Volume No. 11 Issue No.: 1 Page No.: 13-19 July-September 2016

 

REMOVAL OF LEAD IONS IN AQUEOUS SOLU -TION USING CASHEW NUT SHELL DERIVED ADSORBENT

 

Rapeeporn Phromrak, Wikanda Saengngoen and Kamchai Nuithitikul*

Chemical and Process Engineering, Walailak University, Thasala District, Nakhon, SiThammarat (THAILAND)

 

Received on : March 18, 2016

 

ABSTRACT

 

Lead ions which are toxic to human and environment can be usually found in the effluent of wastewater from several industries including paint, battery, steel and alloy manufacturing industries. When lead is accumulated in human body, it could destroy organs, tissues and the nervous system. Several methods have been reported to remove lead ions from water. Among these, adsorption is an easy, efficient and energy saving method. However, a promising adsorbent needs to be produced from no-cost wastes. In this research, cashew nut shells, the waste from a food processing factory, were modified and used as an adsorbent to removelead ions (Pb2+) in aqueous solution. The adsorption study was carried out in a batch vessel at a constant temperature (30oC). The effects of pH of the solution (pH 2.5-10) and the amount of the cashew nut shell-derived adsorbent (2-15g) were investigated. Moreover, the experimental data at the adsorption equilibrium was tested with typical adsorption isotherms : Langmuir and Freundlich isotherms. The results showed that the optimum pH of the solution was 4. The maximum adsorption capacity was found when 2 g of the adsorbent was used to treat 50 mg/L of Pb2+ in aqueous solution. Langmuir adsorption isotherm fitted to the experimental data better than Freundlich isotherm, suggesting a monolayer adsorption of Pb2+ on the homogeneous surface of the adsorbent.

 

Keywords : Adsorption, Cashew nut shell, Lead removal, Adsorption isotherm, Biosorption

 

 

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