Remediation of Antiseptic Components in Wastewater by Photocatalysis Using TiO2 Nanoparticles (original) (raw)
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Titanium dioxide photocatalysis for pharmaceutical wastewater treatment
Environmental Chemistry Letters, 2014
Heterogeneous photocatalysis using the semiconductor titanium dioxide (TiO 2 ) has proven to be a promising treatment technology for water purification. The effectiveness of this oxidation technology for the destruction of pharmaceuticals has also been demonstrated in numerous studies. This review highlights recent research on TiO 2 photocatalytic treatment applied to the removal of selected pharmaceuticals. The discussions are tailored based on the therapeutic drug classes as the kinetics and mechanistic aspects are compound dependent. These classes of pharmaceuticals were chosen because of their environmental prevalence and potential adverse effects. Optimal operational conditions and degradation pathways vary with different pharmaceutical compounds. The main conclusion is that the use of TiO 2 photocatalysis can be considered a state-of-the-art pharmaceutical wastewater treatment methodology. Further studies are, however, required to optimize the operating conditions for maximum degradation of multiple pharmaceuticals in wastewater under realistic conditions and on an industrial scale.
TiO2-assisted photodegradation of pharmaceuticals — a review
Central European Journal of Chemistry, 2012
Pharmaceutical compounds have been detected in the environment and potentially arise from the discharge of excreted and improperly disposed medication from sewage treatment facilities. In order to minimize environmental exposure of pharmaceutical residues, a potential technique to remove pharmaceuticals from water is the use of an advanced oxidation process (AOP) involving titanium dioxide (TiO2) photocatalysis. To evaluate the extent UV/TiO2 processes have been studied for pharmaceutical degradation, a literature search using the keywords ‘titanium dioxide’, ‘photocatalysis’, ‘advanced oxidation processes’, ‘pharmaceuticals’ and ‘degradation’ were used in the ISI Web of Knowledge TM, Scopus TM and ScienceDirect TM databases up to and including articles published on 23 November 2011. The degradation rates of pharmaceuticals under UV/TiO2 treatment were dependent on type and amount of TiO2 loading, pharmaceutical concentration, the presence of electron acceptors and pH. Complete mine...
Application of Titanium Dioxide, 2017
The increasing of emerging micropollutants presence in drinking water sources has brought new challenges to existing water treatment systems (WTS), highlighting the need of innovative and low-cost technological solutions. Recent advances in nanotechnology enable highly efficient and multifunctional processes, providing sustainable alternatives to current water treatment practices. This chapter presents the results of several pilot-scale studies developed to assess the effects of TiO 2 nanoparticles on antibiotic removal efficiency, using different low-cost photocatalytic reactors. The characterization of its photooxidation kinetics also performed considering different test scenarios in order to assess the effects of the major abiotic parameters on oxytetracycline (OTC) removal efficiency, which achieved the maximum values of 96% and 98% using the photocatalysis with TiO 2 and the photocatalytic filtration, respectively. It must be highlighted the surprising regeneration ability showed by the photocatalytic porous medium, developed at a lab-scale, which can completely recover its oxidative properties after few hours of simple sun exposure.
IOSR Journal of Engineering, 2016
This paper presents the photocatalytic degradation of real pharmaceutical wastewater from Abbot Laboratories (Private) Limited, Karachi, Pakistan, using TiO 2 , ZnO, and H 2 O 2. The pretreated sample wastewater was used for degradation experiments and tests were carried out at 38 0 C under pH of 9 and 4 in a stirrer bath reactor equipped with eight ultraviolet tubes. The use of this technique is common in removal of the organic, inorganic pollutants and pathogens. Optimal conditions were selected from reported results of the researchers on advanced oxidation processes (AOPs) for removal of residual pharmaceuticals from real pharmaceutical wastewater. The three catalysts (Titanium dioxide, zinc oxide, and TiO 2 / H 2 O 2) used in this study are effective catalysts in photocatalytic degradation of real pharmaceutical wastewater. The maximum degradation achieved was 45.11% by combined use of TiO 2 and H 2 O 2 at 38 0 C and pH. The degradation improved at higher pH with Zinc oxide and Titanium oxide. The results indicate that for real pharmaceutical wastewater, combined use of TiO 2 / H 2 O 2 is comparatively more effective than ZnO and TiO 2 alone. The degradation of the pharmaceutical wastewater followed pseudo-first-order kinetics. The reaction rate constant was 0.00148/min for TiO 2 / H 2 O 2. This study demonstrates that for real pharmaceutical wastewater reacts differently to catalyst than synthetic pharmaceutical wastewater, or formulated wastewater.
