(660a) Removal of Cadmium Ions from Aqueous Solution Using a New Low-Cost Biosorbent

In recent years, heavy metal pollution has increased as a result of industrial growth, especially in industries such as electroplating, mining, metal finishing, battery production, and welding. Among the heavy metals, one of the most hazardous is cadmium, which accumulates in the human body and causes cancer along with cardiovascular, neurological, and respiratory problems. Hence, it is crucial to sequester cadmium ions from industrial effluent before the contaminated effluent is discharged into the sewage system. There are several traditional treatment methods for removing heavy metals from aqueous effluents, including chemical precipitation, ion exchange, and membrane filtration. These techniques have high operational costs and require the continuous input of chemicals, so they are neither economical nor ecologically sustainable. Therefore, biosorption has gained significant attention as an effective alternative for sequestering toxic heavy metals. In this work, Sorghum X drummondii (Sudangrass), an inexpensive agricultural product, is used as an adsorbent for the removal of cadmium ions under a range of conditions, including variations in initial pH, temperature, contact time, adsorbent dose and initial cadmium ion concentration. Fourier Transform Infrared (FTIR) is used to characterize the surface of the biosorbent and also to investigate the functional groups involved in the process. Scanning Electron Microscopy (SEM) is used to observe the morphology of the biosorbent before and after the adsorption process. Well-known isotherm models are used to describe the equilibrium data, from which the parameters are calculated and reported. Two kinetic stages of adsorption are identified: a fast period, followed by a relatively slow period leading to equilibrium. Thermodynamic parameters, such as the change of free energy, enthalpy, and entropy, were also evaluated for the adsorption of cadmium ions onto Sudangrass.