A study on the ability of processed squeezed bitter almond for the removal of cadmium ions from contaminated water

Heavy metal ions and organic compounds are the most common chemical pollutants that pollute water. Natural water is contaminated with Cd ions at relatively low concentrations and neutralizing Cd polluted water is not only cumbersome but also a prohibitively expensive process. Cd unlike most organic contaminants is difficult to remove because they accumulate in the tissues of living organisms, do not biodegrade, and may be toxic. Adsorption was the most dominant method of Cd ions removal from water due to its low cost, eco-friendliness, high efficiency, and ease of operation however its efficiency depends on absorbent. In the present study processed squeezed bitter almond (PSBA) is abundantly available and used as a bio-adsorbent. PSBA was procured from the local almond oil factor, characterized, and critically examined on its properties, adsorption capacities, isotherms, kinetics, and thermodynamics before its use in the experiment. The Freundlich isotherm model was used and found to be the best to capture the equilibrium data. The stated value for the Langmuir bio-adsorption capacity is 59.52 mg/g. To examine the kinetic behavior of the process, pseudo-first-order and pseudo-second-order kinetic models were examined. The data were seeming to be better described by the pseudo-second-order model. The Cd ions bio-adsorption process employing PSBA is exothermic and spontaneous, according to the thermodynamic analysis.