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Removal characteristics of Zn(II) from aqueous solution by alkaline Ca-bentonite
- Source :
- Desalination. 276:103-108
- Publication Year :
- 2011
- Publisher :
- Elsevier BV, 2011.
-
Abstract
- Zn(II) adsorption from aqueous solution on alkaline Ca-bentonite (ACB) was studied using batch technique and compared with the adsorption onto raw bentonite (RB). The percentage of Zn(II) removal increased with increasing adsorbent dosage, contact time and pH. The optimum initial pH for Zn(II) removal by RB and ACB was 7.0 and 4.0–7.0, respectively. The adsorption data from both RB and ACB experiments could be well-described by the pseudo-second-order kinetic model. The experimental data for Zn(II) adsorption on RB could be described by the Langmuir and Freundlich isotherms while those on ACB could be fit well to the Langmuir isotherm. Langmuir monolayer adsorption capacity of ACB (149 mg g − 1 ) was found to be roughly two times greater than that of RB (73.5 mg g − 1 ). Therefore, ACB is more effective than RB for Zn(II) adsorption from aqueous solution with respect to short equilibrium time, high efficiency and broad pH range. The equilibrium data, SEM and XRD analyses indicate that ACB removes Zn(II) from aqueous solution mainly by surface precipitation, cation exchange and fixation. In summary, the study suggests that ACB is very suitable for potential applications in Zn(II) removal from aqueous solution.
- Subjects :
- Langmuir
Aqueous solution
Precipitation (chemistry)
Mechanical Engineering
General Chemical Engineering
Inorganic chemistry
chemistry.chemical_element
Langmuir adsorption model
General Chemistry
Zinc
symbols.namesake
Adsorption
chemistry
Bentonite
symbols
General Materials Science
Freundlich equation
Water Science and Technology
Subjects
Details
- ISSN :
- 00119164
- Volume :
- 276
- Database :
- OpenAIRE
- Journal :
- Desalination
- Accession number :
- edsair.doi...........b0407251061ef3f8a51b67c06ef1a282