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Additives in the Paper Industry
Abstract
An overview of the paper sector from the point of view of additives use is presented. In the first section, the general trends
of the sector concerned in terms of world production and trade flows are reviewed together with an overall description of
the main characteristics of the production process, including pulp production and paper manufacturing and finishing. The second
part is focused on the description of the different additive classes used to provide paper with the required functional characteristics
and to facilitate and improve the production process as well, namely, retention aids, sizing agents, binders, wet strength
agents, coating agents, optical brightener agents, biocides and dyes. Main compounds or compound families within each additive
class are listed, and some related information regarding their function, world consumption and environmental potential impacts
is also included.
KeywordsAdditives–Binders–Biocides–Optical brighteners–Paper
... However, commercially available cellulose papers that might contain additives were used in this study. Examples of chemical additives used in paper production are binders, sizing agents, coating aids, strength agents (wet and dry), biocides, optical brighteners, and colorants [13]. These additives have the potential to interfere with microbial activity. ...
Natural rubber latex (NRL) is a green and highly potential material for various rubber product applications such as tyres, belts, gloves, and foams. To enhance its application, NRL requires rubber chemicals and other additives to improve its processibility and properties. Epoxidised natural rubber (ENR) is a unique polymer generated through the epoxidation process that replaces the double bonds in the NR polymer chain with an epoxy group. There is a potential to use ENR in its latex form (ENRL) to produce dipped products. One of the vital factor to indicate ENRL suitability for producing dipped products is its biodegradability. This work investigates the biodegradability of ENRL films in a controlled composting environment under laboratory conditions. The degree of biodegradation is measured based on evolved carbon dioxide produced by microorganism activities in aerobic condition. The influence of microbial population on the biodegradation and mineralization rate of ENRL films in the composting environment is discussed. The morphological and chemical changes of the ENRL films were observed and analyzed using scanning electron microscopes, Fourier-transform infrared spectroscopy, gel permeation chromatography and weight loss. Results obtained from this study can be used to predict the preliminary biodegradation rate of ENRL films.
... A significant component of the paper is coating pigments (4%) and chemical additives (3-8%), whose use depends on the grade of the paper [38]. Printing is also the source of trace elements in waste paper. ...
The use of waste from the regional production of waste wood, waste paper, and cardboard in the form of briquettes may be causing an increase in local emissions, both of major elements and trace elements. When burning paper and cardboard briquettes, more than 70% of Mn, Zn, As, and Pb is released into the air from the total content of trace elements in the fuel. The largest amounts of major and trace elements are released when burning paper briquettes (56 g/kg of fuel); half of these amounts are released from burning briquettes from waste wood and coal (23 g/kg of fuel). The pursuit of alternative uses for those cardboard components that are not suitable for recycling cannot be directed to the production of briquettes for residential combustion in the framework of the application of the principles of the circular economy. In particular, the high concentrations of undesirable elements in the emissions released in the gas phase into the atmosphere are an obstacle existing even when the parameters of the PM10 emissions of a boiler are met. This is related to the high ash content of the cardboard (13.5%). Waste paper or cardboard could be added to waste wood at a maximum of 10% to make the pollution produced comparable to the burning of coal briquettes.
... The study also showed that unconverted board made from recycled paper and intended for food packaging may contain DIPN ranging from 11 to 27 mg/kg. Although, since the early 1990s, restrictions in developed countries on the use of elemental chlorine in the paper bleaching process have lowered the possibility of dioxin and furan formation ( Ginebreda et al., 2012), these substances may still be detectable in paper products and other papermill outputs, albeit at very low levels ( Latorre et al., 2005). The presence of dioxins and furans estimated in papermill effluent waters was in the range of approximately 1-10 ng/m 3 ( Latorre et al., 2005), while Munawar et al. identified both in lake sediments near pulp and papermill facilities ( Munawar et al., 2000). ...
Paper product manufacturing involves a variety of chemicals used either directly in paper and pulp production or in the conversion processes (i.e. printing, gluing) that follow. Due to economic and environmental initiatives, paper recycling rates continue to rise. In Europe, recycling has increased by nearly 20% within the last decade or so, reaching a level of almost 72% in 2012. With increasing recycling rates, lower quality paper fractions may be included. This may potentially lead to accumulation or un-intended spreading of chemical substances contained in paper, e.g. by introducing chemicals contained in waste paper into the recycling loop. This study provides an overview of chemicals potentially present in paper and applies a sequential hazard screening procedure based on the intrinsic hazard, physical-chemical and biodegradability characteristics of the substances. Based on the results, 51 substances were identified as potentially critical (selected mineral oils, phthalates, phenols, parabens, as well as other groups of chemicals) in relation to paper recycling. It is recommended that these substances receive more attention in waste paper.
Copyright © 2015 Elsevier Ltd. All rights reserved.
Recent efforts on the expansion of sustainable and commercial primal matters are essential to enhance the knowledge of their hazards and noxiousness to humans and their environments. For example, polysaccharide materials are widely utilized in food, wound dressing, tissue engineering, industry, targeted drug delivery, environmental, and bioremediation due to their attractive degradability, nontoxicity and biocompatibility. There are numerous easy, quick, and efficient ways to manufacture these materials that include cellulose, starch, chitosan, chitin, dextran, pectin, gums, and pullulan. Further, they exhibit distinctive properties when combined favourably with raw materials from other sources. This review discusses the synthesis and novel applications of these carbohydrate polymers in industrial, environmental and biomedical sciences.
The paper tissue industry is a constantly evolving sector that supplies markets that require products with different specific properties. In order to meet the demand of functional properties, ensuring a green approach at the same time, research on bio-coatings has been very active in recent decades. The attention dedicated to research on functional properties has not been given to the study of the morphological and mechanical properties of the final products. This paper studied the effect of two representative bio-based coatings on paper tissue. Coatings based on chitin nanofibrils or polyphenols were sprayed on paper tissues to provide them, respectively, with antibacterial and antioxidant activity. The chemical structure of the obtained samples was preliminarily compared by ATR-FTIR before and after their application. Coatings were applied on paper tissues and, after drying, their homogeneity was investigated by ATR-FTIR on different surface areas. Antimicrobial and antioxidant properties were found for chitin nanofibrils- and polyphenols-treated paper tissues, respectively. The mechanical properties of treated and untreated paper tissues were studied, considering as a reference the same tissue paper sample treated only with water. Different mechanical tests were performed on tissues, including penetration, tensile, and tearing tests in two perpendicular directions, to consider the anisotropy of the produced tissues for industrial applications. The morphology of uncoated and coated paper tissues was analysed by field emission scanning electron microscopy. Results from mechanical properties evidenced a correlation between morphological and mechanical changes. The addition of polyphenols resulted in a reduction in mechanical resistance, while the addition of chitin enhanced this property. This study evidenced the different effects produced by two novel coatings on paper tissues for personal care in terms of properties and structure.
