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The concentrations of naturally occurring radionuclides (226Ra, 228Ra, 228Th, and 40K) in ashes of papers such as magazines and newspapers were determined from the nuclide concentrations in the papers and the ash contents of the papers. The average 226Ra, 228Ra, 228Th, and 40K concentrations in the 34 ashes were respectively 27, 68, 75, and 75Bq kg−1. The radium equivalent activities of the ashes were calculated to evaluate the hazard of g-ray radiation from the ashes in the environment. A copying paper sample showed a high radium equivalent activity of 602Bq kg−1. However, the average radium equivalent activity was 140Bq kg−1 and was lower than the level that causes an environmental health problem.

A commercially available GDL based on carbon paper or carbon cloth as a macroporous substrate was characterized by various physical and electrochemical measurements: mercury porosimetry, surface morphology analysis, contact angle measurement, water permeation measurement, polarization techniques, and ac-impedance spectroscopy. SGL 10BB based on carbon paper demonstrated dual pore size distribution and high water flow resistance owing to less permeable macroporous substrate, and more hydrophobic and compact microporous layer, as compared to ELAT-LT-1400 W based on carbon cloth. The membrane-electrode-assembly fabricated using SGL 10BB showed an improved fuel cell performance when air was used as an oxidant. The ac-impedance response indicated that a microporous layer which has high volume of micropores and more hydrophobic property allows oxygen to readily diffuse towards the catalyst layer due to effective water removal from the catalyst layer to the gas flow channel.

The main goal of this research is to apply AFM to the analysis of coated paper topography in order to find out relationships between sheet gloss and some parameters obtained from AFM, such as roughness and fractal dimension (D). Flooding technique was also developed using appropriated software. Number of hills/flooding volume for 25%, 50% and 75% flooded volume was applied in this research. Ground calcium carbonate and precipitated calcium carbonate were applied in coating colour formulations, alone and blended in three formulations, 75:25, 50:50 and 25:75. The results obtained showed high correlations between sheet gloss with fractal dimension (D) parameter. Finally, flooding technique showed to be very interesting, all of them gave useful information in interpreting the influence of topography on sheet gloss.

The effect of UVC (λmax = 254 nm) treatment on wettability of pigment-coated papers was examined. The paper samples were coated with conventional pigments including ground calcium carbonate (GCC), precipitated calcium carbonate aragonite (PCC), and Kaolin. The coating formulation also included poly(styrene-butadiene) (SB) latex binder and a dispersing agent, sodium polyacrylate (NaPA), for formation of a colloidally stable pigment slurry at a relatively high solids content. A significant decrease of contact angle of water on the studied pigment-coated papers was observed as a result of UVC treatment. The effect was most pronounced for carbonate-based coatings. In addition, the UVC treatment showed long-term stability. A detailed analysis of the surface chemical composition of the PCC-based coatings indicated that the UVC treatment leads to photooxidation and photodegradation, and eventual desorption of a thin NaPA overlayer from the pigment surface. This in turn increases the polarity of the surface and e...

Zinc oxide (ZnO) is a potential pigment material for paper coating to impart brightness and better printing properties. Nano-ZnO, due to its extremely small size, gives paper coating pigment a high covering power apart from anti-fungal and UV-protecting properties. In this work, zinc oxide–soluble starch nanocomposites (nano-ZnO) was prepared by a simple and novel wet chemical method using zinc nitrate and sodium hydroxide as precursors and soluble starch as stabilizing agent. Primary particle size distribution was extracted from small angle X-ray scattering (SAXS) measurements by the hard sphere model and calculated to have an average size of 4.1 nm. This nano-ZnO was coated on the surface of base paper (59 GSM) in a laboratory paper coater and their properties were studied. The brightness, whiteness, paper smoothness, print density, print uniformity, picking velocity and oil absorbency of nano-ZnO coated paper showed significant improvement than that of bulk-ZnO coated paper. In addition, the nano-ZnO coated paper showed excellent anti-fungal and UV-protecting properties that are much essential to enhance the life of a paper.

[EN] Calcined residual paper sludge can be reused and valorized in a safe an environmental way by the construction industry. The highly reactive metakaolin produced by calcination of the paper sludge exhibits good pozzolanic properties and permits its incorporation in cement systems. The pozzolanic reaction of metakaolin in Ca(OH)2-saturated solution at 40 °C is reported in this study as a function of time, up to 1 year. The stability of hydrates phases has been evaluated according to the evolving aqueous conditions. Analytical determinations of the solid phase show early formation of C–S–H phases and a later precipitation of laminar minerals, hydrotalcite and strätlingite, at the expense of the C–S–H phases. The thermodynamic calculations confirm the experimental observations.

