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The extensive use of biocide surfactant benzalkonium chloride (BAC) during the SARS-CoV-2 pandemic has led to the buildup of this hazardous chemical in waste, surface and groundwater. e The study aims to elucidate whether various low-cost household materials are suitable, in their unmodified and untreated form, to effectively adsorb BAC from its aqueous solutions.. Additionally, if a proper adsorbent is identified, a description of the kinetics and thermodynamics of the process is also targeted. From among the five tested materials, a commercially available white household paper towel was chosen to best satisfy the criteria of low price, large availability, and standardization degree, as well as high adsorption capacity within a fairly short time window needed until equilibrium. Batch experiments were carried out with a commercial mixture of BAC-12 and BAC-14 within a temperature range of 18-45 degrees Celsius, and a 25-100 mg/g BAC/adsorbent initial mass ratio range, respectively. The overall process follows a pseudo-second-order kinetic law, with an apparent activation energy of 73.35 KJ/mole. Both the Langmuir and the Redlich–Peterson isotherms describe the equilibrium data at 298 K well, with a Gibbs free energy of −20.64 KJ/mole. These findings are in agreement with previous reports and suggest a hybrid but chemisorption-dominated process. [ABSTRACT FROM AUTHOR]

For the first time the feasibility of using an alkaline wastewater coming from the pulp and paper industry as an activator, partially (50 vol%) replacing commercial sodium hydroxide, in the production of cork-based activated carbons was evaluated. The activated carbons showed the highest value of specific surface area ever reported for cork-based activated carbons (1670 m 2 /g), surpassing several other commercial and waste-based ones. These eco-friendly cork and paper waste-based activated carbons were then evaluated as methylene blue adsorbent materials. The influence of contact time, methylene blue initial concentration and adsorbent amount on the methylene blue removal efficiency by the activated carbons was studied. Extremely fast (>99.9% removal in 5 min) and efficient methylene blue adsorption (uptake of 350 mg/g) by the cork and paper waste-based adsorbents was achieved, which demonstrates the huge potential of these innovative adsorbents. These activated carbons were produced using two unexplored industrial by-products (alkaline wastewater and cork) and, therefore, may be an inexpensive source of activated carbons, which can be used for the effective removal of dyes from wastewaters. Furthermore, despite the very large surface area and high removal efficiency this is not a nano material (being around 30–50 μm in size), its capabilities being due to its unique cork-derived microstructure, and hence it can be handled and removed/filtered much more easily than nanocarbons, and without any associated health or environmental risks. [ABSTRACT FROM AUTHOR]

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Abstract: Glass microfibers are commonly used as biomolecule adsorption media, as structural or disposable components of the optical biosensors. While any improvement in these components are appreciated, utilizing basic tools of traditional approaches may lead to original sensor opportunities as simple, functional designs that can be easily disseminated. Following this pursuit, surface modification of glass microfiber paper surface was performed by 3-aminopropyltriethoxysilane (APTES) and resulting improvement in the cell entrapment capacity could be observed visually, only after Gram staining. Gram staining offered rapid validation of enhanced binding on the glass surface. The same APTES-modified samples were also tested for binding of complementary DNA sequences and the results were less straightforward due to the necessity of DNA visualization by using a fluorescent stain, YOYO-1. Accordingly, when there were no surface modification, DNA and YOYO-1 adsorbed readily on the glass microfiber filter paper, and prolonged the interaction between DNA and YOYO-1. YOYO-1 adsorption on glass could be recognized from the color profile of YOYO-1 emission. This phenomenon can be used to examine suitability of APTES coverage on glass surfaces since YOYO-1 emission can be distinguished by its glass adsorbed versus DNA-bound forms. Aptness of surface coverage is vital to biosensor studies in the sense that it is preceding the forthcoming surface modifications and its precision is imperative for attaining the anticipated interaction kinetics of the surface-immobilized species. The proposed testing scheme offered in this study secures the work, which is aimed to be carried out utilizing such sensing systems and device components. [Copyright &y& Elsevier]

The carbonization of lignocellulosic biomass with ionic liquids (ILs) are considered as an advantageous approach for the preparation of carbonaceous materials. The commonly used imidazolium and pyridinium based ILs have drawbacks such as toxicity, resistance to biodegradation, high cost and viscosity. These issues can be mitigated by diluting ILs with water, although excessive water content above 1 wt% can reduce the solubility of biomass. This research aims to investigate the potential of pretreating wastepaper with a "fully green" ILs, amino acid-based IL with high water content, followed by pyrolysis without IL, in enhancing the properties of biochar. For this purpose, the paper was treated with an aqueous solution of IL cysteine nitrate ([Cys][NO 3 ]), and the IL was not involved in the pyrolysis process to prevent the formation of secondary gaseous pollutants. The findings revealed that the hemicellulose and mineral filler in the paper were eliminated during pretreatment, leading to higher carbon content but lower oxygen content. As a result, the biochar exhibited micropores of 0.42 cm3g-1 and a specific surface area of 1011.21 m2 g−1. The biochar demonstrated high adsorption capacities for Cd2+, enrofloxacin, bisphenol A, ciprofloxacin, and tetracycline, with values of 45.20 mg g−1, 49.82 mg g−1, 49.90 mg g−1, 49.88 mg g−1, and 49.65 mg g−1, respectively. The proposed mechanism for the adsorption of enrofloxacin by the biochar primarily involves physical adsorption such as pore filling and electrostatic interactions, along with chemical adsorption facilitated by graphitic nitrogen. [Display omitted] • Amino acid-based IL with high water content removed the hemicellulose and minerals. • The specific surface area was four times of that of biochar without pretreatment. • More nitrogen was retained in the biochar and provided adsorption sites. [ABSTRACT FROM AUTHOR]

