Variations of organic matters and bacterial community during hyperthermophilic biodrying process of sewage sludge

Abstract

The feasibility of using hyperthermophilic biodrying (HB) technology for sewage sludge biodrying was investigated in this study. Compared with conventional biodrying (CB), HB has significantly enhanced water removal rate. It was found that proteins and lipids were degraded rapidly in the early stage of HB, while hemicellulose and cellulose became the dominant source of nutrition for microorganisms after the thermophilic phase. HB degraded more organic matters than CB and expedited the volatile solids (VS) convert to dissolved organic matters (DOM) during the 21-day biodrying. The protease activity of HB increased quickly in the first three days. In addition, the bacterial community structure of HB changed dramatically in the thermophilic phase, and diversity of bacterial community decreased. These results not only indicated that HB was a promising biodrying technology, but also revealed the potential microbial degradation mechanism of organic matters in HB process.