Arsenic Adsorption Experiments on Chalk Powder
Due to its efficient and low-cost activity, calcium carbonate, a constituent of chalk powder is considered to be one of the strongest adsorbents for the treatment of groundwater that holds inorganic metals. Based on the calcium content, surface area and morphology, chalk powder is used to achieve a high potential rate of arsenic adsorption. The adsorption process is also aided by the porosity and chemical composition of chalk powder. At different settings, the rate of arsenic adsorption is found to be directly proportional to parameters such as contact time, adsorbent dosage, concentration and pH. At different temperatures, the Freundlich adsorption isotherm ruled equilibrium adsorption with the best correlation coefficients (0.999).
At various concentrations, the equilibrium adsorption potential was demonstrated by pseudo second - kinetic order. Negative values of Gibbs energy, enthalpy and entropy indicated that the adsorption mechanism is instinctive and endothermic, with no randomness at the solute-liquid interface. The separation factor RL was found to be in the range of 0< R< 1, indicating that Arsenic adsorption onto Chalk powder was excellent. The above findings led to the decision to use chalk powder as a low-cost adsorbent for removing arsenic from an aqueous solution.
Vijayarani A*, Sailaja BBV and Sirisha D