Flocculation Efficiency of Chitosan for Papermaking Applications

Nicu, Raluca; Bobu, Elena; Miranda, Rubén; Blanco, Ángeles

doi:10.15376/biores.8.1.768-784

Cited by 16 publications

(14 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These characteristics favor a greater contribution from the bridge formation flocculation mechanism. The flocculation of PEI involved a fast aggregation of small particles in the first step, followed by bridge flocculation in a second step, which results in large flocs, as observed previously by Nicu et al (2013). Unlike other high molecular weight polymers, PEI showed not only the capacity to reflocculate the broken flocs under high shear forces but also to form larger flocs than before; while this is in apparent contradiction for bridge formation, it has been observed previously .…”

Section: Floc Behavior Under Shear Forces At Optimal Polymer and Bentsupporting

confidence: 65%

“…At present, there are only a few applications of chitosan in papermaking, mainly focusing on the surface treatments in the production of specialty paper grades (Kuusipalo et al 2005;Bordenave et al 2010;Reis et al 2011), the improvement of the wet and dry strength of paper (Laleg 2001;Nada et al 2006;Jahan et al 2009;Chen et al 2013), water treatment (Wang et al 2009;Miranda et al 2013), or its possible use in wet end applications as an anionic charge neutralization system (Bobu et al 2002;Li et al 2004b;Belosinschi and Bobu 2008;Nicu et al 2011;Nicu et al 2013).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Efficiency of Chitosan and their Combination with Bentonite as Retention Aids in Papermaking

Miranda¹,

Nicu²,

Bobu³

et al. 2016

BioResources

Self Cite

View full text Add to dashboard Cite

In a previous work , the flocculation efficiency of three chitosans differing by molecular weight and charge density were evaluated for their potential use as wet end additives in papermaking. According to the promising results obtained, chitosan (single system) and its combination with bentonite (dual system) were evaluated as retention aids, and their efficiency was compared with poly(diallyl dimethyl ammonium chloride) (PDADMAC) and polyethylenimine (PEI). In single systems, chitosan was clearly more efficient in drainage rate than PDADMAC and PEI, especially those with the lowest molecular weights; however, retention is considerably lower. This drawback can be overcome by using dual systems with anionic bentonite microparticles, with the optimum ratio of polymer:bentonite being 1:4 (wt./wt.). In dual systems, the differences in retention were almost negligible, and the difference in drainage rate was even higher, together with better floc reversibility. The most efficient chitosan in single systems was Ch.MMW, while Ch.LMW was the most efficient in dual systems. The flocculation mechanism of chitosan was a combination of patch formation, charge neutralization, and partial bridge formation, and the predominant mechanism depended on the molecular weight and charge density of the chitosan.

show abstract

Section: Floc Behavior Under Shear Forces At Optimal Polymer and Bentsupporting

confidence: 65%

Section: Introductionmentioning

confidence: 99%

Efficiency of Chitosan and their Combination with Bentonite as Retention Aids in Papermaking

Miranda¹,

Nicu²,

Bobu³

et al. 2016

BioResources

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, at the highest dosages, the number of counts generally decreased due to the aggregation of the previously destabilized DCM and thus, the mean chord size increased, as can be seen in Figure 4. This could be a very positive effect due to the use of chitosan products as they have the advantage of coagulating small particles [30] which cannot be separated otherwise by DAF system. Although flotation is generally promoted by large flocs (high mean chord size), but in some cases a low mean chord size with a higher number of counts indicate that DCM has been destabilized and aggregated forming small flocs that can be also removed subsequently by flotation [8,[28][29].…”

Section: A Single Addition Of the Coagulantmentioning

confidence: 99%

Efficiency of chitosans for the treatment of papermaking process water by dissolved air flotation

Miranda

Nicu

Latour

et al. 2013

Chemical Engineering Journal

Self Cite

View full text Add to dashboard Cite

Interest has grown in bio-polymers as being environmental friendly alternatives to synthetic additives. In this work, two native chitosans with different molecular weights have been evaluated on a laboratory scale for their effectiveness for the removal of contaminants from papermaking process waters by dissolved air flotation (DAF). The use of chitosan quaternary derivatives and the use of the native chitosans in combination with anionic bentonite microparticles have also been tested. Results demonstrate a high efficiency of the native chitosan products at intermediate dosages and furthermore, their efficiency is enhanced by the combined addition of bentonite. For an equivalent removal of contaminants, the required dosage of chitosan is about half that the dosage required in absence of bentonite. Quaternary derivatives have not improved the efficiency of the native chitosan in this case. The optimum treatment would be 50 mg/L of native chitosan and 100 mg/L of bentonite where this treatment is capable of the removal of 83-89% turbidity (residual turbidity 210-320 NTU), 68-71% dissolved turbidity (residual dissolved turbidity of 22-24 NTU), 18-22% total solids (residual total solids of 2750-2900 mg/L) and 19-23% COD (1440-1525 mg/L). The low molecular weight native chitosan is more efficient than the medium molecular weight chitosan in all cases. The Focused Beam Reflectance Measurement (FBRM) is used to assess the aggregation process and to predict the separation efficiency of DAF units either with single or dual systems. The efficiency predicted through the FBRM technique is very similar to that obtained later in the DAF tests.

show abstract

“…Chitosan, an amino-polysaccharide with a linear structure similar to cellulose and a single biopolymer with a cationic charge, appears as an attractive compound to substitute for cellulose derivatives. The main features of chitosan that express an interest in both papermaking and paper heritage conservation are its structural affinity with cellulose; capacity to form hydrogen bonds and act as a strengthening agent; its high cationic charge, which confers antimicrobial properties without toxicity; and very good film-forming properties (Laleg and Pikulik 1993;Bobu et al 2002;Ashori et al 2006;Nicu et al 2013a). …”

Section: Introductionmentioning

confidence: 99%

Chitosan Derivatives as Bio-based Materials for Paper Heritage Conservation

Ciolacu¹,

Nicu²,

Balan³

et al. 2016

BioResources

Self Cite

View full text Add to dashboard Cite

Three water-soluble chitosan derivatives (ChDs)-carboxymethyl-chitosan (CCh), alkyl-chitosan (ACh), and quaternary-chitosan (QCh)-were evaluated as new materials for paper conservation. Several series of samples were prepared by coating different paper types with ChDs or methylcellulose (MC). The ChDs' effectiveness were analyzed by their effects on the strength (tensile energy absorption (TEA), double folds) and water barriers (Cobb60, contact angle (CA)). The coatings on laboratory paper showed strength improvements for the CCh/QCh coatings that were consistent with an increase in the coating weight (CW). The ACh had little effect on the strength, but developed an effective barrier to water. The coatings on printing paper were performed at a constant CW by applying two layers of the same ChD or MC, and by combining CCh or QCh in the first layer with ACh in the second layer. Homogenous coatings based on the CCh or QCh resulted in high strength improvements, comparable to MC, but only ACh coatings developed an effective barrier to water. Combinations of the CCh or QCh with ACh provided the best relationship between the strength and barrier properties and proved their effectiveness as strengthening/protective materials in the treatment of natural aged paper.

show abstract

Flocculation Efficiency of Chitosan for Papermaking Applications

Cited by 16 publications

References 8 publications

Efficiency of Chitosan and their Combination with Bentonite as Retention Aids in Papermaking

Efficiency of Chitosan and their Combination with Bentonite as Retention Aids in Papermaking

Efficiency of chitosans for the treatment of papermaking process water by dissolved air flotation

Chitosan Derivatives as Bio-based Materials for Paper Heritage Conservation

Contact Info

Product

Resources

About