On-site measurement of methanethiol (CH 3 SH) was performed for three years on ships and cars near a pulp and paper plant standing on the shore of Lake Baikal in Siberia, Russia, to investigate the behavior and impact of atmospheric CH 3 SH emitted from a point source. Despite its strong odor, there are few reports on atmospheric CH 3 SH, while many investigations have been carried out on dimethyl sulfide (DMS). In this work, CH 3 SH and DMS were measured every 15 min by a recently developed automated instrument based on single column trapping/separation and chemiluminescence measurement. Hydrogen sulfide, sulfur dioxide and ozone were also measured simultaneously by individual instruments. Of these sulfur compounds, CH 3 SH was dominant and its concentration sometimes reached several tens of ppbv. The concentration of CH 3 SH was high at night, because of the lack of photodecomposition and local winds from the mountain to the lake. Such time variation was marked in the summer. The CH 3 SH level decreased significantly downwind, while decreases in concentrations of other compounds such as DMS and SO 2 were relatively small. From these temporal and spatial variations, the behavior of CH 3 SH is described in this paper. The impact of CH 3 SH near the Siberian big sources is discussed with the presented data.

[EN] The present research is a part of an experimental study about obtaining recycled metakaolinite from a Spanish paper sludge waste as complementary cementing material. The mineral phases formation from paper sludge calcined at different temperatures (700, 750 and 800 °C) and two times of stay in the furnace (2 and 5 h) mixed with saturated lime dissolution are obtained mineral phases: C-S-H gel, stratlingite, tobermorite, hydrotalcite. The C-S-H gels generated in the first stages lose crystallinity and filled the existing holes between stratlingite and hydrotalcite. The different mineral evolves according to their stability fields toward crystalline aggregates more compact where the gels fill hollow.

In this paper the results of an extensive experimental study on the volume change of a water sessile droplet on various papers such as gloss and matte-coated papers and high-grade papers and boards with certain specifications are reported. The droplet on a paper is observed using a computer-controlled and fully automated instrument. The total volume and the contact angle of the sessile droplet are recorded in short time intervals (as short as 150 milliseconds) for about 6–10 min. The evaporation effect on the change of the volume of the water droplet is controlled by measuring the size change of a droplet on a glass surface. The instruments and the material used in the experiments are introduced in detail and the results are displayed in a series of figures and tables. The effects of possible mechanisms on the behavior of the water droplet are discussed, and directions of future studies are indicated. It is concluded that the relationship between water and a cellulose-based substrate cannot be fully under...

This document analyses the importance of topography characterization of coated papers, using precipitated calcium carbonates as pigments, on print quality evaluation. For topographic characterization, a laser profilometry was used as well as scanning electron microscope and a mechanical profilometry. Print quality for inkjet printing was assessed using mottle, gain, optical density and Gamut Area. Surface energy of coated papers and printing inks was evaluated using OWRK method. The results obtained showed that good correlations between print quality characteristics and surface energy as well as topographic properties can be obtained.

Porapak has been studied as a solid-food simulant in experiments on paper and board packaging. Three samples of paper with different recycled pulp content and surface treatment, and of different grammage and thickness, were used for the studies. Kinetic behaviour from 25 degrees C to 100 degrees C and different contact times ranging from 5 min at 100 degrees C to 10 days at 25 degrees C were studied using Porapak or, occasionally, Tenax or milk powder. Similar results were obtained with Porapak and Tenax but those from Porapak were more stable with temperature. Porapak behaves as good solid-food simulant even at high temperature.

Bacterial cellulose (BC) synthesized by Gluconacetobacter sucrofermentans CECT 7291 seems to be a good option for the restoration of degraded paper. In this work BC layers are cultivated and purified by two different methods an alkaline treatment when the culture media contains ethanol and a thermal treatment if the media is free from ethanol. The main goal of these tests was the characterization of BC layers measured in terms of tear and burst indexes, optical properties, SEM, X-ray diffraction, FTIR, degree of polymerization, static and dynamic contact angles, and mercury intrusion porosimetry. The BC layers were also evaluated in the same terms after an aging treatment. Results showed that BC has got high crystallinity index, low internal porosity, good mechanical properties and high stability over time, especially when purified by the alkaline treatment. These features make BC an adequate candidate for degraded paper reinforcement. © 2014 Elsevier Ltd.

