Ni(II) and Cd(II) Simple and Competitive Adsorption on Activated Carbon Oxidized. Influence of the Oxidant Agents HO and NaClO

Abstract

In this study, granular activated carbon, GAC, was modified by oxidation with HO and NaClO aqueous solutions and heat treatment at 900°C. The N adsorption isotherms at − 196°C and SEM and FTIR results were used to characterize the properties of the prepared ACs. Textural parameters such as BET surface area and pore volumes were assessed by gas adsorption. The BET surface area values of solids were between 687 and 876 m2g-1. Additionally, immersion enthalpies of activated carbons in benzene, water, hydrochloric acid and sodium hydroxide solutions and Ni(II) and Cd(II) solutions of 500 mgL were determined, with values between 32 and 145 Jg-1. Ni(II) and Cd(II) adsorption isotherms were determined at pH 6 on activated carbons and competitive adsorption tests were realized between the two ions. The results show that in the tests carried out, the adsorption capacity decreased when the content of chemical groups on the surface also decreased. Finally, the experimental results of adsorption from the solution were adjusted to the Langmuir and Freundlich models and the first model was found to be better. With maximum adsorption capacities, the values for Ni(II) were between 3.99 and 64.9 mgg-1 and for Cd(II) were between 2.61 and 55.2 mgg-1. The values of the competitive adsorption ions present in the solution, Ni(II) and Cd(II), in the activated carbons, decreased compared to those obtained in the simple adsorption, indicating the effect of the an ion competitive presence in adsorption another.

Treatment of PBDEs from Soil-Washing Effluent by Granular-Activated Carbon: Adsorption Behavior, Influencing Factors and Density Functional Theory Calculation

“…The adsorption of BDE-15 was slightly inhibited by high concentration of ClO − . As one of the reagents for oxidative modification of carbon materials [53,54], the oxidation of ClO − destroyed the carbon structure of GAC, resulting in the weakening of π-π interaction between benzene ring of BDE-15 and unsaturated carbon of GAC, while the recovery rate of TX-100 remained basically unchanged, indicating that the change of GAC structure has little effect on the adsorption of TX-100. Good adsorption performance of BDE-15 and recovery effect of TX-100 in the presence of GAC coexisting ions show good practical application potential.…”