Toxic heavy metal cadmium removal using chitosan and polypropylene based fiber composite

The aim of the present work was to evaluate the performance of polypropylene (PP)/sisal fiber (SF)/banana fiber (BF) and chitosan-based hybrid (chitosan(CS)/SF)/BF) composite materials for the adsorptive removal of cadmium (Cd) ions from water waste. Polypropylene is harnessed for its importance in forming strong composite materials for various applications. Chitosan biopolymer encloses a great deal of amino and hydroxyl groups, which provide effective removal of Cd ions from wastewater. The batch adsorption studies proved that the removal of Cd ions was pH-dependent and attained optimum at pH 5.5 for both the composites. Langmuir and Freundlich models were applied for the obtained experimental values. Based on the R² values, it was evidenced that the adsorption process was best fitted with the Freundlich isotherm than Langmuir. The sorption capacity of CS/SF/BF hybrid composite (C_max = 419 mg/g) is higher than PP/SF/BF composite (C_max = 304 mg/g), and allows multilayer adsorption. Kinetics studies revealed that the pseudo-second-order model was followed during the removal of Cd ion from wastewater. The overall evaluation proved that though both the adsorbents are suitable for the removal of Cd ions, the efficiency of CS-based ternary composite material is better than PP-based composite.