Papermaking deposits can be classified as being organic, inorganic, or microbiological. Most paper machine deposits contain a combination of some or all of these major component types. Although inorganic deposits tend to be more of a problem in the stock and flow-piping systems of the paper mill, organic deposits tend to be more problematic in the headbox, wet end, and press section of the paper machine. These contaminants form tacky deposits that can plug forming fabrics and wet press felts. Microorganisms in paper mill systems take two forms: planktonic and sessile. Planktonic organisms do not readily cause problems in the system; however, in the sessile form, these same organisms can become problematic. Inorganic and organic deposits offer a readily available food source for sessile organisms, which attach themselves to deposit surfaces. Several of these organisms classified as slime formers are able to secrete a protective polysaccharide coating around themselves known as biofilm. The slime formers, in combination with inorganic and organic process additives and contaminants, can form deposits that coat process equipment and create sheet quality and runnability problems. In addition to slime formers, anaerobic bacteria can form under deposits. The most common type of anaerobic bacteria found in paper mills is sulfate-reducing bacteria, which is capable of converting sulfate in the system to highly corrosive hydrogen sulfide.

In the present study, calcium sulphate pigment has been synthesized experimentally from commercial grade calcium chloride. The effect of various factors on the particle size of calcium sulphate formed in a wet process and its potential application as pigment in coating recipe has been investigated. The operating factors investigated include concentration of calcium chloride solution, temperature, addition of different rheology modifiers and their optimization. The particle shape and size distribution of synthesized calcium sulphate pigment have been studied through image analyzer, scanning electron microscope (SEM) and particle size analyzer. Significant improvement was observed in various coated paper properties like brightness, whiteness, gloss, stiffness, surface strength and water retention properties of coating color with respect to conventional ground calcium carbonate (GCC) coating pigment.

Wt% of aragonite, a CaCO(3) polymorph, increased with higher hydraulic activity ( degrees C) of limestone in precipitated calcium carbonate (PCC) from the lime-soda process (Ca(OH)(2)-NaOH-Na(2)CO(3)). Only calcite, the most stable polymorph, was crystallized at hydraulic activity under 10 degrees C, whereas aragonite also started to crystallize over 10 degrees C. The crystallization of PCC is more dependent on the hydraulic activity of limestone than CaO content, a factor commonly used to classify limestone ores according to quality. The results could be effectively applied to the determination of polymorphs in synthetic PCC for eco-friendly paper manufacture.

The possibility of co-processing paper sludge with coal in power plants for power production and useful products was investigated as an alternative to the disposal option. The thermal behaviour of the fuels and their blend during pyrolysis and combustion processes was studied, kinetic models were developed and the compatibility of each component in the blend was evaluated. The experiments were conducted in a thermogravimetric analysis system, at non-isothermal heating conditions, over the temperature range 25–850 °C. The effect of the inorganic constituents of the fuels and their mixture on thermal conversion characteristics, reactivity, slagging and fouling propensities and environmental pollution was examined. The thermochemical reactivity of the two fuels was different in both nitrogen and air. Devolatilization of paper sludge occurred earlier and with a higher rate, while its combustion was hindered by the high content of ash. When the two fuels were mixed their pyrolysis or combustion reactivities did not substantially change. A first-order parallel reactions model for pyrolysis and a power low model for combustion fitted the experimental results accurately. The kinetic parameters of the blend could be predicted from the data of the individual components. Co-firing paper sludge with subbituminous coal might somehow improve the slagging/fouling potential of the coal. However, if the mineral matter of paper sludge is partly removed before use, then the combustion behaviour of the mixture could resemble that of coal alone and the overall efficiency of the process would increase.

This study shows the effect of calcination clay wastes from an art paper sludge for the use as supplementary cementing materials in blended cements. The starting clay sludge rich in kaolinite and talc was calcined at 600, 650 and 700 °C between 2 and 5 h, kaolinite was transformed into amorphous metakaolinite. This study reveals that calcination at 650 °C for 2 h is recommended to obtain a good supplementary cementing material for manufacture of blended cements., This research has been supported by the Autonomy Community of Madrid (project ref: GR/AMB/0448/2004) and, to Holmen Paper Madrid Company and T S Laboratory of Lafarge Cements (Toledo, Spain) for its technical support.