The furnish management of tissue materials is fundamental to obtain maximum quality products with a minimum cost. The key fiber properties and fiber modification process steps have a significant influence on the structural and functional properties of tissue paper. In this work, two types of additives, a commercial biopolymer additive (CBA) that replaces the traditional cationic starch and micro/nanofibrillated cellulose (CMF), were investigated. Different formulations were prepared containing eucalyptus fibers and softwood fibers treated mechanically and enzymatically and both pulps with these two additives incorporated independently and simultaneously with drainage in the tissue process range. The use of these additives to reduce the percentage of softwood fibers on tissue furnish formulations was investigated. The results indicated that a maximum of tensile strength was obtained with a combination of both additives at the expense of softness and water absorbency. With a reduction of softwood fibers, the incorporation of additives increased the tensile strength and water absorbency with a slight decrease in HF softness compared with a typical industrial furnish. Additionally, a tissue computational simulator was also used to predict the influence of these additives on the final end-use properties. Both additives proved to be a suitable alternative to reduce softwood fibers in the production of tissue products, enhancing softness, strength and absorption properties.
Environmental risks connected with the combustion of paper/cardboard briquettes are still not sufficiently known. This paper aims to bring attention to the risks related to the utilisation of paper briquettes in local boilers and to characterise these risks by means of the identification of organic compounds in deposits from exhaust flues. The identification of the chemical compounds was performed by pyrolysis gas chromatography with mass spectrometric detection.
Paper/cardboard briquettes contain 119 compounds of biogenic origin derived from major biomass components and 53 additives. Additives are used both for improving the properties of paper and in printing inks. By burning the paper briquettes, the same 53 compounds from the additive group were caught in the deposits from the flue gas pathway, occurring in the range of 1-10% of the concentration of individual compounds (additives) contained in the input fuel. Compounds that are very stable during the combustion process have an enrichment factor (EF) > 30, which corresponded to approximately 3% of the additive capture in deposits. The highest values were found for plasticisers (phthalates). Many of the primary organic compounds contained in the input raw material do not decompose during combustion and can have adverse effects on human health.
The advent of food contact material made from oil palm empty fruit bunch (EFB) fiber serves as a biodegradable alternative to petrochemical-based materials. This material needs to be tested according to strict regulations for its compliance as a food contact material. Present work aims to determine the presence of chemical contaminants in the EFB tray as compared to commercially available bagasse fiber-based tray and recycled Kraft fiber-based tray. The chemical contaminants were detected, and their levels were compared to the established limits. Gas Chromatography-Electron Capture Detector (GC-ECD) was used to detect and quantify Polychlorinated Biphenyls’ (PCBs) presence in all fiber-based trays. Meanwhile, the presence of phthalates, benzophenone, and 4-methylbenzophenone was quantified by means of Gas Chromatography-Mass Spectrometry (GC–MS). The levels of mercury in fiber-based trays was measured by Atomic Absorption Spectroscopy (AAS) and the levels of lead and cadmium was measured by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). Additionally, formaldehyde migrated to aqueous extracts from fiber-based trays at two conditions (cold and hot) was determined by an ultraviolet-visible (UV–vis) spectroscopy. Each fiber-based tray exhibited different innate chemical contaminants. Fortunately, most of the contaminants identified in the EFB fiber-based tray were found at trace levels. Unexpectedly, the migrated formaldehyde level found in hot water extract of recycled Kraft fiber-based tray was the highest and exceeds the limit set in Commission Regulation (EU) No 10/2011, which is at 15 mg/kg of simulant. The results implied that the EFB fiber-based tray was inert and suitable for its application as food contact material.
Littering represents an ecological threat. To date, studies have mainly focused on the formation and quantification of microplastics. Toxicity has generally been considered from the point of view of food safety rather than from an environmental viewpoint. There is an urgent need to develop a framework approach to assessing the ecological hazards associated with litter, particularly packaging litter. In fact, measuring the ecological impacts of packaging and single-use items is clearly a prerequisite for developing a control and mitigation strategy of accidental waste leakage. This study proposes a characterization methodology for the assessment of the ecological hazard of packaging and single-use items made with any material in the event of littering. This preliminary methodology is based on four aspects of ecological hazards: the migration of persistent ecotoxic chemicals by diffusion (type 1); the release of persistent ecotoxic chemicals after degradation (type 2); the physical persistence of the packaging (type 3); and the release of persistent micro-particles due to wear (type 4). A compostable shopping bag was tested using this classification in order to create a preliminary hazard profile. The bag released substances (6-7% of its mass) when soaked in water in less than three days. This leachate showed a high level of biodegradation and caused no adverse effects on germination and root development of cress seeds. The bag, tested according to the EN 13432 standard, does not cause ecotoxic effects after biodegradation when analysed with a plant growth test. The bag fragmented in soil and disappeared in 500 days. The bag, ground to microplastics, showed biodegradability when exposed to soil, with a half-life of 118 days.
Renewable and bio-based materials have gained great interest on an industrial scale owing to environmental issues. Paper industries also are constantly exploring bio-resources for intrinsic chemico-physical property en- hancement of paper and paper products. These bio-resources will potentially increase their cyclability besides making paper compatible beyond traditional uses. Mechanical beating or use of chemical additives or the com- bination of these methods are widely used to improve critical paper characteristics such as strength, surface smoothness, density, brightness, filler retention, water and grease resistivity etc. These chemical additives as mill effluents are hazardous and have detrimental effect on environment. So, to move ahead of traditional practices, the present review discusses about the production and utility of abundantly available renewable bio-polymers and their products such as starch, cellulose, plant-based proteins, microbial biopolymers, animal-based biopolymers, and natural gums etc. They represent ample prospect in terms of research and development on their functionality and industrial applications.
In recent years, the Antarctic territory has seen a rise in the number of tourists and scientists. This has led to an increase in the anthropogenic footprint in Antarctic ecosystems, namely in terms of emerging contaminants, such as Biocides, Persistent Organic Pollutants (POPs) as well as Pharmaceutical and Personal Care Products (PPCPs). Yet scarce information on the presence of these emerging contaminants is available for trophic compartments, especially the phytoplankton community. Using high resolution Fourier-transform ion cyclotron-resonance mass spectrometry (FT-ICR-MS), an untargeted screening of the metabolome of the phytoplankton community was performed. Seventy different contaminant compounds were found to be present in phytoplankton collected at two sites in Port Foster Bay at Deception Island. These emerging contaminants included 1 polycyclic aromatic hydrocarbon (PAH), 10 biocides (acaricides, fungicides, herbicides, insecticides and nematicides), 11 POPs (flame retardants, paints and dyes, polychlorinated biphenyl (PCB), phthalates and plastic components), 5 PCPs (cosmetic, detergents and dietary compounds), 40 pharmaceutical compounds and 3 illicit drugs. Pharmaceutical compounds were, by far, the largest group of emerging contaminants found in phytoplankton cells (anticonvulsants, antihypertensives and beta-blockers, antibiotics, analgesic and anti-inflammatory drugs). The detection of several of these potentially toxic compounds at the basis of the marine food web has potentially severe impacts for the whole ecosystem trophic structure. Additionally, the present findings also point out that the guidelines proposed by the Antarctic Treaty and Protocol on Environmental Protection to the Antarctic Treaty should be revisited to avoid the proliferation of these and other PPCPs in such sensitive environments.
