title: Enhanced primary sludge sonication by heat insulation to reclaim carbon source for biological phosphorous removal.
abstract: Ultrasound pretreatment is a potent step to disintegrate primary sludge (PS). The supernatant of sonicated PS is recycled as an alternative carbon source for biological phosphorus removal. In this study, we investigated the role of temperature on PS disintegration during sonication. We found that a temperature of 60°C yielded a dissolution rate of about 2% soluble chemical oxygen demand (SCOD) as compared to 7% SCOD using sonication at the specific energy (SE) of 7359kJ/kg TS. Using the SE of 6000kJ/kg TS with heat insulation during sonication, the SCOD dissolution rate of PS was similar to the result at the SE of 7051kJ/kg TS without heat insulation. Upon treatment with sonication, the PS released low concentrations of Cu and Zn into the supernatant. The phosphorus-accumulating organisms (PAOs) used the supernatant of sonicated PS as the carbon source. Supplementation with the diluted sonicated PS supernatant (SCOD≈1000mg/L) in anaerobic phase resulted in the release of phosphorus (36mg/L) and the production of polyhydroxyalkanoates (PHAs) (0.36g PHA/g SS). Compared with sodium acetate, higher polyhydroxyvalerate (PHV) faction in the polyhydroxyalkanoates (PHAs) was observed in the biomass when incubated with sonicated PS as the carbon source. This work provides a simple pathway to conserve energy and to enhance efficiencies of ultrasonic pretreatment and the recovery of carbon source from the sludge for improving the phosphorus removal in the ENR system.
authors: Department of Environmental Science and Engineering, DongHua University, 2999 North people Road, Shanghai 201620, PR China.
authors: Qing
authors: Q
authors: Tian
authors: Department of Environmental Science and Engineering, DongHua University, 2999 North people Road, Shanghai 201620, PR China.
authors: Qi
authors: Q
authors: Wang
authors: Department of Environmental Science and Engineering, DongHua University, 2999 North people Road, Shanghai 201620, PR China. Electronic address: tq2004@dhu.edu.cn.
authors: Yanbing
authors: Y
authors: Zhu
authors: Department of Environmental Science and Engineering, DongHua University, 2999 North people Road, Shanghai 201620, PR China.
authors: Fang
authors: F
authors: Li
authors: Department of Environmental Science and Engineering, DongHua University, 2999 North people Road, Shanghai 201620, PR China.
authors: Lin
authors: L
authors: Zhuang
authors: Department of Environmental Science and Engineering, DongHua University, 2999 North people Road, Shanghai 201620, PR China.
authors: Bo
authors: B
authors: Yang
mesh_terms: D057919:Biological Oxygen Demand Analysis; D002244:Carbon / Q000737:chemistry*; D006358:Hot Temperature; D010758:Phosphorus / Q000737:chemistry* / Q000302:isolation & purification*; D054813:Polyhydroxyalkanoates / Q000737:chemistry; D012722:Sewage / Q000737:chemistry*; D013010:Sonication
chemical_list: D054813:Polyhydroxyalkanoates; D012722:Sewage; D010758:Phosphorus; D002244:Carbon
keywords: Biological phosphorus removal; Carbon source; Primary sludge; Sonication; Temperature effect