Cadmium Removal and Recovery from Aqueous Solution Using Conocarpus Nanostructure

Heavy metals are recognized as one of the most toxic groups. They enter the food chain through the waste disposal into the water and environment. This study was carried out with the aim of investigating cadmium ions removal from aqueous solution using conocarpus nanostructure. For this purpose, conocarpus was grinded to nano-size by the ball mill. The effect of experimental parameters such as pH, time, adsorbent dosage and initial concentration of cadmium were studied in batch system. The PSA, FTIR and SEM tests were used to determine the absorbent characteristics. The imaging of adsorbent indicated that surface of conocarpus had many deep pores, which represents the better adsorption of cadmium. 8.5% of adsorbent particles were in the range of nanoparticles and 91.5% of them were in the range of nanostructure. The results showed that optimum pH for cadmium adsorption is 6 and the maximum removal efficiency and adsorption capacity of cadmium are 80.9% and 0.86 mg/g., respectively. Comparing the adsorption isotherm and kinetics models showed that the Langmuir and Ho models, with R2 values of 0.998 and 0.990 respectively, had a better fitting and description of adsorption data than other models. The study showed that conocarpus nanostructure is an effective adsorbent for cadmium removal from aqueous solution.