Characterization of amphoteric bentonite-loaded magnetic biochar and its adsorption properties for Cu 2+ and tetracycline

作者：Hongyan Deng, Haixia He, Wenbin Li, Touqeer Abbas, Zhifeng Liu · 发表于：PeerJ · 年份：2022 · DOI：10.7717/peerj.13030 · 被引用次数：17 · 研究领域：Adsorption and biosorption for pollutant removal、Phosphorus and nutrient management、Clay minerals and soil interactions

To realize simultaneous adsorption of heavy metal and antibiotic pollutants by a BC-based recyclable material, Fe 3 O 4 magnetic biochar (MBC) was prepared by co-precipitation method. Then different ratios of dodecyl dimethyl betaine (BS-12)-modified bentonite (BS-B) were loaded on the surfaces of biochar (BC) and MBC to prepare BS-B-loaded BC and MBC composites, called BS-B/BC and BS-B/MBC, respectively. The physicochemical and structural properties of the composites were characterized by scanning electron microscopy, Fourier transform infrared spectrometry, thermogravimetric analysis, specific surface area (S BET ) analysis, and vibrating sample magnetometry, and the adsorption efficiencies of BS-B/BC and BS-B/MBC to Cu 2+ and tetracycline (TC) were studied. The following results were obtained. (1) Compared with BS-B/BC, BS-B/MBC had decreased pH and cation exchange capacity (CEC) and increased S BET . The pH, CEC, and S BET of BS-B/BC and BS-B/MBC decreased with the increase in the BS-12 proportion of BS-B. The surface of BS-B/MBC became rough after Fe 3 O 4 loading. (2) The residual rate of BS-B/MBC was higher than that of BS-B/BC after high-temperature combustion, and the residual rate decreased with the increase in the BS-12 proportion of BS-B. The 2D infrared spectra showed that Fe 3 O 4 and BS-12 were modified on the surface of BS-B/MBC. MBC and BS-B/MBC had splendid magnetism and could be separated by external magnetic field. (3) Compared with unmagnetized ones, the ...