Fabrication of chitosan-modified magnetic durian shell biochar for removal of the microplastics

Microplastics (MPs) are an emerging threat to terrestrial ecosystems and have attracted global attention. In this study, durian shell was used as biochar raw material to provide magnetism, and then it was modified with chitosan to make chitosan-modified magnetic biochar (CMBC). The prepared CMBC was used to simulate the adsorption of MPs in sewage. Experimental results showed that the amount of CMBC was 0.1 g, pH was 10, the concentration of 160 mg/L had the optimal adsorption effect, the adsorption rate reached up to 97.22 %, and the adsorption capacity was 15.56 mg/g. According to the adsorption kinetic analysis, the adsorption process conformed to be the Freundlich model. The removal rate of MPs still remained at 76.41 % when CMBC, a green environmentally friendly adsorption material, was recycled for five times. This research broadens the understanding for the evaluation of magnetic biochar effectiveness in the adsorption of MPs pollution.