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Environmental Science and Pollution... Feb 2024The uncontrolled discharge of industry- and consumer-derived micropollutants and synthetic contaminants into freshwater bodies represents a severe threat to human health... (Review)
Review
The uncontrolled discharge of industry- and consumer-derived micropollutants and synthetic contaminants into freshwater bodies represents a severe threat to human health and aquatic ecosystem. Inexpensive and highly efficient wastewater treatment methods are, therefore, urgently required to eliminate such non-biodegradable, recalcitrant, and toxic organic pollutants. In this context, advanced oxidation processes, particularly heterogenous photocatalysis, have received enormous attention over the past few decades. Among the different classes of photocatalysts explored by the scientific community, heterojunction photocatalysts, in general, and binary heterojunction photocatalysts, in particular, have shown tremendous promise, attributed to their many distinct advantages. As such, the present review highlights the application of diverse array of binary heterojunction photocatalysts for eliminating water-borne contaminants. Specifically, a bibliometric analysis has been conducted to identify the ongoing research trend and future prospects of heterojunction photocatalysts. It appears that metal oxide/metal oxide-based heterojunctions have superior thermal and mechanical stability compared to other heterojunction photocatalysts. In contrast, metal oxide/non-metal semiconductor-based heterojunctions are extremely effective in pollutant degradation without significant leaching of metal ions. The review concludes by proposing novel strategic research guidelines in order to make further advances in this rapidly evolving cross-disciplinary field of topical interest.
Topics: Humans; Ecosystem; Bibliometrics; Body Fluids; Environmental Pollutants; Oxides
PubMed: 38180651
DOI: 10.1007/s11356-023-31592-4 -
Chemosphere Sep 2023Manganese oxides (MnOx) are recognized as a strongest oxidant and adsorbent, of which composites have been proved to be effective in the removal of contaminants from... (Review)
Review
Manganese oxides (MnOx) are recognized as a strongest oxidant and adsorbent, of which composites have been proved to be effective in the removal of contaminants from wastewater. This review provides a comprehensive analysis of Mn biochemistry in water environment including Mn oxidation and Mn reduction. The recent research on the application of MnOx in the wastewater treatment was summarized, including the involvement of organic micropollutant degradation, the transformation of nitrogen and phosphorus, the fate of sulfur and the methane mitigation. In addition to the adsorption capacity, the Mn cycling mediated by Mn(II) oxidizing bacteria and Mn(IV) reducing bacteria is the driving force for the MnOx utilization. The common category, characteristics and functions of Mn microorganisms in recent studies were also reviewed. Finally, the discussion on the influence factors, microbial response, reaction mechanism and potential risk of MnOx application in pollutants' transformation were proposed, which might be the promising opportunities for the future investigation of MnOx application in wastewater treatment.
Topics: Manganese; Wastewater; Oxides; Manganese Compounds; Oxidation-Reduction; Bacteria
PubMed: 37327824
DOI: 10.1016/j.chemosphere.2023.139219 -
Water Research Sep 2023A comparative study of the different advanced oxidation processes (Fe(II)-Oxone, Fe(II)-HO, and Fe(II)-NaClO) was carried out herein to analyze the characteristics of...
Behavior of organic components and the migration of heavy metals during sludge dewatering by different advanced oxidation processes via optical spectroscopy and molecular fingerprint analysis.
