FIBRE FLOC MORPHOLOGY AND DEWATERABILITY OF A PULP SUSPENSION: ROLE OF FLOCCULATION KINETICS AND CHARACTERISTICS OF FLOCCULATION AGENTS
The aim of this investigation was to find out how properties of a flocculation agent and flocculation kinetics affect the morphology of fibre flocs and how dewatering of a fibre suspension may be attributed to floc morphology. Fibre flocculation, analysed in terms of floc size, mass fractal dimensio...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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North Carolina State University
2009-05-01
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| Series: | BioResources |
| Subjects: | |
| Online Access: | http://ojs.cnr.ncsu.edu/index.php/BioRes/article/viewFile/BioRes_04_2_0640_Liimatainen_HTN_Fibre_Floc_Morphol_Dewater/366 |
| _version_ | 1798044814344716288 |
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| author | Henrikki Liimatainen Antti Haapala Jani Tomperi Jouko Niinimäki |
| author_facet | Henrikki Liimatainen Antti Haapala Jani Tomperi Jouko Niinimäki |
| author_sort | Henrikki Liimatainen |
| collection | DOAJ |
| description | The aim of this investigation was to find out how properties of a flocculation agent and flocculation kinetics affect the morphology of fibre flocs and how dewatering of a fibre suspension may be attributed to floc morphology. Fibre flocculation, analysed in terms of floc size, mass fractal dimension, floc strength, and the kinetic constant of flocculation, was measured with a digital image analysis system using cationic polyacrylamides as flocculants and NaCl as a coagulant. The results suggest that the kinetics of fibre flocculation is not a key factor determining floc properties but follows from the high bonding ability of the flocculation agent, which also lies behind the high floc density and size, i.e., the factors that lead to fast flocculation and improved floc properties are partly the same. In addition to interfibre bonding strength, the structure of the bonding layer of polymeric flocculants was found to be a significant factor describing floc morphology. Dewaterability of the fibre suspension was improved by increased floc density, which promotes fast water flow through the large voids around the dense flocs, while large, irregular flocs induced loose floc packing, which further improved dewatering by creating larger voids. Increased floc strength seemed to reduce the sealing of fluid passageways, particularly on the surface of the wire, where fibre squeezing could blind the filter fabric. |
| first_indexed | 2024-04-11T23:11:29Z |
| format | Article |
| id | doaj.art-ec5e6fbaf3a14dc5ae521e407c00ce87 |
| institution | Directory Open Access Journal |
| issn | 1930-2126 |
| language | English |
| last_indexed | 2024-04-11T23:11:29Z |
| publishDate | 2009-05-01 |
| publisher | North Carolina State University |
| record_format | Article |
| series | BioResources |
| spelling | doaj.art-ec5e6fbaf3a14dc5ae521e407c00ce872022-12-22T03:57:51ZengNorth Carolina State UniversityBioResources1930-21262009-05-0142640658FIBRE FLOC MORPHOLOGY AND DEWATERABILITY OF A PULP SUSPENSION: ROLE OF FLOCCULATION KINETICS AND CHARACTERISTICS OF FLOCCULATION AGENTSHenrikki LiimatainenAntti HaapalaJani TomperiJouko NiinimäkiThe aim of this investigation was to find out how properties of a flocculation agent and flocculation kinetics affect the morphology of fibre flocs and how dewatering of a fibre suspension may be attributed to floc morphology. Fibre flocculation, analysed in terms of floc size, mass fractal dimension, floc strength, and the kinetic constant of flocculation, was measured with a digital image analysis system using cationic polyacrylamides as flocculants and NaCl as a coagulant. The results suggest that the kinetics of fibre flocculation is not a key factor determining floc properties but follows from the high bonding ability of the flocculation agent, which also lies behind the high floc density and size, i.e., the factors that lead to fast flocculation and improved floc properties are partly the same. In addition to interfibre bonding strength, the structure of the bonding layer of polymeric flocculants was found to be a significant factor describing floc morphology. Dewaterability of the fibre suspension was improved by increased floc density, which promotes fast water flow through the large voids around the dense flocs, while large, irregular flocs induced loose floc packing, which further improved dewatering by creating larger voids. Increased floc strength seemed to reduce the sealing of fluid passageways, particularly on the surface of the wire, where fibre squeezing could blind the filter fabric.http://ojs.cnr.ncsu.edu/index.php/BioRes/article/viewFile/BioRes_04_2_0640_Liimatainen_HTN_Fibre_Floc_Morphol_Dewater/366FlocculationFloc structureFloc sizeFractal dimensionDewatering |
| spellingShingle | Henrikki Liimatainen Antti Haapala Jani Tomperi Jouko Niinimäki FIBRE FLOC MORPHOLOGY AND DEWATERABILITY OF A PULP SUSPENSION: ROLE OF FLOCCULATION KINETICS AND CHARACTERISTICS OF FLOCCULATION AGENTS BioResources Flocculation Floc structure Floc size Fractal dimension Dewatering |
| title | FIBRE FLOC MORPHOLOGY AND DEWATERABILITY OF A PULP SUSPENSION: ROLE OF FLOCCULATION KINETICS AND CHARACTERISTICS OF FLOCCULATION AGENTS |
| title_full | FIBRE FLOC MORPHOLOGY AND DEWATERABILITY OF A PULP SUSPENSION: ROLE OF FLOCCULATION KINETICS AND CHARACTERISTICS OF FLOCCULATION AGENTS |
| title_fullStr | FIBRE FLOC MORPHOLOGY AND DEWATERABILITY OF A PULP SUSPENSION: ROLE OF FLOCCULATION KINETICS AND CHARACTERISTICS OF FLOCCULATION AGENTS |
| title_full_unstemmed | FIBRE FLOC MORPHOLOGY AND DEWATERABILITY OF A PULP SUSPENSION: ROLE OF FLOCCULATION KINETICS AND CHARACTERISTICS OF FLOCCULATION AGENTS |
| title_short | FIBRE FLOC MORPHOLOGY AND DEWATERABILITY OF A PULP SUSPENSION: ROLE OF FLOCCULATION KINETICS AND CHARACTERISTICS OF FLOCCULATION AGENTS |
| title_sort | fibre floc morphology and dewaterability of a pulp suspension role of flocculation kinetics and characteristics of flocculation agents |
| topic | Flocculation Floc structure Floc size Fractal dimension Dewatering |
| url | http://ojs.cnr.ncsu.edu/index.php/BioRes/article/viewFile/BioRes_04_2_0640_Liimatainen_HTN_Fibre_Floc_Morphol_Dewater/366 |
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