In accordance with global estimations, approx. 15 million tons of residues are yearly generated from paper and pulp industry, which are traditionally used as biofuels or just disposed in landfills. However, residues composition and laws in force urge producers to search for new waste management strategies. From another point of view, the construction industry uses more than 33% of total natural resources, worldwide which has led several governments to limit the use of natural raw materials for building. In particular, fired brick industry produces yearly approx. 1600 billion bricks which represents millions of tons of natural resources consumption. Therefore, the goal is to contribute to reduce the amount of used clay. Thus, this paper explores the mineral and technological properties of brick made by using different percentages of paper pulp residues and fired at 900 °C. Results indicate that by increasing the replacement ratio, blend requires larger amounts of water which leads to a proportional increasing of shrinkage during drying. In spite of mineral transformations are not influenced by paper pulp residue, the porosity is linearly increased which leads to reduce compressive strength and thermal conductivity up to 30% for 20% of replacement ratio, in both cases. Thus, it is concluded that series made by replacing up to 10% show compressive strength above 5 MPa, water absorption beyond 20% and toxicity indexes meet the mandatory requirements.
An investigation of the hydrolysis of diluted alkyl ketene dimer (AKD) dispersion was carried out under different conditions from which a kinetic model for predicting the AKD hydrolysis during its storage and papermaking process was proposed. As observed, the higher pH, elevated temperature, and longer time can accelerate the hydrolysis of AKD in the water medium. The results showed that the proposed model could provide a satisfactory description of AKD hydrolysis at various conditions, in which the R‐squared of the correlation coefficient (R2) between the measured and predicted data was 0.978. Based on this model, a successful controlling strategy aimed at optimizing the chemical efficiency in the practical application can be determined. This article is protected by copyright. All rights reserved
The present study focused on the combustion of four types of briquettes made from paper and cardboard waste produced in Ouagadougou (Burkina Faso). Rotary and tubular kilns were used to study the combustion. The combustion mean temperatures, nitrogen, phosphorus and potassium (NPK) content in the ash and heavy metals content in the ash and the flue gas were analyzed. The combustion steady phase mean temperatures ranged from 950 °C to 750 °C were obtained according to briquettes type. The temperature favored the transfer of the heavy metal in the flue gas comparatively to the ash mainly for Hg, Cd and Pb. The Pb, Hg and Mn content in flue gas and the ash are higher than their content in the parent wood used for paper production due to the additive during the manufacturing process. The results showed a high content of heavy metal in flue gas produced by combustion of briquette made with office paper and in the ash for the briquette made of corrugated cardboard. Furthermore, the low heavy metal contain in the ash allow their use for soil amendment. However, ash contained a low proportion of NPK (less than 2%) which does not allow their usage as fertilizer alone.
Recycled paper is an important raw material to provide sustainability of natural resources and reduce the environmental impact of the use of paper from recycled pulp in the packaging industry. Hence, recycled paper production is higher in terms of volume and utilization. Recycled paper products are used in the packaging industry partially or fully. Such usage leads to the presence of heavy metals due to recycled and chemical additive sources. The present study aims at determining the amounts and also identifying the sources of heavy metals such as Pb, Cd, Zn, Ni, and Cu contained in recycled testliner (TL) and fluting (FLT), which are main products used in production of corrugated cardboard. The metals in the structure of the paper used in packages directly or indirectly in contact with foods are heavy metals. Mean values of 2.6 mg kg⁻¹ Pb (lead), 2.8 mg kg⁻¹ Zn (zinc), 0.094 mg kv Cd (cadmium), 1.8 mg kg⁻¹ Ni (nickel), and 25.4 mg kg⁻¹ Cu (copper) were detected in test liner and fluting papers using inductively coupled plasma optical emission spectrometry (ICP-OES). The main sources of heavy metals are colorants, mainly consisting of conventional paint and pigments as well as spot and Pantone Matching System (PMS) colorants.
Information security has attracted broad attention in today’s information age, and information encryption on paper has been widely studied since paper is still the most important information carrier. Fluorescent inks are commonly used in information encryption on paper, but they suffer from background fluorescence interference. Herein, we develop a background-free and easy-performed method for information encryption based on inkjet printing of upconversion nanoparticles (UCNPs). The UCNPs can efficiently eliminate background fluorescence interference since phosphors in paper cannot be activated by near-infrared (NIR) light. Moreover, owing to their small size, excellent dispersibility and good stability, UCNPs inks can be directly applied to commercial inkjet printers for convenient and high-throughput information encryption on paper. Information was easily printed on different kinds of paper substrates and the information can only be visualized under NIR light excitation. Furthermore, a novel information encryption strategy was designed by utilizing UCNPs with different excitation wavelengths. Only excitation at defined wavelength can obtain the correct information. This proposed information encryption strategy can completely avoid background fluorescence interference, and it also features easy operation, high throughput as well as low costs, indicating its good promise to serve as a household encryption method in our daily life.
This study demonstrated a headspace gas chromatographic (HS-GC) method for the determination of residual epichlorohydrin (ECH) and the by-product 1,3-dichloro-2-propanol (DCP) in polyamine epichlorohydrin (PAE) solution. It was based on the vapor-liquid phase equilibrium of these analytes at 60 °C for 30 min in a closed headspace sample vial before GC measurement. It was found that matrix of the PAE solution had the effect on the headspace equilibrium of these species and therefore a standard addition must be applied in the method validation. The results showed that the present method has a good measurment precision (RSD <2.90%) and accuracy (recoveries from 93.6 to 105%), and the limit of quantitation (LOQ) is 3.75 mg/L for ECH and 0.8 g/L for DCP. The present method is suitable to be used for analyzing the chlorinated volatile organic compounds in the commercial PAE resin solutions.
3-Monochloro-1,2-propandiol (3-MCPD) is a carcinogenic food contaminant. 3-MCPD is formed during food processing, and can also be derived from food contact packaging materials, including paper. Wet-strength resin is often added into paper food packaging to provide moisture resistance and thus enhancing food shelf-life and consumer usage. The wet-strength resins which are manufactured from epichlorohydrin-based starting materials, are known to initiate the formation of 3-MCPD. Thus, the objectives of this study were: 1) to validate an analytical method for the analysis 3-MCPD in duplex paper packaging, 2) to analyze3-MCPD content in duplex paper, and 3) to analyze 3-MCPD migration from duplex paper packaging into food simulants. 3-MCPD content in duplex paper was analyzed by a validated GC-MS method with linearity value (R 2 ) of 0.993, limit of detection (LOD) of 6.65 ppb, limit of quantification (LOQ) of 22.15 ppb, and recovery range of 83.00–114.13%. The 3-MCPD content of five sample duplex papers obtained from different packaging paper manufacturers were ranging from 753.43 to 825.36 ppb, and there was no significant differences between the samples. Direct contact between food simulants and duplex paper for 24 hours at 40°C generated migration of 3-MCPD at levels of 40.55 to 57.61%.
The paper industry is one of the most significant industrial branches that contributes to water pollution. Recent studies regarding the chemical composition of wastewaters from modern paper production sites are sparse, and organic contaminants originating from this source may remain undetected and uncontrolled. Therefore, for this study, non-target screening analyses of wastewaters from five different paper production sites were performed, including an extended analysis of one facility, for the identification of volatile non-polar to semi-polar organic contaminants. The identified contaminants were also traced in the adjacent river. Several specific agents related to paper production, including photoinitiators, ink and thermal paper constituents, were present in most wastewaters and were therefore considered to be characteristic paper industry contaminants. A couple of contaminants identified in this study are being reported for the first time and might be toxic, but have been neglected in previous studies. Bisphenol A and 2,4,7,9-tetramethyl-5-decyne-4,7-diol were found in untreated wastewaters, treated wastewater and in river water. Bisphenol A was present in river water downstream from where the paper industry discharges at a concentration that was reported to affect the reproduction of gastropods. Thus, our findings imply that paper industry discharges pose a risk to the populations of sensitive macroinvertebrates.
