Department Of Environmental Science And Technology
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Item 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, ShakuntalaPolycyclic 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.Item Novel Zinc ferrite composite with starch and carboxy methyl starch from biowaste precursor for the removal of Ni (II) ion from aqueous solutions(Taylor and Francis Ltd., 2023-06-19T00:00:00) Sharma, Dimple; Jasrotia, Rimzim; Singh, Jandeep; Mittal, Sunil; Singh, HarminderIn the present work, Zinc ferrite composites with Mango starch (MS) and carboxymethyl mango starch (CMMS) were synthesized for the removal of Ni (II) ions from aqueous solutions. Composites prepared were characterized by Fourier Transform Infrared (FTIR) Spectroscopy, X-Ray Diffraction (XRD) analysis, pH of point zero charge (pHzpc), Scanning Electron Microscopy (SEM), and BET. Batch adsorption technique was used to study effect of various parameters such as pH, adsorbent dose, contact time, concentration, and temperature for removal of Ni (II) ions from aqueous solutions. The optimum time, pH, adsorbent dose and temperature required for ZFN@ MS and ZFN@ CMMS in this study was 110 min., 7 & 8, 0.1 g and 308 K, respectively. Out of various adsorption isotherms, Freundlich isotherm model fitted best with adsorption data. Maximum adsorption capacity for removal of Ni (II) were found to be 65.3 and 208.3 mg/g, respectively by using Zinc ferrite@ MS and Zinc ferrite@ CMMS adsorbents. Lagergren Pseudo second order model best fitted with results which indicated that the process of adsorption was chemical in nature. The value of adsorption energy for ZFN@ MS was 50 kJ/mol and for ZFN@ CMMS, it was 31.62 kJ/mol. Thermodynamic study revealed that process was endothermic and non-spontaneous in nature. Regeneration studies were conducted for five cycles where Zinc ferrite@ MS showed 71% regeneration efficiency and Zinc ferrite@ CMMS showed 78% regeneration efficiency for nickel ion removal from aqueous solution. � 2023 Taylor & Francis Group, LLC.Item Robust removal of cationic dyes by zinc ferrite composites in single and ternary dye systems(Elsevier B.V., 2023-05-02T00:00:00) Rimzim; Singh, Jandeep; Mittal, Sunil; Singh, HarminderFor the continuous economic growth and development of society, clean and safe water is the basic necessity. Therefore, it is necessary to treat contaminated water. Magnetic ferrite composites with bio-waste materials are less explored in the area of research, so these need to be focused. In present study, novel magnetic Zinc Ferrite Pine Cone composite was prepared and used for the efficient removal of Crystal Violet, Malachite Green and Methylene Blue (Dye) from aqueous solution in single and ternary dye system. Various characterization techniques such as FTIR (Fourier Transform Infrared Spectroscopy), XRD (X-Ray Diffraction), FE-SEM (Field Emission Scanning Electron Microscopy), EDS (Energy Dispersive Spectroscopy), TGA (Thermogravimetric Analysis) and BET (Brunauer-Emmett-Teller Analysis) are used for the structure elucidation of Zinc Ferrite and Zinc Ferrite Pine cone (Composite). Batch adsorption method was used for the removal of dyes in single and ternary dye system. Lagergren pseudo second order adsorption model fits best in the kinetic studies whereas, Langmuir adsorption isotherm showed better results with maximum adsorption capacity 76.33, 200 and 94.33 mg/g for single dye system and 9.46, 20.45 and 27.93 mg/g respectively in ternary dye system for dyes CV, MG and MB. Thermodynamic study confirmed about the spontaneous nature of adsorption process. The regeneration ability of the composite in both the systems was studied up to five cycles. So, it becomes clear that the composite (Zinc Ferrite Pine Cone) will work as best alternative for dyes removal in single and ternary dye system. � 2023 Elsevier B.V.Item 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 KumarNanomaterials 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.Item Co-transport and deposition of fluoride using rice husk-derived biochar in saturated porous media: Effect of solution chemistry and surface properties(Elsevier B.V., 2023-02-10T00:00:00) Kumar, Rakesh; Sharma, Prabhakar; Rose, Pawan Kumar; Sahoo, Prafulla Kumar; Bhattacharya, Prosun; Pandey, Ashok; Kumar, ManishFluoride (F?) contamination in water is a global health concern, threatening the well-being of millions. This study investigated the role of ZnCl2/FeCl3-rice husk-modified biochar (Zn-BC and Zn/Fe-BC) in treating F?-contaminated surface and groundwater under the influence of varying solution chemistry, co-existing ions, and biochar-amended through column transport experiments. Modified biochar showed maximum F? adsorption, 99.01% and 91.90% using Zn/Fe-BC and Zn-BC, respectively, than 85.87% using raw biochar (R-BC). Raw/modified biochars were characterized with FESEM-EDAX, FTIR, XRD, particle size, surface area, electro-kinetic potential, and point of zero charge analyses. Langmuir and pseudo-second-order kinetic could explain that F?