Adsorption Dynamics of Chromium (VI) Ions onto Activated Carbon Prepared using Microwave from Silk Cotton Fruit Walls (Ceiba pentandraL.)

Heavy metal ion pollution due to the presence of Chromium (VI) in the environment has become a serious concern because of rapid industrialization. The acute toxicity of chromium to aquatic life, human and the stringent effluent standard to be met by industries as specified by regulatory organizations has necessitated the development of innovative, effective and economical methods for treating Chromium bearing wastewater. Present investigation is the evaluation of adsorption capability of activated carbon prepared from fruit walls of Silk Cotton (Ceiba pentandraL.) using Chromium (VI) ion as model adsorbate. ZnCl₂ is used as activating agent and micro wave heating is adopted to prepare the activated carbon. Batch mode adsorption experiments were carried out to assess the effects of the system variables such as contact time, adsorbent dosage, pH and initialmetal ion concentration. Experimental data obtained were fitted with linearised forms of Legergren, Ho and Webber Morrispseudo first order , pseudo second order and intra particle diffusion kinetic models respectively. The statistical tool Sum of Squared Error (SSE) inferred that for second order kinetic model was more suitable to describe the above adsorption. The intra particle diffusion is found to be the rate determining step.