Herein, bifunctional two-dimensional copper-aluminum modified filter paper composite (2D-Cu/Al–C) was successfully prepared by simple calcination and showed ultrahigh adsorption performance and degradation potential. The adsorption removal of TC on 2D-Cu/Al–C all exceeded 92.2% under solution conditions of 10–200 mg/L TC, 100 mg/L 2D-Cu/Al–C, pH 8 and 298 K. The pseudo-second-order kinetic and Langmuir models better fitted the kinetic and isotherm data via spontaneous and exothermic process, and the maximum capacity of the 2D-Cu/Al–C was 2391.78 mg/g. Additionally, 2D-Cu/Al–C showed desired specific adsorption for TC (TC: 98.7%, norfloxacin: 5.8%, sulfamethoxazole: 2.1%, and ciprofloxacin: 1.8%) and it could effectively adsorbed TC even in the binary system (various coexisting ions or natural organic matter). After TC adsorbed on adsorbent was mineralized into CO 2 and H 2 O by adding peroxydisulfate to generate high electrode potential radical in another limited systems, the 2D-Cu/Al–C still had ∼89.12% on TC removal (initial concentration of 50 mg/L) after five experimental cycles. Zeta potential, FT-IR and XPS results indicated that the multi-adsorption mechanism, including electrostatic interactions, complexation, and H-bonds, played a vital role in the fast and efficient adsorption process. Thus, the way of combining adsorption and regeneration via degradation are green, non-polluting strategy which are expected to be applied for water purification in future environmental remediation. [Display omitted] • Two-dimensional copper-aluminum oxide (2D-Cu/Al–C) composite was synthesized. • The maximum adsorption capacity of 2D-Cu/Al–C towards TC was 2391 mg/g. • Adsorption on 2D-Cu/Al–C decreased in the order of TC > NOR > SMX > CIP > AC. • The 2D-Cu/Al–C still had 89.2% on TC removal after degradation cycles. • Adsorption mechanisms are electrostatic interactions, complexation, and H-bonds. [ABSTRACT FROM AUTHOR]

“Adsorption deinking” is a new concept for ink removal from suspensions using polymer particles instead of air bubbles (flotation) in a process with high efficiency, concerning the consumption of energy and water. We studied the influence of different papers and inks, of the deinking solution (compared with water), and of the duration of deinking. The process is characterized not only by the colour of polymer particles, but also by the properties in suspension such as charge, turbidity or particle size. Further it is shown, that dynamic surface tension is a useful tool to characterize not only the surfactant in suspension, but also its interaction with other substances (cellulose and ink). The efficiency of adsorption deinking is strongly influenced by the properties in suspension which depend on the type of paper. [ABSTRACT FROM AUTHOR]

The dynamic pore systems and high surface areas of flexible metal-organic framework materials make them excellent candidates to be used in different kinds of adsorption processes. However, the adsorption and desorption behaviors of therapeutic drugs on metal-organic frameworks in solution are not fully developed. Here, we systematically investigated the adsorption and desorption behaviors of a typical therapeutic drug, verapamil, over several Zr-based metal-organic frameworks [e.g., Zr-FUM, UiO-66(Zr), UiO-66(Zr)-NH2 and UiO-66(Zr)-2COOH] as well as ZrO2 in an acetonitrile solution by using paper spray mass spectrometry. In contrast to other materials, UiO-66(Zr)-2COOH demonstrated a superior adsorption performance to verapamil due to their strong acid-base and/or hydrogen-bond interactions, and the adsorption process fitted well with the pseudo-second-order kinetic model. As verapamil-adsorbed materials were used for desorption experiments, ZrO2 demonstrated the most favorable desorption performance, whereas UiO-66(Zr)-2COOH yielded the poorest desorption capability. These Zr-based materials had also been coated at the surface with filter papers for the analysis of various drugs and proteins in the process of paper spray mass spectrometry. The results demonstrated that among the studied materials, ZrO2-coated paper gave the most favorable desorption performance as a pure drug solution, whereas the paper from UiO-66(Zr) demonstrated the optimal capability in the analyses of therapeutic drugs in a complex matrix (e.g., blood) and a protein (e.g., myoglobin). [ABSTRACT FROM AUTHOR]

Based on surface science, adsorption of mineral oil, water, gas products (typified by CO2 and CH4), and acids (typified by formic acid) on meta-aramid insulation paper has been investigated by molecular dynamics simulations. When the adsorption process finishes, the free volume fraction in the crystalline region is very small owing to the stable molecular arrangement of fiber. In addition, the number of pores on the surface of the meta-aramid fiber and the pore size are small, and the stable configuration of hydrogen bonds plays an important role, so it is difficult for the mineral oil and aging products to enter the meta-aramid crystalline region. The irregular arrangement of molecules in the amorphous region means that it is easier for the mineral oil and aging products to enter the amorphous region than the crystalline region, and the influence of these substances on the amorphous region is greater than that on the crystalline region. The order of the adsorption strengths of the four types of aging products on meta-aramid fiber is formic acid > water > CO2 > CH4. Therefore, it is necessary to monitor the acid and water contents in transformers with meta-aramid insulation paper as the solid insulation material. [ABSTRACT FROM AUTHOR]

The bagasse fly ash, obtained from the local sugar industry, has been used as an inexpensive and effective adsorbent for the removal of color from pulp and paper industry. Effect of various operating variables, viz., contact time, initial concentration, adsorbent dose and particle size on the removal of color has been studied and discussed. It is found that for optimum removal of color, contact time for adsorption equilibrium equals to 60 min., at dosage of 2 g/l of baggase fly ash. The material exhibits good removal capacity (86%) and follows both the Langmuir and the Freundlich models. [ABSTRACT FROM AUTHOR]

A portable fiber-optic spectroscopic system (TRANSPEC) has been developed for non-destructive measurement of aged transformer insulating paper. Following successful measurement of degree of polymerization (DP) of a range of transformer-aged paper samples, the system has now been shown to separate the oil and paper information for measurement of DP in oil-wetted paper samples. In addition, the system has been shown to be capable of the prediction of both oil and water content of paper to a high accuracy, and is also capable of identifying and quantifying different water species. Spectroscopic measurements have been used together with gravimetric water adsorption measurements to investigate the kinetics of uptake of water vapour into paper from air in the case of nominally dry and oil-impregnated samples. Relationships between water adsorption parameters and properties of the paper insulation have also been investigated using measurements under controlled conditions. [ABSTRACT FROM AUTHOR]

Filter media, including those prepared from cellulosic materials, often suffer from permeability loss during continued use. To help understand such issues, one can take advantage of an extensive body of related research in such fields as industrial filtration, water purification, enhanced oil recovery, chromatography, paper manufacture, and the leaching of pollutants from impoundments. Though the mechanisms that appear to govern permeability-loss phenomena depend a lot on the details of various applications, the published research has revealed a number of common features. In particular, flow through a porous bed or fiber mat can be markedly reduced by deposition of particles or colloidal matter in positions that either block or partially restrict fluid flow. Progress has been achieved in the development of mechanistic models, as well as the use of such models in numerical simulations to explain various experimental findings. Further research of this type needs to be applied to cellulosic materials, which tend to be much more elongated in comparison to the bed materials and suspended matter considered most often by most researchers active in research related to permeability loss. [ABSTRACT FROM AUTHOR]