Recycled paper was made with Precipitated Calcium Carbonate (PCC) which is famous for alkaline mineral filler. Filling behavior, whiteness, opacity and mechanical property change according to shape of PCC. Calcite PCC was difficult to disperse and to be filled uniformly because calcite PCC hardly aggregated but it could improve tensile strength as its amount increases. A suitable filler to be filled in recycled paper was needle-like aragonite and it could increase folding resistance slightly when aragonite of 10 wt% against dried pulp mass was added. PCC already synthesized was not effective on improvement of optical property but a new process, In-situ process, developed whiteness and opacity because PCC nucleated on fiber surface and then diffused reflection happens on surface. Whiteness of recycled paper made by In-situ process was 64 which is 92% of standard presented by Korea Public Procurement Service.

In contradiction to the proposition of Nicoleau and Nonat, it is shown that the rate of hydration of anhydrous tricalcium silicate (C3S) cannot be controlled by the rate of dissolution of the anhydrous phase in typical C3S pastes except at extremely early ages. The strongest evidence for this is the observation that the hydration of C3S in pastes is strongly accelerated by the addition of afwillite seeds, to the extent that it hydrates almost completely by 7 days. It is suggested that the hydration rate at later ages is primarily controlled by the porosity and permeability of the hydration products.

In this research the thermal stability of paper and its components are investigated, in order to evaluate the effect of the artificial weathering treatments, carrying on measurements of thermal gravimetry; also some SEM observations are performed to follow the degradative phenomena. Our work allowed to correlate the level of degradation of the artificially aged paper samples with that of the naturally aged ones. TGA curves of the weathered samples show changes in respect to the starting materials; particularly, the chemical oxidation appears as the most degradative action in respect to the other physical treatments.

Paper being the basis of different documents is often the subject of forensic examination. Growing number of bogus or in other manner fraudulently alternated documents causes necessity of identification of individual paper sheets and discrimination between sheets being the parts of analyzed questioned document. Frequently it is necessary to distinguish between paper of the same type but of a different age. Thus, it is essential to know whether the degradation process of paper influences the possibility of differentiation between paper samples. Samples of five types of office paper from different manufacturers were artificially aged in a climatic chamber under 65% relative humidity in air at 90 °C for various periods of time up to 35 days. The conditioned samples were examined by the use of infrared and Raman spectroscopy. Three cards of each paper type were chosen for the experiment. Three different spots on each paper card were measured to assure reproducibility of the experiment in both spectroscopic methods. The possibility of differentiation between aged samples was evaluated. The 2D correlation analysis based on the Noda’s method was carried out using ATR FTIR spectra as an input data for generating the correlation maps. It was found that pattern of 2D maps allow to distinguish tested paper samples, identified its components and get insight into paper degradation mechanism.

For analytical applications in portable sensors to be used in the point-of-need, low-cost SERS substrates using paper as a base, are an alternative. In this work, SERS substrates were produced on two different types of paper: a high porosity paper (Whatman no. 1); and a low porosity paper (commercially available office paper, Portucel Soporcel). Solutions containing spherical silver nanoparticles (AgNPs) and silver nanostars (AgNSs) were separately drop-casted on hydrophilic wells patterned on the papers. The porosity of the paper was found to play a determinant role on the AgNP and AgNS distribution along the paper fibres, with most of the nanoparticles being retained at the illuminated surface of the office paper substrate. The highest SERS enhancements were obtained for the office paper substrate, with deposited AgNSs. A limit of detection for rhodamine-6G as low as 11.4 ± 0.2 pg could be achieved, with an analytical enhancement factor of ≈107 for this specific analyte. The well patterning technique allowed good signal uniformity (RSD of 1.7%). Besides, these SERS substrates remained stable after 5 weeks of storage (RSD of 7.3%). Paper-induced aggregation of AgNPs was found to be a viable alternative to the classical salt-induced aggregation, to obtain a highly sensitive SERS substrates.

Recognition of multiple partial discharge (PD) sources in high voltage equipment has been a challenging task until now. The work reported here, aims to recognize multiple PD sources in oil-impregnated paper using Cluster Analysis (CA) and Fuzzy Logic (FL). The typical sources of PD in transformer are identified and the corresponding single source PD defect laboratory models are fabricated. From the measured PD signals, the necessary statistical parameters are extracted by applying CA for classification. A Fuzzy based algorithm has been developed to recognize single source PDs. The developed algorithm has also been applied to recognize multiple PD sources.

Four residues generated in a Kraft, pulp and paper plant, were characterized by X-ray fluorescence spectroscopy (XFA), powder X-ray diffraction (XRD), thermogravimmetric analysis (TG) and Fourier transform infrared spectroscopy (FTIR). A quantitative phase composition model, that accounts for the observed data and for the physico-chemical conditions of formation, was postulated for each material. Emphasis was given on the identification of the mineral components of each material. The green liquor dregs and the lime mud contain Calcite and Gipsite. The slaker grits contains Calcite, Portlandite, Pirssonite, Larnite and Brucite. The Calcite phase, present in the dregs and in the lime mud, has small amounts of magnesium replacing calcium. The wood ash contains Quartz as the major crystalline mineral phase.

