266654 Preparation of Novel Zirconium Immobilized Carbon for Adsorption of Arsenate From Water

Thursday, November 1, 2012: 4:05 PM
329 (Convention Center )
Narahari Mahanta and Chen J. Paul, Department of Civil & Environmental Engineering, National University of Singapore, Singapore, Singapore

Abstract

Arsenic is the naturally occurring carcinogenic metalloid and present in environment in several oxidation states. Arsenic contamination in natural water is a serious threat and challenging issue worldwide due to its acute and chronic toxicity, especially through ingestion through drinking water. In the present study, we explored the application of Zirconium immobilized carbon particle for the adsorption of arsenate from aqueous environment. For this, carboneous materials was prepared from old leaf by acid treatment. Raman spectra revealed that the prepared carbons are amorphous in nature. To increase the arsenic removal efficiency, Zr (IV) was chemically immobilized to these carbon based materials. For the immobilization process, the derived carbon materials were mixed in Zr (IV) salt solution and subsequently treated with NH4OH. Designed nano-adsorbent was screened under scanning electron microscope (SEM) analysis to explore the morphology and the presence of Zirconium on the carbon was confirmed by Energy dispersive spectroscopy and elemental analysis. These designed nano-adsorbent was used for the removal of the arsenate from water. To investigate the adsorption efficiency, designed amount of nano-adsorbent was mixed with arsenate solutions and kept for constant shaking. The effect of pH on the adsorption behavior in the batch adsorption study was carried out at a wide range of pH ranging from 2 to 11. It was observed that the pH has a strong influence on the adsorption behavior of arsenate. The maximum adsorption was achieved in the pH value at 2.5 and the trend decreases with increasing in pH. The applicability of the Langmuir adsorption isotherms well described the adsorption process and at optimal pH the adsorption efficiency was about 117.6 mg/gm. From the adsorption study, it was observed that around 70 % of final efficiency was adsorbed at initial 30 minutes time and after that it slows down. This indicates that the rate of adsorption was quite faster. Fourier transform infrared spectroscopy of unmodified, Zirconium immobilized and arsenic adsorbed carbon was investigated in detail. Hence from the above results it can be concluded that, these novel zirconium immobilized carbon sorbents are efficient in removing arsenate from water and can be an attractive as low cost alternative for the treatment of arsenic contaminated waste water.


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See more of this Session: Environmental Applications of Adsorption III: Liquid Phase
See more of this Group/Topical: Environmental Division