Catalysts
The extensive application of antibiotics in human and veterinary medicine has led to their widespread occurrence in a natural aquatic environment. Global health crisis is associated with the fast development of antimicrobial resistance, as more and more infectious diseases cannot be treated more than once. Sulfamethoxazole, trimethoprim and ciprofloxacin are the most commonly detected antibiotics in water systems worldwide. The persistent and toxic nature of these antibiotics makes their elimination by conventional treatment methods at wastewater treatment plants almost impossible. The application of advanced oxidation processes and heterogeneous photocatalysis over TiO2-based materials is a promising solution. This highly efficient technology has the potential to be sustainable, cost-efficient and energy-efficient. A comprehensive review on the application of various TiO2-based photocatalysts for the degradation of sulfamethoxazole, trimethoprim and ciprofloxacin is focused on high...
Photodegradation of Antibiotic Using TiO2 as a Catalyst: A Review
IJPSM, 2021
The use of antibiotics in the community harms the environment. Due to the use of antibiotics is a risk of antibiotic resistance. Photodegradation was a method that could be used to reduce this impact. Photodegradation is a decomposition process using photon energy assistance. The photodegradation process requires a photocatalyst, which is a semiconductor material when subjected to an energy photon. This jump of electrons causes electron holes that can interact with water solvents to form radicals. TiO 2 is the most common photocatalyst that is used for the destruction of pollutants in aqueous solutions. Photochemically, TiO 2 is a stable, non-toxic, widely available, and low-cost manufacturing process. Increasing the concentration of TiO 2 catalyst will also increase the photodegradation activity of antibiotics, and the longer time of the irradiation time will increase the antibiotic degradation.
Journal of Engineering
The aim of this study was to investigate antibiotic amoxicillin removal from synthetic pharmaceutical wastewater. Titanium dioxide (TiO2) was used in photocatalysis treatment method under natural solar irradiation in a tubular reactor. The photocatalytic removal efficiency was evaluated by the reduction in amoxicillin concentration. The effects of antibiotics concentration, TiO2 dose, irradiation time and the effect of pH were studied. The optimum conditions were found to be irradiation time 5 hr, catalyst dosage 0.6 g/L, flow rate 1 L/min and pH 5. The photocatalytic treatment was able to destruct the amoxicillin in 5 hr and induced an amoxicillin reduction of about 10% with 141.8 kJ/L accumulated solar energy per liter of solution.
Photocatalytic Degradation of Some Antibiotics in Aqueous Solution
2009
Antibiotics are emerging contaminants in the aquatic environment because of their adverse effects on aquatic life and humans. Antibiotics wastewater has high COD and very low BOD 5 , and hence is difficult to treat biologically. The objective of this research was to study the feasibility of using the ultraviolet (UV)/titanium dioxide (TiO 2 ) photocatalytic process to degrade the antibiotics amoxicillin, ampicillin and cloxicillin in aqueous solution. No significant degradation occurred by UV irradiation per se. UV/TiO 2 photocatalysis was more effective for amoxicillin and cloxacillin degradation than for ampicillin degradation. pH has a great effect on amoxicillin, ampicillin and cloxacillin degradation and high degradation was achieved in both acidic and basic conditions. However, UV/TiO 2 photocatalysis did not improve the biodegradability of the amoxicillin, ampicillin, and cloxacillin aqueous solution. Addition of H 2 O 2 at optimum concentration not only achieved complete degradation of amoxicillin, ampicillin and cloxacillin but also improved the biodegradability of the antibiotics aqueous solution.
Photocatalytic degradation of the antibiotic chloramphenicol and effluent toxicity effects
Ecotoxicology and Environmental Safety, 2016
Chloramphenicol sodium succinate (CAP, C 15 H 15 Cl 2 N 2 Na 2 O 8) is a broad-spectrum antibiotic exhibiting activity against both Gram-positive and Gram-negative bacteria as well as other groups of microorganisms only partially removed by conventional activated sludge wastewater treatment plants. Thus, CAP and its metabolites can be found in effluents. The present work deals with the photocatalytic degradation of CAP using TiO 2 as photocatalyst. We investigated the optimization of reaction contact time and concentration of TiO 2 considering CAP and its by-products removal as well as effluent ecotoxicity elimination. Considering a CAP real concentration of 25 mg L À 1 , kinetic degradation curves were determined at 0.1, 0.2, 0.4, 0.8, 1.6 and 3.2 g L À 1 TiO 2 after 5, 10, 30, 60 and 120 min reaction time. Treated samples were checked for the presence of by-products and residual toxicity (V. fischeri, P. subcapitata, L. sativum and D. magna). Results evidenced that the best combination for CAP and its by-products removal could be set at 1.6 g L À 1 of TiO 2 for 120 min with an average residual toxicity of approximately 10%, that is the threshold set for negative controls in most toxicity tests for blank and general toxicity test acceptability.