Sampling restrictions in analysis of cultural heritage materials narrow the choice of appropriate analytical methods considerably. In this work, near- and mid-FT-IR reflectance data were related to paper properties determined with classical analytical methods using partial least-squares. Nondestructive determination of properties, which are of importance for evaluation of the long-term stability of historical paper, i.e., ash content, lignin content, degree of polymerization of cellulose, pH, and aluminum content, is possible. With the use of a considerable sample set, satisfactory reliability was achieved for all properties but aluminum content. Considering that with age, chemical properties of paper change, dating of historical documents was attempted for the first time, also with success.

Publicación en versión online: 15 de noviembre de 2006, This work reports the project of thermal effects in mineralogy and texture of the paper sludge to employ them as pozzolanic material. For this reason, the chemistry and mineralogical composition has been studied, as well as its morphology by XRD, SEM and EDX. The initial sludge has been treated to 700, 750 and 800 °C during 2 and 5 h being observed that initial kaolinite becomes metakaolinite and that its pozzolanic activity with a paper sludge treated to 700 °C for 2 h is comparable to that of a commercial metakaolinite. The transformation of kaolinite after the dehydroxylation is to convert in amorphous metakaolinite. At the temperature mentioned above, calcite from the initial sludge is maintained active. It is concluded that the pozzolanic activity of metakaolinite is strongly related to the crystallinity of the original kaolinite. Well-ordered kaolinite is transformed into more reactive metakaolinite., This research has been supported by the Spanish Ministry of Science and Technology (project ref: MAT2003-06479-C03-01/02), Holmer Paper–Papelera Peninsular Company and TC laboratory of Lafarge.

Porous conducting carbon paper acts as an electrode backing material in a fuel cell. It not only assists in the flow of electrons and gases but also provides mechanical support to the MEA. The electrically conducting carbon paper (porosity ∼70%) was prepared using laminated assembly of chopped carbon fiber porous preforms and applying combined paper making and composite making technique. The green paper was subjected to different heat treatment temperatures (HTT), which was found to influence the characteristics of the paper significantly. The processing of the paper was carried out at a very fast carbonization rates, 900 °C/h as compared to 10–20 °C/h used conventionally, making the complete process highly cost efficient. The paper when used in the unit fuel cell assembly showed I – V performance comparable to that of the commercially available Toray carbon paper.

International audience; Water cleaning of paper leaves is a preliminary step in many customary deacidification treatments of ancient books in conservation workshops. Usually, the washing solutions are considered “waste waters” and they are thrown away. In this work, an analytical protocol for the analysis of wash waters for the assessment of the conservation state of ancient books is proposed. Wash waters of leaves under different conservation conditions of a 16th-century- rinted book were investigated using UV-Vis, IR, Raman, NMR, EPR, XRF, ESI-MS, ICP-MS, CE-PDA and elemental microanalysis. Analysis of the wash water extracts allowed one to identify a large number of degradation by-products, ranging from low-molecular mass organic acids to cellulose oligomers. Reasons for the very different conservation conditions of the leaves emerged, indicating that wash water analysis provides a deep insight into the conservation state and composition of leaves as well as degradation reactions occurred on them

Natural pozzolans are defined as either raw (volcanic material, limestone) or calcined natural materials (burnt shale, calcined kaolinite) with pozzolanic properties. Historically, they are among the oldest materials that have been used in combination with lime for construction purposes. For example, Santorin earth is a natural pozzolan from a volcanic eruption around 1500 BCE on an island of the same name in Greece. Over the last decades, research into cement matrices has been changing direction, owing to deeper environmental concerns over the impact of the cement industry and its consequences for climate change. Global environmental policies are increasingly strict, prioritizing the re-use rather than the disposal of industrial wastes. In this context, one of the biggest challenges is the search for strategies that promote the industrial rotation of high volumes of wastes in their productive cycles. The main purpose of this research is to widen the existing knowledge base on the behavior of new mineral pozzolans of high added value in the cement sector, lending special attention to paper sludge wastes generated in the process of paper manufacture, in which recycled paper is used as a raw material. The results to date show that, once thermally activated (in the range of 650–700°C), paper sludge turns out to be an alternative source of recycled metakaolin. This product is characterized by its high pozzolanic activity and improved performance with regard to the benefits of certain binary cements. The possibility of incorporating this industrial waste in cements along with other already standard pozzolans focuses, as mentioned, on the notable increase in the production of these types of cements. This is due, at present, to the extensive constructive applications for type-II cements (single additive) and to their lower economic and energetic costs that also makes them more suitable in times of economic crisis. In the present paper, the influence that pozzolan blends (activated paper sludge and fly ash) have on the reaction kinetics of ternary blended cements (6 and 21% of replacement) is evaluated, paying special attention to the identification and evolution of hydrated phases with increasing reaction times. The results obtained represent a pioneering research line at a global level and represent a starting point for future investigations because in the case of using paper sludge, release of CO2 from organic matter is very low and is listed as zero release

