生物炭与表面活性剂联合强化淋洗去除污染土壤中PAHs的效果及其机制  

Mechanism underlying the effects of biochar combined with surfactant enhanced washing on removal of PAHs from contaminated soil

作　　者：于金龙 孙梨宗[2] 薛晨阳 贾春云[2] 台培东[2] 李英华[1] YU Jin-long;SUN Li-zong;XUE Chenyang;JIA Chun-yun;TAI Pei-dong;LI Ying-hua(School of Resources and Civil Engineering,Northeastern University,Shenyang 110819,China;Key Laboratory of Pollution Ecology and Environmental Engineering,Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China)

机构地区：[1]东北大学资源与土木工程学院,沈阳110819 [2]中国科学院污染生态与环境工程重点实验室中国科学院沈阳应用生态研究所,沈阳110016

出　　处：《生态学杂志》2021年第12期4034-4043,共10页Chinese Journal of Ecology

基　　金：国家重点研发课题(2019YFC1803802、2018YFC1800703);国家自然科学基金项目(41877146、41673132);沈阳市中青年科技人才支持计划项目(RC200123)资助。

摘　　要：采用生物炭吸附与表面活性剂淋洗联合修复PAHs污染场地土壤,通过外源添加700℃制备的稻壳生物炭,研究了添加生物炭对非离子型表面活性剂TX-100淋洗PAHs效果的影响;通过老化后的含芘高岭土模拟污染土壤,研究了生物炭吸附与TX-100淋洗联合修复的驱动机制。强化淋洗修复结果显示:TX-100浓度为10 g·L^(-1),淋洗时间为16 h,固液比为1∶10,转速为150 r·min^(-1),对本研究选取的PAHs浓度为94.97 mg·kg^(-1)的污染土壤的淋洗效果最好,解吸率达66.2%;添加1%土壤质量的稻壳生物炭,稳定14 d后,TX-100对PAHs解吸率从对照的66.2%提高到了80.6%(P<0.05),其中四环PAHs的解吸量占比最高(42.1%)。高岭土模拟结果显示:添加1%土壤质量的生物炭14 d后,高岭土中芘含量从50 mg·kg^(-1)降低至27.77 mg·kg^(-1),同时TX-100可以有效洗脱生物炭上吸附的芘,解吸率达80.2%。扫描电镜和光谱学分析显示:生物炭可以吸附TX-100,而被吸附的TX-100又会占据部分生物炭孔道,后者在1600 cm^(-1)处的C=O和C=C吸收振动峰和1103~1025cm^(-1)处的C-O-C吸收振动峰明显减弱,进一步导致PAHs从固相向液相的迁移。因此,在表面活性剂淋洗修复前,添加生物炭可以显著提高土壤PAHs的解吸率。Biochar adsorption and surfactant washing were used to remediate PAHs contaminatedsoil.Rice husk biochar prepared at 700℃was added to examine the effect of biochar addition onthe washing of PAHs by nonionic surfactant TX-100.The underlying mechanism of biochar ad-sorption combined with TX-100 washing was examined by simulating contaminated soil withpyrene-containing kaolin after aging.The results of enhanced washing remediation showed thatwhen the concentration of TX-100 was 10 g·L^(-1),washing time was 16 h,the ratio of solid toliquid was 1∶10,and the rotating speed was 150 r·min^(-1),a desorption rate of 66.2%wasobtained for the contaminated soil with PAHs concentration of 94.97 mg·kg^(-1).After the ricehusk biochar with 1%soil mass was added and stabilized for 14 days,the desorption rate ofPAHs by TX-100 increased from 66.2%to 80.6%(P<0.05),and the desorption rate of tetra-cyclic PAHs was the highest(42.1%).Kaolin simulation results showed that after adding biochar 1%of soil mass for 14 days,the content of pyrene in kaolin decreased from 50 mg·kg^(-1)to 27.77mg·kg^(-1).TX-100 could effectively wash out pyrene adsorbed on biochar,with desorption ratereaching 82.4%.Scanning electron microscope and spectroscopic analysis showed that biocharcould adsorb TX-100,while the adsorbed TX-100 occupied part of the pores of biochar,and theabsorption vibration peaks of C=O and C=C at 1600 cm^(-1) and C-O-C at 1103-1025 cm^(-1)wereobviously weakened,which further led to the migration of PAHs from solid phase to liquid phase.Therefore,before using surfactants for washing and remediation,biochar addition can significantlyimprove the desorption rate of soil PAHs.

关 键 词：生物炭 表面活性剂 PAHS 界面迁移 

分 类 号：X53[环境科学与工程—环境工程]