Research
| Title： | Carbon Source Recovery from Waste Activated Sludge by Low-Temperature Thermal Hydrolysis Process |
|---|---|
| First author： | Wu, Yuqi; Jiang, Yinghe; Song, Kang |
| Journal： | JOURNAL OF ENVIRONMENTAL ENGINEERING |
| Years： | 2020 |
| DOI： | 10.1061/(ASCE)EE.1943-7870.0001631 |
| Abstract： | To recover a preferred carbon source from waste activated sludge (WAS), this study systematically investigated the effects of a low-temperature thermal hydrolysis process (THP) on WAS solubilization and dewaterability at 25 degrees C-120 degrees C for 60 min. Experimental results indicated that organics [soluble chemical oxygen demand (SCOD), proteins, carbohydrates, and lipids] and nutrients (N and P) were efficiently released into the sludge supernatant after THP. Deoxyribonucleic acid (DNA) tests identified 60 degrees C as the threshold of sludge cell disintegration, which increased DNA from nearly 0-166.64 mg/L. Sludge dewaterability deteriorated after THP, as evidenced by longer filtration times and higher water contents of sludge cake, particularly at 120 degrees C, which was due to the release of abundant soluble extracellular polymeric substances. The optimal heating temperature for carbon source recovery was 80 degrees C, which achieved the highest biodegradability (5-day biochemical oxygen demand/SCOD 0.62), satisfied SCOD/total nitrogen (18.6), and had acceptable dewaterability. |
