UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Fractal dimension of large aggregates under different flocculation conditions

Moruzzi, RB; de Oliveira, AL; da Conceicao, FT; Gregory, J; Campos, LC; (2017) Fractal dimension of large aggregates under different flocculation conditions. Science of The Total Environment , 609 pp. 807-814. 10.1016/j.scitotenv.2017.07.194. Green open access

[img]
Preview
Text
Moruzzi et al 2017 UCL Discovery.pdf - Accepted version

Download (1MB) | Preview

Abstract

The two-dimensional fractal dimension (Df) of large aggregates of kaolin (> 540 μm) during the shear flocculation process for kaolin solution was investigated using non-intrusive in situ image-based acquisition system. Separate experiments were also carried out for three different sized sub-ranges of large aggregates (0.540–1.125 mm; 1.125–1.750 mm; 1.750–2.375 mm). Digital images were taken at a frequency of 10 Hz for 10 s for each different pairs of gradients of velocity (Gf) of 20 and 60 s− 1 and flocculation times of 2; 3; 4; 5; 10; 20; 30; 60; 120 and 180 min. For the same conditions, particle size distribution (PSD) was also determined. Under the investigated conditions, the lowest Gf produced the greatest Df (1.69) at a flocculation time of 30 min for the whole range of aggregates. Also, the evolution of the longest length of aggregate (l) and Df with time, showed that the dynamic steady-state was reached at different times for each shear rate and l ranges. However, Df varied for each size sub-range (ca. 1.1 to 1.8). Finally, the behavior of the aggregate structure may be understood by the predominance of different aggregation mechanisms such as cluster-cluster for Gf of 60 s− 1 and particle-cluster for Gf of 20 s− 1.

Type: Article
Title: Fractal dimension of large aggregates under different flocculation conditions
Open access status: An open access version is available from UCL Discovery
DOI: 10.1016/j.scitotenv.2017.07.194
Publisher version: http://doi.org/10.1016/j.scitotenv.2017.07.194
Language: English
Additional information: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions.
Keywords: Flocculation,Fractal dimension,Shear rate,Aggregates
UCL classification: UCL
UCL > Provost and Vice Provost Offices
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Civil, Environ and Geomatic Eng
URI: https://discovery.ucl.ac.uk/id/eprint/10050637
Downloads since deposit
88Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item