Tagasaste ( Chamaecytisus proliferus (L.F.) ssp. palmensis ) trimming residues are considered to be agricultural waste, since they cannot be converted into valuable products. The chemical characteristics of tagasaste trimming wood and eucalyptus wood are similar in ash, holocellulose, lignine, xylan and acetyl groups. Thus, tagasaste wood trimmings could be an adequate raw material for hydrothermal treatment and pulp and paper-making. An experimental design was performed to study the influence of process variables: temperature (170–192°C), pulping time (30–90 min), active alkali concentration (12–20%), liquid–solid ratio (4 : 1–8 : 1) and anthraquinone concentration (0–0.1%) on the properties of pulps (yield, kappa index, viscosity, alcohol–benzene extractives, holocellulose, lignin and α-cellulose contents and brightness) and paper sheets (stretch index, burst index and tear index) obtained from tagasaste residues. Pulps with acceptable physical and chemical properties can be obtained operating at 170°C for 60 min with 12% active alkali concentration, 0.1% anthraquinone concentration and 8 : 1 liquid–solid ratio.

Non-metallic mineral fillers strongly influence the characteristics and quality of paper. "Visocica" limestone and "Virpazar" dolomite were used to prepare paper samples in this study. The characteristics of such paper samples produced on a laboratory paper machine are presented. The used fillers and paper pulp were also characterized. The following paper characteristics were investigated: gramature, thickness, softness, air permeability, resistance to tearing and stretching, paper ash and retention. The experiments were performed in order to compare the influence of the physico-chemical and structural qualities of the examined carbonate type fillers on the paper properties. The results of the investigation indicated the technological reasons for using these non-metallic mineral raw materials as fillers in the paper industry regarding the mechanical paper characteristics, as well as other properties.

Isotope Ratio Mass Spectrometry (IRMS) has been shown to be a useful tool in the comparison of materials that are chemically identical either through man-made production processes or for materials that have been naturally produced. Paper therefore, is an ideal material for this type of measurement given that it is manufactured from a naturally produced product that can be difficult to discriminate based on physical feature comparison alone. To determine whether carbon isotopes are useful for discriminating document papers, 125 samples from Australia and New Zealand were collected over a 24-month period. When measured, a range of 8‰ was observed. A homogeneity study was undertaken to examine the range of values expected from paper sources including single sheets, single reams and multiple reams from the same brand. These results can also be used to suggest how best to sample from these different sources. After characterizing the natural variation of the material, a range of 1‰ was defined for use as a benchmark for discrimination. Utilizing this threshold, 68% of the 125 collected samples (when paired against each other) could be discriminated using the carbon isotope abundances alone. Additionally, correlation was observed when measured values were plotted against their production region of origin.

Uptake properties of Ni2+ were examined for unmilled and milled paper sludge calcined at various temperatures to develop a new usage of waste paper sludge. Since paper sludge mainly consists of cellulose ([C6H(10)O5]n) fibers, calcite (CaCO3), kaolinite (Al2Si2O5(OH)4) and talc (Mg3Si(4)O(10)(OH)2), amorphous and crystalline CaO(MgO)-Al(2)O(3)-SiO(2) compounds are formed by calcining paper sludge. Wet and dry milling treatments were performed to accelerate solid-state reaction to form the above mentioned target compounds. The crystalline phases originally present decompose at increasing calcining temperature (up to 800 degrees C) in the order cellulose