A comparative study of the different advanced oxidation processes (Fe(II)-Oxone, Fe(II)-HO, and Fe(II)-NaClO) was carried out herein to analyze the characteristics of organic components and the migration of heavy metals in waste activated sludge. With the Fe(II)-Oxone and Fe(II)-HO treatments, sludge dewaterability was significantly improved, however, sludge dewaterability was deteriorated by the Fe(II)-NaClO treatment. The enhanced sludge dewaterability by the Fe(II)-Oxone and Fe(II)-HO treatments was strongly correlated with the shifted organic components, particularly proteins, in soluble extracellular polymeric substances (S-EPS), while the deteriorated sludge dewaterability by the Fe(II)-NaClO treatment was strongly correlated with the over release of organic components from bound EPS (B-EPS) to S-EPS. For both the Fe(II)-Oxone and Fe(II)-HO treatments, the radicals preferentially attacked humic acid-like organic components over the protein-like organic components in S-EPS, while for the Fe(II)-NaClO treatment, interestingly, the radicals preferentially attacked the protein-like organic components in both S-EPS and B-EPS. The hydrophilic functional groups like phenolic OH and CO of polysaccharides may be more preferentially migrated to S-EPS of sludge by the Fe(II)-NaClO treatment compared to the other two treatments. With the Fe(II)-Oxone and Fe(II)-HO treatments, the proportion of aliphatic compounds as well as the much oxygenated organic components with a low desaturation and a low molecular weight increased. While with the Fe(II)-NaClO treatment, the proportion of low oxygenated organic components with a high desaturation and a high molecular weight increased. The concentration of total organic carbon, particularly the concentration of proteins, may be the key factor determining the shift of Zn and Cu from sludge solid to liquid phase, along with the high oxidation extent of organic components and close binding to CHOS and CHON compounds as indicated by density functional theory (DFT) calculation. This study systematically revealed the simultaneous sludge dewatering and migration of heavy metals when the role of organic components was factored into herein.
Topics: Sewage; Hydrogen Peroxide; Waste Disposal, Fluid; Water; Metals, Heavy; Oxidation-Reduction; Spectrum Analysis; Proteins; Ferrous Compounds
PubMed: 37454458
DOI: 10.1016/j.watres.2023.120336 -
Chemosphere Nov 2023The rapid and efficient mineralization of the chemotherapeutic drug busulfan (BSF) as the target pollutant has been investigated for the first time by three different...
The rapid and efficient mineralization of the chemotherapeutic drug busulfan (BSF) as the target pollutant has been investigated for the first time by three different heterogeneous EF systems that were constructed to ensure the continuous electro-generation of HO and OH consisting of: i) a multifunctional carbon felt (CF) based cathode composed of reduced graphene oxide (rGO), iron oxide nanoparticles and carbon black (CB) (rGO-FeO/CB@CF), ii) rGO modified cathode (rGO/CB@CF) and rGO supported FeO (rGO-FeO) catalyst and iii) rGO modified cathode (rGO/CB@CF) and multi walled carbon nanotube supported FeO (MWCNT-FeO) catalyst. The effects of main variables, including the catalyst amount, applied current and initial pH were investigated. Based on the results, HO was produced by oxygen reduction reaction (ORR) on the liquid-solid interface of both fabricated cathodes. OH was generated by the reaction of HO with the active site of ≡Fe on the surface of the multifunctional cathode and heterogeneous EF catalysts. Utilizing carbon materials with high conductivity, the redox cycling between ≡Fe and ≡Fe was effectively facilitated and therefore promoted the performance of the process. The results demonstrated almost complete mineralization of BSF through the heterogeneous systems over a wide applicable pH range. According to the reusability and stability tests, multifunctional cathode exhibited outstanding performance after five consecutive cycles which is promising for the efficient mineralization of refractory organic pollutants. Moreover, intermediates products of BSF oxidation were identified and a plausible oxidation pathway was proposed. Therefore, this study demonstrates efficient and stable cathodes and catalysts for the efficient treatment of an anticancer active substance.
Topics: Busulfan; Ferric Compounds; Hydrogen Peroxide; Electric Conductivity; Environmental Pollutants; Nanocomposites; Soot; Ferrous Compounds
PubMed: 37690550
DOI: 10.1016/j.chemosphere.2023.140129 -
Plant Science : An International... Jul 2023Chromium contamination of the soil is a major scientific concern with reference to crop productivity and human health. In recent years, several approaches are being...
Nitric oxide and hydrogen peroxide mediated regulation of chromium (VI) toxicity in wheat seedlings involves alterations in antioxidants and high affinity sulfate transporter.
