Performance Assessment of Sawdust as Adsorbent for Cr (VI) Removal from Aqueous Solutions: a Kinetic Modeling (original) (raw)
Related papers
International Journal of Engineering Research and Technology (IJERT), 2015
https://www.ijert.org/comparative-studies-of-removal-of-hexavalent-chromium-crvi-from-wastewater-using-natural-adsorbents-prepared-from-neem-leaves-and-sawdust https://www.ijert.org/research/comparative-studies-of-removal-of-hexavalent-chromium-crvi-from-wastewater-using-natural-adsorbents-prepared-from-neem-leaves-and-sawdust-IJERTV4IS090841.pdf In the present investigation natural adsorbents such as saw dust and neem (Azadirachta indica) leaves are used as adsorbents to remove hexavalent chromium Cr(VI) from waste water. The equilibrium studies are systematically carried out in a batch process covering various process parameters that include contact time, adsorbent dosage, initial chromium concentration, pH, temperature for both the adsorbents. The results are compared. For sawdust the effective percentage removal of hexavalent chromium is observed within the pH range of 2 to 4, and at lower initial concentrations. For neem leaves the effective percentage removal of chromium is observed within a pH range of 6 to 8, and at lower initial concentrations. Langmuir and Freundlich constants are found for both the adsorbents. The adsorption capacity of sawdust is 23.52 mg/g and for that of neem leaves is 9.19 mg/g. The percentage removal for sawdust is 99.8 and for neem is 85 and hence saw dust is found to be a better adsorbent among the two for adsorbing hexavalent chromium.
2016
Ag2O/sawdust nanocomposite (Ag2O/SD NC) as adsorbent of Cr(VI) was prepared by precipitation method. The as-prepared sample was characterized by various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The SEM micrographs show formation of Ag2O nanoparticles within 50–60 nm in size which have been homogeneously dispersed on the sawdust surface. The as-prepared Ag2O/SD NC were used to remove Cr(VI) from aqueous solutions. To determine the optimal conditions for adsorption, the effect of important parameters such as pH, contact time, initial concentration of Cr(VI), amount of adsorbent, temperature and ionic strength were investigated. It was found that the Ag2O/SD NC showed a high Cr(VI) removal capacity of 20.75 mg/g at 25 o C. The experimental data were well described by the pseudo-second-order kinetics and Langmuir isotherm model. Thermodynamic studies for the adsorption system were calculated and s...
Thermodynamic and Kinetic Studies of Chromium (VI) Adsorption by Sawdust Activated Carbon
2014
Low cost activated carbon, prepared from saw dust of Ziziphus jujube by chemical activation with phosphoric acid (H3PO4) was characterized and utilized for the removal of Cr (VI) ions from aqueous solutions under different conditions of solution pH, contact time, initial concentration, carbon dose and temperature. Adsorption of Cr (VI) ions was found highly pH dependent that increased with decrease in solution pH. The removal of Cr (VI) ions increased with increase in temperature, initial concentration and contact time until equilibrium was established. Langmuir’s isotherm model and pseudo second order kinetic equation were found better fitted to describe the experimental data. Thermodynamic study revealed the feasibility, spontaneity and endothermic nature of the adsorption process. The used carbon was regenerated by treating with HCl solution. In comparison to other adsorbents, the results indicated that the prepared saw dust activated carbon could be an eco-environment friendly a...
Chromium Removal from Aqueous Medium Using Modified Sawdust
One of the serious environmental issues is the presence of toxic heavy metals contaminants in water bodies because of discharge of untreated heavy metals due to urbanization, combustion byproducts, automobile emissions, mining activities.Chromium is widely used in many industries and usually present in high concentration in the aqueous medium. This study involved the investigation of the adsorption of hexavalent form of the heavy metal (Cr) by modified teakwood sawdust. The study demonstrated that the teak wood sawdust has a moderate potential to remove hexavalent chromium.The equilibrium data of adsorption very well fitted into the models and the maximum loading capacity was obtained from adsorption isotherms by applying the Langmuir model.