An Effective Way of Removing Nickel (II) from Aqueous Solutions Using Powder of Mosambi Fruit Peelings as a Low Cost Sorbent

The removal of heavy metals from waste water has recently become the subject of considerable interest owing to strict legislations introduced to control water pollution. Heavy metals like Zn, Cu, Ni, and As are known to have toxic effects at very low concentrations as well as very high concentration. The aim of this study is to analyse the removal of Ni (II) from aqueous solutions. In the present investigation, the powder of Mosambi fruit peelings (PMFP) was used as an inexpensive and efficient adsorbent for Ni (II) removal from aqueous solutions. The influence of physico-chemical key parameters such as the initial metal ion concentration, pH, agitation time, particle size and adsorbent dosage has been considered in batch tests. Sorbent ability to adsorb Ni (II) ions was examined and the mechanism involved in the process investigated. The optimum results were determined at an initial metal ion concentration of 50 (mg L-1), pH=4, agitation time – 90 min, an adsorbent dose (125 mg/50 ml) and the particle size (0.6 mm). The % adsorption, Langmuir constants [Q0=29.41(mg/g) and b=0.4789(L/mg)], Freundlich constant Kf= 23.92(mg/g) and n=2.24(L/mg), Lagergren rate constants [Kad (min-1) = 4.37 x 10-2] for [Ni (II)] 50 (mg L-1), were determined for the adsorption system as a function of sorbate concentration. The equilibrium data obtained were tested using Langmuir, Freundlich adsorption isotherm models, and the kinetic data obtained were fitted to pseudo first order model. If low cost adsorbents perform well in removing heavy metals at low cost, they can be adopted and widely used in industries not only to minimize cost inefficiency, but also to improve profitability. Heavy metal removal with the above adsorbent appears to be technically feasible, eco-friendly and has high efficacy.