Chromium contamination of the soil is a major scientific concern with reference to crop productivity and human health. In recent years, several approaches are being employed in managing metal toxicity in crop plants. Here, we have investigated about potential and probable crosstalk of nitric oxide (NO) and hydrogen peroxide (HO) in mitigating hexavalent chromium [Cr(VI)] toxicity in wheat seedlings. Cr(VI) toxicity reduced the fresh mass and overall growth due to accumulation of reactive oxygen species (ROS) and decreased efficiency of AsA-GSH cycle and downregulation of high affinity sulfate transporter. However, exogenous treatment of NO and HO significantly alleviated Cr toxicity. Application of NO and ROS scavengers reversed stress mitigating effects of NO and HO, respectively suggesting that endogenous NO and HO are necessary for rendering Cr toxicity tolerance. Furthermore, NO rescued negative effect of diphenylene iodonium (DPI, NADPH oxidase inhibitor) and HO reversed the negative effect of c-PTIO suggesting that they exhibit independent signalling in mitigating Cr stress. Altogether, data indicated that NO and HO rendered mitigation of Cr stress by up-regulating enzymes (activity and relative gene expression) and metabolites of AsA-GSH cycle, high affinity sulfate transporter (relative gene expression) and glutathione biosynthesis which collectively controlled occurrence of oxidative stress.
Topics: Humans; Antioxidants; Seedlings; Hydrogen Peroxide; Nitric Oxide; Triticum; Reactive Oxygen Species; Chromium; Oxidative Stress; Glutathione
PubMed: 37023859
DOI: 10.1016/j.plantsci.2023.111697 -
Chemosphere Oct 2023Contaminants in water pose a significant challenge as they are harmful and difficult to treat using conventional methods. Therefore, various new methods have been... (Review)
Review
Contaminants in water pose a significant challenge as they are harmful and difficult to treat using conventional methods. Therefore, various new methods have been proposed to degrade organic pollutants in water, among which the photo-Fenton process is considered promising. In recent years, Fe-based metal-organic frameworks (Fe-MOFs) have gained attention and found applications in different fields due to their cost-effectiveness, non-toxic nature, and unique porous structure. Many researchers have applied Fe-MOFs to the photo-Fenton process in recent years and achieved good results. This review focuses on describing different strategies for enhancing the performance of Fe-MOFs in the photo-Fenton process. Also, the mechanism of MOF in the photo-Fenton process is described in detail. Finally, prospects for the application of Fe-MOFs in photo-Fenton systems for the treatment of organic pollutants in water are presented. This study provides information and ideas for researchers to use Fe-MOFs to remove organic pollutants from water by photo-Fenton process.
Topics: Iron; Metal-Organic Frameworks; Hydrogen Peroxide; Water Pollutants, Chemical; Oxidation-Reduction; Environmental Pollutants; Water
PubMed: 37536536
DOI: 10.1016/j.chemosphere.2023.139673 -
Environmental Science and Pollution... Jul 2023The WO nanostructures were synthesized by a simple hydrothermal route in the presence of CTAB and gemini-based twin-tail surfactant. The impact of using these special...
The WO nanostructures were synthesized by a simple hydrothermal route in the presence of CTAB and gemini-based twin-tail surfactant. The impact of using these special shape and size directing agents for the synthesis of nanostructures was observed in the form of different shapes and sizes. The WO web of chains type nanostructure was obtained using CTAB in comparison to the cube-shaped nanoparticles through twin-tail surfactant. On contrary, the twin-tail surfactant provides sustainable and controlled growth of cube shape nanoparticles of size ~ 15 nm nearly half of the size ~ 35 nm obtained using conventional surfactant CTAB, respectively. For the detailed structural features, the Williamson-Hall analysis method was implemented to find out the crystalline size and lattice strain of the prepared nanostructures. Owing to the strong quantum confinement effect, the WO cube-shaped nanoparticles with an optical band gap of 2.69 eV of the prepared nanoparticles showed excellent photocatalytic efficacy toward organic pollutant (fast green FCF) compared to the web of chain nanostructures with an optical band gap of 2.66 eV. The ability of the prepared systems to decompose the organic pollutant (fast green FCF) in water was tested under visible light irradiations. The percentage degradation was found to be 94% and 86% for WO cube-shaped nanoparticles and WO web of chains, respectively. The simplicity of the fabrication method and the high photocatalytic performance of the systems can be promising in environmental applications to treat water pollution.
