表面活性剂SDBS和Tween 80强化过硫酸盐氧化后土壤中石油烃的缺氧生物降解

Surfactants SDBS and Tween 80 enhance anoxic biodegradation of petroleum hydrocarbons(PHC)in soil pretreated with persulfate

化学氧化和微生物联合修复是去除土壤中石油烃(PHC)的有效技术,但氧化后土壤中残留PHC的生物有效性较低,难以进一步生物降解。向过硫酸盐(PS)氧化后的土壤中加入不同质量浓度和质量比的表面活性剂十二烷基苯磺酸钠(SDBS)和聚氧乙烯山梨醇酐单油酸酯(Tween 80),探究其对PS氧化后土壤中PHC解吸、土著微生物群落结构和丰度、PHC缺氧降解的影响。结果表明,缺氧条件下PS氧化和微生物联合降解去除了土壤中30.84%的ΣPHC(C^(10)~C^(30))。向PS氧化后土壤中加入SDBS和Tween 80能够有效促进PHC解吸,解吸效果随表面活性剂质量浓度和混合体系中Tween 80比例的增加而增加。加入3000 mg·L^(-1)表面活性剂继续缺氧培养120 d后,氧化后土壤中Firmicutes和Proteobacteria的总数量较对照组减少了2.13~2.58个数量级,抑制了土壤中PHC的缺氧降解。加入800 mg·L^(-1)表面活性剂后,土壤中Firmicutes和Proteobacteria的总数量较对照组增加了0.17~0.81个数量级,促进了PHC的缺氧降解,在SDBS∶Tween 80=1∶3时ΣPHC残留率最低(较对照组降低了15.80%)。本研究结果可为深层石油污染土壤的微生物修复提供参考。

Chemical oxidation combined with biodegradation is an effective technology for removing petroleum hydrocarbons(PHC)from soil.However,the residual PHC in soil after oxidation is difficult to be further biodegraded due to their low bioavailability.The surfactants of sodium dodecyl benzene sulfonate(SDBS)and polyoxyethylene sorbitan monooleate(Tween 80)with different doses and mass ratios were added to the soil pretreated with persulfate(PS),to investigate their effect on PHC desorption,indigenous microbial community composition and abundance,PHC anoxic biodegradation.The results showed that 30.84%ofΣPHC(C^(10)~C^(30))in soil were removed by PS oxidation combined with anoxic biodegradation.SDBS and Tween 80 were added to the soil pretreated with PS had effectively promoted the desorption of PHC,the effect increased with the increase of surfactant’s concentration and the proportion of Tween 80 in the mixed system.After 120 d of continued anoxic incubation,the total amount of Firmicutes and Proteobacteria in soil added surfactants with the concentration of 3000 mg·L^(-1)decreased by 2.13~2.58 orders of magnitude compared with the control treatment,which inhibited the anoxic biodegradation of PHC.The total amount of Firmicutes and Proteobacteria in soil added surfactants with the concentration of 800 mg·L^(-1)increased by 0.17~0.81 orders of magnitude compared with the control treatment,which promoted the anoxic biodegradation of PHC,the residual rate ofΣPHC was lowest at SDBS:Tween 80=1:3(15.80%lower than the control group).This study can provide a reference for the microbial remediation of subsurface soil contaminated with PHC.