Department Of Environmental Science And Technology
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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 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 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 LtdItem Sequestration of heavy metals from contaminated water using magnetic carbon nanocomposites(Elsevier B.V., 2022-03-30T00:00:00) Kataria, Navish; Chauhan, Amit Kumar; Garg, V.K.; Kumar, ParmodHeavy metals are toxic to flora, fauna and human beings. This study focused on removing toxic metals from an aqueous medium using magnetic carbon (Fe3O4@Carbon) nanocomposites. The biogenic green synthesis approach was used to fabricate the magnetic nanocomposite using low-cost poplar sawdust powder. The characterization of the nanocomposites was done using FESEM, TEM BET and FTIR. The sequestration of Pb (II), Cu (II) and Cr (VI) from water by Fe3O4@Carbon nanocomposites were studied under batch mode. The adsorption capacities for Pb (II), Cu (II) and Cr (VI) were 151.5, 48.08, and leaves49.29 mg/g respectively. The removal of metals by magnetic composites was studied in a mono, binary and tertiary network of metal ions. Adsorption isotherms studies indicated the chemosorption of Cu (II) and Cr (VI) onto the surface of nanocomposites. The thermodynamic analysis revealed that removal of studied metals ions is spontaneous and feasible. In this study, the effectiveness of magnetic nanocomposites is also explored for the removal of other heavy metals from tap water and simulated water sample. The heavy metal removal efficiency of the nanocomposites was not affected up to thrice reuse of adsorbent. � 2022Item Biodegradation of monocrotophos by indigenous soil bacterial isolates in the presence of humic acid, Fe (III) and Cu (II) ions(Elsevier Ltd, 2021-07-20T00:00:00) Singh, Simranjeet; Singh, Joginder; Ramamurthy, Praveen C.; Kumar, Vijay; Bhardwaj, Sonali; Garg, Vinod KumarThree bacteria, namely Streptomyces sp. MCP1, Rhizobium leguminosarum MCP2 and Bacillus subtilis MCP3, isolated from an arable field, have been used for the biodegradation of monocrotophos (MCP). The bacterial strains were characterized based on the 16S rRNA gene sequence. MCP was subjected to biological degradation in two ways, i.e., with or without using Fe(III), Cu(II), and humic acid (HA). The isolates were capable of degrading MCP in an order: MCP2 (Bacillus subtilis) > MCP1 (Streptomyces sp.) > MCP3 (Rhizobium leguminosarum). With the application of Cu(II) and Fe(III), the biodegradation of MCP was from 83 to 92% and 78 to 87%, respectively. Altogether, under different conditions, the order of inhibition of MCP biodegradation was apparently as HA > Fe(III) > Cu(II). Mass spectrometric and UV�visible spectrophotometric results showed that MCP biodegradation's only pathway included major intermediatory metabolites (E) 4-amino-4-oxobut-2-en-2-yl dimethyl phosphate, dimethyl phosphate, methyl hydrogen phosphate and phosphonate. � 2021 Elsevier LtdItem 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 LtdItem Applications of Fe3O4@AC nanoparticles for dye removal from simulated wastewater(Elsevier Ltd, 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.Item 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 LtdItem Optimization of Pb (II) and Cd (II) adsorption onto ZnO nanoflowers using central composite design: isotherms and kinetics modelling(Elsevier B.V., 2018) Kataria N.; Garg V.K.This study focused to optimization and screening of parameters for the adsorption of Cd (II) and Pb (II) onto ZnO nanoflowers. These were synthesized by low temperature hydrothermal methods. The surface properties of ZnO nanoflowers, before and after metal adsorption were characterized by FTIR, FESEM and EDX spectra. The adsorption parameters were optimized using central composites design. Adsorption behaviour and metals-adsorbent interaction was evaluated using batch mode experiments and isothermal models. Maximum adsorption capacity of ZnO nanoflowers was 71.5 mg/g and 115 mg/g for Cd (II) and Pb (II), respectively. In isotherms studies, Freundlich model is best fitted to metal adsorption data that indicated multilayer adsorption of Cd (II) and Pb (II) onto ZnO. The rate mechanism of metals ions adsorption was well explained by pseudo-second order models. The Adsorption efficiency of ZnO nanoflowers was analysed in spiked ground water sample also. The reusability of ZnO nanoflowers was also explored upto three cycles.