摘要
A magnetic biochar adsorbent(BM–OH–BC)was prepared through NaOH–ball milling co-modification with walnut shells as the raw material,and its oil adsorption characteristics were investigated.The adsorption properties of oil pollutants were compared before and after the NaOH-ball-milling co-modification,and the mechanism of NaOH-ball-milling on oil pollutants was investigated by scanning electron microscope-energy dispersive X-ray spectroscopy,BET,X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy.The experimental results showed that the oil adsorption capacity of BM–OH–BC can reach 2.75 g/g,which is 129%higher than that of unmodified biochar.Moreover,after five adsorption and desorption cycles,the adsorption rate of BM–OH–BC only decreased by 5.9%,which was because the oil adsorption of BM–OH–BC is mainly chemical adsorption.The adsorption processes involving single layer,heterogeneous phase and multilayer made BM–OH–BC have excellent adsorption properties.After biochar co-modification,the specific surface area of BM–OH–BC increased to 466 m^(2)/g,the total pore volume increased to 0.245 cm^(3)/g,the average pore size decreased to1.90 nm,and the number of hydrophobic non-polar functional groups increased,leading to the enhancement of its oil absorption capacity.This study provides a reference for the treatment of oil-contaminated water bodies.
基金
This work was financially supported by the National Natural Science Fund of China(No.42007415)
the Natural Science Foundation of Shaanxi Province(No.2020SF-435)。
