Browsing by Author "Garg, V.K"

Now showing 1 - 4 of 4

Applications of Fe3O4@AC nanoparticles for dye removal from simulated wastewater
(Elsevier, 2019) Joshi, S; Garg, V.K; Kataria, N; Kadirvelu, K.
This study deals with the removal of cationic dyes from the simulated wastewater using Fe3O4 nanoparticles loaded activated carbon. Fe3O4@AC nanoparticles were synthesised using co-precipitation methods. The Fe3O4@AC nanoparticles (nps) were characterised using different techniques and data revealed that the synthesised nanoparticles were 6–16 nm in diameter. pHpzc of Fe3O4@AC nanoparticles was 7.8. BET surface area of Fe3O4@AC nps was found to be 129.6 m2/g by single point method and 1061.9 m2/g by multipoint method. Adsorption experiments were performed to optimize the effect of process conditions such as pH of solution, nanoparticles dose, temperature, concentration of dye and contact time on contaminant removal. The maximum uptake capacity of Fe3O4@AC was found to be 138 and 166.6 mg/g for methylene blue and brilliant green dyes, respectively. In order to assess dye adsorption behaviour, adsorption isotherm models viz., Langmuir, Freundlich and Temkin were applied to the data. Langmuir isotherm best fitted [R2 = 0.993 (MB) and R2 = 0.920 (BG)] to the experimental data of both the dyes. Further, Pseudo-second order rate equation fitted better to the experimental data. Reuse potential of the nanoparticles was also investigated for the removal of both the dyes and it is inferred from the data that the synthesised nanoadsorbent has promising reuse potential, therefore can be used for several cycles. © 2019 Elsevier Ltd
Green synthesis, activation and functionalization of adsorbents for dye sequestration
(Springer, 2019) Mudhoo, A; Gautam, R.K; Ncibi, M.C; Zhao, F; Garg, V.K; Sillanpää, M.
The release of recalcitrant dyes into the biosphere is a threat because of pollution and environmental health issues. Adsorption using commercial activated carbon has been effective in industrial dye-loaded effluent remediation to some acceptable extent. However, commercial activated carbon suffers from limitations related to cost, relatively lower adsorption capacity, fewer microporous and mesoporous networks in comparison with other competing adsorbents, and reduced adsorption efficiency after regeneration. Here we review the recent developments in applying microwave irradiation, ultrasonication, ionic liquids and nanoscience for the preparation, activation, and physical, chemical and biological functionalization of novel and more potent adsorbents such as metal, mineral, carbon and polymer-based nanoparticles for dye removal. We observed that microwave and ultrasound irradiation and the use of ionic liquids are highly beneficial for the preparation of adsorbent materials; those adsorbents display enhanced porous structures and morphologies that account for much larger surface areas for faster adsorption interactions. Graphene-based, magnetic, cellulose-based and nanocomposite adsorbents are more selective and thermally more stable, faster in dye adsorption kinetics, have higher adsorption capacities for many dyes and can be regenerated for reuse without significant decrease in adsorption capacity. The scales of fabrication of green adsorbents do not go beyond the kilogram scale. © 2018, Springer Nature Switzerland AG.
Molecular mechanisms of action of tocotrienols in cancer: Recent trends and advancements
(MDPI AG, 2019) Aggarwal, V; Kashyap, D; Sak, K; Tuli, H.S; Jain, Aklank; Chaudhary, A; Garg, V.K; Sethi, G; Yerer, M.B.
Tocotrienols, found in several natural sources such as rice bran, annatto seeds, and palm oil have been reported to exert various beneficial health promoting properties especially against chronic diseases, including cancer. The incidence of cancer is rapidly increasing around the world not only because of continual aging and growth in global population, but also due to the adaptation of Western lifestyle behaviours, including intake of high fat diets and low physical activity. Tocotrienols can suppress the growth of different malignancies, including those of breast, lung, ovary, prostate, liver, brain, colon, myeloma, and pancreas. These findings, together with the reported safety profile of tocotrienols in healthy human volunteers, encourage further studies on the potential application of these compounds in cancer prevention and treatment. In the current article, detailed information about the potential molecular mechanisms of actions of tocotrienols in different cancer models has been presented and the possible effects of these vitamin E analogues on various important cancer hallmarks, i.e., cellular proliferation, apoptosis, angiogenesis, metastasis, and inflammation have been briefly analyzed. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.
Pb2+ and Cd2+ recovery from water using residual tea waste and SiO2@TW nanocomposites
(Elsevier, 2020) Joshi, S; Kataria, N; Garg, V.K; Kadirvelu, K.
This work reports the fabrication of SiO2@TW nanocomposites and their application for Pb2+ and Cd2+ ions sequestration from simulated water. Residual tea waste has also been used for metal ions sequestration to compare the potential of SiO2@TW nanocomposites. The SEM, TEM, BET, FTIR and EDX techniques were employed for the characterization of SiO2@TW nanocomposites and residual tea waste. Particle sizes of SiO2@TW nanocomposites was in the range of 6.8-12 nm. The experiments were carried out in batch mode to explore the effect of various operating parameters on the sequestration of Pb2+ and Cd2+ ions from water. The experimental data was subjected to various thermodynamic, kinetic and isothermic models. According to Langmuir model, the maximum adsorption efficiency of the SiO2@TW nanocomposites was 153 mg/g for Pb2+ and 222 mg/g for Cd2+ but maximum adsorption efficiency of residual tea waste for Pb2+ was 125 mg/g and for Cd2+ was 142.9 mg/g. This study suggested that due to the presence of active sites SiO2@TW nanocomposites has greater potential for metal sequestration than residual tea waste. 2020 Elsevier Ltd