Topics: Nanostructures; Oxides; Tungsten; Surface-Active Agents
PubMed: 37253911
DOI: 10.1007/s11356-023-27891-5 -
Environmental Science and Pollution... Oct 2023Ionic liquids (ILs) are the class of materials which are purely ionic in nature and liquid at room temperature. Their remarkable properties like very low vapour... (Review)
Review
Ionic liquids (ILs) are the class of materials which are purely ionic in nature and liquid at room temperature. Their remarkable properties like very low vapour pressure, non-inflammable and high heat resistance are responsible for their use as a very appealing solvent in a variety of industrial applications in place of regular organic solvents. Because ILs are water soluble to a certain extent, the industrial wastewater effluents are found to contaminate with their traces. The non-biodegradability of ILs attracts the attention of the researchers for their removal or degradation from wastewater. Numbers of methods are available for the treatment of wastewater. However, it is very crucial to use the most efficient method for the degradation of ILs. Advanced oxidation process (AOP) is one of the most important techniques for the treatment of ILs in wastewater which have been investigated during last decades. This review paper covers the cost-effective Fenton, photochemical and photocatalytic AOPs and their combination that could be applied for the degradation of ILs from the wastewater. Theoretical explanations of these AOPs along with experimental conditions and kinetics of degradation or removal of ILs from water and wastewater have been reported and compared. Finally, future perspectives of IL degradation are presented.
Topics: Ionic Liquids; Wastewater; Solvents; Water; Oxidation-Reduction; Water Pollutants, Chemical; Oxidative Stress; Hydrogen Peroxide; Water Purification
PubMed: 37715035
DOI: 10.1007/s11356-023-29777-y -
Environmental Science & Technology Jul 2023Volatile organic compounds (VOCs) harm the environment and human health and have been of wide concern and purified efficiently by catalytic oxidation. Spinel oxides,... (Review)
Review
Volatile organic compounds (VOCs) harm the environment and human health and have been of wide concern and purified efficiently by catalytic oxidation. Spinel oxides, mainly composed of transition metal elements with low price and extensive sources, have been widely investigated as efficient and stable catalysts for VOCs oxidation due to their adjustable element composition, flexible structure, and high thermal/chemical stability. However, it is necessary to dissect the design of the spinel in a targeted way to satisfy the removal of different types of VOCs. This article systematically summarizes the recent advances regarding the application of spinel oxides for VOCs catalytic oxidation. Specifically, the design strategies of spinel oxides were first introduced to clarify their effect on the structure and properties of the catalyst. Then the reaction mechanism and degradation pathway of different kinds of VOCs on the spinel oxides were in detail summarized, and the characteristic requirements of the spinel oxides for various VOCs purification were analyzed. Furthermore, the practice applications were also discussed. Finally, the prospects were proposed to guide the rational design of spinel-based catalysts for VOCs purification and intensify the understanding of reaction mechanisms.
Topics: Humans; Oxides; Volatile Organic Compounds; Oxidation-Reduction; Aluminum Oxide; Catalysis
PubMed: 37313598
DOI: 10.1021/acs.est.2c09861 -
Environmental Science & Technology Nov 2023The industrial effluent from glyphosate production has high salinity and refractory organic contaminants. The removal of organics and the recycling of inorganic salts...
The industrial effluent from glyphosate production has high salinity and refractory organic contaminants. The removal of organics and the recycling of inorganic salts from this kind of water are challenging issues. In this study, electro-Fenton (EF) and membrane distillation (MD) were coupled in a single reactor utilizing a membrane-based electrode (Mem-GDE) with the ability to bidirectionally transfer vapor and oxygen and electrochemically synthesize HO. The operating thermal conditions for MD significantly promoted Fenton reactions and, thus, the removal of glyphosate. During operation, Fe species deposited on the Mem-GDE and enhanced its catalytic activity and adsorptive capacity, which markedly increased the apparent reaction rate constant of glyphosate by 6 times. This novel EF-MD process simultaneously removed organics and concentrated the inorganics, which is very meaningful for decreasing the costs for subsequent crystallization and achieving high-quality crystal salts. This study provides an efficient method for the treatment of organic-inorganic hybrid wastewater.
Topics: Distillation; Hydrogen Peroxide; Salts; Wastewater; Water Pollutants, Chemical; Oxidation-Reduction; Glyphosate
PubMed: 37556354
DOI: 10.1021/acs.est.3c02987