杨木生物炭对水溶液中3种磺胺类抗生素的混合吸附

MIXED SORPTION OF THREE AQUEOUS SULFONAMIDES ONTO THE BIOCHAR DERIVED FROM POPLAR WOOD CHIPS

利用杨树木屑在限氧条件下,制备出3种不同热解温度下的生物炭,以探究其对水溶液混合磺胺类药物(SAs)的吸附机制。结果表明:350℃烧制的生物炭(BC350)孔径以大孔为主,而500℃(BC500)与650℃(BC650)以介孔为主;生物炭表面芳香性随着热解温度提高而增强。伪二级模型较适合描述生物炭吸附SAs的动力学过程;Freundlich等温模型对杨木生物炭拟合度较好;杨木生物炭具有较大的SAs吸附容量,BC650的SAs吸附容量为秸秆类生物炭的2.6~104倍。吸附热力学计算表明,杨木生物炭对磺胺吸附兼有物理吸附与化学吸附,以化学吸附为主。根据不同pH值条件下3种SAs的分子形态,得出3种SAs的竞争吸附能力依次为SPD>SMZ>SDZ。

Discharge of sulfonamides(SAs)poses seriously potential ecological risk on the aquatic environment.In this paper,the biochar derived from poplar wood chips(PWCs)was produced under three pyrolysis temperatures to investigate the sorption mechanism of SAs in the aqueous solution.The experiment result showed that the pore channel of BC350 and BC500-BC650 was dominated by the macropores and mesopores,respectively.The increase of pyrolysis temperature enhanced the polycyclic aromatic surface of the biochars.The pseudo-secondary-order kinetic model and the Freundlich model could be applied to describe the kinetics and isothermal process of biochar sorption,respectively.The maximum sorption capacity of SAs of BC650 was about 2.6 to 104 times on herb-residue biochars.Based on the calculation of thermodynamics,the sorption of PWC involved the physical and chemical sorption simultaneously,but dominated by chemical sorption.The sorption affinity of three SAs was in the descending order of SPD>SMZ>SDZ,thanked to the support from their molecular morphology analysis.