原料和制炭方式对生物炭吸附抗生素的影响

为研究原料和制炭方法对生物炭吸附抗生素性能的影响，选取芦苇、棉杆和竹柳，经限氧和曝氧法制备得到生物炭，研究其对土霉素（OTC）和磺胺甲恶唑（SMX）的吸附性能及其吸附机理.研究发现：物源特征和制炭方法共同决定了生物炭对抗生素的吸附功效.芦苇和棉秆宜采用限氧法制备成炭，竹柳宜采用曝氧法制备成炭；整体上以曝氧竹柳炭对抗生素的吸附性能最优，单一浓度（50mg/L）下，其对OTC和SMX的吸附量分别为11.98和10.12mg/g.批吸附实验和傅里叶变换红外光谱分析表明，π-π EDA相互作用是竹柳炭吸附抗生素的主要机理.静电吸引有助于高pH值下曝氧竹柳炭对OTC的吸附，而孔隙填充可能对曝氧竹柳炭吸附SMX起到促进作用.曝氧竹柳炭对抗生素的吸附性能优于其他炭品，是去除水体抗生素的优选材料.

Biomass feedstocks and carbonization methods affect antibiotic adsorption on biochar

Biochar has been reported as a useful adsorbent of organic contaminants. Here, reed, cotton stalk, and bamboo willow were selected as feedstocks to produce biochars via oxygen-limited or aerobic methods for carbonization. The obtained biochars were first characterized for their physical and chemical properties and then investigated for their performance in adsorbing oxytetracycline (OTC) and sulfamethoxazole (SMX). It was found that both feedstocks and carbonization methods affected OTC and SMX adsorption. Reed and cotton stalks were better carbonized under oxygen-limited conditions to produce biochars (O₂-limited biochars), whereas bamboo willow was suitable to produce biochars via aerobic carbonization (aerobic biochar). The aerobic biochar adsorbed 11.98 and 10.12mg/g of OTC and SMX, respectively, from a solution with an initial concentration of 50mg/L of the biotics. Batch adsorption experiments and the Fourier transform infrared spectroscopic analysis indicated that π-π electron donor-acceptor interaction was the primary mechanisms for OTC and SMX adsorption on the aerobic biochar. Electrostatic attraction further promoted OTC adsorption on aerobic biochar at high pHs, whereas pore filling could contribute to SMX adsorption. This work showed that aerobic biochar were better adsorbents of OTC and SMX than O₂-limited biochars, and suggested that biochar adsorbents can be tailor-made for different contaminants by judicious selection of feedstocks and carbonization processes.