title: Effect of power ultrasound on crystallization characteristics of magnesium ammonium phosphate.
abstract: Magnesium ammonium phosphate (MAP) crystallization could be utilized for the recovery of phosphorus from wastewater. However, the effectiveness of the recovery is largely determined by the crystallization process, which is very hard to be directly observed. As a result, a specific ultrasonic device was designed to investigate the crystallization characteristics of MAP under various ultrasonic conditions. The results demonstrated that the metastable zone width (MZW) narrowed along with the rising of the ultrasonic power. Similarly, for the 6mM MAP solution, with the ultrasonic power gradually enhanced from 0W to 400W, the induction time was shortened from 340s to 38s. Meanwhile, the crystallization rate was accelerated till the power reached 350W, and then remained a constant value. It can be observed from the scanning electron microscopy (SEM), the MAP crystal became bigger in size as well as the crystal size distribution (CSD) became broad and uneven, with the increase of ultrasonic power. The results indicate that the crystallization process enhanced by power ultrasound could be used as an effective method to eliminate and recover the phosphorus from wastewater.
authors.affiliation: School of Civil Engineering and Architecture, University of Jinan, Jinan 250022, PR China. Electronic address: lipingqiu@163.com.
authors.forename: Liping
authors.initials: L
authors.lastname: Qiu
authors.affiliation: School of Civil Engineering and Architecture, University of Jinan, Jinan 250022, PR China. Electronic address: 1056836790@qq.com.
authors.forename: Liang
authors.initials: L
authors.lastname: Shi
authors.affiliation: School of Civil Engineering and Architecture, University of Jinan, Jinan 250022, PR China. Electronic address: 575057319@qq.com.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Liu
authors.affiliation: School of Civil Engineering and Architecture, University of Jinan, Jinan 250022, PR China.
authors.forename: Kang
authors.initials: K
authors.lastname: Xie
authors.affiliation: School of Civil Engineering and Architecture, University of Jinan, Jinan 250022, PR China; The College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100022, PR China.
authors.forename: Jiabin
authors.initials: J
authors.lastname: Wang
authors.affiliation: School of Civil Engineering and Architecture, University of Jinan, Jinan 250022, PR China.
authors.forename: Shoubin
authors.initials: S
authors.lastname: Zhang
authors.affiliation: School of Civil Engineering and Architecture, University of Jinan, Jinan 250022, PR China.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Song
authors.affiliation: School of Civil Engineering and Architecture, University of Jinan, Jinan 250022, PR China.
authors.forename: Liquan
authors.initials: L
authors.lastname: Lu
keywords: Crystal size distribution; Crystallization; Magnesium ammonium phosphate; Metastable zone width; Power ultrasound