Nettle ash as a low cost adsorbent for the removal of nickel and cadmium from wastewater

This study was focused on nettle ash as an alternative adsorbent for the removal of nickel (II) and cadmium (II) from wastewater. Batch experiments were conducted to determine the factors affecting adsorption of nickel (II) and cadmium (II). The adsorption process is affected by various parameters such as contact time, solution pH and adsorbent dose. The optimum pH required for maximum adsorption was found to be 6. The experimental data were tested using Langmuir, Freundlich and Tempkin equations. The data were fitted well to the Langmuir isotherm with monolayer adsorption capacity of 192.3 and 142.8 mg/g for nickel and cadmium, respectively. The adsorption kinetics were best described by the pseudo second order model. The cost of removal is expected to be quite low, as the adsorbent is cheap and easily available in large quantities. The present study showed that nettle ash was capable of removing nickel and cadmium ions from aqueous solution.