School Of Environment And Earth Sciences

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    Synthesis of nanocellulose for the removal of naphthalene from simulated wastewater
    (Springer Science and Business Media Deutschland GmbH, 2023-06-29T00:00:00) Ranwala, Pooja; Pal, Jitender; Garg, Vinod Kumar; Rani, Shakuntala
    Polycyclic aromatic hydrocarbons are one among the strenuous problems of indemnity of hydrosphere brought on by the unintended release of refractory chemicals into the environment. Naphthalene has been removed from aqueous solution using various adsorbents, such as activated carbon, graphene oxide, etc�in yesteryears. This study describes the synthesis of nanocellulose from rice husk and its application for the removal of naphthalene from simulated wastewater. To characterize the synthesized nanocellulose, SEM, TEM, BET, FTIR, XRD, zeta potential, AFM, TGA, DSC, and EDX techniques were used. The nanocellulose surface area was 1.152�m2�g?1. The experiments were conducted in batch mode to investigate the impact of various operating conditions on naphthalene adsorption. Maximum removal of naphthalene was at pH 2 within 150�min. The experimental data were subjected to various models, viz.,�thermodynamic, kinetic, and isotherm models. Error analysis confirmed that the pseudo second-order equation�and Langmuir model fitted well to the experimental data. The maximum removal of the naphthalene was ~80%. The desorption and reusability efficiency of nanocellulose was also evaluated. According to this study, nanocellulose has a higher potential for naphthalene removal due to the presence of active sites. � 2023, Institute of Chemistry, Slovak Academy of Sciences.
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    Hybrid nanomaterials for the removal of organic pollutants from wastewater
    (Elsevier, 2023-04-21T00:00:00) Sharma, Anchal; Chauhan, Amit Kumar; Kataria, Navish; Garg, Vinod Kumar
    Nanomaterials have recently gained the attention of the scientific community due to their multifarious applications and excellent properties. The unique properties of nanomaterials include small size, high surface area-to-volume ratio, porous structure, magnetic behavior, thermal stability, photocatalysis, etc. Industrial activities are continuously enhancing the pollutant load in different environmental matrices, including aqueous systems. These pollutants may enter the food chain and exert adverse health effects and environmental problems. At this stage, interventions are urgently required to handle water pollutants. Several hybrid nanomaterials including metal oxide/carbon nanocomposites, metal doped composites, surface-functionalized carbon nanotubes and graphene oxide, metal oxide-coated metal oxide frameworks, bimetallic coated biopolymers, metal-coated biomaterials, green fabricated metal/carbon nanocomposites, etc., are being designed and fabricated for the treatment of wastewater. Hybrid nanomaterials have been utilized in various treatment methods such as adsorption, photocatalysis and catalytic reduction, membrane filtration, and an advanced oxidation process for the removal of inorganic and organic compounds. This chapter focuses on the application of hybrid nanomaterials for the removal of organic pollutants from wastewater systems. It also describes the current research progress of nanotechnology in environmental applications with a special emphasis on pollution prevention and the removal of environmental contaminants from contaminated drinking water and industrial wastewater. � 2023 Elsevier Inc. All rights reserved.
