eprintid: 10070927
rev_number: 19
eprint_status: archive
userid: 608
dir: disk0/10/07/09/27
datestamp: 2019-03-26 11:20:30
lastmod: 2021-10-24 23:30:22
status_changed: 2019-03-26 11:20:30
type: article
metadata_visibility: show
creators_name: Moruzzi, RB
creators_name: da Silva, PG
creators_name: Sharifi, S
creators_name: Campos, LC
creators_name: Gregory, J
title: Strength assessment of Al-Humic and Al-Kaolin aggregates by intrusive and non-intrusive methods
ispublished: pub
divisions: UCL
divisions: B04
divisions: C05
divisions: F44
keywords: Aggregates, Floc resistance, Image analysis, Flocculation
note: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions.
abstract: Resistance to breakage is a critical property of aggregates generated in water and wastewater treatment processes. After flocculation, aggregates should ideally keep their physical characteristics (i.e. size and morphology), to result in the best performance possible by individual separation processes. The integrity of aggregates after flocculation depends upon their capacity to resist shear forces while transported through canals, passages, apertures, orifices and other hydraulic units. In this study, the strength of Al-Humic and Al-Kaolin aggregates was investigated using two macroscopic measurement techniques, based on both intrusive and non-intrusive methods, using image analysis and light scattering based equipment. Each technique generates different information which was used for obtaining three floc strength indicators, namely, strength factor (SF), local stress from the hydrodynamic disturbance (σ) and the force coefficient (γ) for two different study waters. The results showed an increasing trend for the SF of both Al-Humic and Al-Kaolin aggregates, ranging from 29.7% to 78.6% and from 33.3% to 85.2%, respectively, in response to the increase of applied shear forces during flocculation (from 20 to 120 s −1 ). This indicates that aggregates formed at higher shear rates are more resistant to breakage than those formed at lower rates. In these conditions, σ values were observed to range from 0.07 to 0.44 N/m 2 and from 0.08 to 0.47 N/m 2 for Al-Humic and Al-Kaolin, respectively. Additionally, it was found that for all studied conditions, the resistance of aggregates to shear forces was nearly the same for Al-Humic and Al-Kaolin aggregates, formed from destabilized particles using sweep coagulation. These results suggest that aggregate strength may be mainly controlled by the coagulant, emphasizing the importance of the coagulant selection in water treatment. In addition, the use of both intrusive and non-intrusive techniques helped to confirm and expand previous experiments recently reported in literature.
date: 2019-06-15
date_type: published
official_url: https://doi.org/10.1016/j.seppur.2019.02.033
oa_status: green
full_text_type: other
language: eng
primo: open
primo_central: open_green
article_type_text: Journal Article
verified: verified_manual
elements_id: 1634158
doi: 10.1016/j.seppur.2019.02.033
lyricists_name: Campos, Luiza
lyricists_name: Gregory, John
lyricists_id: LCCAM91
lyricists_id: JGREG96
actors_name: Campos, Luiza
actors_id: LCCAM91
actors_role: owner
full_text_status: public
publication: Separation and Purification Technology
volume: 217
pagerange: 265-273
issn: 1873-3794
citation:        Moruzzi, RB;    da Silva, PG;    Sharifi, S;    Campos, LC;    Gregory, J;      (2019)    Strength assessment of Al-Humic and Al-Kaolin aggregates by intrusive and non-intrusive methods.                   Separation and Purification Technology , 217    pp. 265-273.    10.1016/j.seppur.2019.02.033 <https://doi.org/10.1016/j.seppur.2019.02.033>.       Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/10070927/1/Moruzzi%20et%20al%202018%20UCL%20Discovery.pdf