The corrosion inhibitive effect of Derris indica leaves extract (DILE) on aluminium in 1 M NaOH is investigated at different temperatures. For this purpose, weight loss studies and electrochemical methods including potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) technique are employed. Surface analysis of the treated and untreated aluminium coupons are done by using metallurgical microscopy. About 60.2% of maximum corrosion inhibition efficiency is attained with an optimum inhibitor concentration of 1.2 g/L. Both weight loss and electrochemical studies confirmed that DILE plays a crucial role in the formation of a protective layer over metal surfaces. Also, electrochemical measurements revealed that DILE behaves as a mixed type of corrosion inhibitor. The kinetic parameters and thermodynamic parameters are calculated using Arrhenius theory and transition state theory. Langmuir adsorption isotherm was found to be the best fit and physical adsorption mechanism was proposed.

Development of highly efficient, low cost adsorbents for heavy metal ion removal from wastewater is an enduring undertaking. Two major groups of nanocomposite adsorbents are reviewed here. The magnetic carbon family is first discussed including the preparation of such materials. Various carbon sources have been used in the preparation, and the structural characteristics have been analyzed. Cr(VI) removal studies unveil a wide range of performance. The second group adsorbents is polymer functionalized nanocomposites. One notable polymer is polyaniline which is a redox polymer. The redox nature allows the composite materials to facilitate Cr(VI) reduction to Cr(III) which is prone to precipitate under neutral pH condition. The studies show that polyaniline can be feasibly synthesized in situ to cover the support surface, while the support provides mechanical strength and suitable surface area for Cr adsorption. A similar approach is the in situ synthesis of poly(acrylic acid) in the presence of support materials. This group of materials have been applied in Pb(II) removal and the performance is analyzed. 38 environment. Hexavalent chromium Cr(VI) is 500 times more toxic 39 and carcinogenic than trivalent chromium Cr(III). Cr(VI) is considered 40 to cause severe diseases such as dermatitis and lung cancer. According to the drinking water regulations recommended by EPA, the maximum-1 41 concentration for total Cr in drinking water is 0.1 mg L. The World

Industrial processes and anthropogenic activities generate huge amounts of wastes in the form of chemicals, such as heavy metals, dyes, fertilizers, pharmaceutically active chemicals, battery effluents and so on. When these chemicals are left untreated and discarded in the ground or surface waters, they not only cause pollution and harm the ecosystem but also cause toxic effects on the health of human beings, animals and food crops. There are several methods of removal of these toxic materials from the wastewaters, and adsorption by bio-sorbents has been demonstrated as one of the most inexpensive, efficient and convenient methods. Citrus is one of the largest grown fruit crops in the tropical and subtropical regions on the planet. After processing of the fruits at food processing industries, approximately half of the fruit mass is discarded as waste, which causes a number of pollution problems. Alternately, this biomass can be converted to bio-sorbents for the removal of harmful and toxic chemicals from the industrial effluents and wastewaters. The first part of this article contains a thorough review on the biotransformation of citrus waste for the production of biofuel and valuable compounds by fermentation involving microorganisms. The second and concluding part reviews the recent progress in biotransformation of citrus waste biomass (that may be remaining post-extraction of valuable compounds/biofuel generation) into efficient adsorbent substrate materials and their adsorption capacities. The article also includes the details of the synthesis process and mechanisms of adsorption processes.

MoS nanosheets were prepared by a facile hydrothermal method and its morphology and structural properties were characterized by FE-SEM and 2 XRD analysis. MoS nanosheets reinforced Ni composite coatings were prepared by a simple electrodeposition method using various 2 concentrations of MoS in Watts nickel plating bath. Surface morphology, microstructure and crystal orientation of pure Ni and Ni-MoS 2 2 composite coatings were characterized by FE-SEM and XRD analysis. Microhardness and wear resistance of pure Ni coating were improved by the addition of MoS nanosheets in the Ni matrix to use as solid lubricant.

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