Since the first connection between Fenton chemistry and biomedicine, numerous studies have been presented in this field. Comprehensive presentation of the guidance from Fenton chemistry and a summary of its representative applications in cancer therapy would help us understand and promote the further development of this field. This comprehensive review first supplies basic information regarding Fenton chemistry, including Fenton reactions and Fenton-like reactions. Subsequently, the current progress of Fenton chemistry is discussed, with some corresponding representative examples presented. Furthermore, the current strategies for further optimizing the performance of chemodynamic therapy guided by Fenton chemistry are highlighted. Most importantly, future perspectives on the combination of biomedicine with Fenton chemistry or a wider range of catalytic chemistry approaches are presented. We hope that this review will attract positive attention in the chemistry, materials science, and biomedicine fields and further tighten their connections.

Biomedicine Meets Fenton Chemistry.

Harvesting solar energy for energy and environmental applications is an ever-fascinating field of research. Although semiconductor photocatalysis is the potential tool for recalcitrant degradation, it still suffers from rapid recombination, inability to utilize visible light, and lower photocatalytic performance. Recently, the Z-scheme photocatalysts are becoming research hotspots for their strong redox ability, charge carrier separation, and ability to exploit visible light. This review provides insights into the fundamental mechanism, synthesis strategies, and characterization techniques of Z-scheme photocatalysts. The recent advancements in their applications in visible-light-driven pollutants degradation are also reviewed.

Z-scheme photocatalysts for visible-light-driven pollutants degradation: A review on recent advancements

Food dyes are a large group of dyes which have been widely used in the food industry. The presence of them in aquatic media results in water pollution. In this work, a heterogeneous photo-assisted peroxymonosulfate (PMS) activation process was used to degrade Azorubine (AZB). Fe2O3 loaded on multi-wall carbon nanotube (Fe@MWCNT) was synthesized and applied to activate PMS under UVA-LED irradiation. Fe@MWCNT catalyst was characterized by XRD, FTIR, EDX-map, BET, FESEM, and TEM analyses. UVA-LED/Fe@MWCNT/PMS process removed around 95% of AZB from aqueous solution under pH= 5, PMS= 1.8 mM, and 130 mg/L Fe@MWCNT. Sulfate radicals showed a higher contribution for AZB degradation compared to hydroxyl radicals and singlet oxygen. Pseudo-first-order model was fitted on AZB degradation with a rate constant of 0.095 min−1. Bicarbonate ions and humic acid had an ultra-inhibitory effect on the oxidative process. Carboxylic acids were monitored during AZB degradation, with the results indicating that aromatic rings of AZB were opened by the attack of sulfate and hydroxyl radicals. Six cycles of the catalyst reuse demonstrated no significant change in the performance of the UVA-LED/Fe@MWCNT/PMS process. The implementation of the UVA-LED/Fe@MWCNT/PMS process was also successfully studied on other food dyes and real wastewater. UVA-LED/Fe@MWCNT/PMS process was an efficient approach for the degradation of organic contaminants in water with high stability.

Azurobine degradation using Fe2O3@multi-walled carbon nanotube activated peroxymonosulfate (PMS) under UVA-LED irradiation: performance, mechanism and environmental application

In the present study, mpg-C3N4/Ag/ZnO NWs/Zn photocatalyst plates were fabricated through facile dip-coating process of silver (Ag) and mesoporous graphitic carbon nitride (mpg-C3N4) onto zinc oxide nanowires (ZnO NWs) previously formed by electrochemical anodizing of Zn plates. The structure, optical and electrochemical characterizations of the fabricated samples were investigated by XRD, FESEM, EDX, TEM, FTIR, BET, PL, UV–vis DRS, and EIS analyses. To evaluate the photocatalytic activity of the plates, the main key factors such as number of photocatalyst plates, dye concentration, initial pH, and reaction time for the degradation of Direct Orange 26 (DO26) dye under ultraviolet (UV) light illumination were studied. The best photocatalytic efficiency of 94 % was achieved using four photocatalyst plates, 10 mg/L DO26, and pH = 6 in 120 min of reaction time. The integration of the mpg-C3N4/Ag/ZnO NWs/Zn plates, adsorption, and photolysis inferred the existence of a synergy index of 5 for the degradation of target pollutant. In the presence of edetate disodium (EDTA-2Na) and ethanol (EtOH), degradation efficiency of DO26 was remarkably dropped to 43.6 % and 19.3 % by the photocatalytic process respectively, indicating the major role of h+ and OH in the destruction of target molecules. The overwhelming photocatalytic mechanism of the photocatalyst was further clarified for the elimination of DO26. The fabricated photocatalyst demonstrated remarkable stability and recyclability for four consecutive catalytic cycles. Fabrication of the mpg-C3N4/Ag/ZnO NWs/Zn plates is anticipated to be a rational design for photocatalytic degradation of various pollutants.

