Farshid Ghanbari

Bio: Farshid Ghanbari is an academic researcher from Ahvaz Jundishapur University of Medical Sciences. The author has contributed to research in topics: Chemistry & Catalysis. The author has an hindex of 36, co-authored 97 publications receiving 3896 citations. Previous affiliations of Farshid Ghanbari include Shahid Beheshti University of Medical Sciences and Health Services.

A comparative study of electrocoagulation, electrochemical Fenton, electro-Fenton and peroxi-coagulation for decolorization of real textile wastewater: Electrical energy consumption and biodegradability improvement

Abstract: The main problem of textile wastewater is strong color which must be removed before discharge to the environment. Electrochemical processes have been separately studied for decolorization of synthetic dyes and colored wastewater. In this study, iron-based electrochemical processes including electrocoagulation (EC), electrochemical Fenton (ECF), electro-Fenton (EF) and peroxi-coagulation (PC) were applied for real textile wastewater decolorization in similar conditions. The effects of initial pH, electrical current and electrolysis time on decolorization were evaluated. COD removal, electrical energy consumption, iron consumption and BOD 5 /COD ratio of each process were compared. All the processes sufficiently removed color from the wastewater in as much as between 77% and 94% decolorization efficiency was gained. The results indicated that decolorization efficiency in EC and EF processes was strongly dependent on initial pH. At optimum conditions, the highest energy consumption and iron consumption were found in EF and PC respectively. Electrochemical processes based on Fenton reagent (ECF, EF and PC) enhanced BOD 5 /COD ratio from 0.137 to over 0.3 while EC process could not increase BOD 5 /COD ratio significantly. All the processes followed the second order kinetic for COD parameter in optimum conditions. As a comparison from the obtained results, the ECF process was more effective than the other processes with regard to color and COD removals.

Generation of sulfate radical through heterogeneous catalysis for organic contaminants removal: Current development, challenges and prospects

Abstract: Sulfate radical-based advanced oxidation processes (SR-AOPs) employing heterogeneous catalysts to generate sulfate radical (SO4 −) from peroxymonosulfate (PMS) and persulfate (PS) have been extensively employed for organic contaminant removal in water. This article aims to provide a state–of–the–art review on the recent development in heterogeneous catalysts including single metal, mixed metal, and nonmetal carbon catalysts for organic contaminants removal, with particular focus on PMS activation. The hybrid heterogeneous catalyst/PMS systems integrated with other advanced oxidation technologies is also discussed. Several strategies for the identification of principal reactive radicals in SO4 −–oxidation systems are evaluated, namely (i) use of chemical probe or spin trapping agent coupled with analytical tools, and (ii) competitive kinetic approach using selective radical scavengers. The main challenges and mitigation strategies pertinent to the SR-AOPs are identified, which include (i) possible formation of oxyanions and disinfection byproducts, and (ii) dealing with sulfate produced and residual PMS. Potential future applications and research direction of SR-AOPs are proposed. These include (i) novel reactor design for heterogeneous catalytic system based on batch or continuous flow (e.g. completely mixed or plug flow) reactor configuration with catalyst recovery, and (ii) catalytic ceramic membrane incorporating SR-AOPs.

Cobalt-catalyzed sulfate radical-based advanced oxidation: A review on heterogeneous catalysts and applications

Abstract: Recently sulfate radical-based advanced oxidation processes (SR-AOPs) attract increasing attention due to their capability and adaptability in decontamination. The couple of cobalt and peroxymonosulfate (PMS) is an efficient way to produce reactive sulfate radicals. This article reviews the state-of-the-art progress on various heterogeneous cobalt-based catalysts for PMS activation, including cobalt oxides, cobalt-ferrite and supported cobalt by diverse substrates. We summarize the intrinsic properties of these catalysts and their fundamental behaviors in PMS activation, as well as synthetic approaches. In addition, influencing factors and synergistic techniques of Co/PMS systems in organic degradation and possible environmental applications are also discussed. Finally, we propose perspectives on challenges related to cobalt-based catalysts, heterogeneous Co/PMS systems and their potential applications in practical environmental cleanup.

Persulfate-Based Advanced Oxidation: Critical Assessment of Opportunities and Roadblocks.

Abstract: Reports that promote persulfate-based advanced oxidation process (AOP) as a viable alternative to hydrogen peroxide-based processes have been rapidly accumulating in recent water treatment literature. Various strategies to activate peroxide bonds in persulfate precursors have been proposed and the capacity to degrade a wide range of organic pollutants has been demonstrated. Compared to traditional AOPs in which hydroxyl radical serves as the main oxidant, persulfate-based AOPs have been claimed to involve different in situ generated oxidants such as sulfate radical and singlet oxygen as well as nonradical oxidation pathways. However, there exist controversial observations and interpretations around some of these claims, challenging robust scientific progress of this technology toward practical use. This Critical Review comparatively examines the activation mechanisms of peroxymonosulfate and peroxydisulfate and the formation pathways of oxidizing species. Properties of the main oxidizing species are scrutinized and the role of singlet oxygen is debated. In addition, the impacts of water parameters and constituents such as pH, background organic matter, halide, phosphate, and carbonate on persulfate-driven chemistry are discussed. The opportunity for niche applications is also presented, emphasizing the need for parallel efforts to remove currently prevalent knowledge roadblocks.