Copyright © 2015 Elsevier B.V. All rights reserved.
The delignification efficiency of different laccase enzymes was examined on the eucalyptus Kraft pulp. The laccase enzyme from Trametes versicolor showing the highest delignification efficiency was selected and used in the elemental chlorine-free bleaching sequence for improving the pulp bleachability. An appreciable reduction in chlorine dioxide consumption was also obtained. Further reduction in chlorine dioxide consumption was obtained when the same laccase treated pulp was subjected to an acid treatment after the extraction stage followed by the DEPD sequence. Elemental-chlorine free bleaching was also performed using the xylanase-laccase treated pulp. Xylanase treatment was incorporated to the laccase mediator system in the elemental-chlorine free bleaching both sequentially and simultaneously. The bleaching sequence DEPD followed and in both the cases, the reduction in chlorine dioxide consumption was greater in comparison to the control. The chlorine dioxide consumption was reduced further when xylanase-laccase treated pulp was given an additional acid treatment. The final pulp properties of the treated pulps were comparable to the control pulp.
The decorative laminates industry is a highly competitive industrial sector. To be profitable,
manufacturers of impregnated papers for surface laminated MDF and particleboards need to significantly reduce
their production costs. Melamine formaldehyde resin (MF) formulations are commonly used for impregnation
and coating of such papers, melamine being an important, but costly raw material used in high quantities.
While MF is substituted by cheaper urea formaldehyde resins (UF) in the core impregnation, for paper surface
films pure MF is used. Therefore, a further reduction in cost could be achieved if a portion
of the melamine in the surface film was replaced by urea. In the present contribution, recent results of
technological tests on paper laminates using a novel melamine–urea–formaldehyde resin (MUF)
formulation are reported and their performance is compared to traditional surfaces made from MF.
In this study a rapid at-line ATP (adenosine triphosphate) analysis is applied in papermaking. This ATP analysis takes less than a minute, and the information can be utilized instantly to adapt the biocide program. The study shows the effect of different biocide strategies at paper mills. Comparison is made between oxidative and reductive biocides on the one hand, and on the other hand between continuous vs. batch additions of biocide. Continuous biocide addition keeps the microbial activity at a constant level. However, a long production period without a boil-out might result in accumulation of resistant bacteria, which cannot be eliminated without changing the biocide strategy. Batch addition of biocide creates a high temporary concentration of biocide in the process. This causes lower temporary microbial activity in the process, but between the doses the microbial activity may rise to an intolerable level. Batch addition causes chemical variation to the wet end of a paper machine more easily than continuous addition. This can affect the performance of papermaking chemicals and cause problems with retention, fixing, etc. Both biocide addition strategies can be used if they are monitored and optimized properly. Rapid ATP analysis is a suitable tool for both purposes.
Retention aids can be defined as very-high-mass, water-soluble polymers that are added to cellulosic fiber slurries before the formation of paper in order to improve the efficiency with which fine particles, including cellulosic fines, are retained in the paper product. Optimization of retention aid performance can be a key to achieving efficient and environmentally responsible papermaking objectives. This article reviews various published theories related to retention aid use. Findings related to three main classes of retention aid polymers are considered: cationic acrylamide copolymers (cPAM), anionic acrylamide copolymers (aPAM), and polyethylene oxide (PEO). While many aspects of the interactions of each of these classes of retention aid products can be understood based on colloid chemistry principles, further research is needed in order to more fully bridge the gap between theory and practice.
This review considers research related to internal sizing agents. Such chemicals, when added as emulsions or in micellar form to slurries of cellulosic fibers before paper is made, can make the product resist water and other fluids. Significant progress has been achieved to elucidate the modes of action of alkylketene dimer (AKD), alkenylsuccinic anhydride (ASA), rosin products, and other sizing chemicals. Recent findings generally support a traditional view that efficient hydrophobation requires that the sizing chemicals contain hydrophobic groups, that they are efficiently retained on fiber surfaces during the papermaking process, that they become well distributed on a molecular scale, and that they need to be chemically anchored. A variety of studies have quantified ways in which internal sizing treatments tend to be inefficient, compared to what is theoretically possible. The inefficient nature of chemical and physical processes associated with internal sizing, as well as competing reactions and some interfering or contributing factors, help to explain apparent inconsistencies between the results of some recent studies.
What is the best way to minimize the environmental impact of using a product such as paper? Three debating teams were formed within a university class. One team advocated increased recycling of paper. Another team pointed to evidence showing reduced environmental impact and lower net CO2 emissions if the paper is incinerated rather than recycled. A third team advocated the replacement of paper by items such as porcelain plates and video screens, cutting costs and reducing waste by multiple reuse.
Samples of effluents, sludge, pulp, final products (paper) and soil were collected from the identified pulp and paper mills in India. The samples were analysed for 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) and other dioxin congeners and precursors. Pulp and paper mills using chlorine for the bleaching process showed the presence of 2,3,7,8-TCDD in effluent samples. In the effluent and pulp samples from mills where chlorine dioxide was used as a bleaching agent, the 2,3,7,8-TCDD congener ranged from below the detection limit 0.05 to 0.12 ngL(-1)/ngg(-1). The relative standard deviation of reproducibility and the percent recovery of 2,3,7,8-TCDD were 2.07 and 82.4% in pulp and 2.8 and 92% in effluent, respectively. The 1,3,6,8-TCDD was the only other major dioxin congener found in the treated and untreated effluent and sludge samples. However, dichlorobenzene, trichlorophenyl, and hexachlorobiphenyl were detected in all samples. The formation of dioxins can be minimised by replacing chlorine with chlorine dioxide in bleaching processes in pulp and paper mills.
Alkenyl succinic anhydride (ASA) was added to the agents that would increase the resistance of cellulose fibers to the adsorption of water under neutral/alkaline conditions (at pH's in the range of 7.5-8.5) in the 1960's by O. Wurzburg and E. Mazzerella of the National Starch and Chemical Company [1]. The sodium salt of ASA can be complexed with alum in a similar manner to resin acids to size in acid papermaking. Furthermore, commercial ASA products are also being used in acid papermaking, pH 4.5-6.5, in the manufacture of recycle linerboard, fine paper, roofing and molded products. The development of ASA gave papermakers an alternative to AKD (alkyl ketene dimer), a product that had been developed by C. Weissgerber of Hercules Chemical Company [2]. Both materials are applied to cellulose fibers in the form of cationic dispersion prior to the fibers being formed into a web, pressed and dried. The two sizing agents have helped papermakers make the transition from acid papermaking using clay as the primary pigment to neutral/alkaline papermaking using calcium carbonate.
We measured wet-strength and dry-strength properties of newsprint impregnated with polymers in the polyvinylamine family. Polyvinylamine is a recently commercialized polymer with the potential to increase the tolerance of wood-containing papers to water-based printing processes. Poly(N-vinylformamide) (PNVF), the precursor to polyvinylamine (PVAm), increased dry strength but not wet strength. Both PVAm and partially converted PNVF-co-PVAm copolymers increased both wet strength and dry strength dramatically. Over the range of 56% to 100% conversion of PNVF to PVAm, there was little difference in the wet strength of the resulting paper. The wet strength of PVAm-impregnated newsprint was a little higher at pH 10 than at lower pH values. Drying at 120°C gave only slightly higher wet strength than did drying at room temperature.
