Adsorption of cadmium(II) ions from aqueous solution onto kaolinite and metakaolinite

Abstract

The removal of cadmium(II) ions from aqueous solution by adsorption on kaolinite (KAO.1) and metakaolinite (MKB) was investigated depending on the initial concentration, adsorbents dosage, initial pH of solution, and contact time. The influences of those factors have been experimentally verified by a batch method at (27±3 °C). These results have showed that the amount of cadmium(II) ions adsorbed increases with increased contact time and that equilibrium adsorption is reached in 10 minutes, the optimum value of pH was 8.0 and the effect of absorbent dose for the uptake of cadmium(II) ions by kaolinite and metakaolinite was found to decrease by increasing the adsorbent dose. The experimental results obtained are described by Langmuir, Freundlich and Dubinin-Kaganer-Radushkevich (D-K-R) isotherm models. The Langmuir and D-K-R adsorption isotherms described the adsorption data very well. The maximum adsorption capacity; Q max , determined from the Langmuir adsorption isotherm studies was found to be 7.407 and 9.174 mg/g for KAO.1 and MKB respectively. Pseudo-first order, pseudo-second order, Elovich and the intraparticular diffusion kinetic models were used to describe the kinetic data obtained. The experimental data fitted well to the pseudo-second order kinetic model, which indicates that 12Jean Serge ESSOMBA et al.chemical adsorption is the rate-limiting step. The results indicate that kaolinite and metakaolinite adsorb cadmium(II) ions efficiently and could be employed as a low-cost alternative in waste water treatment for the elimination of cadmium(II) ions.

Efficient adsorption of Cd(ІІ) ions from aqueous media onto a semi‐interpenetrating bio‐composite

“…The present study shows the best adsorption capacity of s‐IPNs‐3 is 49.75 mg g −1 of Cd(II) ions. In comparison, the adsorption capacities of many other sorbents for Cd(II) ions have been reported; 90.91 mg g −1 for nanocrystalline Ni (15 wt%)‐doped α‐Fe 2 O 3 , 94.05 mg g −1 for the oxide adsorbent MgO‐SiO 2 , 30.4 mg g −1 for 2CS‐Hhnal, and 7.407 and 9.174 mg g −1 for kaolinite and metakaolinite, respectively, 10.31 and 8.62 mg g −1 for penicone and biochar, respectively), and 88.8, 97.62, and 86.73% using expanded perlite, Fluidgel and Tectone grandis L. f. leaf powder…”

“…Several procedures have been developed for the removal of Cd(II) ions from aqueous media using chemical sorbents {nanocrystalline Ni (15 wt%)‐doped α‐Fe 2 O 3, oxides of MgO‐SiO 2, industrial and agriculture residues; kaolinite, metakaolinite, penicone, biochar, expanded perlite, Fluidgel, Tectone grandis L. f. leaf powder), and a Schiff‐base derived from chitosan and 2‐hydroxynaphthaldehyde . The negative charges on the surface of this last polymeric species allows it to attract Cd(II) ions from aqueous media—a crucial property in industrial applications…”

Isotherm Study on the Adsorption of Cadmium (II) onto Hydroxyapatite from Sea Shells Synthesized by Low Temperature Hydrothermal Method

“…The experimental result for the adsorption of Cd 2+ during times are illustrated in Fig 4. It is clear from the graph that concentration of Cd 2+ decreased with increasing time of adsorption. It reached to a constant value beyond which no further adsorption took place [9].…”

Bioremediation of aquaculture wastewater using microalgae Chlorella vulgaris

“…Conventional methods (e.g. chemical precipitation, membrane filtration, electrolytic processes and adsorption) have been widely used for decontamination of effluents, however these techniques exhibit disadvantages such as high reagent cost, energy requirements and sludge generation [2]. Microalgae have been reported to remove CO2, nitrogen, phosphorus, and toxic metals from a different type of wastewaters, becoming an attractive alternative as wastewater treatment [3].…”