Characteristics of Cd(II) Biosorption into Streamer Biofilm Matrices

Abstract

This study analyzed the characteristics of Cd(II) biosorption into the natural streamer biofilm matrices collected from the Brantas River in Indonesia to develop streamer biofilms as biosorbent pollutant ions. The biosorption features were studied by investigating the kinetics of adsorption and the adsorption isotherm of Cd(II) into the streamer biofilm. The adsorption sites of biofilms were investigated by analyzing the biofilms' electric charge characteristics and Fourier Transform Infrared Spectroscopy (FTIR) spectra. The results of this study suggest that the adsorption of Cd(II) to the biofilm streamer is a physicochemical process where the electrically charged sites promoted by ionization functional groups in the biofilm polymers functioned as adsorption sites. The adsorption of Cd(II) into streamer biofilm is well suited to the Langmuir adsorption pattern. Cd(II) adsorption's maximum capacity to the biofilm is estimated to be approximately 14.29 mmol/g, while the equilibrium constant is approximately 0.06 L/mmol. This study demonstrates the biosorption of Cd(II) using biofilm streamers that formed naturally in rivers in Indonesia, a phenomenon that had rarely been reported. This study's results reveal that the natural streamer biofilm formed in Indonesia's Brantas River is a promising biosorbent for Cd(II) removal in water pollution treatments.