This article reviews the chemistries of wet-strength additives, examines the mechanisms proposed for wet-strength development, and discusses the methods used to deduce these mechanisms. Among the acid-curing resins, urea-formaldehyde resins appear to impart wet strength only by self-crosslinking, while melamine-formaldehyde resins also seem to crosslink the cellulose directly. Among neutral/alkaline-curing resins, azetidinium resins (comprising most polyamide-epichlorohydrin resins) react with cellulose carboxylate groups. At higher addition levels, self-crosslinking becomes more significant. Epoxide resins react analogously and also with the hydroxyl groups of cellulose. Aldehyde resins crosslink cellulose reversibly through hemiacetal bonds, with self-crosslinking through the amide groups also a likely possibility, at least among polyacrylamide-glyoxal resins. For polyethyleneimine, no mechanism suggested so far seems satisfactory.
Decrease of adsorbable organic chlorine (AOX) is becoming the most important criterion for the efficiency of pulp mill effluent treatment in the 1990s. Two methods, designated MYCOR and MYCOPOR which utilize the white-rot fungus Phanerochaete chrysosporium have earlier been developed for the color removal of pulp mill effluents, but the processes have also a capacity to decrease the amount of chlorinated organic compounds. Lignin peroxidases (ligninases) preduced by P. chrysosporium may dechlorinate chlorinated phenols. In this work possibilities to use selected white-rot fungi in the treatment of E1 -stage bleach plant effluent were studied. Phlebia radiata, Phanerochaete chrysosporium and Merulius (Phlebia) tremellosus were compared in shake flasks for their ability to preduce laccase, lignin peroxidase(s) and manganese-dependent peroxidase(s) and to remove color from a medium containing effluent. Softwood bleaching effluents were treated by carrier-immobilized P. radiata in 21 bioreactors and a 10 1 Biostat(R)-fermentor. Dechlorination was followed using Cl- ion and AOX determinations. All fungi removed the color of the effluent. In P. radiata cultivations AOX decrease was ca. 4 mg 1-1 in one day. Apparent lignin peroxidase activities as determined by veratryl alcohol oxidation method were negligible or zero in a medium with AOX content of ca. 60 mg 1-1, prepared using about 20% (v/v) of softwood effluent. However, the purification of extracellular enzymes implied that large amounts of lignin peroxidases were present in the medium and, after the purification, in active form. Enzyme proteins were separated using anion exchange chromatography, and they were further characterized by electrophoresis (SDS-PACE) to reveal the kind of enzymes that were present during AOX decrease and color removal. The most characteristic lignin peroxidase isoenzymes in effluent media were LiP2 and LiP3.
The behaviour of 4,40-diaminostilbene-2,20-disulfonate (DSD), a fluorescent whitening agent, in aqueous solution was investigated under
monochromatic irradiation (�irr: D 313, 334 and 365 nm) at room temperature; depending on the pH, two different behaviours were observed.
At pH � 4:2, with the predominant molecular form (DSD), only the photoisomerisation process occurs leading to a photostationary
state rich in cis-isomer, a non-emitting compound. At pH � 3:0, with the diprotonated form .DSDH2
2C
/, the photoisomerisation process
was followed by a slowphotodegradation of the resulting cis-isomer. For prolonged irradiation, the total disappearance of DSDH2 2C was observed. The nature of the photoproducts depended on the irradiationwavelength. The initial quantum yields ( ) of the direct trans–cis photoisomerisation were measured and the absorption spectra of the cis-isomers were calculated
A bleached softwood kraft pulp was treated with fluorescent whitening agentsTinopal UP and Leucophor AP under different conditions. The kinetics ofadsorption-chemical interaction between optical brighteners and pulp wasdescribed by an exponential kinetic equation. An entropy heterogeneity of thepulp surface related to the active sorption centers, their accessibility and theirspatial orientation was confirmed. The activation energy values obtained werefound independent of the brightener concentration and on the increase of pulpwhiteness. A decisive role of the entropy factors was ascertained.
In recent years, there has been considerable study on the environmental impacts of kraft bleached pulp mills on the aquatic environment. These studies have focused on the discharge and toxicity of chlorinated organic compounds of AOX. Data from Scandinavian and North American mills show that the discharge of polychlorinated organic compounds can be significantly reduced with modern bleaching and effluent treatment technologies. An important step is to reduce the use of elemental chlorine (Cl2) and to substitute other oxidizing agents, including, for example, chlorine dioxide, peroxide, and oxygen. These steps halt the formation of recently discovered by‐products such as dioxins, as well as other highly chlorinated materials. In certain circumstances (e.g., fluff pulp mills), total AOX discharges have been reduced by over 90%, to as little as 0.1 kg/t. Analyses of effluents from these facilities also show that, contrary to lay expectations, remaining chlorinated materials have low chlorine substitution, are water soluble (will not bioaccumulate), and are easily degradable. Chronic toxicity testing in both laboratory tests, as well as environmental models (e.g., mesocosms) demonstrate that these modern processes virtually eliminate toxic effects in the receiving waters. These multiple technologies are being rapidly implemented by most Scandinavian and North American mills.
Laboratory-scale biological treatment studies with bleached kraft mill effluents assessed and optimized the removal of chlorinated organic compounds as well as aquatic and microbial toxicity. Three conventional biological processes, namely activated sludge and two stabilization basin treatment systems, were compared under conservative conditions of elevated sludge age (i.e. 15–25days) and hydraulic retention times (i.e. 0.5–1day and 15days for the respective systems) as well as moderate temperatures for the treatment of softwood kraft bleachery effluents from a modernized mill using oxygen delignification and 60% chlorine dioxide substitution. Enhanced treatment performance was achieved with the optimized activated sludge, facultative stabilization basin and aerated stabilization basin processes as indicated by consistently high removals of conventional organic contaminants, polychlorinated phenolics (i.e. 85–93%), adsorbable organic halogen (i.e. 43–58%) and toxicity. The high level of polychlorinated phenolics removal was considered representative of an enhanced treatment capability for hard-to-degrade organics. The ultimate degree of biotreatability of various in-plant bleaching and non-bleaching process effluents from the kraft mill was also tested.
Biological treatment studies with bleached kraft mill effluents (BKME) assessed the removal of hepatic MFO induction potency towards fish. Bench-scale activated sludge, facultative stabilization basin, and aerated stabilization basin processes were compared under conservative conditions of elevated sludge age and hydraulic retention times as well as moderate temperatures for the treatment of bleachery effluents from a modernized bleached kraft mill using oxygen delignification and 60% chlorine dioxide substitution. Optimized treatment for the removal of hard-to-degrade organics also consistently removed more than 85–90% of effluent-induced MFO activity of fish, based on laboratory bioassays. Follow-up mill-site pilot scale testing with an activated sludge treatment process in extended-aeration mode also demonstrated >90% reductions in the MFO induction potential of whole mill effluent. Characterization of various in-plant process waters sampled at the mill indicated that the softwood-line bleach plant was a major contributor (>70%) to the MFO induction potential of untreated and biologically-treated BKME.