Xylan is known as a strength-enhancing agent for paper. However, it is difficult to adsorb xylan onto cellulose fibers because it carries the same negative charge as fibers. Therefore, either cationization of xylan or addition of cationic polyelectrolyte is required to maximize the effect of xylan use. In this study, cationic polyelectrolyte was used to promote xylan adsorption onto cellulose fiber. The effect of the polyelectrolyte type on the successive adsorption of xylan and its influence on paper properties was examined. The mechanism for improving paper strength by xylan adsorption on polyelectrolyte pre-formed layers was investigated through the viscoelastic properties of the preformed layers on model cellulose films using Quartz Crystal Microbalance with Dissipation (QCM-D). Both tensile and tear indices of paper were improved with the adsorption of xylan onto pulp fibers. It was suggested that the adsorbed xylan onto the polyelectrolyte preformed layer formed a complex layer that gave rise to a large contact area between xylan and fiber. The increase in the physical strength of paper depended on the structure of the polyelectrolyte-xylan layers. Highly charged cationic polyelectrolytes that form a flat adsorption layer gave a relatively lower increase in physical properties. On the other hand, thicker and more viscous adsorbed layers improved paper strength significantly. [ABSTRACT FROM AUTHOR]

Abstract: The reaction kinetics of alkaline phosphatase (ALP) adsorbed on paper was quantified by image analysis using a colorimetric technique under conditions of excess enzyme. A classical reaction kinetics approach integrated with image processing technique was used to analyse the coloured product formation from the enzyme substrate reaction against time. The order of reaction and rate constant of enzyme activities on paper surface were calculated. ALP was either physisorbed directly on paper or adsorbed on paper treated with a monolayer of a high molecular weight cationic polyacrylamide (CPAM), an anionic polyacrylic acid (PAA) or a high molecular weight polyethylene oxide (PEO). The reaction rate of enzymatic paper follows a first order reaction with respect to the concentration of enzyme–substrate complex. ALP immobilized on paper has a reaction rate 2 to 3 orders of magnitude lower than the free ALP enzyme in buffer solution. This might be due to a critical loss of enzyme flexibility upon adsorption. No increase in reaction rate was achieved by immobilizing ALP on paper treated with a high molecular weight cationic polyacrylamide (CPAM) or a highly charged anionic polyacrylic acid oligomer (PAA), which suggests the enzyme orientation was not significantly affected. However, the reaction rate for ALP on PEO treated paper was lower than that on CPAM or PAA treated papers. That is probably due to some PEO-enzyme interaction affecting the tertiary structure of the ALP enzyme. [Copyright &y& Elsevier]

Highlights: [•] Applicability of nanostructured latex coating for protein patterning was demonstrated. [•] Surface properties of latex coated paper were modified by short-wave IR irradiation. [•] Nanopatterned topography with hydrophilic and hydrophobic regions was formed. [•] Directed protein immobilization and improved protein adsorption was achieved. [•] Results are of interest in developing paper-based diagnostics and analytical tools. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) are considered an effective adsorbent for VOCs adsorption due to their excellent physical properties. But the adsorption properties of CNTS are greatly weakened due to the agglomeration effect. As a new type of structural material, microfiber composite can effectively solve this problem. In this work, camphor was used as the precursor to growing carbon nanotubes directly on the surface of paper-like stainless steel fibers (PSSF) by chemical vapor deposition, and the microfiber composite carbon nanotube membrane was prepared. The effects of growth time, temperature and flow rate of carrier gas on the growth of carbon nanotubes were discussed. The mechanism of mass transfer enhancement of the adsorption process of toluene by microfiber composites was investigated by constructing a mixed fixed bed of carbon nanotubes and composites. Compared with the structured bed of 3 cm CNTs, the length of unused bed (LUB) of 1.5 cm CNTs+ 1.5 cm CNTs/PSSF decreased by 0.209 cm, and the bed utilization ∆Z increased from 59.36 % to 66.33 %. The mixed fixed bed adsorption process can be well-fitted by the Yoon-Nelson model (R2 =0.91). [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: In the present study, catalytic wet oxidation (CWO) was investigated for the destruction of organic pollutants in the thermally pretreated effluent from a pulp and paper mill under moderate temperature and pressure conditions. The thermal pretreatment studies were conducted at atmospheric pressure and 368K using copper sulfate as a catalyst. The thermal pretreatment reduced COD by about 61%. The filtrate of the thermal pretreatment step was used at pH 8.0 for CWO at 383–443K temperature and a total pressure of 0.85MPa for 4h. Catalysts used for the reaction include copper sulfate, 5% CuO/95% activated carbon, 60% CuO/40% MnO2, and 60% CuO/40% CeO2. Maximum COD reduction was found to be 89% during CWO step using 5% CuO/95% activated carbon with a catalyst loading of 8gl−1 at 443K and 0.85MPa total pressure. Overall COD reduction for the pretreatment and the CWO was found to be 96%. Besides this, 60% CuO/40% CeO2 catalyst also exhibited the similar activity as that of obtained with 5% CuO/95% activated carbon catalyst at 423K temperature and 0.85MPa total pressure. The pH of the solution during the experimental runs decreases initially due to the formation of carboxylic acid and then increases due to the decomposition of acids. [Copyright &y& Elsevier]

Abstract: In this work, sludge-based activated carbon (SAC) was prepared from paper mill sewage sludge by physical activation with steam. The adsorption efficiency of SAC to cationic methylene blue (MB) and anionic reactive red 24 (RR 24) from aqueous solutions was investigated using fixed-bed adsorption column. The effects of influent dye concentration, particle size, adsorbent mass and flow rate on the breakthrough characteristics of the adsorption system were determined. Desorption of dyes on SAC was repeated for several cycles in HCl, NaOH and deionized water. The results showed that breakthrough time and exhaustion time increased with decreasing inlet dye concentration, particle size, flow rate and increasing adsorbent mass. The adsorption capacity of SAC in fixed-bed column was lower than that obtained from equilibrium study. However, the SAC adsorption performance was much better than commercial activated carbon, indicating the enormous potential of SAC for removing dyes. In addition, the lower desorption rate of MB than of RR 24 demonstrated that cationic dye was more stable on SAC. [Copyright &y& Elsevier]

