Subramanyan Vasudevan

Bio: Subramanyan Vasudevan is an academic researcher from Council of Scientific and Industrial Research. The author has contributed to research in topics: Adsorption & Langmuir adsorption model. The author has an hindex of 38, co-authored 96 publications receiving 3725 citations. Previous affiliations of Subramanyan Vasudevan include Central Electro Chemical Research Institute & Academy of Scientific and Innovative Research.

Electrochemistry: as cause and cure in water pollution—an overview

Abstract: This article reviews both the pollution by the electrochemical industry and the use of electrochemistry to clean water. Main pollutants include Pd, Cd, Ni, Hg and other metals and cyanide as well as organic pollutants. The cause for water pollution by electrochemistry is due to the effluents from different electrochemical industries such as mercury from chlor-alkali industry; lead, cadmium and mercury from battery industry; heavy metals and organic contaminants from electroplating wastes; contaminants from corrosion processes; and persistent organic pollutants from the synthesis and use of pesticides, dyes and pharmaceuticals. Most pollutants can be successfully eliminated or converted to non-toxic materials by methods based on the electrochemical principles. Electrochemical depolluting methods are mainly electrodialysis, electrocoagulation, electroflotation, anodic processes, cathodic processes and electrochemical advanced oxidation processes.

Adsorption kinetics, isotherms, and thermodynamic studies for Hg2+ adsorption from aqueous medium using alizarin red-S-loaded amberlite IRA-400 resin

Abstract: Alizarin red-S-modified amberlite IRA-400 resin (ARSA) was applied for Hg2+ removal from the aqueous medium which is a highly toxic metal ion. The adsorption process which was pH dependent, showed maximum adsorption of Hg2+ in the pH range 6–8. ARSA exhibited good monolayer adsorption capacity for Hg2+ (303.03 mg g−1) at 25°C and the isotherm was well fitted by the Langmuir model. Moreover, the adsorption was evaluated thermodynamically and the negative values of Gibbs free energy revealed the spontaneity of adsorption process. The practical applicability of ARSA was explored for the adsorption of Hg2+ metal ion from a real water sample. The values of ΔH and ΔS were found to be 79.87 kJ mol−1 and 0.26 J mol−1 K−1, respectively.

The adsorption of phosphate by graphene from aqueous solution

Abstract: Graphene was prepared by a facile liquid phase exfoliation and characterized by Raman spectroscopy, Fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy and zeta potential measurements. A systematic study of the adsorption process was performed by varying pH, ionic strength and temperature. The experimental results showed that graphene is an excellent phosphate adsorbent with an adsorption capacity of up to 89.37 mg g−1 at an initial phosphate concentration of 100 mg L−1 and temperature of 303 K. The adsorption kinetics was modeled by first and second order rate, Elovich and Weber and Morris intraparticle diffusion models. The rate constants for all of these kinetic models were calculated and the results indicate that the second order kinetics model was well-suited to model the kinetic adsorption of phosphate. The Langmuir, Freundlich and D–R isotherm models were applied to describe the equilibrium isotherms and the isotherm constants were determined. Equilibrium data were well-described by the typical Langmuir adsorption isotherm. Thermodynamic studies revealed that the adsorption reaction was a spontaneous and endothermic process.

Functionalization of Graphene: Covalent and Non-Covalent Approaches, Derivatives and Applications

Abstract: Approaches, Derivatives and Applications Vasilios Georgakilas,† Michal Otyepka,‡ Athanasios B. Bourlinos,‡ Vimlesh Chandra, Namdong Kim, K. Christian Kemp, Pavel Hobza,‡,§,⊥ Radek Zboril,*,‡ and Kwang S. Kim* †Institute of Materials Science, NCSR “Demokritos”, Ag. Paraskevi Attikis, 15310 Athens, Greece ‡Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo naḿ. 2, 166 10 Prague 6, Czech Republic

Electrochemical advanced oxidation processes: A review on their application to synthetic and real wastewaters

Abstract: Over the last decades, research efforts have been made at developing more effective technologies for the remediation of waters containing persistent organic pollutants. Among the various technologies, the so-called electrochemical advanced oxidation processes (EAOPs) have caused increasing interest. These technologies are based on the electrochemical generation of strong oxidants such as hydroxyl radicals ( OH). Here, we present an exhaustive review on the treatment of various synthetic and real wastewaters by five key EAOPs, i.e., anodic oxidation (AO), anodic oxidation with electrogenerated H 2 O 2 (AO-H 2 O 2 ), electro-Fenton (EF), photoelectro-Fenton (PEF) and solar photoelectro-Fenton (SPEF), alone and in combination with other methods like biological treatment, electrocoagulation, coagulation and membrane filtration processes. Fundamentals of each EAOP are also given.

Environmental applications of graphene-based nanomaterials.

Abstract: Graphene-based materials are gaining heightened attention as novel materials for environmental applications The unique physicochemical properties of graphene, notably its exceptionally high surface area, electron mobility, thermal conductivity, and mechanical strength, can lead to novel or improved technologies to address the pressing global environmental challenges This critical review assesses the recent developments in the use of graphene-based materials as sorbent or photocatalytic materials for environmental decontamination, as building blocks for next generation water treatment and desalination membranes, and as electrode materials for contaminant monitoring or removal The most promising areas of research are highlighted, with a discussion of the main challenges that we need to overcome in order to fully realize the exceptional properties of graphene in environmental applications

Efficient techniques for the removal of toxic heavy metals from aquatic environment: A review

Abstract: The controversy related to the environment pollution is increasing in human life and in the eco-system. Especially, the water pollution is growing rapidly due to the wastewater discharge from the industries. The only way to find the new water resource is the reuse of treated wastewater. Several remediation technologies are available which provides a convenience to reuse the reclaimed wastewater. Heavy metals like Zn, Cu, Pb, Ni, Cd, Hg, etc. contributes various environmental problems based on their toxicity. These toxic metals are exposed to human and environment, the accumulation of ions takes place which causes serious health and environmental hazards. Hence, it is a major concern in the environment. Due to this concern, the significance of developing technology for removing heavy metals has been increased. This paper contributes the outline of new literature with two objectives. First, it provides the sketch about treatment technologies followed by their heavy metal capture capacity from industrial effluent. The treatment performance, their remediation capacity and probable environmental and health impacts were deliberated in this review article. Conclusively, this review paper furnishes the information about the important methods incorporated in lab scale studies which are required to identify the feasible and convenient wastewater treatment. Moreover, attempts have been made to confer the emphasis on sequestration of heavy metals from industrial effluent and establish the scientific background for reducing the discharge of heavy metals into the environment.