Facile fabrication of mpg-C3N4/Ag/ZnO nanowires/Zn photocatalyst plates for photodegradation of dye pollutant

Electrochemical activation of peroxides for treatment of contaminated water with landfill leachate: Efficacy, toxicity and biodegradability evaluation

Several efforts have been conducted to reach an efficient and safe process for degradation of organic pollutants in water environments. Percarbonate (PC) or solid hydrogen peroxide has gained great attention as an alternative for hydrogen peroxide in advanced oxidation processes. In current work, sono-photo activation method was used to PC activation for degradation of Acid Orange 7 (AO7). Ultrasound (US) and ultraviolet light emitted diode (UVC-LEDs) were prosperous in the generation of free radicals in presence of PC. Under optimum conditions (pH = 6.0, PC = 1.5 mM, 100 W US power and 90 reaction time), 93% of AO7 was eliminated while its rate constant was 0.0315 min−1. There was a promotional effect for chloride and nitrate ions at high concentration in PC/US/UVC-LEDs process. Nitrate ions photolysis and sonolysis could degrade AO7 indicating that hydroxyl radical are generated in absent of PC. A major role for hydroxyl radical and minor role for superoxide radical were determined by trapping experiments. PC/US/UVC-LEDs was also applied for an actual matrix which was not successful as well as synthetic solution. By-products of AO7 degradation was identified and proposed reaction was illustrated. This article conclusively states that PC/US/UVC-LEDs can be a new method for the degradation of organic pollutants in water.

Sono-photo activation of percarbonate for the degradation of organic dye: The effect of water matrix and identification of by-products

In this work, a simple method was used for the preparation of CuO@activated carbon (AC) composite for peroxydisulfate (PDS) activation to treat a real textile wastewater for the first time. The characteristics of the catalyst were determined by several methods. The performance of various processes was evaluated on total organic carbon (TOC) removal from the textile wastewater. Around 61 % of TOC was eliminated under the conditions of PDS = 7 mM, CuO@AC = 1 g/L, pH = 7 and 60 min reaction time. Other parameters were also studied indicating that 95 % of color, 72 % of COD (Chemical Oxygen Demand) and 70 % of BOD (Biochemical Oxygen Demand) were removed during treatment process. Kinetic studies showed that pseudo-first order was well fitted for color, COD, BOD and TOC removals with obtained rate constants of 0.054, 0.023, 0.021 and 0.018 min−1 respectively. The reusability and stability of CuO@AC catalyst were tested; the results demonstrated that three cycles of catalyst use were acceptable and copper leaching was negligible. Acute toxicity of raw and treated wastewater was also evaluated by Daphnia magna. According to acute toxicity results, PDS/CuO@AC process removed the toxicity of textile wastewater significantly. As a conclusion, PDS/CuO@AC process can be applied for real wastewater treatment and detoxification. This process can be an alternative oxidation process for the degradation of organic pollutants.

Real textile wastewater treatment by a sulfate radicals-Advanced Oxidation Process: Peroxydisulfate decomposition using copper oxide (CuO) supported onto activated carbon

Fatemeh Mirzaei

Papers

Sono-photo activation of percarbonate for the degradation of organic dye: The effect of water matrix and identification of by-products

Real textile wastewater treatment by a sulfate radicals-Advanced Oxidation Process: Peroxydisulfate decomposition using copper oxide (CuO) supported onto activated carbon