure with the best ZnO-modified clay. The proposed treatment of raw clays seems promising to treat pollutants, especially in developing countries.
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