改性秸秆吸附微生物对土壤中石油烃降解及演化特征的影响

Biological degradation and transformation characteristics of total petroleum hydrocarbon in soil by oil-degradation bacteria adsorbed on a modified corn stalk

以甲基丙烯酸丁酯-苯乙烯改性玉米秸秆(BMGS)为载体吸附微生物对油污土壤进行了模拟降解实验,研究BMGS作为菌剂载体对油污土壤的降解效果,同时利用GC-MS指纹图谱深入分析TPH(total petroleum hydrocarbon)的重要组分——正构烷烃的降解演化规律和特性。结果表明:BMGS具有较高吸油能力(10.3 g·g^(-1)),大于原秸秆(RMS)5.7 g·g^(-1);在3%含油量的油污土壤中,加入用BMGS吸附的菌剂的降解半衰期(14.8 d)均短于空白与用原秸秆(RMS)吸附的半衰期(36.1 d和33.0 d)。降解演化特性表明,2种秸秆RMS与BMGS材料对正构烷烃降解的促进作用依次提高,主峰碳数均出现前移,且BMGS的效果更为明显。加入BMGS后有利于菌剂降解较难降解的偶碳数正构烷烃和类异戊二烯烷烃,并且在降解前、后期,对低、高碳数正构烷烃的降解优势完成增效作用,高碳数正构烷烃平均降解率达到91.25%,较好地解释BMGS吸附菌剂后可以缩短降解TPH半衰期及提高降解率的原因。

Oil-degradation bacteria adsorbed on modified corn stalk with methyl butyl acrylate and styrene modified corn stalk （BMGS） were used to study degradation effects on oil-contaminated soil, that was based on a carrier BMGS in process of simulated experiment. At the same time, the degradation and transformation laws of normal alkanes of important components of TPH （total petroleum hydrocarbon） were studied through analysis of GC-MS fingerprint. The degradation effect shows that BMGS has high oil absorption capacity （10.3 g·g^-1）, more than the original straw （RMS） 5.7 g·g^-1. In the 3% oil-contaminated soil, the half-life （14.84 d） of the bacteria degradation adsorbed on BMGS shortens than the half-life （36.1 d and 33.01 d） adsorbed with the original straw （RMS）. The degradation transformation characteristics show that the degradation effect on normal alkanes with two kinds of RMS and BMGS straw material increases in order and the main peak carbon shows a forward movement, and the effect of BMGS is better obviously. It is helpful to degrade even carbon number normal alkanes and isoprenoid alkanes difficultly degradation with BMGS, and respectively in the pre and post of degradation, low and high carbon number alkanes is respectively used to important carbon source, the degradation rate of high carbon number alkanes reaches 91.25%, all above can explain satisfactorily the results of shortening half-life and increasing the rate of degradation dealt with oil-degradation bacteria adsorbed on BMGS.