Porous materials consisting of activated carbon and amorphous CaO-Al(2)O(3)-SiO(2) (CAS) compound were prepared from refuse paper and plastic fuel (RPF), (a mixture of old paper and plastic) by carbonizing and/or activating treatments. Samples formed by chemical activation using K(2)CO(3) showed a high specific surface area (S(BET)) of 1330 m(2)/g but a lower ash content due to being washed after activation. By contrast, samples prepared by physical activation using steam showed rather lower S(BET) (510 m(2)/g) due to higher ash contents. The physically activated samples showed much higher uptake properties for Ni(2+) (a representative heavy metal) and phosphate ions (a representative of a harmful oxyanion) than the chemically activated samples because of the higher content of amorphous CAS in the former samples. By contrast, the chemically activated samples showed higher uptake for methylene blue (MB, a representative organic material) than the physically activated samples because of the higher activated carbon content of higher surface area. Although differences in the sorption properties for Ni(2+), phosphate ion and MB were found between the physically and chemically activated samples, both samples show excellent multiple sorption properties for cation-anion combinations and inorganic-organic sorbents.

The electrochemical degradation of agri-based paper mill wastewater (black liquor) was investigated in a 2 dm3 electrolytic batch reactor using iron plate electrodes. Of the four-, six-, and eight-plate configurations, a current density of 55.56 A/m2 at neutral pH with a six-plate arrangement was found to be optimal, achieving a maximum chemical oxygen demand (COD) and color removal of 80% and 90% (175 platinum−cobalt units (PCU)), respectively. The chemical dissolution of iron was strongly influenced by pH0. Electrochemical treatment at higher pH0 (pH0 ≥ 9) increases the dissolution of iron electrodes by an order of magnitude. At the optimal current density, the iron electrode consumed is 31.27 g/m2·h, achieving maximum COD removal. An increase in salinity reduces the treatment time significantly, and the sludge settling characteristics also improve. The addition of polyacrylamide (10 mg/dm3) to the electrochemical reactor enhances the COD removal rate with a very short treatment time with excellent slud...

The paper used as a printing substrate in electro photographical techniques should achieve appropriate structure, surface and optical properties as well as thermal stability. Printing products are often exposed to negative influence from external climate conditions. Surface treatment with varnishing and lamination is a common solution for protecting the final products against light, higher temperatures and elevated relative humidity. In the context of the applied research done in cooperation with the printing industry we studied permanence and durability of paper, image of prints and final printed product. We were also examining the influence of accelerated artificial ageing of paper and colour prints in electro photographic printing technique (Xeikon), with two types of surface treatment on the quality of the printed products. Determination of basic physical, chemical and surface characteristics (mechanical strength, optical and colorimetric characteristics of paper) as well as the evaluation of permanence according to EN ISO 9706 (∞) have shown unsuitable optical and colorimetric properties of paper. The evaluation of durability of paper and prints after accelerated artificial ageing according to the EN ISO 5630-3 standard indicates unsuitable optical and colorimetric properties, which consequently cause low optical and colorimetric stability. Colour prints with a surface protection of polymer varnish or foil protection are very unstable, causing deterioration of colour, contrasts and colour balance. The results of research work are very useful for the evaluation of durable printing paper used for various new digital printing systems and for evaluation of printing material of permanent quality.

Paper mill sludge (characterized by 29.0% of organic substances such as cellulose, lignin and tannins and 71.0% of inorganic substances such as kaolinite and carbonates) was studied in a mixture with soil in order to evaluate its effects on soil capability for retaining heavy metals. Attention was focused on cadmium and lead sorption and two parameters were investigated, the contact time of paper mill sludge–soil mixture and the paper mill sludge–soil ratio in the mixture. Results showed that paper mill sludge and soil interact to form ‘new’ sorbing sites. Taking into account sorption results of lead, the retention of which by soil is substantially increased by sludge addition, can highlight this modification. Also, the amount of sorbed cadmium was increased by sludge addition.

We have been investigating zeolite synthesis from paper sludge (PS) ashes. This technique is essential from the viewpoint of recycling of wasting materials.In our previous study, the PS ashes from 20 paper mills in Fuji area of Shizuoka Pref. were examined on suitability for starting materials in the zeolite synthesis, and they were classified into 4 types of compositional ranges in terms of talc-kaolinite-calcite composition ; that is, ranges (A) and (B) were suitable for the zeolite synthesis and ranges (C) and (D) were not suitable.In this study, we selected representative 4 mills that had discharged PS corresponding to the above 4 types of compositional ranges, and the chemical and mineralogical compositions of PS from these 4 mills were analyzed for 5 days. As a result, the following conclusions were obtained.The PS samples from the mills that had initially discharged PS belonged in the ranges (A) and (B) did not change into the ranges (C) and (D) for the period of 5 days. The samples belonged in (A) and (B) showed again being suitable for the zeolite synthesis.PS discharged from a paper mill that makes products including a lot of kaolinite is suitable for the zeolite synthesis. However. PS containing too much calcite is not suitable.

