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The flocculation of papermaking fibersWollwage, John Carl, January 1938 (has links) (PDF)
Thesis (Ph. D.)--Institute of Paper Chemistry, 1938. / Includes bibliographical references (p. 176-177).
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The effect of organic compounds on coagulationCormier, Barbara Louise, 1942- January 1976 (has links)
No description available.
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Polymer Aids for Settling and Filtration of Oil Sands TailingsWang, Xiaoyan Unknown Date
No description available.
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The particle size selectivity of suspended sediment delivery from drainage basinsStone, Peter Michael January 1996 (has links)
The delivery of suspended sediment from drainage basins has frequently been quantified in mass terms by use of the suspended sediment budget approach, which identifies sources, storage and output of mobilised sediment. This thesis investigates the particle size characteristics of the sediment associated with the key components of the suspended sediment budgets of four drainage basins in Devon, U. K. to determine whether particle size selectivity occurs in the delivery of suspended sediment from the hillslopes to the basin outlet. Attention focused on pasture land because previous studies had indicated that this was the dominant source of suspended sediment and that arable fields and channel banks were relatively insignificant in these catchments. Samples of sediment were mobilised from pasture hillslopes using a field-portable rainfall simulator; samples of suspended sediment were collected from the river channel during storm events either manually, by automatic pump samplers or by using rising limb siphon samplers; suspended sediment deposited on the channel bed was sampled using bed traps and by resuspending sediment deposited on the river bed during low flows; and sediment deposited on the floodplain during overbank flooding was collected using Astroturf mat traps or by sampling surface material. Samples were collected to investigate both temporal and spatial variability in grain size behaviour. All sediment samples were pretreated to remove organic matter and their chemically dispersed (absolute) particle size composition was measured using a Coulter LS 130 laser granulometer. The particle size composition of transported/deposited sediment was compared with that of the samples from potential sources to determine whether particle size selectivity had occurred. Where possible, measurements of the natural in situ particle size distribution (effective particle size) were also undertaken by quick return of samples to the laboratory for immediate measurement without pre-treatment using the laser granulometer. Particle size selectivity was found to have occurred in the mobilisation of sediment from the hillslope pasture land sources. Seasonal variations were identified in the particle size characteristics of both sediment mobilised from the hillslopes and suspended sediment samples. Spatial variations were identified in the particle size composition of sediment deposited on the floodplain. These seasonal and spatial variations reflect the particle size selectivity of detachment, transport and deposition processes which is in turn influenced by the aggregation or flocculation (effective particle size) of the sediment.
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Flocculating agents as aids for rapid pectin determinations in preserve manufacturingVarseveld, George Wallace 08 May 1953 (has links)
Graduation date: 1953
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The effect of floc microstructure and shear on dewatering processesKhan, Konika Moushumi, Chemical Sciences & Engineering, Faculty of Engineering, UNSW January 2007 (has links)
This work investigated the effect of floc microstructure (size and fractal structure) and shear forces on dewatering processes, which are crucial for environmental and economical aspects in many industries. Due to limitations inherent In experimental investigations, a numerical code using the discrete element method and including some novel force models (polymer bridging force, elastic bending moment and a modified concept of rolling friction torque) was developed to simulate the consolidation behavior of flocculated systems. The code showed good agreement with experimental results. The elastic behavior of aggregates is known to depend on the backbone structure (stress bearing structure of the aggregate). However, there is little known about backbone structure. It was found that backbone represents a fractal structure with a fractal dimension value close to 1 and increasing with increase of aggregate mass fractal dimension. The dewatering process was characterized by compressive and hindered settling behavior. The numerical study of compressive rheology with different aggregate microstructure showed that the compaction results from a reduction of the correlation length rather than increase in fractal dimension. The compressive behavior is consistent with theoretical models at higher compressive stresses but is not well described at low compressive stresses. A semi- empirical model is presented describing the compressive rheology in both regions via a correction factor derived using dimensional analysis. The hindered settling behavior was in good agreement with the theoretical model based on the assumption of self similar structure. The investigation revealed that shear effect is not due entirely to hydrodynamics and can arise from the particle bonding mechanism alone. The study showed that low shear increases compressibility but high shear is detrimental. At low shear, bond bending at local voids results in solid densification. High shear increases kinetic energy and kinetic repulsion of the particles. The effect of shear is analogous to the anomalous behavior of the water density- temperature function. At low temperature bond breakage increases the density and at high temperature thermal expansion decreases the density. The investigation showed that shear increases the permeability due to bending of the structure in the shear direction, resulting in large pores.
