光-氧氧化预处理褐煤微生物降解效果提升的原因

预处理方法对煤的微生物降解效果影响较大,光-氧氧化预处理是一种具有应用前景的煤预处理方式,其在环保性和实际可操作性等方面具有一定的优越性。为探究经光-氧氧化预处理后,氧化煤微生物降解效果得到提升的原因,利用自制的旋转床光化学反应器对四种褐煤进行光-氧氧化预处理,并比较黄孢原毛平革菌对褐煤预处理前后的降解效果。通过元素分析、工业分析、红外光谱分峰拟合、定量分析、煤的比表面积分析和润湿性表征,探讨了煤在预处理前后的组成、结构特征和物理性质的变化。结果表明:黄孢原毛平革菌对四种光-氧氧化褐煤的降解效果均比原褐煤有较大幅度的提升;光-氧氧化褐煤的含氧量和含氢量增加,富氢程度和富氧程度增大,比表面积增大,润湿性增强,这些结构和性质的改变可能是黄孢原毛平革菌对光-氧氧化褐煤降解效果优于原煤的原因。

Reasons of Enhancement of Microbial Degradation of Lignite by Photo-oxygen Oxidation Pretreatment

The pretreatment methods of coal have great influences on the effectiveness of the microbial degradation of coal. Photo-oxygen oxidation is a promising way of coal pretreatment, which has certain advantages in terms of environmental protection and practical operability. In order to explore the mechanisms for the enhancement of microbial degradation of oxidized coal after the photo-oxygen oxidation pretreatment, four kinds of lignite were pretreated by a homemade rotatory bed photochemical reactor, and the degradation of coals by using P.chrysosporium before and after pretreatment were evaluated. Furthermore, the composition, structural characteristics and physical properties of coals before and after the pretreatment were investigated through the proximate and ultimate analysis, quantitative analysis of the peak distribution of the infrared spectrum, specific surface area analysis and the wettability analysis of coals. The results show that the degradation effectiveness of the four kinds of oxidized lignite are higher than that of the raw one. With the increasing oxidation of the oxygen and hydrogen content in the oxidized coal, the degree of the hydrogen enrichment and oxygen enrichment increases, the specific surface area increases, and the wettability all increases. These structure and property changes may be regarded as part of the reasons that the biodegradation of oxidized lignites is better than that of the raw ones.