Adsorption of copper(II), cadmium(II), nickel(II) and lead(II) from aqueous solution using biosorbents
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Adsorption of copper(II), cadmium(II), nickel(II) and lead(II) from aqueous solution using biosorbents Huan-Ping Chao · Chung-Cheng Chang
Received: 16 May 2012 / Accepted: 5 September 2012 / Published online: 21 September 2012 © Springer Science+Business Media, LLC 2012
Abstract Three types of agricultural waste, citrus maxima peel (CM), passion fruit shell (PF) and sugarcane bagasse (SB), were used to produce biosorbents for removing the heavy metal ions of copper(II), cadmium(II), nickel(II) and lead(II) from a pH 5.0 solution. The properties of biosorbents were characterized using scanning electron microscopy (SEM), zeta potential analyzer, Fourier transform infrared (FTIR) spectroscopy, elemental analyzer and tests of cation exchange capacity (CEC). The result indicated that the selected biosorbents possess rich carboxyl (COOH) and hydroxyl (OH) groups to produce a complexation with the heavy metals. Moreover, the negative surface charge of the biosorbent might adsorb the metal ions through the ion exchange. All of the adsorption isotherms indicated that Ltype characters represented complexation and ion exchanges that were the adsorption mechanisms of biosorbents toward heavy metals. Biosorbents with higher oxygen content might generate high adsorption capacities. The adsorption capacities of CM and PF, estimated from the fitting to the Langmuir isotherm, are similar to those reported by others regarding biosorbents. Keywords Heavy metal · Adsorption · Biosorbent · Agricultural waste · Functional group
H.-P. Chao () Department of Bioenvironmental Engineering, Chung Yuan Christian University, Chung-Li 32023, Taiwan, ROC e-mail: [email protected] C.-C. Chang Department of Civil Engineering, Chung Yuan Christian University, Chung-Li 32023, Taiwan, ROC
1 Introduction Industrial processes can generate a large amount of heavy metal that is discharged into wastewater treatment plants (WWTPs). Several methods have been applied to remove heavy metal ions from the wastewater, including precipitation, flotation, ion exchange, membrane-related process, and electrochemical technique (González-Muñoz et al. 2006; Satapathy and Natarajan 2006; Bessbousse et al. 2008). Precipitation is used when the concentration is high, but must be followed by advanced treatments to further reduce the effluent concentration and its impact on the environment and human health. For wastewater with low concentration of heavy metal, ion-exchange is the most common treating method in WWTPs. However, ion exchange resins need high production costs (Kurniawan et al. 2006). A number of researchers have intended to develop biosorbents with low costs, and high adsorption capacities to remove the harmful heavy metals in recent years (Febrianto et al. 2009; Ofomaja and Naidoo 2010). Two types of biosorbents were frequently used to remove heavy metal ions in the solution: agricultural wastes, including fruit peels, straw, coconut coir, and so on (Rocha et al. 2009; Zheng et al. 2009; Reddy et al. 2011); and microorganisms, such as bacteria, yeasts, fung
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