College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China. E-mail:
J Environ Sci (China). 2021 Feb;100:228-239. doi: 10.1016/j.jes.2020.07.012. Epub 2020 Aug 6.
Biochar has been widely applied for the remediation of petroleum-contaminated soil. However, the effect of biochar on the transport of petroleum degradation bacteria has not been studied. A typical Gram-positive petroleum degradation bacteria-Corynebacterium variabile HRJ4 was used to study the effect of different biochars on bacterial transport and retention. Results indicated that the addition of biochar in sand was effective for reducing the transport of bacteria and poplar sawdust biochar (PSBC) had a stronger hinder effect than corn straw biochar (CSBC). The hindrance was more evident with pyrolysis temperature of biochar raised from 300°C to 600°C, which was attributed to the increase of specific surface area (309 times). The hindrance effect also enhanced with higher application rate of biochar. Furthermore, the reduction of HRJ4 transport was more obvious in higher (25 mmol/L) concentration of NaCl solution owing to electrostatic attraction enhancement. The adsorption of biochar to HRJ4 was defined to contribute to the hindrance of HRJ4 transport mainly. Combining the influence of feedstocks and pyrolysis temperature on HRJ4 transport, it suggested that specific surface area had the greatest effect on HRJ4 transport, and pore-filling, electrostatic force also contributed to HRJ4 retained in quartz sand column. At last, phenol transportation experiment indicated that the restriction of biochar on HRJ4 enhanced the phenol removal rate in the column. This study provides a theoretical basis for the interaction of biochar and bacteria, which is vital for the remediation of oil-contaminated soil and groundwater in the field.
生物炭已被广泛应用于修复石油污染土壤。然而，生物炭对石油降解菌运移的影响尚未得到研究。本文采用典型的革兰氏阳性石油降解菌-变栖克雷伯氏菌（Corynebacterium variabile HRJ4），研究了不同生物炭对细菌运移和截留的影响。结果表明，在砂中添加生物炭可有效降低细菌的运移，而杨木木屑生物炭（PSBC）比玉米秸秆生物炭（CSBC）的阻碍作用更强。随着生物炭热解温度从 300°C 升高到 600°C，比表面积（增加了 309 倍）增加，阻碍作用更加明显。随着生物炭施用量的增加，阻碍作用也增强。此外，在较高（25 mmol/L）NaCl 溶液中，由于静电引力增强，HRJ4 的运移减少更为明显。生物炭对 HRJ4 的吸附被认为是主要导致 HRJ4 运移受阻的原因。结合生物炭原料和热解温度对 HRJ4 运移的影响，表明比表面积对 HRJ4 运移的影响最大，而孔填充、静电力也有助于 HRJ4 被保留在石英砂柱中。最后，苯酚运移实验表明，生物炭对 HRJ4 的限制增强了柱中苯酚的去除率。本研究为生物炭与细菌的相互作用提供了理论依据，这对于石油污染土壤和地下水的修复具有重要意义。
