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Khosla E.,Hans Raj Mahila Maha Vidyalaya | Kaur S.,Guru Nanak Dev University | Dave P.N.,Krantiguru Shyamji Krishna Verma Kachchh University
Chemistry and Ecology | Year: 2015

The adsorption behaviour of Basic Red 12, Acid Orange 7 and Acid Blue 1 on zinc oxide nanoparticles (ZNP) has been investigated to understand the physicochemical process involved and to explore the possible use of nanoparticles in the treatment and management of textile waste matter. The dye removal capacity of ZNP towards Basic Red 12, Acid Orange 7 and Acid Blue 1 was found to be 15.64, 6.78 and 6.38 mg g−1, respectively. The adsorption process was pH dependent and optimum pH values of 9.0, 2.0 and 4.0 were obtained for Basic Red 12, Acid Orange 7 and Acid Blue 1, respectively. Equilibrium was established after 1.0 h for all dyes. Langmuir, Freundlich and Temkin isotherm models were applied to the system. The adsorbent ZNP was characterised using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) and Fourier transform infrared (FTIR) techniques. SEM analysis revealed the noticeable nanoporous morphology of the material. The results of FTIR spectroscopy showed that the process is driven by an electrostatic complexation mechanism. XRD studies revealed the nanocrystalline structure of ZNP. BET surface area measurement suggested a high pore volume and large surface area for the adsorbent. The kinetic measurements suggested pseudo-second-order kinetic processes with high regression coefficients and smaller standard error of estimate values and lower residual sum of squares. The thermodynamic measurements suggested that all processes were exothermic and accompanied by negative values for Δ G0, Δ S0 and Δ H0. © 2014, © 2014 Taylor & Francis. Source


Khosla E.,Hans Raj Mahila Maha Vidyalaya | Kaur S.,Guru Nanak Dev University | Dave P.N.,Krantiguru Shyamji Krishna Verma Kachchh University
Desalination and Water Treatment | Year: 2013

Toxic dyes can be removed from textile effluents and recovered using dead biomass obtained, as waste from the food industry. In this work, tea waste (TW) was employed to assess its adsorptive capacity for the acidic and basic dyes that usually are present in textile industry waste water. Equilibrium and kinetic experiments were performed in batch and column mode. Adsorption equilibrium and fluid solid mass transfer constant data were analyzed through the concept of ion-exchange sorption isotherm. The equilibrium data were fitted with Langmuir and Freundlich models. Several operation variables, such as TW dosage, contact time, initial pH, and temperature, on the removal of dyes were investigated. The removal efficiency increased with increase in TW dosage. The adsorption process followed pseudo-first-order kinetics. Thermodynamic parameters like ΔH°, ΔS°, and ΔG° were analyzed. The processes were spontaneous for the acidic as well as basic dyes. These results suggest that TW is a potential low-cost food industry waste for textile industry waste water treatment. TW was characterized using Scanning electron micrograph and Fourier transform infrared spectroscopy and techniques. © 2013 © 2013 Balaban Desalination Publications. Source


Khosla E.,Hans Raj Mahila Maha Vidyalaya | Kaur S.,Guru Nanak Dev University | Dave P.N.,Krantiguru Shyamji Krishna Verma Kachchh University
Journal of Chemical and Engineering Data | Year: 2012

The adsorption behavior of Basic Red-12 on eucalyptus bark (EB) and its surface derivatives obtained after cationic, anionic, and nonionic surfactant treatment in aqueous solution has been investigated to understand the physicochemical process involved and to explore the potential use of low-cost materials in textile effluent treatment and management. The results revealed that cationic, anionic, and nonionic surfactant modified EB can remove Basic Red-12 dye up to (243.6, 923.0, and 193.28) mg·g -1, respectively, while raw EB can remove dye up to 146.8 mg·g -1 only at 303 K. The adsorption process is found to be pH-dependent, and the optimum pH obtained is 2 to 5. The equilibrium was established in 2 h for EB and in 5 h for surface-modified EB. The process obeys the Langmuir and Freundlich models. Scanning electron microscopic analysis reveals a conspicuous surface morphology change after surfactant modification. The results of Fourier transform infrared (FTIR) spectroscopy reveal that the process is electrostatic complexation mechanism driven. The kinetic measurements suggest Lagergren kinetic processes. The thermodynamical measurements suggest that all processes are exothermic accompanied with negative ΔG o, ΔH o, and ΔS o. © 2012 American Chemical Society. Source


Dave P.N.,Krantiguru Shyamji Krishna Verma Kachchh University | Kaur S.,Guru Nanak Dev University | Khosla E.,Hans Raj Mahila Maha Vidyalaya
Indian Journal of Chemical Technology | Year: 2011

Sorption experiments are carried out using sewage sludge for the removal of basic dye basic red-12 from aqueous solution. Effects of process parameters such as initial pH, adsorbent dosage, initial dye concentration, contact time and effect of temperature are investigated. The biosorbent is characterized by FTIR, SEM and XRD. The adsorption of dye is pH dependent. The rate of sorption increases with increase in temperature, and the process is found to be endothermic. Equilibrium is established in 120 min. The pseudo first-order equation, pseudo second-order equation and intraparticle diffusion models are tested. The results showed that the process followed pseudo first order equation very well and intraparicle diffusion plays an important role in the sorption process. The Langmuir and Freundlich equations are applied to the data related to adsorption isotherm and the observed maximum adsorption capacity was found to be 295.85 mg/g. Thermodynamic parameters; {increment}H°, {increment}G°and {increment}S° are also evaluated. Column experiments are also carried out to evaluate the bulk removal of color from effluents. The effects of inlet concentration and bed height are evaluated. Source


Dave P.N.,Krantiguru Shyamji Krishna Verma Kachchh University | Kaur S.,Guru Nanak Dev University | Khosla E.,Hans Raj Mahila Maha Vidyalaya
Indian Journal of Chemical Technology | Year: 2011

The efficiency of eucalyptus bark as a low cost adsorbent for removing an azo dye from an aqueous solution has been investigated in batch mode. The azo dye, Eriochrome black-T (EBT) is removed by adsorption over field waste eucalyptus bark after minimum chemical treatment. The investigations are carried out to study the effects of pH, adsorbate concentration, adsorbent dosage, contact time and temperature. The thermodynamic parameters were obtained from Langmuir and Freundlich adsorption isotherm models. The kinetic studies showed that the adsorption reaction is of first order. A fixed-bed column has been designed, and necessary parameters have been calculated by applying a mass transfer kinetic approach. Experiments are also performed for the recovery of loaded dye through chemical regeneration of spent columns. Source

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