Background: The method of collection as well as the packaging conditions in which samples are submitted to laboratories play a critical role on the acquisition of reliable results on diagnostic tests. Alternative methods however have been proposed, as the adsorption of blood or serum in filter paper. In this work, it was evaluated the viability of using serum or whole blood samples from bovines collected in filter paper for serological testing against bovine herpesvirus type 1 (BoHV-1). Materials, Methods & Results: One hundred and seven whole blood and serum samples were collected by standard methods. Serum neutralization test was used as a golden standard method for evaluation of the serum samples. The same samples of both whole blood and sera were also adsorbed on filter paper strips for further comparisons. Optimal conditions for serum and blood elution from filter paper were determined. Adsorbed samples on filter paper disks were eluted in PBS and subsequently diluted further with PBS 5% skimmed milk. The eluates were tested for antibodies to BoHV-1 in an indirect ELISA (iELISA) and matched with the results obtained by serum neutralization of standard serum samples. Comparison between results obtained by serum neutralization of standard serum samples and the ones from the iELISA of serum eluted from paper disks resulted in sensitivity, specificity, positive and negative predictive values of 95, 94, 80, 99%, respectively, and a correlation coefficient (κ) of 0.83. Comparison between the results of serum neutralization of standard serum samples and the ones from the iELISA of blood eluted from paper disks resulted in sensitivity, specificity, positive and negative predictive values of 91, 97, 87, 98% , respectively, and a correlation coefficient (κ) of 0.86. Standard serum samples were also tested in the iELISA and the results compared with those of iELISA from samples eluted from filter paper. Comparison of the results from iELISA between serum samples and serum eluted from filter paper resulted in sensitivity, specificity, positive and negative predictive values of 91, 81, 69, 95%, respectively, and a correlation coefficient (κ) of 0.66. The comparison of iELISA results between standard serum and blood samples eluted from filter paper resulted, in sensitivity, specificity, positive and negative predictive values of 78, 92, 82, 89%, respectively, and a correlation coefficient (κ) of 0.70. Fifty samples collected on filter paper were retested eight months later in order to determine whether those would retain its viability; both sensitivity and specificity remained unaltered. Discussion: Sampling on filter paper has been successfully described for antibody detection in a number of diseases such as Aujeszky's disease virus and Newcastle disease virus. In this work, it has been demonstrated that both blood and sera collected in filter paper can be used for submission of samples aiming detection of antibodies to BoHV-1 in an iELISA, without significant loss of sensitivity and specificity. Submission of samples on filter paper is a practical and economical alternative as no special conditions are required for storaging and transporting. This method also enables the collection of samples from distant places assuring its quality for serological tests. [ABSTRACT FROM AUTHOR]

Abstract: The effect of polymer on the retention and the thermal stability of bioactive enzymatic papers was measured using a colorimetric technique quantifying the intensity of the enzyme–substrate product complex. Alkaline phosphatase (ALP) was used as model enzyme. Three water soluble polymers: a cationic polyacrylamide (CPAM), an anionic polyacrylic acid (PAA) and a neutral polyethylene oxide (PEO) were selected as retention aids. The model polymers increased the enzyme adsorption on paper by around 50% and prevented enzyme desorption upon rewetting of the papers. The thermal deactivation of ALP retained on paper with polymers follows two sequential first order reactions. This was also observed for ALP simply physisorbed on paper. The retention aid polymers instigated a rapid initial deactivation which significantly decreased the longevity of the enzymatic papers. This suggests some enzyme–polymer interaction probably affecting the enzyme tertiary structure. A deactivation mathematical model predicting the enzymatic paper half-life was developed. [Copyright &y& Elsevier]

Abstract: The thermal stability of two enzymes adsorbed on paper, alkaline phosphatase (ALP) and horseradish peroxidase (HRP), was measured using a colorimetric technique quantifying the intensity of the product complex. The enzymes adsorbed on paper retained their functionality and selectivity. Adsorption on paper increased the enzyme thermal stability by 2–3 orders of magnitude compared to the same enzyme in solution. ALP and HRP enzymatic papers had half-lives of 533h and 239h at 23°C, respectively. The thermal degradation of adsorbed enzyme was found to follow two sequential first-order reactions, indication of a reaction system. A complex pattern of enzyme was printed on paper using a thermal inkjet printer. Paper and inkjet printing are ideal material and process to manufacture low-cost–high volume bioactive surfaces. [Copyright &y& Elsevier]

Chitosan/polycaprolactam (PA6) nanofibrous filter paper (NFP) was prepared by electrospinning technique. Characterization with Fourier transformation infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) indicated that there was weak interaction (hydrogen bonds) between PA6 and chitosan, and the average diameter of the composite nanofibers decreased as the chitosan content was increased. The maximum adsorption capacity of Cr(VI) on the NFP via filtration (114.7 mg g −1 ) was much higher than that via static adsorption (81.7 mg g −1 ) and shaking adsorption (80.7 mg g −1 ). Because the Cr(VI)-containing solution was forced to flow through the whole membrane in filtration, the chelation sites inside the membrane could be exploited, leading to the enhancement of the Cr(VI) adsorption. The hydrogen bonds between chitosan and PA6 could enhance the mechanical strength and the acid fastness of the NFP. Therefore, the NFP desorbed by H 2 SO 4 can be well reinstated, and the adsorption capacity of Cr(VI) decreased slightly (only 17.9%) after three filtration cycles. On the basis of X-ray photoelectron spectroscopy (XPS) analysis, the possible mechanism for the Cr(VI) removal was that Cr(VI) was initially adsorbed on the NFP due to the electrostatic attraction, and subsequently reduced to the less toxic form Cr(III) by the amino groups of chitosan. [ABSTRACT FROM AUTHOR]

Abstract: This study examines and quantifies the effect of cationic polyacrylamide (CPAM) dissolution kinetics and charge density on the adsorption and aggregation state of gold nanoparticles (AuNPs) on paper and the resulting Surface Enhanced Raman Scattering (SERS) performance. Dissolution kinetics of CPAM of different charge density was studied by monitoring their viscosity and hydrodynamic diameter over regular intervals of time. It was found that the degree of dissolution of CPAM greatly affected the surface coverage and aggregation of AuNPs on the CPAM pre-adsorbed paper substrate and their SERS reproducibility. CPAM of higher charge density dissolves faster and produced a more uniform aggregation and higher surface coverage of AuNPs on paper for a higher and more reproducible Raman EF. Understanding the CPAM dissolution process enables the optimization of SERS performance of the AuNPs-paper as a bio-diagnostic platform. [Copyright &y& Elsevier]

