Document Detail

Thermodynamic and kinetic studies of As(V) removal from water by zirconium oxide-coated marine sand.
MedLine Citation:
PMID:  23423866     Owner:  NLM     Status:  Publisher    
Arsenic contamination of groundwater is a major threat to human beings globally. Among various methods available for arsenic removal, adsorption is fast, inexpensive, selective, accurate, reproducible and eco-friendly in nature. The present paper describes removal of arsenate from water on zirconium oxide-coated sand (novel adsorbent). In the present work, zirconium oxide-coated sand was prepared and characterised by infrared and X-ray diffraction techniques. Batch experiments were performed to optimise different adsorption parameters such as initial arsenate concentration (100-1,000 μg/L), dose (1-8 g/L), pH of the solution (2-14), contact time (15-150 min.), and temperature (20, 30, 35 and 40 °C). The experimental data were analysed by Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models. Furthermore, thermodynamic and kinetic parameters were evaluated to know the mode of adsorption between ZrOCMS and As(V). The maximum removal of arsenic, 97 %, was achieved at initial arsenic concentration of 200 μg/L, after 75 min at dosage of 5.0 g/L, pH 7.0 and 27 ± 2 °C. For 600 μg/L concentration, the maximum Langmuir monolayer adsorption capacity was found to be 270 μg/g at 35 °C. Kinetic modelling data indicated that adsorption process followed pseudo-second-order kinetics. The mechanism is controlled by liquid film diffusion model. Thermodynamic parameter, ΔH°, was -57.782, while the values of ΔG° were -9.460, -12.183, -13.343 and -13.905 kJ/mol at 20, 30, 35 and 40 °C, respectively, suggesting exothermic and spontaneous nature of the process. The change in entropy, ΔS° = -0.23 kJ/mol indicated that the entropy decreased due to adsorption of arsenate ion onto the solid adsorbent. The results indicated that the reported zirconium oxide-coated marine sand (ZrOCMS) was good adsorbent with 97 % removal capacity at 200 μg/L concentration. It is interesting to note that the permissible limit of arsenic as per World Health Organization is 10 μg/L, and in real situation, this low concentration can be achieved through this adsorbent. Besides, the adsorption capacity showed that this adsorbent may be used for the removal of arsenic from any natural water resource.
Tabrez Alam Khan; Saif Ali Chaudhry; Imran Ali
Related Documents :
24869646 - Development of vitrification protocol in rubia akane (nakai) hairy roots using a system...
23114546 - Solution mediated phase transformation (rho to sod) in porous co-imidazolate based zeol...
22321856 - Modifying fe(3)o(4) nanoparticles with humic acid for removal of rhodamine b in water.
25251756 - Morphology-conductivity relationship in crystalline and amorphous sequence-defined pept...
24076746 - Structural transitions of epitaxial ceria films on si(111).
23566116 - Potential of coconut water and soy milk for use as storage media to preserve the viabil...
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2013-2-20
Journal Detail:
Title:  Environmental science and pollution research international     Volume:  -     ISSN:  1614-7499     ISO Abbreviation:  Environ Sci Pollut Res Int     Publication Date:  2013 Feb 
Date Detail:
Created Date:  2013-2-20     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9441769     Medline TA:  Environ Sci Pollut Res Int     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Department of Chemistry, Jamia Millia Islamia, New Delhi, 110025, India,
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Next Document:  Dechlorination and organohalide-respiring bacteria dynamics in sediment samples of the Yangtze Three...