Copolymer latexes of styrene and acrylates (mainly butyl acrylate) were synthesized. Sodium dodecyl sulfate and ethoxylated nonyl phenol containing ten ethylene oxide units were used as surfactants, and potassium persulfate was used as initiator. Coating for paper was made based on the copolymer latexes with white pigments. The performances of coated paper were measured. By varying experimental conditions such as comonomer proportion and amounts of emulsifiers and of initiator, a copolymeric latex suitable for paper coating was prepared. Paper coated with the latex showed satisfactory properties in glossiness, smoothness as well as ink absorbability. Copyright © 1999 John Wiley & Sons, Ltd.
The behaviour of 4,4′-diaminostilbene-2,2′-disulfonate (DSD), a fluorescent whitening agent, in aqueous solution was investigated under monochromatic irradiation (λirr.=313, 334 and 365nm) at room temperature; depending on the pH, two different behaviours were observed. At pH≥4.2, with the predominant molecular form (DSD), only the photoisomerisation process occurs leading to a photostationary state rich in cis-isomer, a non-emitting compound. At pH≤3.0, with the diprotonated form (DSDH22+), the photoisomerisation process was followed by a slow photodegradation of the resulting cis-isomer. For prolonged irradiation, the total disappearance of DSDH22+ was observed. The nature of the photoproducts depended on the irradiation wavelength. The initial quantum yields (φ) of the direct trans–cis photoisomerisation were measured and the absorption spectra of the cis-isomers were calculated.
Fluorescent whitening agents (FWAs) used in laundry detergents were determined in aqueous samples from sewage treatment plants and rivers using solid-phase extraction (SPE) and high-performance liquid chromatography (HPLC) with post-column UV irradiation and fluorescence detection. FWAs were extracted from 10−200-mL water samples with C18 bonded- phase silica extraction disks and eluted with methanol-containing tetrabutylammonium ion-pairing reagent. No further sample cleanup steps were necessary due to the sensitive and selective fluorescence detection. Recovery of FWAs from raw sewage, primary effluent, secondary effluent, and river water ranged from 76 to 96%. The overall precision of the method, indicated by the relative standard deviation, ranged from 1 to 11%. The limit of quantification was less than 30 ng/L. The concentrations of the two most frequently used FWAs ranged from 7 to 21 μg/L in primary effluent, from 2.6 to 8.9 μg/L in secondary effluent, and from 0.04 to 0.57 μg/L in river water. FWA mass flows calculated from river water concentrations ranged from 0.45 to 1.2 mg day-1 person-1. If calculated on the basis of the consumed amount of FWAs, 1.4−5.6% was found in surface water. Light-induced isomerization and liquid−solid partitioning of FWA isomers were studied in samples of raw sewage and primary and secondary effluent. Isomers formed during the exposure to sunlight were found to have lower affinity for the suspended solids in sewage than the parent FWAs.
The dynamic wetting of a commercial alkyl ketene dimer (AKD) wax was measured on model cellulosic surfaces. The variables investigated were temperature and the surface composition. The model surfaces consisted of cellulose and cellulose acetate films as well as glass. These surfaces are smooth by industrial standards but not on a molecular level. The objective of the study was to predict the extent of AKD wetting during the time frame of papermaking. For smooth surfaces, AKD particles wet but do not spread on the hydrophilic surfaces investigated. AKD wetting proceeds from the balance of the interfacial forces with the viscous dissipation. The effect of gravity can be neglected for papermaking conditions. The Hoffman−Tanner equation modified for partial wetting provided a very good fit of the dynamic wetting. The slope of the graph is a function of temperature but not of the solid surface composition. Maslyiah's model also fits the experimental results well, but with a physically unrealistic value of the fitting parameter. For partial wetting, the complex but rigorous Cox equation is recommended to estimate the slip length over macroscopic wetting dimensions.
Styrene copolymer sizing agents in paper are determined by pyrolysis gas chromatography. Styrene monomer derived from the styrene sequences in the copolymer is used as the key product in the pyrograms of paper samples. The amounts of the sizing agents retained in paper samples are determined with a precision of about 1.4% relative standard deviation. The results obtained suggest that about 80% of the sizing agents added in the-pulp slurry ape retained in the paper samples studied. Furthermore, the amounts of the sizing agents in paper are interpreted in terms of the degree of sizing.
In model aqueous solutions containing 3-chIoro-l,2-propanediol (arising by the interaction of hydrochloric acid with lipids in protein hydrolysate and ammonia, 3-amino-1,2-propanediol was found as the main reaction product together with smaller amounts of glycerol. The reaction mechanism of formation of these two compounds was outlined and discussed as well as the possibilities of formation of some other amino analogues of glycerol chlorohydrins. 3-Amino-1,2-pro-panediol was also identified in commercially available seasonings (hydrolyzed vegetable protein) being present in concentrations of 30 mg kg-1.
A series of polyacrylamides covering a wide molecular weight range were synthesized and employed as retention aids in a model papermaking system of cellulose fibers and titanium dioxide. The ability of the polymer to increase the proportion of added titanium dioxide that is retained in the formed paper sheet is strongly dependent on molecular weight, but not on pH. Adsorption isotherms on both pigment and fibers are strongly molecular weight dependent. Polyacrylamides have no more than a weak flocculating effect on fiber suspensions and stabilize dispersions of titanium dioxide. However, with mixed dispersions of fibers and pigment, in the same ratio (10:1) as in paper formation, strong coflocculation is evidenced by the higher molecular weight polyacrylamides. In this model system pigment retention is a consequence of a heteroflocculation by adsorbed polymer bridging between the particles of titanium dioxide and cellulose fibers, possibly augmented by improved filtration in the forming sheet. Electrostatic effects appear to be unimportant in the system under study.
Polyamideamine-epichlorohydrin (PAE) resin is a crosslinked heteropolymer having cationic charges, and has been widely used as a wet strength agent of paper in the papermaking process. In this study, more accurate molecular mass values of PAE were determined by size exclusion chromatography attached with a multi angle laser light scattering detector (SEC-MALS). The obtained weight average molecular mass (Mw) values of commercial and laboratory-made PAE samples were 1,140,000 and 494,000, respectively, and these values were much higher than those reported so far. SEC-MALS analysis also revealed that PAE molecules had highly crosslinked structures and extremely wide molecular mass distributions. Molecular mass values and content of 3-hydroxy-azetidinium (AZR) groups in PAE and PAE intermediates during the course of PAE synthesis were also determined by the SEC-MALS and 1H NMR methods, and the relationships between these values and the wet strength development of handsheets prepared with these PAE samples were studied. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2249–2255, 2005
The finish obtainable on coated paper depends on the materials used as well as the way in which it is calendered. The rheological properties of the coated mixtures revealed the difference between them. When the apparent viscosity, η, was calculated and plotted against the shear rate, γ, on a log–log graph, an approximate linear relations were obtained. On the other hand, a plot is drawn between the shear rate and shear stress, in which a hysteresis loop is obtained connecting the up and down curves. It is clear from these plotting, that the rheological properties for the prepared coating mixtures show time-dependent behavior, because they are share rate dependence, and they can form sol–gel character. Moreover, the pigments used in the coating mixture were usually chosen because of their different impacts on coating color properties and also on the properties of the coating layer. Therefore, one can use the coating mixture to have higher optical properties and to improve the permeability of the sheets. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1666–1678, 2000
Polyamidoamine-epichlorohydrin wet-strength resins for paper contain small amounts of 1,3-dichloro-2-propanol and 3-chloro-1,2-propanediol formed by side reactions from epichlorohydrin used in the production process. Normally some residues of these substances are transferred to the wet-strength treated paper. An analytical method has therefore been developed for the simultaneous determination of 1,3-dichloro-2-propanol and 3-chloro-1,2-propanediol in paper in the 0.05–2 mg/kg range. The compounds are simultaneously extracted and silylated with a solution of N,O-bis-(trimethylsilyl)trifluoroacetamide in acetonitrile and finally determined by capillary gas chromatography-mass spectrometry in the selective ion monitoring mode against an internal standard. The detection limits are 0.04 mg/kg for both 1,3-dichloro-2-propanol and 3-chloro-1,2-propanediol.
