内环流系统中污泥厌氧消化效能及其流变特性研究

自主设计的搅拌内环流厌氧反应器连续运行64 d,考察了高有机浓度剩余污泥厌氧消化过程中有机物转化与生物产气之间的关系,分析了污泥流变特性的变化,并探讨了污泥消化效能和流动特征。结果表明,消化过程中平均总有机物去除率在30%以上,最高为45%,VSS含量从16. 92 g/L降低至3. 575 g/L,VFA浓度从(460. 02±0. 5) mg/L降低至(50. 20±0. 26) mg/L,且产气率迅速增加,甲烷含量高达52. 9%。污泥TSS与污泥稳态黏度呈正相关,Pearson系数为0. 816 2。在反应器消化过程中,微生物和内环流体系的作用对絮体结构和污泥成分的影响可减缓污泥流变特性(黏度和触变性)随污泥量增加而增强的趋势。

Sludge Anaerobic Digestion Efficiency and Rheological Properties in Internal Circulation System

The relationship between organic substance transformation and biogas production in sludge anaerobic digestion with high organic concentration was investigated in a self-designed internal circulation stirring anaerobic reactor which operated continuously for 64 days. Meanwhile,variation of sludge rheological properties was analyzed,and sludge digestion efficiency and flow characteristics were discussed. The results showed that the average removal rate of total organic substance could reach more than 30% and the highest was 45%. The VSS content decreased from 16. 92 g/L to 3. 575 g/L. The concentration of VFA decreased from( 460. 02 ± 0. 5) mg/L to( 50. 20 ± 0. 26) mg/L,and the biogas yield improved rapidly and the methane content was up to 52. 9%. The TSS of the sludge was positively correlated with sludge viscosity under steady state,and the Pearson’s coefficient was 0. 816 2. The effect of microorganisms and the internal circulation system on the floc structure and sludge composition reduced the sludge rheological properties (viscosity and thixotropy) during digestion process,which represented an increasing trend with the increase of sludge dosage.