Removal of Toxic Cation from Aqueous E-Waste Material using ZnO as a Nanoadsorbent by Adsorption TechniqueAuthor(s): Dr. Renu Nayar
The harmful content of E –waste poses a threat to human health and environment. Its toxicity mixed with our environment courses harmful effects in health of living things .Materials such as carcinogenic chemicals concentrated acids toxic metals found in E-waste affects in our daily life. E-waste if improperly disposed can leach toxic ions like lead cadmium, chromium, mercury and other harmful substances into soil, surface and groundwater. A representative sample off E-waste was chosen for the removal of some heavy metals using ZnO as a nanoadsorbent. In the present study investigated the removal of toxic metals [Pb (II), Cd (II), and Hg (II)] from aqueous e waste sample solution by nano adsorbent zinc oxide (ZnO). The values show that adsorption capacity of toxic metals increases with concentration, contact time and solution of pH and then decreases with dosage of adsorbent[ZnO]. The equilibrium time was attained after 30 min for cadmium and mercury .Maximum removal percentage was achieved at an adsorbent loading weight of 0.3 mg/l for Cd (II) and 0.25 mg/l for Hg (II) .Equilibrium conditions were found to be at pH 4 and 6 for Cd (II) and Hg (II) while the greatest rate of adsorption of Pb (II) ions was observed at the pH = 4, with adsorbent dosage 0.3 mg/l and equilibrium time one hour on ZnO. Adsorption is an effective purification and separation process used in especially waste water treatment .Freundich adsorption isotherm model were applied to analyze adsorption data and found to be applicable to these adsorption process. Experiment was applied for toxic metal ions by Batch adsorption .The adsorption isotherm were determined using Freundlich equation.