College of Resources and Environment, Institute of Tropical Agriculture and Forestry, Hainan University, Renmin Road, Haikou 570228, China.
College of Resources and Environment, Institute of Tropical Agriculture and Forestry, Hainan University, Renmin Road, Haikou 570228, China; College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China.
Sci Total Environ. 2018 Mar;616-617:1384-1391. doi: 10.1016/j.scitotenv.2017.10.177. Epub 2017 Oct 23.
In this study, the impacts of various cations, cation strength and pH on ofloxacin (OFL) adsorption to cassava residue-derived biochars were determined. The associated adsorption mechanisms are discussed. The biochars were prepared at pyrolysis temperatures ranging from 350°C to 750°C, and labeled as CW350, CW450, CW550, CW650 and CW750. The Freundlich model provided the best fit to describe the adsorption capacity of OFL and the Freundlich coefficient (logK) increased with increasing pyrolysis temperature. The inclusion of Zn or Al increased OFL sorption capacities of five biochars, while Cu reduced sorption to CW450 and CW550. No significant impacts on OFL sorption were observed in the presence of K and Ca. The concentration of Ca affected the adsorption capacity of CW550, but had no significant impact on other biochars. The pH of OFL solution, ranging from 3 to 9, had no significant changes on OFL adsorption by all the tested biochars. Results of FTIR spectra and zeta potential indicated that electrostatic interactions, cationic exchange, metal bridging and micropore filling could be the main sorption mechanism between OFL and biochars. These studies indicated that cassava residue can be converted into biochars that are effective adsorbents for removing OFL from aqueous solution.
在这项研究中，测定了各种阳离子、阳离子强度和 pH 值对木薯渣衍生生物炭吸附氧氟沙星（OFL）的影响。讨论了相关的吸附机制。生物炭在 350°C 到 750°C 的热解温度范围内制备，并标记为 CW350、CW450、CW550、CW650 和 CW750。Freundlich 模型最适合描述 OFL 的吸附容量，且随着热解温度的升高，Freundlich 系数（logK）增加。Zn 或 Al 的加入增加了五种生物炭对 OFL 的吸附容量，而 Cu 则降低了 CW450 和 CW550 的吸附。K 和 Ca 的存在对 OFL 的吸附没有显著影响。Ca 的浓度影响了 CW550 的吸附容量，但对其他生物炭没有显著影响。OFL 溶液的 pH 值范围为 3 到 9，所有测试的生物炭对 OFL 的吸附均无明显变化。FTIR 光谱和 ζ 电位的结果表明，静电相互作用、阳离子交换、金属桥接和微孔填充可能是 OFL 与生物炭之间的主要吸附机制。这些研究表明，木薯渣可以转化为生物炭，生物炭是从水溶液中去除 OFL 的有效吸附剂。