The Ni–zero-valent iron magnetic biochar composites (Ni–ZVI-MBC) were synthesized from paper mill sludge and used as an adsorbent for the removal of pentachlorophenol (PCP) from the synthetic and real paper mill effluent. The synthesized Ni–ZVI-MBC was characterized and analyzed for the stability of Ni and ZVI particles in the biochar matrix. The Ni–ZVI-MBC involves simultaneous adsorption and dechlorination mechanism resulting in higher PCP removal efficiency. The presence of Ni as a catalyst in Ni–ZVI-MBC enhances the dechlorination rate and the adsorption of PCP by preventing the accumulation of PCP in the biochar matrix. The effect of operating parameters (solution pH, Ni loading, initial PCP concentration in the solution and temperature) on adsorption and dechlorination efficiency was studied. The exhausted Ni–ZVI-MBCs were used for the brick formation and the bricks showed good compressive strength and negligible heavy metal and PCP leaching. [ABSTRACT FROM AUTHOR]

Abstract: Deinking is an important step in recycling of waste paper and flotation is commonly used in this process. By studying the interaction between added surfactant and the solid surfaces of ink pigment and pulp, the fundamental mechanism of flotation deinking can be better understood. In this work, the adsorption of two anionic surfactants (sodium dodecyl sulfate, SDS and sodium octanoate, C8) on both a model ink (hydrophobic carbon black) and a model fiber (hydrophilic office paper) was studied. The effect of pH on the SDS adsorption and the co-adsorption of calcium and surfactant on both surfaces also were investigated. The SDS adsorbs on carbon black as a tail-down monolayer (hemimicelle) while on paper fiber as a head-down, head-out bilayer (admicelle). The C8 forms admicelles on both carbon black and paper fiber indicating the stronger interaction of the carboxylate group with the carbon surface than the surfactant sulfate group, causing the C8 to adsorb at higher levels than SDS on carbon black. This helps explain why soaps are used widely as the surfactant in flotation deinking operations. Calcium causes surfactant adsorption to increase on carbon black as it adsorbs between negatively charge surface sites and the anionic head group of the surfactant (bridging) especially at low surfactant levels while not enhancing surfactant adsorption on paper fiber, explaining its activation effect in deinking processes. At high surfactant loadings, increasing surfactant concentration can cause calcium adsorption to decrease (calcium exclusion effect), probably due to covering up of negative adsorption sites on the surface. [Copyright &y& Elsevier]

Membrane fouling is the major factor limiting the wider applicability of the membrane-based technologies in water treatment and in separation and purification processes of biorefineries, pulp and paper industry, food industry and other sectors. Endeavors to prevent and minimize fouling requires a deep understanding on the fouling mechanisms and their relative effects. In this study, Brunauer-Emmett-Teller (BET) nitrogen adsorption/desorption technique was applied to get an insight into pore-level membrane fouling phenomena occurring in ultrafiltration of wood-based streams. The fouling of commercial polysulfone and polyethersulfone membranes by black liquor, thermomechanical pulping process water and pressurized hot-water extract was investigated with BET analysis, infrared spectroscopy, contact angle analysis and pure water permeability measurements. Particular emphasis was paid to the applicability of BET for membrane fouling characterization. The formation of a fouling layer was detected as an increase in cumulative pore volumes and pore areas in the meso-pores region. Pore blocking was seen as disappearance of meso-pores and micro-pores. The results indicate that the presented approach of using BET analysis combined with IR spectroscopy can provide complementary information revealing both the structure of fouling layer and the chemical nature of foulants. [ABSTRACT FROM AUTHOR]

Abstract: The surface free energy is an essential paper property affecting liquid/ink interaction with the ink-jet paper surface. Different ways of calculating surface energy components for ink-jet papers is introduced. The results given by the very useful van Oss–Chaudhury–Good (vOCG) bi-bidentate model are compared with simpler mono-bidentate and mono-monodentate models. The unbalance in the acid–base (AB) values of the vOCG-model is compensated for, and occasional negative roots obtained are removed when applying the simpler mono-bidentate- and mono-monodentate models. The simple and elegant mono-monodentate model produces comparable values with the other models, and is thus recommended. The calculated percent work of adhesion between the probe liquids and substrates correlates well with surface energy component values. Also the percent work of adhesion between the inks and substrates correlates with surface energy values. [Copyright &y& Elsevier]

On dried filter paper coated with silver nanoparticles, surface-enhanced Raman scattering (SERS) spectra of p-hydroxybenzoic acid (PHBA) were studied, and high-quality SERS spectra were obtained, indicating that the silver-coated filter paper is a highly SERS-active substrate. The analysis showed that the adsorption behavior of PHBA molecules on silver nanoparticles coated on filter paper was different from that in silver aqueous colloids. On the filter paper, it was found that the SERS spectra of PHBA changed with the proportion of PHBA molecules and silver nanoparticles, indicating that the adsorption behavior of PHBA molecules changed with the proportion. The probable reasons are given. [Copyright &y& Elsevier]

A hybrid montmorillonite (Mt)-rich/chitosan composite (MCC) with high adsorption performance was synthesized for the decolorization of water used in the joss paper process. The performance was reported in terms of the dye removal. The composite expressed higher performance than chitosan or Mt-rich clay, respectively. The optimum condition for complete dye removal was achieved when using at least 0.6 g of the composite over a wide pH range (3–10) and initial dye concentration (10–100 mg L−1). The composite showed good reusability without the requirement of regeneration, adsorbing the dye completely for up to eight successive cycles of adsorption (>1.33 gdye gMCC−1). Thermodynamic analyses revealed the degree of spontaneity and the endothermic adsorption process. From the isotherm studies, the Koble–Corrigan isotherm model fitted very well to the experimental data, revealing that the composite had a heterogeneous surface with various active sites to adsorb the dye molecules. This also evidenced the synergistic electrostatic attraction and hydrophobic interaction between the dye and the composite. The pseudo-second-order model best explained the kinetic rate of adsorption. From evaluation of the adsorption process using the Webber and Morris equation and Boyd model, the rate-limiting step consisted of film diffusion and intra-particle diffusion. [ABSTRACT FROM AUTHOR]

