Experimental Investigation on Chromium(vi) Removal From Aqueous Solution Using Activated Carbon Resorcinol Formaldehyde Xerogels

Abstract

Abstract. The adsorption of chromium(VI) metal ion in aqueous solutions by activated carbon resorcinol formaldehyde xerogels (ACRF) was investigated. The results showed that pore structure, surface area and the adsorbent surface chemistry are important factors in the control of the adsorption of chromium(VI) metal ions. The isotherm parameters were obtained from plots of the isotherms and from the application of Langmuir and Freundlich Isotherms. Based on regression analysis, the Langmuir isotherm model was the best fit. The maximum adsorption capacity of ACRF for chromium (VI) was 241.9 mg/g. The pseudo-second-order kinetic model was the best fit to the experimental data for the adsorption of chromium metal ions by activated carbon resorcinol formaldehyde xerogels. The thermodynamics of Cr(VI) ions adsorption onto ACRF was a spontaneous and endothermic process.

Adsorption of hexavalent chromium from aqueous solution byLeucaena leucocephalaseed pod activated carbon: equilibrium, kinetic and thermodynamic studies

“…The positive value of DH o suggests an endothermic nature of the adsorption of Cr(VI) by the adsorbent over the temperature range of 298-318 K. The value of DH o , which is below the value corresponding to physical adsorption (Abbas & Trari, 2015) indicates that Cr(VI) ions are physisorbed to the LLAC-3 surface. A similar observation was reported for Cr(VI) adsorption onto walnut shell (Ghasemi et al, 2015), activated carbon resorcinol formaldehyde xerogels (Oyedoh & Ekwonu, 2016) and paper mill sludge (Gorzin & Abadi, 2017).…”

“…The presence of peak 1383 cm À1 comes from the CH 3 symmetric deformation. The feature emerging at 941 cm À1 confirms the formation of Cr ¼ O chromate anion bonds which indicates adsorption of Cr(VI) onto LLAC-3 surface (Oyedoh & Ekwonu, 2016). The bands between 890 cm À1 and 805 cm À1 can be assigned to CH outof-plane deformation.…”

“…The Langmuir isotherm model is employed based on monolayer adsorption of adsorbate on homogeneous active sites and thus saturation is attained, beyond which no further attachment of adsorbate on adsorbent takes place. It also operates with the assumption that there is no interaction between the adsorbed molecules on adjacent sites (Oyedoh & Ekwonu, 2016). The non-linear model which was proposed by Langmuir (1918) is presented in Equation 3.…”

Optimization of adsorption of Cr(VI) from aqueous solution by Leucaena leucocephala seed shell activated carbon using design of experiment

“…Some peaks were shifted and disappeared, and new ones were developed. The new peak observed at 941.29 cm −1 is attributed to Cr=O bond of CrO 2− 7 onto the LLAC (Oyedoh and Ekwonu 2016). In addition, a change of intensity and shift of the carbonyl stretching band (C=O) from 1681.96 to 1631.83 cm −1 is as a result of contact between the chromium solution and LLAC.…”

Synthesis, characterization and isothermal studies of Mg-Fe Layered hydroxide with bentonite clay for the removal of alizarin blue dye from aqueous solution

“…Some of the materials include chitosan-clay composite, walnut shell. Kaolinate and montmorillonite and palm kernel shell charcoal (Oyedoh and Ekwonu, 2016). The method of adsorption for dyes removal is very useful due to the cost effectiveness, availability of naturally sourced materials and efficiency in the treatment of high strength industrial waste water with quality effluent.…”