Assessing biodegradation potential of PAHs in complex multi-contaminant matrices

This study sought to extend validation of a cyclodextrin based extraction method for the assessment of PAH-biodegradation potential to complex multi-contaminant matrices. To this end, four reference materials (RMs) were produced by blending, in different proportions, soils impacted with diesel, lubricating oil and spent oxide. These reference materials had modest ∑PAH (16 US EPA) concentrations that ranged from 5.6 ± 0.5 to 44.4 ± 4.5 mg kg⁻¹. However, extractable petroleum hydrocarbon (EPH) concentrations were comparatively high (up to 2520 ± 204 mg kg⁻¹). To complement these RMs, two further soils from a municipal gas plant (MGP) with highly elevated concentration of PAHs ranging from 877 ± 52 to 2620 ± 344 mg kg⁻¹ were also tested. Results showed, regardless of matrix complexity, that PAH biodegradation within the four RM substrates, and two MGP soils correlated well with biodegradation predicted by hydroxypropyl-β-cyclodextrin (HPCD) extraction.     

驯化筛选微生物对油制气废水的降解特性

从5个菌源分离到的16株菌中筛选出S－2、Y－3和XH－3为优势菌种,分别用它们及其混合菌M－3研究对油制气废水的降解,60h之后CODcr的去除率为38．4％－44．0％,酚类化合物的去除率为95．4％－97．0％,芳烃类化合物的去除率为47．1％－53．7％,但氨氮的去除率只有14．0％－17．6％。采用GC／MS分析了处理前后废水中的芳烃类化合物,所筛选的微生物对芳环数≤3的芳烃类化合物降解能力强,还可去除一定量芳环数为4－6的芳烃类化合物。加入共代谢基质葡萄糖,可使CODcr、氨氮及可萃取有机物的去除率分别提高13．1％－22．9％、18．4％－22．7％及13．1％－18．1％;加入乙醇,可使CODcr、氨氮及可萃取有机物的去除率分别提高12．5％－21．2％、29．7％－42．2％及6．7％－7．7％。废水中芳烃类化合物的总去除率分别比无葡萄糖和无乙醇时提高了17．7％－21．7％和15．4％－21．2％。所筛选驯化的菌种有效地提高了油制气废水的降解效率。