Iminodiacetic acid was immobilized on waste paper by chemical modification in order to develop a new type of adsorption gel for heavy metal ions. Adsorption behavior of the gel was investigated for a number of metal ions, specifically Cu(II), Pb(II), Fe(III), Ni(II), Cd(II), and Co(II) at acidic pH. From batch adsorption tests, the order of selectivity was found to be as follows: Cu(II)≫Fe(III)>Pb(II)>Ni(II)≫Co(II)>Cd(II). Column tests were carried out for pairs of metal ions to understand the separation and pre-concentration behavior of the gel. It was found that mutual separation of Ni(II) from Co(II) and that of Pb(II) from Cd(II) can be achieved at pH 3. Similarly, selective separation of Cu(II) from Cu(II)–Fe(III) and Cu(II)–Pb(II) mixtures at pH 1.5 and 2, respectively, was observed by using this new adsorption gel. In all cases, almost complete recovery of the adsorbed metal was confirmed by elution tests with HCl. [Copyright &y& Elsevier]

Abstract: A new method for detection of viruses has been developed. The entire assay can be performed within 2h, and consists of a polyelectrolyte-multilayer-modified cellulosic filter paper combined with immunodetection. The M13 bacteriophage was used as a model virus. A visual colour-based detection system, anti-M13 horseradish peroxidase (HRP) conjugate and 3,3′,5,5′-tetramethylbenzidine (TMB), was selected to allow semi-quantitative assessment by human eye, or quantitative assessment using a digital scanner. By filtering a volume of 0.50ml, it was possible to visually detect a concentration of 106 pfu/ml. The detection limit was improved to 5×104 pfu/ml by increasing the volume of the sample to 100ml. For comparison, it was only possible to detect a concentration of 107 pfu/ml using conventional sandwich enzyme-linked immunosorbent assay (ELISA) with the same detection system. [Copyright &y& Elsevier]

Effluent reuse is a common practice for sustainable industrial water use. Salt removal is usually carried out by a combination of membrane processes with a final reverse osmosis (RO). However, the presence of silica limits the RO efficiency due to its high scaling potential and the difficulty of cleaning the fouled membranes. Silica adsorption has many advantages compared to coagulation and precipitation at high pHs: pH adjustment is not necessary, the conductivity of treated waters is not increased, and there is no sludge generation. Therefore, this study investigates the feasibility of using pseudoboehmite and its calcination product (γ-Al2O3) for silica adsorption from a paper mill effluent. The effect of sorbent dosage, pH, and temperature, including both equilibrium and kinetics studies, were studied. γ-Al2O3 was clearly more efficient than pseudoboehmite, with optimal dosages around 2.5–5 g/L vs. 7.5–15 g/L. The optimum pH is around 8.5–10, which fits well with the initial pH of the effluent. The kinetics of silica adsorption is fast, especially at high dosages and temperatures: 80–90% of the removable silica is removed in 1 h. At these conditions, silica removal is around 75–85% (<50 mg/L SiO2 in the treated water). [ABSTRACT FROM AUTHOR]

Abstract: Materials and technologies for cryogenic tanks design are still in the developmental stage. New design concepts demand that composite structure not only carries mechanical loads but provides hermetism. This paper aims at defining a cryogenic tank concept design and developing a barrier layer with impregnated aramid paper to prevent permeation of gases through a composite sandwich wall of the tank. A number of aramid fiber paper sheets have been coated with different resin systems and tested for helium permeability. Permeation kinetics show that there are at least two mass transport mechanisms running simultaneously: diffusion and hydrodynamic flow through micro-porous media. The long period of unsteady permeability was determined. Despite some technological imperfections of the laboratory-made samples, a low level of permeability was achieved, which satisfied the official requirements. Both steady level of permeability and kinetics of unsteady period can be used for quality control purposes. [Copyright &y& Elsevier]

Abstract: In this study, the efficiency of six ion exchange resins to reduce the dissolved organic matter (DOM) from a biologically treated newsprint mill effluent was evaluated and the dominant removal mechanism of residual organics was established using advanced organic characterisations techniques. Among the resins screened, TAN1 possessed favourable Freundlich parameters, high resin capacity and solute affinity, closely followed by Marathon MSA and Marathon WBA. The removal efficiency of colour and lignin residuals was generally good for the anion exchange resins, greater than 50% and 75% respectively. In terms of the DOM fractions removal measured through liquid chromatography–organic carbon and nitrogen detector (LC–OCND), the resins mainly targeted the removal of humic and fulvic acids of molecular weight ranging between 500 and 1000gmol−1, the portion expected to contribute the most to the aromaticity of the effluent. For the anion exchange resins, physical adsorption operated along with ion exchange mechanism assisting to remove neutral and transphilic acid fractions of DOM. The column studies confirmed TAN1 being the best of those screened, exhibited the longest mass transfer zone and maximum treatable volume of effluent. The treatable effluent volume with 50% reduction in dissolved organic carbon (DOC) was 4.8 L for TAN1 followed by Marathon MSA – 3.6L, Marathon 11 – 2.0L, 21K-XLT – 1.5L and Marathon WBA – 1.2L. The cation exchange resin G26 was not effective in DOM removal as the maximum DOC removal obtained was only 27%. The resin capacity could not be completely restored for any of the resins; however, a maximum restoration up to 74% and 93% was achieved for TAN1 and Marathon WBA resins. While this feasibility study indicates the potential option of using ion exchange resins for the reclamation of paper mill effluent, the need for improving the regeneration protocols to restore the resin efficiency is also identified. Similarly, care should be taken while employing LC–OCND for characterising resin-treated effluents, as the resin degradation is expected to contribute some organic carbon moieties misleading the actual performance of resin. [Copyright &y& Elsevier]

Natural menthol was coated on craft paper by impregnation and studied as volatile corrosion inhibitor for copper in hydrochloric acid environment. The effect of menthol on copper corrosion was studied by gravimetric and electrochemical methods such as potentiodynamic polarization and electrochemical impedance measurements. The results indicate that menthol adsorbs on the metal surface, which protects copper against further corrosion. The adsorption behaviour of menthol on copper surface was found to obey Temkin's adsorption isotherm. [ABSTRACT FROM AUTHOR]

