[Ultrasonic sludge treatment and its application on aerobic digestion].
In order to enhance the degradation efficiency of waste activated sludge (WAS) in conventional aerobic digestion, various ultrasonic assisted treatment methods were investigated including ultrasonic disintegration of influent sludge, ultrasonic improvement of influent sludge activity and ultrasonic disintegration of return sludge. Firstly the effects of ultrasonic sludge treatment were studied to choose appropriate ultrasonic parameters, and then the experiments of aerobic digestion with different ultrasonic treatments were carried out. The results show that 1.0 W/mL, 10 minutes ultrasonic treatment can increase soluble chemical oxygen demand (SCOD) in the supernatant phase of sludge sample by 5.4 times and decrease total suspended solid (TSS) by 16%; 0.05 W/mL, 10 min ultrasonic treatment can increase the specific oxygen uptake rate (SOUR) of sludge sample by 29%. The two kinds of ultrasonic influent sludge pretreatment can't improve aerobic digestion effectively. Ultrasonic return sludge disintegration can enhance the volatile suspended solid (VSS) degradation ratio by 15%. Furthermore, the settlement performance of digested sludge is still good and the pollutant concentrations of supernatant phase increase slightly. So ultrasonic return sludge disintegration is considered as the most appropriate assisted treatment mode for aerobic digestion.
Li
Huan
H
Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China.
Jin
Yi-ying
YY
Nie
Yong-feng
YF
Li
Lei
L
Yang
Hai-ying
HY
D001421:Bacteria, Anaerobic / Q000254:growth & development / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism; D012037:Refuse Disposal / Q000379:methods*; D012722:Sewage / Q000382:microbiology*; D014465:Ultrasonics
D012722:Sewage; D010100:Oxygen