Puthiya Veetil Nidheesh

Bio: Puthiya Veetil Nidheesh is an academic researcher from National Environmental Engineering Research Institute. The author has contributed to research in topics: Wastewater & Chemistry. The author has an hindex of 36, co-authored 113 publications receiving 4817 citations. Previous affiliations of Puthiya Veetil Nidheesh include Council of Scientific and Industrial Research & National Institute of Technology Calicut.

Degradation of dyes from aqueous solution by Fenton processes: a review

Abstract: Several industries are using dyes as coloring agents. The effluents from these industries are increasingly becoming an environmental problem. The removal of dyes from aqueous solution has a great potential in the field of environmental engineering. This paper reviews the classification, characteristics, and problems of dyes in detail. Advantages and disadvantages of different methods used for dye removal are also analyzed. Among these methods, Fenton process-based advanced oxidation processes are an emerging prospect in the field of dye removal. Fenton processes have been classified and represented as “Fenton circle”. This paper analyzes the recent studies on Fenton processes. The studies include analyzing different configurations of reactors used for dye removal, its efficiency, and the effects of various operating parameters such as pH, catalyst concentration, H2O2 concentration, initial dye concentration, and temperature of Fenton processes. From the present study, it can be conclude that Fenton processes are very effective and environmentally friendly methods for dye removal.

Heterogeneous Fenton catalysts for the abatement of organic pollutants from aqueous solution: a review

Abstract: Fenton processes have gained much attention in the field of wastewater treatment during recent years. In order to overcome the disadvantages of Fenton processes, research has focused more on the heterogeneous Fenton process, with highly active and stable solid catalysts. This review reports on advances in the field of heterogeneous Fenton processes in recent years, especially focusing on the various heterogeneous catalysts used. After a general introduction to the various Fenton processes, their advantages and the importance of heterogeneous Fenton processes, various catalysts used in heterogeneous Fenton processes are described in detail. These catalysts are divided into iron minerals, zero-valent iron, waste materials, iron- and iron oxide-loaded materials, and clay. The properties, stability, activity and pollutant degradation mechanism of various catalysts are also discussed in detail.

Advanced Oxidation Processes in Water/Wastewater Treatment: Principles and Applications. A Review

Abstract: Advanced oxidation processes (AOPs) constitute important, promising, efficient, and environmental-friendly methods developed to principally remove persistent organic pollutants (POPs) from waters and wastewaters. Generally, AOPs are based on the in situ generation of a powerful oxidizing agent, such as hydroxyl radicals (•OH), obtained at a sufficient concentration to effectively decontaminate waters. This critical review presents a precise and overall description of the recent literature (period 1990–2012) concerning the main types of AOPs, based on chemical, photochemical, sonochemical, and electrochemical reactions. The principles, performances, advantages, drawbacks, and applications of these AOPs to the degradation and destruction of POPs in aquatic media and to the treatment of waters and waste waters have been reported and compared.

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.