This paper proposes an analytical model for calculating the number of fibre–fibre contacts per unit fibre length from the cross-sectional dimensions of the fibres in a sheet and sheet density. This model has been verified with data of the number of fibre–fibre contacts measured directly in handsheets. The measured fibre–fibre contacts in the handsheets were classified into full and partial contacts. The model best fits this data when 1.5 partial contacts are equated to one full contact. A plot of measured versus predicted equivalent full contacts produced a linear correlation with a slope of 0.99 and correlation coefficient of R 2 = 0.93. The model was used to derive expressions for the fraction of the available fibre surface, which is bonded to other fibres, a quantity called the Relative Bonded Area (RBA). The validity of the model was checked using experimental data for RBA. RBA was determined both by nitrogen adsorption ( $$ {\hbox{RBA}}_{{\hbox{N}}_2 } $$ ) and by scattering coefficient (RBAsc). The extrapolation method of Ingmanson and Thode to determine S 0, the scattering coefficient of an unbonded sheet, proved to be inaccurate. We estimated S 0 for some samples from their linear relationship between scattering coefficient and nitrogen adsorption. The new model accurately predicted both $$ {\hbox{RBA}}_{{\hbox{N}}_{\hbox{2}} } $$ and RBAsc. [ABSTRACT FROM AUTHOR]

Adsorption cooling and desalination systems have a distinct advantage over other systems that use low‐grade waste heat near ambient temperature. Since improving their performance, including reliability and failure prediction, is challenging, developing an efficient diagnostic system is of great practical significance. The paper introduces artificial intelligence (AI) and an automated machine learning approach (AutoML) in a real‐life application for a computational diagnostic system of existing adsorption cooling and desalination facilities. A total of 1769 simulated data points containing data indicating a failure status are applied to develop a comprehensive AI‐based Diagnostic (AID) system covering a wide range of 42 input parameters. The paper introduces a conditional monitoring system for adsorption cooling and desalination systems. The novelty of the presented study mainly consists of two aspects. First, the intelligent system predicts the health or failure states of various components in a complex three‐bed adsorption chiller installation using the extensive input data sets of 42 different operating parameters. The developed AID expert tool, based on selecting the best from 42 models generated by the DataRobot platform, was validated on the complex, existing three‐bed adsorption chiller. The AID system correctly identified healthy and failure states in various installation components. The developed expert system is very efficient (AUC = 0.988, RMSE = 0.20, LogLoss = 0.14) in predicting emergency states. The proposed method constitutes a quick and easy technique for failure prediction and represents a complementary tool compared to the other condition monitoring methods. [ABSTRACT FROM AUTHOR]

Abstract: Methanol is one of the major hazardous air pollutants emitted from chemical pulp mills. Its collection and treatment is required by the Maximum Achievable Control Technology portion of the 1998 Cluster Rule. The objective of this study is to investigate the technical feasibility of combined adsorption and photocatalytic regeneration for the removal and destruction of methanol. To facilitate the regeneration, activated carbon (AC) was coated with commercially available photocatalyst by a spray desiccation method. Laboratory-scale experiments were conducted in a fixed-bed reactor equipped with an 8W black light UV lamp (peak wavelength at 365nm) at the center. The photocatalyst loaded onto AC had no significant impact on the adsorption capacity of the carbon. High humidity was found to greatly reduce the material’s capacity in the adsorption and simultaneous adsorption and photocatalytic oxidation of methanol. The photocatalytic regeneration process is limited by the desorption of the adsorbate. Increasing desorption rate by using purge air greatly increased the regeneration capacity. When the desorption rate was greater than the photocatalytic oxidation rate, however, part of the methanol was directly desorbed without degradation. [Copyright &y& Elsevier]

A novel microporous ZIF-67 membrane coating on paper-like stainless steel fibers (ZIF-67 membrane/PSSF) was successfully synthesized by a wet layup papermaking-sintering method followed by the seed-induced growth method. The effects of key factors such as crystallization temperature, synthesis time and Hmim/Co2+ (2-methylimidazole/cobalt chloride) molar ratio on the morphology structure of the samples were studied by the modern characterization techniques including SEM, EDX, TEM, XRD, BET, FTIR and TGA, respectively. The experimental result indicated that the as-synthesized ZIF-67 membrane/PSSF was extremely compact with the average membrane thickness of 4.8 μm. And the sample exhibited high BET surface area (440.9 m2/g), uniform pore size (1.881 nm) and large pore volume (0.2096 cm3/g). The adsorption breakthrough experiment of toluene was performed on different bed reactors filled with ZIF-67 membrane/PSSF and granular ZSM-5 zeolites, respectively. The experiment data was well fitted by Yoon–Nelson model, where the values of rate constant in the fixed bed with ZIF-67 membrane/PSSF increased by 32.2% compared with that of commercial ZSM-5 zeolites at the flow rate of 100 mL/min. And the bed pressure drop and length of unused bed (LUB) were dramatically reduced by 39.6% and 16.8% in 3 cm ZIF-67 membrane/PSSF fixed bed. In conclusion, mass transfer efficiency was significantly enhanced based the structured ZIF-67 membrane/PSSF fixed bed, and this new material is a promising adsorptive material for VOCs removal. Image 1 • ZIF-67 membrane was successfully coated on stainless steel fibers. • High BET surface area of 440.9 m2/g was obtained by ZIF-67 membrane fixed bed. • ZIF-67 membrane/PSSF exhibited uniform average pore size of 1.881 nm. • Mass transfer can be enhanced in the fixed bed filled with ZIF-67 membrane/PSSF. [ABSTRACT FROM AUTHOR]

In the last decade, biochar application research has emerged as a hot topic in water treatment studies, which made biochar adsorption one of the primary wastewater treatment strategies. This paper presents a global bibliometric analysis of 2673 publications from the Web of Science database, spanning 2011–2022. For a comprehensive understanding of the research status and trends in biochar adsorption for wastewater treatment, the advanced quantitative and visual analysis tools (i.e., CiteSpace and ArcGIS) were employed. The results showed that China emerged as the leading country with the most published articles. The key research area is on the magnetic adsorption of biochar in wastewater. The articles summarized in the review demonstrated unequivocally that biochar can treat a wide range of wastewater even though the adsorption mechanisms of biochar on heavy metals, inorganic salts and organic pollutants in wastewater are not entirely consistent. The review further analyzes the factors affecting the performance of biochar in adsorbing pollutants from wastewater and the improvement measures of biochar functional characteristics, proposing the future research directions focusing on the improvement of the adsorption capacity of biochar products. The information synthesis and discussion would provide valuable insights on the historical, current, and future trends in biochar research, beneficial to solve the practical problems of water pollution and improve the quality of the environment. [ABSTRACT FROM AUTHOR]

