Fractal dimension of large aggregates under different flocculation conditions
Autor(a) principal: | |
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Data de Publicação: | 2017 |
Outros Autores: | , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1016/j.scitotenv.2017.07.194 http://hdl.handle.net/11449/169978 |
Resumo: | 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. |
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Fractal dimension of large aggregates under different flocculation conditionsAggregatesFlocculationFractal dimensionShear rateThe 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.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Estadual Paulista (UNESP) Instituto de Geociências e Ciências ExatasDepartment of Civil Environmental and Geomatic Engineering University College LondonUniversidade Estadual Paulista (UNESP) Instituto de Geociências e Ciências ExatasFAPESP: 2013/01634-3FAPESP: 2013/21355-1FAPESP: 2013/25641-9FAPESP: 2010/50694-0Universidade Estadual Paulista (Unesp)University College LondonMoruzzi, Rodrigo B. [UNESP]de Oliveira, André L. [UNESP]da Conceição, Fabiano T. [UNESP]Gregory, JohnCampos, Luiza C.2018-12-11T16:48:33Z2018-12-11T16:48:33Z2017-12-31info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article807-814application/pdfhttp://dx.doi.org/10.1016/j.scitotenv.2017.07.194Science of the Total Environment, v. 609, p. 807-814.1879-10260048-9697http://hdl.handle.net/11449/16997810.1016/j.scitotenv.2017.07.1942-s2.0-850264766002-s2.0-85026476600.pdfScopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengScience of the Total Environment1,546info:eu-repo/semantics/openAccess2023-10-18T06:07:03Zoai:repositorio.unesp.br:11449/169978Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T15:15:01.726870Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Fractal dimension of large aggregates under different flocculation conditions |
title |
Fractal dimension of large aggregates under different flocculation conditions |
spellingShingle |
Fractal dimension of large aggregates under different flocculation conditions Moruzzi, Rodrigo B. [UNESP] Aggregates Flocculation Fractal dimension Shear rate |
title_short |
Fractal dimension of large aggregates under different flocculation conditions |
title_full |
Fractal dimension of large aggregates under different flocculation conditions |
title_fullStr |
Fractal dimension of large aggregates under different flocculation conditions |
title_full_unstemmed |
Fractal dimension of large aggregates under different flocculation conditions |
title_sort |
Fractal dimension of large aggregates under different flocculation conditions |
author |
Moruzzi, Rodrigo B. [UNESP] |
author_facet |
Moruzzi, Rodrigo B. [UNESP] de Oliveira, André L. [UNESP] da Conceição, Fabiano T. [UNESP] Gregory, John Campos, Luiza C. |
author_role |
author |
author2 |
de Oliveira, André L. [UNESP] da Conceição, Fabiano T. [UNESP] Gregory, John Campos, Luiza C. |
author2_role |
author author author author |
dc.contributor.none.fl_str_mv |
Universidade Estadual Paulista (Unesp) University College London |
dc.contributor.author.fl_str_mv |
Moruzzi, Rodrigo B. [UNESP] de Oliveira, André L. [UNESP] da Conceição, Fabiano T. [UNESP] Gregory, John Campos, Luiza C. |
dc.subject.por.fl_str_mv |
Aggregates Flocculation Fractal dimension Shear rate |
topic |
Aggregates Flocculation Fractal dimension Shear rate |
description |
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. |
publishDate |
2017 |
dc.date.none.fl_str_mv |
2017-12-31 2018-12-11T16:48:33Z 2018-12-11T16:48:33Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://dx.doi.org/10.1016/j.scitotenv.2017.07.194 Science of the Total Environment, v. 609, p. 807-814. 1879-1026 0048-9697 http://hdl.handle.net/11449/169978 10.1016/j.scitotenv.2017.07.194 2-s2.0-85026476600 2-s2.0-85026476600.pdf |
url |
http://dx.doi.org/10.1016/j.scitotenv.2017.07.194 http://hdl.handle.net/11449/169978 |
identifier_str_mv |
Science of the Total Environment, v. 609, p. 807-814. 1879-1026 0048-9697 10.1016/j.scitotenv.2017.07.194 2-s2.0-85026476600 2-s2.0-85026476600.pdf |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Science of the Total Environment 1,546 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
807-814 application/pdf |
dc.source.none.fl_str_mv |
Scopus reponame:Repositório Institucional da UNESP instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Repositório Institucional da UNESP |
collection |
Repositório Institucional da UNESP |
repository.name.fl_str_mv |
Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
|
_version_ |
1808128486675578880 |