Synthetic thickeners, either polyacrylate or associative types, have been extensively used in paper coating. However, systematic research on the effect of these thickeners on coated paper surface structure in the presence of plastic pigment is still inadequate. In the current work, we compared and contrasted several commercial plastic pigments (PP), focusing on two hollow sphere and two solid bead plastic pigments having various particle sizes. Two types of polymeric thickeners were also selected, and their influence on the roughness and surface structure of coated paper were investigated. The results confirmed that the incorporation of plastic pigment in the clay coating mixtures resulted in a substantial decrease in the roughness of coated paper. The effect was particularly pronounced with hollow sphere plastic pigments. The addition of polymeric thickeners further reduced the roughness of the coated paper, for both clay/PP and ground calcium carbonate/PP systems. In coating mixtures based on clay, it w...

The first part of this paper analyses the influence of the molecular weight and concentration of carboxymethyl cellulose (CMC) and of kaolin concentration on rheology of the coating colours and on paper properties coated with ultra lightweight coatings (ULWC). In the second part, relationships between the rheological characteristics of the coating colour formulations and coated paper surface quality was also studied. New indexes on paper roughness at micro-scale are presented (RZI and SRI). In general, they show good correlation with sheet gloss. A new gloss index (SGI) is presented, accounting for the contribution of gloss from machine direction (MD) and cross direction (CD). Porosimetry was used to access microstructural characteristics in order to correlate them with light scattering and gloss properties. The former property is closely related to Hg intrusion volume of the coated layer while gloss is related to surface porosity with pore diameters in the range of 7–15 μm as measured by Hg intrusion volume.

High-yield bagasse pulp was prepared by mechanical treatment after soaking in cold 10% sodium hydroxide. One-, two- and three-stage bleaching of the pulp were investigated by using hydrogen peroxide (P) and/or sodium dithionite (D), in different sequences. Paper sheets were prepared and tested for the strength properties and brightness value. The effect of ageing on paper properties and brightness was investigated. It was found that three-stage bleaching by using two steps with hydrogen peroxide and one step with sodium dithionite provides the optimum bleaching results with regard to the strength properties and the brightness values. Comparable results were also obtained after paper ageing. The best bleaching sequence is PPD followed by DPP and then PDP.

Concentrated aqueous solutions of pH-neutral salts were evaluated for their effectiveness at deacidifying photo-oxidized filter paper. Short immersions in these solutions successfully neutralized acidic paper sheets. However, subsequent rinses to remove excess salt were necessary to prevent yellowing upon thermal aging. Sheets treated with concentrated solutions of calcium chloride showed no significant chemical damage from the treatment and deteriorated more slowly during thermal aging compared with untreated sheets. Sample papers that were given a dilute alkaline rinse after the concentrated salt treatment degraded less upon thermal aging than papers treated with either solution alone. This method of neutral deacidification was also evaluated for use prior to chemical reduction of oxidized paper with sodium borohydride. A treatment procedure involving steps of deacidification, chemical reduction, and alkalization was found to greatly stabilize photo-oxidized papers against thermal aging, as well...

A reference collection of mostly 20th-century photographic paper was surveyed for the presence of optical brightening agents. Only fiber-based, gelatin silver paper was assessed. In all, 1,804 samples were examined, dating from 1896 to 2004 and representing 40 different manufacturers. No optical brightening agents were found in samples dating from 1896 to 1949. The first occurrence of optical brightening agent was found in samples dating between 1950 and 1954. Between 1955 and 1964, the frequency of occurrence for optical brightening agents increased rapidly. Toward the latter part of this date range the occurrence of optical brighteners rose, with 70% of all samples showing brighteners. Between 1965 and 1979, occurrence of optical brightening agents declined to a low of 39% of all samples. A marked increase in occurrence was observed after 1980, when 81% of samples exhibited optical brightening agents. These results indicate that a significant proportion, and for some time periods a significant m...

In this study a model for the drying process in paper production plants was developed based on the mass and heat balances around drying cycles. Relationships for the heat transfer coefficients between the web and the air as well as between the drying cylinder and the web were extracted from the closed-loop plant operation data. It was found that the heat transfer coefficients could be represented effectively in terms of moisture content, basis weight and reel velocity. The effectiveness of the proposed model was illustrated through numerical simulations. From the com- parison with the operation data, the proposed model represents the paper plant being considered with sufficient ac- curacy.