Preparation of Magnetic Chitosan/Coffee Residue Composites and Their Application in Adsorption of Dyes

Abstract

The excessive use of chemical substances has contributed to environmental pollution. Organic and inorganic wastes, as a result of rapid industrialization and urbanization, have led to an enormous water pollution problem. Trace amounts of any of these water contaminants are significant hazard on the environment and human beings. The discovery of synthetic dyes displaced the protagonist natural dyes due to their low production cost, better resistance against the environment, and brightness. The textile industry and other industries such as paper, plastic, cosmetics are the primary customers of synthetic dyes. Most of these synthetic dyes are stable (due to their complex aromatic structures), toxic, non-biodegradable. Dye compounds are difficult to decompose and dangerous if the aquatic system is exposed in a large concentration. Trace amounts of synthetic dyes can be recognized easily in the aquatic system and reduce the photosynthetic activity of the marine ecosystem by preventing the penetration of light and oxygen. Researchers have attempted to develop a separation method for removing various pollutants and improve the quality of discharged wastewater. One of the methods is magnetic separation or separation technology employing magnetic adsorbents. Magnetic separation provides convenient tools for treating wastewater treatment against traditional separation methods such as filtration or sedimentation. Magnetic carriers can easily be separated from a mixture or medium by applying an external magnetic field. Preparation of magnetic carriers from non-magnetic precursors has been successfully carried out using a simple procedure. Magnetic microparticles were entrapped in chitosan and coffee residue. Magnetic chitosan/coffee residue composites (MCCC) have been developed and exhibit good sorption behavior towards synthetic dyes in aqueous solution. The MCCC has shown promising tools for dyes removal in wastewater. The MCCC was characterized by Fourier-Transform Infrared Spectroscopy, UV-visible spectrophotometer. The results indicated that the adsorption behavior was influenced by type of dyes, the mass ratio of chitosan and coffee residue.