Sun Binbin, Lian Fei, Bao Qiongli, Liu Zhongqi, Song Zhengguo, Zhu Lingyan
Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, China; College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, China.
Environ Pollut. 2016 Jul;214:142-148. doi: 10.1016/j.envpol.2016.04.017. Epub 2016 Apr 12.
The interaction between biochar (BC) and antibiotics with the presence of low molecular weight organic acids (LMWOAs) is largely unknown, although it is crucial for understanding the role of BC in reducing the bioavailability of antibiotics in rhizosphere. The impacts of two typical LMWOAs (citric and malic acids) on sorption of sulfamethoxazole (SMX) by crop-straw BCs produced at 300 °C (BCs300) and 600 °C (BCs600), respectively, were examined. The sorption of SMX on BCs increased more than 5 times with the concentration of LMWOAs increasing from 0 to 100 mmol/L, which was mainly attributed to the elevated microporosity of BCs (measured by CO2) after treated by LMWOAs. The pore development of BCs was mainly derived from the release of dissolved organic residues from BC by LMWOA washing. For H2O2-oxidized BCs, however, LMWOAs had little effect on SMX sorption by BCs300 but greatly increased that by BCs600, which can be explained by the distinct sorption mechanisms of SMX on BCs300 and BCs600. These results indicate that the impact of LMWOAs on SMX sorption is highly dependent on the properties of BCs and LMWOAs, as well as their interaction mechanisms.
尽管生物炭（BC）与抗生素在低分子量有机酸（LMWOAs）存在下的相互作用对于理解生物炭在降低根际抗生素生物有效性中的作用至关重要，但其情况仍很大程度上未知。分别研究了两种典型的低分子量有机酸（柠檬酸和苹果酸）对300°C（BCs300）和600°C（BCs600）制备的作物秸秆生物炭吸附磺胺甲恶唑（SMX）的影响。随着低分子量有机酸浓度从0增加到100 mmol/L，磺胺甲恶唑在生物炭上的吸附增加了5倍多，这主要归因于低分子量有机酸处理后生物炭微孔率（通过二氧化碳测定）的提高。生物炭的孔隙发展主要源于低分子量有机酸洗涤使生物炭中溶解有机残留物的释放。然而，对于过氧化氢氧化的生物炭，低分子量有机酸对BCs300吸附磺胺甲恶唑影响不大，但极大地增加了BCs600对其的吸附，这可以通过磺胺甲恶唑在BCs300和BCs600上不同的吸附机制来解释。这些结果表明，低分子量有机酸对磺胺甲恶唑吸附的影响高度依赖于生物炭和低分子量有机酸的性质及其相互作用机制。
