An ultrasound-based monitoring of kaolinite flocculent settling processes

• Published in: Applied acoustics 2023-02, Vol.203, p.109186, Article 109186
• Main Authors: Tian, Chang, Zheng, Songlin, Su, Mingxu
• Format: Article
• Language: English
• Subjects: Attenuation; Concentration; Particles flocculent settling; Ultrasound
• ISSN: 0003-682X; 1872-910X
• DOI: 10.1016/j.apacoust.2022.109186

An ultrasonic method, which apply in the particles flocculent settling, was proposed and studied based on the ECAH model. Comparing with the interface settling method, microscopic imaging and online sampling method, the phenomenon of flocculation and settling was observed accordingly and the settling stages were analyzed simultaneously by both the interface settling velocity and ultrasonic attenuation coefficient. The correlation between the process of flocculation and ultrasonic parameters was established accordingly, which provided data support for the application of ultrasonic technique to the online detection of kaolinite particle flocculent settling processes. [Display omitted] •An ultrasonic method, which apply in the particles flocculent settling process, was proposed and studied based on the ECAH model.•The duration of each settling stage and it’s change rate were analyzed simultaneously by both the interface settling velocity and ultrasonic attenuation coefficient.•The presented method is suitable for online monitoring particles flocculent settling process in high turbidity water. In order to implement real-time monitoring of flocculent settling processes, an ultrasonic method based on the ECAH model was proposed and studied, particularly by considering the influence of particle irregularity on sound attenuation. Numerical simulations were conducted to evaluate the influence of critical physical parameters’ variation on the attenuation coefficient. Meanwhile, an integrated experimental system including ultrasonic measurement, interface settling velocity measurement, microscopic imaging and online sampling methods was established. The experiments of kaolinite particle suspensions with four different initial mass concentrations were carried out, and the phenomenon of flocculation and settling was observed accordingly. The duration of each settling stage and its change rate were analyzed simultaneously by both the interface settling velocity and ultrasonic attenuation coefficient. The analysis results show that for the same flocculent settling stage, the relative deviation of duration obtained by two methods above were 0%, 7.32%, −10.57%, 1.62% and 1.63%, respectively. The mechanisms and characteristics of each stage in the precipitation process were discussed in detail. At the same time, the volume concentrations obtained by ultrasonic method were compared with the results of weighing after on-line sampling. The deviations under the four initial mas