Glycerol monochlorohydrin, (3-chloro-1,2-propanediol), which occurs in chemical hydrolysates of proteins, reacted with amino acids in model aqueous solutions to form the corresponding glycerylamino acids, i.e. N-(2,3-dihydroxypropyl)-amino acids. N-(2,3-dihydroxy-propyl)-derivatives of 15 amino acids were prepared and analyzed by gas chromatography and gas chromatography-mass spectrometry. No N-(2,3-dihydroxypropyl)-amino acid was detected in a freshly produced commercial soybean hydrolysate. Amounts up to ∼1 mg-kg-1 of N-(2,3-dihyproxypropyl)-serine and -threonine were found in a stored hydrolysate. Higher amounts of N-(2,3-dihydroxypropyl)-amino acids (up to about 10 mg-kg-1) were found in the alkaline treated and with 3-chloro-1,2-propanediol fortified hydrolysate. N-(2,3-dihydroxypropyl)-amino acids represent a new class of amino acids not previously reported in foodstuffs.
A study of 25 paper mill slime deposits and one additive revealed nine pink-pigmented bacterial isolates, eight of which were
different from pink-pigmented bacteria identified in the paper industry in the middle 1900s. The pink-pigmented bacteria described
previously in pulp and paper included Micrococcus agilis, Bacillus subtilis, Serratia sp. and Alcaligenes viscosus. With the exception of one isolate, Micrococcus sp., these isolates possessed many cultural, biochemical and chemical properties which were different from the ones previously
reported for paper mills. Eight of these bacteria were Gram-negative rods or filamentous, aerobic and positive for catalase
production. Two isolates were methylotrophic, oxidizing methanol and identified as Methylobacterium zatmanii. Cellular fatty acid analysis and other characteristics showed one isolate to be Roseomonas sp. Using 16S rRNA gene sequencing, one isolate which was a Gram-negative rod was identified as Deionococcus grandis. Four bacteria had cells that were long or filamentous and these were isolated from mills with pink slime problems. The identity
of one of the filamentous bacteria was determined by 16S rRNA gene sequencing to be close to Flectobacillus sp. strain MWH38. Most of the isolates were susceptible to 11 industrial biocides. Journal of Industrial Microbiology & Biotechnology (2000) 25, 74–80.
The mechanical, physical, and chemical properties of recycled pulps were evaluated after a series of treatments designed to improve and/or modify the pulp characteristics. Tensile strength, bursting strength, and apparent density of the pulps decreased with recycling. However, the tear strength, in most cases, increased after the first recycle and then decreased after the second recycle. Carboxyl content and WRV of pulps also decreased with recycling. Chemical treatments did not increase the bonding ability of recycled pulps and, in most cases, decreased the physical properties of the pulps. Altering the physical state of the cellulose microstructure through additional swelling did not appear to be a significant factor for strength restoration. It may be that the hemicelluloses plan a greater role in recycling than originally thought.
Paper-mill effluents are characterized by the presence of color and suspended solids, bad smell, high concentration of nutrients that cause eutrophication of receiving waters, and high toxicity overall. This study attempts to give an overview of organic compounds that contribute to the toxicity of paper-mill waters and effluents, their levels, toxicological characterization and the methodologies used for their analysis. Families included are natural products, such as resin and fatty acids (wood extractives), additives used during paper-making, such as biocides, surfactants and phenolic compounds and by-products generated during bleaching, such as dioxins and furans. Several extraction methods, such as liquid-liquid extraction (LLE) or solid phase extraction (SPE) followed by gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-mass spectrometry (LC-MS) with atmospheric pressure chemical ionization (APCI) or electrospray (ESP) are described and method performance is discussed for each family of compounds. This study contributes to the characterization of the organic fraction of paper-mill effluents and highlights elimination strategies.
Wastewater treatment sludge and power boiler fly ash were combined and composted in mixed and static windrows 50 m long, 4 m high and 6 m wide. Moisture content was maintained above 50%. The final compost had a pH of 8.5, contained high concentrations of specific nutrients, and an average C:N ratio of 43:1. All metal, PCB, chlorophenol and PAH concentrations were below levels stipulated by local regulations. Over the first 8 weeks of the composting period dioxin concentration decreased by 45% to 41 pg/g TEQ. Leachate tests indicated minimal (<0.1 mg/l Cu and Pb; <50 mg/l Na, P, and SO4−2) leaching of contaminants from the composted material. Application of compost (8 cubic yards/acre) at a sod farm improved soil characteristics as measured by a number of parameters. The dioxin concentration in the final soil/compost mixture was 3 pg/g TEQ, allowing the soil/compost mixture to be classified as agricultural soil. It was concluded that composting produced an acceptable soil conditioner attractive for large volume users of inexpensive soil material (sod farms, golf courses, land reclamation sites).
The manufacture of paper generates significant quantities of wastewater; as high as 60 m3/tonne of paper produced. The raw wastewaters from paper and board mills can be potentially very polluting. Indeed, a recent survey within the UK industry has found that their chemical oxygen demands can be as high as 11 000 mg/l. This paper reviews the processes involved in paper making and examines the effects which they could have on the environment. It also evaluates the treatment processes which are used to minimise these effects. In line with the majority of UK practice, it focuses mainly on aerobic biological treatment and, in particular, on the activated sludge process. This means that there is an in-depth discussion about the problems associated with filamentous bacteria and sludge “bulking”. The paper also discusses the way in which anaerobic digestion can be applied to the treatment of liquid wastes from the manufacture of paper.
The two fluorescent whitening agents (FWAs) that are currently used in laundry detergents in Switzerland (DAS 1, a diaminostilbene, and DSBP, a distyrylbiphenyl) were studied in ten different Swiss rivers. Two-week-composite-samples were analyzed once a month for 1 year. In most of the investigated rivers, concentrations ranged from 6–120 ng l−1 for DAS 1 and from 10–70 ng l−1 for DSBP. Average per capita loads were 1.8 and 1.3 mg d−1 inhabitant−1 for DAS 1 and DSBP, respectively. Higher concentrations were found in rivers with densely populated catchment areas and below FWA manufacturing plants (DAS 1: 100–1000 ng l−1; DSBP: 50–1100 ng l−1). Only sampling locations situated below FWA manufacturing plants showed significantly increased per capita loads compared to the other stations investigated (8.0 mg DAS 1 d−1 inhabitant−1 at Weil (below Basel) on the river Rhine; 23.1 mg DSBP d−1 inhabitant−1 at Porte du Scex on the river Rhône). Thus, these FWAs can be applied as molecular markers for production wastewater. The measurements made in Swiss rivers allowed for the development of a mass balance for FWAs. This mass balance indicates that 13% of the FWAs being used are discharged to surface waters.