-biochar interactions are dominated by chemisorption at ambient temperature while physisorption at higher temperatures. The influence of salt concentrations and co-occurring ions reduced F? sorption using Zn/Fe-BC. Increased salt strengths led to reduced electrophoretic mobility of biochar particles, i.e., biochar�biochar particles attract each other and increase the hydrodynamic diameter, which ultimately reduces the active sites on biochar for F? adsorption. Co-transport and deposition of biochar and F? in saturated porous media revealed lower mobility of biochar, and maximum F? adsorption was observed at 10 mM salt strength. Biochar transport is governed by electrostatic interactions, whereas F? transport mainly occurs through chemisorption. In rural areas, hand pumps and tube wells are generally used as source of potable water for drinking and cooking purposes; thus, biochar-mediated sand columns can be utilized for defluoridation. Thus, Zn/Fe-BC can be utilized as a potential bio-adsorbent for F?-contaminated natural surface and groundwater with optimum preparation and treatment costs. � 2023 The AuthorsItem 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 KumarNanotechnology 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 LtdItem 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 KumarZinc 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.Item Adsorption of Zn(II) on Pristine and SPLP/TCLP Leached Rice Straw Biochar: an Interplay of Precipitation and Ion Exchange(Institute for Ionics, 2022-11-15T00:00:00) Bhardwaj, Akanksha; Nag, Shilpa; Hussain, Khadim; Arora, Meenu; Pandey, Puneeta; Babu, J. NagendraThe inorganic mineral content in biochar influences the adsorption of Zn(II) metal ions. Metal ion adsorption on mineral rich rice straw biochar is influenced upon washing. Rice straw slow pyrolysis biochar BC1-3, respectively, prepared at 400, 500, and 600��C, were leached under Toxicity Characteristic Leaching Procedure (TCLP) and Synthetic Precipitation Leaching Procedure (SPLP) conditions to furnish BT1-3 and BS1-3, respectively. The Zn(II) adsorption studies were carried out for pH and dose optimization, initial concentration, isotherm fit, and kinetic studies. The Zn(II) adsorption by B(C/S/T)1�3 showed Langmuir and Freundlich isotherm, with pseudo-second-order kinetics at optimum pH 5 and dose 1�g/L. The adsorption of Zn(II) followed the trend BC3(qm 47�mg/g) > BC2 > BC1 > BS2 > BS1 > BS3 > BT2 > BT1 > BT3 (qm 3.5�mg/g), i.e., metal ion adsorption decreased with extent of leaching. The Zn(II) adsorption on biochar involved precipitation as dominant factor for metal ion adsorption on the biochars followed by ion exchange and proton exchange. The precipitation of Zn(II) ions in case of BC1-3 is attributed to the pH of biochar, which increases with proportion of minerals to organic content in biochar. In case of biochar BS1-3 and BT1-3, ion exchange and proton exchange mechanisms driven by demineralization are responsible for Zn(II) adsorption. The adsorption mechanism for Zn(II) on biochar is supported by XPS, solid state NMR studies. Graphical Abstract: [Figure not available: see fulltext.] � 2022, The Author(s), under exclusive licence to Springer Nature Switzerland AG.Item 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 KumarThis 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.Item A novel CaO nanocomposite cross linked graphene oxide for Cr(VI) removal and sensing from wastewater(Elsevier Ltd, 2022-04-27T00:00:00) Singh, Simranjeet; Naik, T.S. Sunil Kumar; Anil, Amith G.; Khasnabis, Sutripto; Nath, Bidisha; U, Basavaraju; Kumar, Vineet; Garg, V.K.; Subramanian, S.; Singh, Joginder; Ramamurthy, Praveen C.A novel green nanocomposite has been prepared by immobilizing CaO nanoparticles (CaO NPs) on the surface of graphene oxide. Biogenic CaO-NPs were synthesized from Lala clamshells. Morphological and structural characterizations of the nanocomposite were studied extensively. The adsorption capacity (qmax) of the nanocomposite for removing Cr(VI) was 38.04 mg g?1. In addition to this, the adsorption data were adequately simulated with Langmuir, Freundlich, Temkin, and pseudo-second-order models, suggesting that the adsorption process was the combination of external mass transfer and chemisorption. Electrostatic interaction was the dominant mechanism for Cr(VI) removal. In addition, the synthesized nanocomposites also serve as an excellent sensor for Cr(VI) sensing, with a limit of detection (LOD) of 0.02 ?M utilizing electrochemical methods. Therefore, this green nanocomposite can simultaneously serve as an adsorbent and sensor for Cr(VI)removal from aqueous solutions. � 2022 Elsevier Ltd
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