title: Enhancement of ultrasonic disintegration of sewage sludge by aeration.
abstract: Sonication is an effective way for sludge disintegration, which can significantly improve the efficiency of anaerobic digestion to reduce and recycle use of sludge. But high energy consumption limits the wide application of sonication. In order to improve ultrasonic sludge disintegration efficiency and reduce energy consumption, aeration was introduced. Results showed that sludge disintegration efficiency was improved significantly by combining aeration with ultrasound. The aeration flow rate, gas bubble size, ultrasonic density and aeration timing had impacts on sludge disintegration efficiency. Aeration that used in later stage of ultrasonic irradiation with low aeration flow rate, small gas bubbles significantly improved ultrasonic disintegration sludge efficiency. At the optimal conditions of 0.4 W/mL ultrasonic irradiation density, 30 mL/min of aeration flow rate, 5 min of aeration in later stage and small gas bubbles, ultrasonic sludge disintegration efficiency was increased by 45% and one third of ultrasonic energy was saved. This approach will greatly benefit the application of ultrasonic sludge disintegration and strongly promote the treatment and recycle of wastewater sludge.
authors.affiliation: School of Environment and Natural Resource, Renmin University of China, Beijing 100872, China. Electronic address: zhaohe628@163.com.
authors.forename: He
authors.initials: H
authors.lastname: Zhao
authors.affiliation: College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
authors.forename: Panyue
authors.initials: P
authors.lastname: Zhang
authors.affiliation: School of Environment and Natural Resource, Renmin University of China, Beijing 100872, China. Electronic address: zgm@ruc.edu.cn.
authors.forename: Guangming
authors.initials: G
authors.lastname: Zhang
authors.affiliation: School of Environment and Natural Resource, Renmin University of China, Beijing 100872, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Cheng
mesh_terms: D012722:Sewage; D013010:Sonication; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater
chemical_list: D012722:Sewage; D062065:Wastewater
keywords: Aeration; Gas bubble size; Ultrasonic irradiation density; Ultrasonic irradiation stages; Ultrasonic sludge disintegration