Effluents from pulp and paper mills are highly toxic and are a major source of aquatic pollution. More than 250 chemicals have been identified in effluents which are produced at different stages of papermaking. Their toxic nature is derived from the presence of several naturally occurring and xenobiotic compounds which are formed and released during various stages of papermaking. This article reviews the origins and effects of major pollutants present in pulp and paper mill effluents. The progress made in their reduction/elimination via aerobic, anaerobic and abiotic routes, as well as further scope, is also discussed.
This study was designed to apply cleaner production concepts in a Turkish pulp and paper mill, for the first time in Turkey, to introduce the concept as well as to provide a framework for future initiatives. To achieve this objective a comprehensive waste reduction audit was conducted at SEKA Balikesir pulp and paper mill. First, audit schemes from different sources were examined and compiled that resulted in the methodology employed in this work. The audit covered water emissions and water usage. Then, the collected data were compared with international environmental performance indicators from other companies in the USA, Canada, Australia, and Europe. This comparison provided specific opportunities for improvement at different processes in the mill. For each viable opportunity, different waste reduction measures were analyzed and determined. Furthermore, the benefits of the identified waste reduction options were analyzed for increasing production efficiency and achieving target raw effluent pollution loads from the mill.
Previous investigations have shown that laccase catalyzed oxidation of lignin containing wood fibers can enhance the strength of medium density fiberboards. In the present work it was investigated if laccase treatment had any impact on the tensile strength of a high yield unbleached kraft pulp. Treatment with laccase alone had only a very little effect on the wet strength of the pulp, whereas addition of lignin rich extractives increased the wet strength after the enzyme treatment significantly. A mediated oxidation gave a similar improvement of the wet tensile strength although no lignin was added to the fiber suspension. Furthermore, it was found that a heat treatment combined with a mediated oxidation gave a higher improvement in wet tensile strength than could be accounted for by the individual treatments. No change in dry tensile strength from the laccase treatment was observed. It is suggested that the observed improvement in wet tensile strength is related to polymerization of lignin on fibers in the hand sheet and/or coupling of phenoxy radicals on lignin associated to adjacent fibers. For the different mediators studied, a correlation was found between oxygen consumption upon mediated oxidation and generation of wet strength in the pulp.
Oxygen containing C-3 chlorohydrocarbons are secondary products of C-3 chlorohydrocarbons formed during oxidation at air, in the metabolism of pesticides and by chlorination of drinking water. These compounds are mutagenic, genotoxic and carcinogenic. 2-Chloroacroleins are extremely strong mutagens and genotoxins and form 1,N2-cyclic deoxyguanosine adducts. The role of such adducts in mutagenicity and carcinogenicity is discussed.
Chlorinated derivatives of bisphenol A were detected in the final effluents of eight paper manufacturing plants in Shizuoka, Japan, where thermal paper and/or other printed paper is used as the raw material. Their amounts were determined by gas chromatography/mass spectrometry (GC/MS) after treatment with N, O-bis(trimethylsilyl)trifluoroacetamide, and ranged from traces to 2.0 microg/l. They are likely produced by chlorination of bisphenol A, which was released into the effluents from the pulping process of wastepaper, during or after bleaching with chlorine.
The effect of ozone based oxidation on removing recalcitrant organic matter (ROM) and enhancing the biodegradability of alkaline bleach plant effluent was investigated. A bubble column ozonation tower was used in the study. The experiments were carried out at different temperatures (20 degrees C and 60 degrees C) and pH (9 and 11), with a number of biological and chemical parameters being monitored including BOD5, COD, TC, pH, color, and molecular weight distribution of organics (nominal cut off of 1,000 Da). Biodegradability of the effluent was determined based on BOD5/COD of the wastewater throughout the process. For all the experiments, ozonation enhanced the biodegradability of the effluent by 30-40%, which was associated with noticeable removal of ROM including high molecular weight (HMW) and color-causing organics by about 30% and 60%, respectively. While the biodegradability of HMW fraction increased by about 50%, there was no biodegradability improvement for low molecular weight (LMW) portion, which was originally readily biodegradable (with BOD5/COD of about 0.5). Statistical analysis of variance (ANOVA) revealed neither pH nor temperature played significant role on the ozonation process at 95% confidence level.
Nonylphenol is a toxic xenobiotic compound classified as an endocrine disrupter capable of interfering with the hormonal system of numerous organisms. It originates principally from the degradation of nonylphenol ethoxylates which are widely used as industrial surfactants. Nonylphenol ethoxylates reach sewage treatment works in substantial quantities where they biodegrade into several by-products including nonylphenol. Due to its physical-chemical characteristics, such as low solubility and high hydrophobicity, nonylphenol accumulates in environmental compartments that are characterised by high organic content, typically sewage sludge and river sediments, where it persists. The occurrence of nonylphenol in the environment is clearly correlated with anthropogenic activities such as wastewater treatment, landfilling and sewage sludge recycling. Nonylphenol is found often in matrices such as sewage sludge, effluents from sewage treatment works, river water and sediments, soil and groundwater. The impacts of nonylphenol in the environment include feminization of aquatic organisms, decrease in male fertility and the survival of juveniles at concentrations as low as 8.2 microg/l. Due to the harmful effects of the degradation products of nonylphenol ethoxylates in the environment, the use and production of such compounds have been banned in EU countries and strictly monitored in many other countries such as Canada and Japan. Although it has been shown that the concentration of nonylphenol in the environment is decreasing, it is still found at concentrations of 4.1 microg/l in river waters and 1 mg/kg in sediments. Nonylphenol has been referred to in the list of priority substances in the Water Frame Directive and in the 3rd draft Working Document on Sludge of the EU. Consequently there is currently a concern within some industries about the possibility of future regulations that may impose the removal of trace contaminants from contaminated effluents. The significance of upgrading sewage treatment works with advanced treatment technologies for removal of trace contaminants is discussed.
Chemical additives for the production of pulp & paper. Deutscher Fachverlag GmbH. Frankfurt am Main
- Committe
- Zt
Committe ZT (2008) Chemical additives for the production of pulp & paper. Deutscher Fachverlag GmbH. Frankfurt am Main
The environmental impacts and behaviour of TCMTB Information memo-randum of the BC Ministry of Environment, Waste Management Program, Toxicology Unit 44
- Ward
- Jeh
Ward JEH (1989) The environmental impacts and behaviour of TCMTB. Information memo-randum of the BC Ministry of Environment, Waste Management Program, Toxicology Unit 44. Directive 2002/61/EC of the European Parliament and of the Council of 19 July 2002 amending for the nineteenth time Council Directive 76/769/EEC relating to restrictions on the marketing and use of certain dangerous substances and preparations (azocolourants).
Occupational allergic contact dermatitis from formaldehyde resin in clothing
- S E Cockayne
- Ajg Mcdonagh
- D J Gawkrodger
- SE Cockayne
Cockayne SE, McDonagh AJG, Gawkrodger DJ (2001) Occupational allergic contact derma-titis from formaldehyde resin in clothing. Contact Dermatitis 44(2):109–110
The environmental impacts and behaviour of TCMTB. Information memorandum of the BC Ministry of Environment
- Jeh Ward
Chemical additives for the production of pulp & paper. Deutscher Fachverlag GmbH
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