Sumanjit Kaur

Adsorption Kinetics for the Removal of Hazardous Dye Congo Red by Biowaste Materials as Adsorbents

The present work aims to investigate the removal of dye congo red from aqueous solutions by two low-cost biowaste adsorbents such as ground nut shells charcoal (GNC) and eichhornia charcoal (EC) under various experimental conditions. The effect of contact time, ionic strength, temperature, pH, dye concentration, and adsorbent dose on the removal of dye was studied. The kinetic experimental data were fitted to pseudo-first order, pseudo-second order, intraparticle diffusion, Elovich model, and Bangham’s model. Results imply that adsorption of congo red on these adsorbents nicely followed the second order kinetic model and maximum adsorption capacity was found to be 117.6 and 56.8 mg g−1 for GNC and EC at 318 K, however it increases with increase in temperature for both adsorbents. Equilibrium isotherms were analyzed by Langmuir, Freundlich, Temkin, Dubinin and Radushkevich, and Generalized Isotherms. Freundlich isotherm described the isotherm data with high-correlation coefficients. The results of the present study substantiate that biowaste material GNC and EC are promising adsorbents for the removal of the dye congo red.

Comparative studies of zinc, cadmium, lead and copper on economically viable adsorbents

Lead and cadmium are very important metals even at trace levels because many health hazards are associated with them. Whereas, zinc and copper are toxic only when these are present at higher concentrations. Their removal from the contaminated samples is of utmost importance. The technique of adsorption using various economically viable adsorbents such as bagasse, bottom ash, rice husk ash, sawdust, and used tea leaves has been applied for their removal from aqueous solutions. Various parameters such as contact time, adsorbent dose, and metal concentrations were studied, optimized and applied to the present study. The equilibrium data obtained were analyzed in the light of Freundlich and Langmuir isotherms. Results revealed that rice husk ash is most efficient in removing lead and copper from aqueous solutions in comparison to the other adsorbents. Whereas in the case of cadmium, bottom ash was found to be of maximum efficiency. Bagasse was of maximum efficiency in removing zinc.

Adsorptive removal of dye crystal violet onto low-cost carbon produced from Eichhornia plant: kinetic, equilibrium, and thermodynamic studies

AbstractEichhornia charcoal is used as a potential adsorbent to remove dye crystal violet (CV) from aqueous solutions. Material was characterized for its surface chemistry by elemental analysis, Boehm titrations, point of zero charge measurements, Brunauer–Emmett–Teller, scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. Adsorption conditions were optimized by considering the effect of contact time, pH, initial concentration of the dye, and temperature. It is surmised that adsorption of CV increases with increase in pH, temperature, amount of adsorbent, ionic strength, and contact time. The equilibrium adsorption data were analyzed by Langmuir, Freundlich, Temkin, Dubinin and Radushkevich and generalized isotherms models. Adsorption kinetics were contemplated using pseudo-first order, pseudo-second order, intraparticle diffusion, Elovich model, and Bangham’s model. Equilibrium adsorption of CV was better explained by Langmuir adsorption model and evidenced the ma...

Adsorption of dye crystal violet onto surface-modified Eichhornia crassipes

AbstractEichhornia charcoal is modified with sodium dodecyl sulfate (SDS) is an anionic surfactant being employed as an adsorbent for the removal of dye crystal violet from aqueous solutions. Morphology and surface of the adsorbent were characterized by elemental analysis, Boehm titrations, point of zero charge measurements, Brunauer, Emmett, Teller, scanning electron microscope, FTIR and XRD techniques. Batch adsorption experiments were conducted to evaluate the effect of contact time, pH, initial dye concentration, temperature, adsorbent dose, and salt (NaCl) concentration. Adsorption mechanism of the dye for the adsorbent has been monitored through different kinetics and adsorption isotherm models. Positive value of change in entropy (∆S) and change in enthalpy (∆H) insinuated that adsorption process occurs with increase in randomness and endothermic, whereas negative values of free energy change (∆G) signifies the spontaneous nature of the present system. It was alluded that kinetics followed a pseudo...