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    Phytobiomass-based nanoadsorbents for sequestration of aquatic emerging contaminants: An Overview
    (Elsevier Ltd, 2023-02-15T00:00:00) Sharma, Anchal; Kumar, Nitin; Mudhoo, Ackmez; Garg, Vinod Kumar
    Nanotechnology that is based on phytobiomass is a technique that has the potential to play a major role in wastewater treatment since it is environmentally friendly, easy to deploy, and cost-effective. This technology employs plant parts such as leaves, flowers, stems, seeds and roots, and agricultural wastes to synthesize nanoadsorbents. These nanoadsorbents have unique properties, such as smaller size, higher surface-volume ratio, magnetic behaviour, thermal stability, selectivity, porous structure, surface functionalization, catalytic properties and target-specific capabilities, which make them an attractive material for removing �Emerging Contaminants� from contaminated water and wastewater. Pharmaceuticals, personal care products, endocrine disruptors, surfactants, disinfectants, flame retardants and pesticides are the various classes of emerging contaminants used almost every day globally. Adsorption is one green and sustainable technology that has shown excellent performance when employing nanoadsorbents to purify contaminated water. It is an effective and efficient technology for removing emerging contaminants that inform polluted water or wastewater to restore water quality. This review aims to summarize the current research progress in the use of different nanoadsorbents synthesized from various plant parts for removing aqueous emerging contaminants. � 2023 Elsevier Ltd
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    Biogenic fabrication of ZnO@EC and MgO@EC using Eucalyptus leaf extract for the removal of hexavalent chromium Cr(VI) ions from water
    (Springer Science and Business Media Deutschland GmbH, 2023-01-04T00:00:00) Chauhan, Amit Kumar; Kataria, Navish; Gupta, Renuka; Garg, Vinod Kumar
    Zinc and magnesium oxide nanoparticles were fabricated using green synthesis method for the sequestration of hexavalent chromium Cr(VI) from the aqueous medium. The biogenically prepared ZnO@EC and MgO@EC nanoparticles were successfully loaded on the Eucalyptus. The prepared nanomaterials were characterized using various techniques such as FESEM, TGA, XRD, EDX, FTIR, BET, and elemental mapping. FE-SEM analysis has revealed the surface morphology of ZnO nanoparticles, which were rod-like and spherical in shape, whereas MgO nanoparticles were of irregular shape. Batch mode was selected to remove the hexavalent chromium from aqueous solution using the prepared nanomaterials. The Cr(VI) adsorption was carried out under optimized conditions, viz., pH (3.0), adsorbent dose (0.05�g), contact time (150�min), temperature (25 � 2��C), and initial concentration (50�mg/L). The experimental results were compared using the different isotherm models; The observations have indicated that experimental data fit better with Freundlich (R2 = 0.99) and Langmuir (R2 = 0.99)�isotherms, respectively. The maximum adsorption capacity of ZnO@EC and MgO@EC for Cr(VI) was found to be 49.3 and 17.4�mg/g, respectively. The regeneration study of the adsorbents was conducted using different desorbing agents viz., ethanol, NaOH, and NaCl. The desorbing agent NaOH performed better and showed removal percentage of 34.24% and 20.18% for ZnO@EC and MgO@EC, respectively, after the three reusability cycles. The kinetics of reaction was assessed using the pseudo-first-order and pseudo-second-order kinetic models. The experimental data of both the nanomaterials ZnO@EC and MgO@EC obeyed pseudo-second-order model with correlation coefficient values 0.999 and 0.983, respectively. The thermodynamic study confirmed that adsorption was feasible, spontaneous, and endothermic. The adsorbents were tested for spiked real water which confirms their applicability and potential in real water systems also. The results indicated fair removal of chromium suggesting applicability of both adsorbents. � 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
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    Utilization of biosynthesized silica-supported iron oxide nanocomposites for the adsorptive removal of heavy metal ions from aqueous solutions
    (Springer Science and Business Media Deutschland GmbH, 2022-06-07T00:00:00) Garg, Rishav; Garg, Rajni; Khan, Md. Amir; Bansal, Manjeet; Garg, Vinod Kumar
    This study deals with heavy metal ions removal from simulated water using biosynthesized silica-supported iron oxide nanocomposites (nano-IOS). Agricultural and garden wastes have been utilized to prepare nano-IOS through a green synthesis process. Nano-IOS was characterized by XRD, SEM, FTIR, and zeta potential analysis. The nanocomposites were used to remove five heavy metals, viz., Pb2+, Cd2+, Ni2+, Cu2+, and Zn2+, with optimization of reaction parameters including pH, the concentration of heavy metals, adsorbent dosage, and contact time in batch mode experiments. The optimized dose of nano-IOS was 0.75�g/L for the adsorption of Pb2+, Cd2+, Ni2+, Cu2+, and Zn2+ (10.0�mg/L) with a contact duration of 70�min at pH 5.0 for Pb2+, Cd2+, and Cu2+ and 6.0 for Ni2+ and Zn2+. The adsorption behavior of the nano-adsorbent was well described by Langmuir adsorption isotherm and pseudo-second-order kinetic model indicating chemisorption on the surface of nano-IOS. The adsorption was also found spontaneous and endothermic. Thus, the environmentally benign and bio-synthesized nano-IOS can be utilized as an effective nano-adsorbent for the rapid sequestration of heavy metal ions�from water and wastewater. � 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.