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Chemical and physical properties of acid mine drainage flocBohan, Catherine M. January 1900 (has links)
Thesis (M.S.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains ix, 63 p. : ill. Includes abstract. Includes bibliographical references (p. 57-63).
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Morphological and biochemical studies of Zoogloea ramigera species in pure cultureCrabtree, Koby T. January 1966 (has links)
Thesis (Ph. D.)--University of Wisconsin, 1966. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.
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Flocculation and settling properties of discharged drilling waste /Niu, Haibo, January 2003 (has links)
Thesis (M.Eng.)--Memorial University of Newfoundland, 2003. / Bibliography: leaves 128-136. Also available online.
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Improved filler retention by co-flocculation of fines and filler particles.Matyumza, Ntombozuko C. 04 1900 (has links)
Thesis (MScFor)--Stellenbosch University, 2005. / ENGLISH ABSTRACT: The retention of filler particles and drainage are important aspects of papermaking. A
number of important paper properties depend in the quality and quantity of filler retained
in the paper. Fines, fillers and pulp fibres all have a negative charge and are kept apart by
electrostatic forces. This causes a decrease in the effectiveness of cationic retention aids
thereby causing a high cationic demand. This in turn implies that the retention of fines
and filler particles in a formed sheet is not efficient, especially in the presence of anionic
trash. In order to improve printability, print quality and dimensional stability, a large
percentage of mineral pigments / fillers either in the form of internal loading or external
coating should be added.
It was found that coflocculation of fines and filler particles resulted in an even
distribution of filler particles in the form of miero-flocs and the filler retention was
maintained. Opacity was improved without much reduction in paper strength. An
increased filler content without coflocculation of fines reduced sheet strength properties.
The filler particles interfered with the development of fibre-to-fibre bonds and occupied
spaces that otherwise might have contained fibres.
This study showed that the most beneficial effect of coflocculation of filler with fines was
obtained, with regards to paper strength, opacity, filler retention and printability, when
the charge of the fibre furnish was maintained at -0.1 leu with the 0.1% addition of
cationic PAM retention aid. / AFRIKAANSE OPSOMMING: Twee belangrike aspekte van papiervervaardiging is die retensie van vulstowwe en
ontwatering. 'n Aantal belangrike papiereienskappe is afhanklik van die hoeveelheid en
kwaliteit van vulstowwe wat in papier voorkom. Veselpuin, vulstowwe en pulp-vesels is
almal negatief gelaai, gevolglik verseker elektrostatiese kragte dat hierdie deeltjies los
van mekaar bly. Laasgenoemde verminder die doeltreffendheid van kationiese
retensiemiddels en dit gee aanleiding tot 'n hoë kationiese aanvraag. Die retensie van
veselpuin en vulstof deeletjies in papier is gewoonlik nie voldoende in die
teenwoordigheid van anioniese afvalkomponente nie. Om aan papier verbeterde drukeienskappe,
drukkwaliteit en dimensionele stabiliteit te gee, moet 'n groot persentasie
minerale pigmente en/of vulstowwe as 'n interne lading of eksterne bestryking voorsien
word.
Daar is bevind dat kot1okkulasie van fynstowwe en vulstofdeeltjies, 'n egalige
verspreiding van vulstof-partikels as mikro-t1okke tot gevolg het en dat vulstof-retensie
op aanvaarbare vlakke behou is. Ook is ondeurskynendheid verbeter sonder 'n
beduidende verswakking in die papiersterkte. 'n Toename in vulstofinhoud, sonder
kot1okkulasie van fynstowwe, het die papier sterkte-eienskappe verlaag. Vulstofdeeltjies
bëinvloed die ontwikkeling van vesel-tot-vesel binding. Hierdie deeltjies beset ruimtes
wat andersins deur vesels benut sou word.
Hierdie studie het getoon dat die voordeligste effek van kot1okkulasie van vulstowwe met
fynstowwe verkry is, ten opsigte van papiersterkte, ondeurskynendheid, vulstof retensie
en drukeienskappe, wanneer die lading van die pulpsuspensie by -0.1 leu gehou was met
'n byvoeging van 0.1% kationiese PAM retensie-hulpmiddel.
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