Low cost and regenerable composites based on chitin/bentonite for the adsorption potential emerging pollutants

Composites based on bentonite and chitin were prepared and its application for trimethoprim (TMP) adsorption from aqueous solution was investigated. Composites were characterized by ATR-FTIR, XRD, DSC and TGA. Characterization data revealed the intercalation of the chitin macromolecules into the bentonite interlayer. Several important parameters of TMP adsorption were explored including the composition of composites, pH medium, isotherms, contact time, and reused in batch experiments. Batch adsorption studies showed that TMP adsorption on composites increased with increase in bentonite content on composites and in acid medium. Langmuir adsorption model showed the best agreement with the experimental data used to describe adsorption isotherms. Langmuir isotherm indicated that the maximum adsorption capacity of TMP was 67 mg/g. Sectioned composite had around 100% adsorption capacity after three regeneration cycles.