Nickel removal from aqueous solutions using sheep manure wastes

This paper reports a study on the potential use of sheep manure waste (SMW) for the removal of nickel ions from aqueous solutions. The adsorption of nickel ions from aqueous solutions on SMW has been studied as functions of contact time, initial pH, amount of sorbent, sorbent particle size, initial concentration of nickel ions, salt, and chelating agents. The experimental results showed that the SMW has a high affinity for nickel binding, where 79% removal of 100 ppm initial nickel ions concentration was obtained using 8.0 mg SMW/mL, at pH 6.5 in 4 minutes equilibrium time. The equilibrium adsorption data were analyzed using four different isotherms: the Langmuir, Freundlich, Redlich-Peterson, and Sips isotherm equations. The results of the kinetic studies showed that the adsorption of nickel ions on SMW is a pseudo-first order with respect to the nickel ions solution concentration.