表面活性剂对茫崖诺卡氏菌降解鄂尔多斯盆地富油煤过程的影响

Effects of surfactants on biodegradation processes of tar-rich coals in ordos basin by Nocardia mangyaensis

50 mL液体培养基中加入茫崖诺卡氏菌液、富油煤和表面活性剂,在温度30℃、振荡转速160 r/min的恒温振荡培养箱中降解富油煤,考察降解时间、菌液用量、加煤量和表面活性剂对富油煤降解效果的影响。结果表明低浓度的表面活性剂十二烷基硫酸钠(SDS)、直链烷基苯磺酸盐(LAS)、吐温-80(Tw-80)和聚乙二醇辛基苯基醚(Triton X-100)能改变煤炭的表面性质,增加煤炭的亲水性,有利于菌种与煤炭接触,其中Triton X-100效果最为明显。茫崖诺卡氏菌降解富油煤的最优工艺条件:菌液浓度200 mL/L,煤样浓度18 g/L,Triton X-100浓度1000 mg/L,降解时间15 d。在此条件下,富油煤的降解率达到57.8%。红外分析表明,煤中部分芳香环和羧基被茫崖诺卡氏菌降解,有机大分子已很大程度被解离成小分子。GC-MS显示降解液中主要含有烷烃类、酯类、醇类、羧酸类、胺类等小分子物质,相对分子量在92~647之间。

The Nocardia mangyaensis,tar-rich coal and surfactants were added to 50 mL liquid medium,and biodegradation experiments were performed in a temperature incubator at 30℃,oscillation speed of 160 r/min.The effects of biodegradation time,inoculation size,coal amount and surfactants on the biodegradation effect of tar-rich coal were investigated.The results showed that low concentrations of sodium lauryl sulfate(SDS),straight chain alkyl benzene sulfonate(LAS),Tween-80(Tw-80),polyethylene glycol octylphenyl ether(Triton X-100)could change the surface properties of coal and increased the hydrophilicity of coal,which was conducive to the contact between bacteria and coal.Among them,TritonX-100 had the most obvious effect.The optimal process conditions for the biodegradation of tar-rich coal by Nocardia mangyaensis were bacteria concentration of 200 mL/L,coal concentration of 18 g/L,Triton X-100 concentration of 1000 mg/L and incubation time of 15 d.Under these technological conditions,the biodegradation rates reached 57.8%.Infrared analysis showed that part of aromatic rings and carboxyl groups in coal samples were biodegraded by Nocardia mangyaensis,and organic macromolecules were largely dissociated into small molecules.GC-MS showed that the degradation liquid mainly contained small molecular substances such as alkanes,esters,alcohols,carboxylic acids,amines,and the relative molecular weights were between 92 to 647.