Study on Simulated Adsorption of Two Kinds of Biochar on Different Degradable Microplastics

The harm of microplastics (MPs) has been widely confirmed, but there are various problems in the existing removal technology. In this study, two kinds of biochar were used to simulate the adsorption of non-degradable MPs polypropylene (PP), polyethylene (PE) and degradable MPs butylene terephthalate (PBAT) and polylactic acid (PLA). It was found that the absorption rate of PLA by coconut biochar was 35.79%, and the absorption rate of PE was 38.42%. While the absorption rate of PBAT by bamboo biochar was 51.24%, and the absorption rate of PP was 46.65%. Different factors, such as pH, temperature, time, dosage, affected adsorption rate of different MPs polymers. Microscopic characterization confirmed that MPs were commonly detected on biochar. The adsorption rate of non-degradable MPs is greater than that of degradable plastics. The adsorption equilibrium time of coconut biochar is shorter than that of bamboo. This study can provide a reference for the use of biochar to remove MPs.