Preparation of chitosan-industrial hemp residue superfine powder-Fe @ZIF67 composite as a recyclable and low cost adsorbent for congo red and heavy metal as (V)

Dye and heavy metal pollution has caused serious damage to water. It became a study hotspot to treatment at domestic and abroad. The abandoned industrial hemp residue after extraction of cannabidiol (CBD) commonly causes resource waste and environmental pollution. Herein, the industrial hemp residue is reused to prepare a recyclable composite with chitosan and Fe@ZIF67 magnetic metal material for the pollutant treatment. The properties of the synthesized composite are characterized by SEM, TG, BET, FT-IR, XRD, VSM, and Zeta potential analysis. Congo red (CR) and As (V) are adopted to evaluate the adsorption properties of composite. The composite shows the best adsorption effect for CR when the addition of industrial hemp residue is 20%, and the adsorption capacity is 166 mg/g. Whereas the best adsorption effect for As (V) occurs at the addition of industrial hemp residue is 2%, and the adsorption capacity is 22 mg/g. The results reveal that the developed composite has good adsorption effect on CR and As (V), suggesting the recycling of industrial hemp residue has potential for water production and industrial wastewater treatment. It may provide useful insights into the development of recovery and utilization of industrial hemp residue. Graphical abstract