Abstract: This review paper investigates the synthesis of porous structures with controlled hole pattern and provides an overall view of the various factors involved when synthesizing such porous materials. The following factors are discussed: 1) various methods of synthesis to produce the porous structures; 2) materials which the porous structures are made of; 3) control of the pore structure; 4) various applications of such porous materials. The materials of the porous structures and the control of the pore structure will also be discussed separately under each different method, as these two factors are closely dependent on the method of fabrication. [Copyright &y& Elsevier]

Paper packaging materials are widely used as sustainable green materials in food packaging. The production or processing of paper materials is conducted in an environment that contains organic chlorides; therefore, potential food safety issues exist. In this study, the adsorption behavior of organic chlorides on paper materials was investigated. Chloropropanol, which has been extensively studied in the field of food safety, was employed as the research object. We studied the adsorption mechanism of chloropropanol on a crystalline nanocellulose (CNC) model. The results demonstrated that physical adsorption was the prevailing process, and the intermolecular hydrogen bonds acted as the driving force for adsorption. The adsorption effect assumed greatest significance under neutral and weakly alkaline conditions. A good linear relationship between the amount of chloropropanol adsorbed and the amount of CNC used was discovered. Thus, the findings of this study are crucial in monitoring the safety of products in systems containing chloropropanol and other chlorinated organic substances. This is particularly critical in the production of food-grade paper packaging materials. [ABSTRACT FROM AUTHOR]

Hemicelluloses and lignin present in the spent liquor (SL) of neutral sulfite semichemical (NSSC) pulping process can potentially be converted into value-added products such as furfural, hydroxymethylfurfural, levulinic acid, phenols and adhesives. However, the direct conversion of hemicelluloses and lignin of SL into value-added products is uneconomical due to the dilute nature of the SL. To have a feasible downstream process for utilizing lignocelluloses of SL, the lignocelluloses should initially be separated from the SL. In this study, an adsorption process (via applying activated carbon) was considered for isolating the dissolved lignin and hemicelluloses from the SL of an NSSC pulping process. Under the optimal conditions of pH, SL/AC weight ratio, time and temperature of 5.7, 30, 360 min and 30 °C, the maximum lignin and hemicellulose adsorptions were 0.33 and 0.25 g/g on AC. The chemical oxygen demand (COD) and turbidity of the SL were decreased by 11% and 39%, respectively, as a result of lignocellulose adsorption on AC. Also, the incineration behavior of the SL-treated AC was studied with a thermo-gravimetric analysis (TGA). [Copyright &y& Elsevier]

A research on the preparation of Carbon Waste Powder, CWP, was conducted and made from carbon rod waste which was extracted from used zinc-carbon batteries. This research was an effort to overcome environmental problem caused by battery waste by converting into adsorbent for methyl orange (MO) that frequently used by textile industries. The prepared powder was then analyzed to understand its characteristic peaks, crystallinity, and to compare the properties with other carbonaceous forms, i.e. a commercial Carbon Paper (CP), and a commercial meso-carbon micro-beads (MCMB). The analysis found that CWP is dominated by graphitic carbon. An adsorption experiment was then conducted to study their adsorption ability to methyl orange solution. The result found that those three carbonaceous materials have the ability to adsorb methyl orange with different activities. MCMB has the highest adsorption capacity of 0.197 mg.g-1. Meanwhile, CWP and CP show adsorption capacity of 0.066 mg.g-1 and 0.062 mg.g-1, respectively. Methyl orange adsorption on CWP and CP were under second order, which means the adsorption could be four times faster as the MO solution doubled. Moreover, the rate constant of MO adsorption on CWP is 8×10-4 min-1, which was higher than the rate constant of MO adsorption on CP. It confirmed that the CWP can be used as a promising adsorbent for dye waste water. [ABSTRACT FROM AUTHOR]

In this paper, coal measure kaolin after flotation decarburization was made into an adsorbent by ball milling and acid modification to absorb methylene blue in water, achieving the treatment of waste with waste. The objective of this paper is to expand the application of coal measure kaolin, reduce its stock, and lower the raw material cost of adsorbents while treating wastewater containing methylene blue. The optimum milling time, acid boiling conditions, and adsorption conditions were investigated. Furthermore, the adsorption mechanism was investigated by kinetic calculation. The results show that the optimum milling time is 7 h. Relatively good acid modification conditions include a boiling temperature of 100 °C, a stirring time of 135 min, a stirring speed of 1000 r·min−1, and a concentration of hydrochloric acid of 8 mol·L−1. When 0.05 g of flotation kaolin adsorbent was used to adsorb the solution with pH 12 and a methylene blue concentration of 100 mg·L−1, the optimal adsorption conditions were a 38.05 °C adsorption temperature, a 160 r·min−1 stirring speed, and a 31.02 min stirring time. Under these optimal conditions, the adsorption quantity reached 39.92 mg·g−1. The adsorption process involves physical adsorption and spontaneous adsorption. The adsorption type is known as the quasi-second-order adsorption kinetic model. The adsorption form is heterogeneous adsorption in which a monolayer and a multi-molecular layer coexist. [ABSTRACT FROM AUTHOR]

The adsorption isotherm and the mechanism of the buffering effect are important controls on phosphorus behaviors in estuaries and are important for estimating phosphate concentrations in aquatic environments. In this paper, we derive phosphate adsorption isotherms in order to investigate sediment adsorption and buffering capacity for phosphorus discharged from sewage outfalls in the Yangtze Estuary and Hangzhou Bay near Shanghai, China. Experiments were also carried out at different temperatures in order to explore the buffering effects for phosphate. The results show that P sorption in sediments with low fine particle fractions was best described using exponential equations. Some P interactions between water and sediment may be caused by the precipitation of CaHPO4 from Ca2+ and HPO42- when the phosphate concentration in the liquid phase is high. Results from the buffering experiments suggest that the Zero Equilibrium Phosphate Concentrations (EPC0) vary from 0.014 mgl-1 to 0.061 mgl-1, which are consistent with measured phosphate concentrations in water samples collected at the same time as sediment sampling. Values of EPC0 and linear sorption coefficients (K) in sediments with high fine particle and organic matter contents are relatively high, which implies that they have high buffering capacity. Both EPC0 and K increase with increasing temperature, indicating a higher P buffering capacity at high temperatures. [ABSTRACT FROM AUTHOR]

The optimization of the thermal treatment of cationic starch in the paper industry offers the opportunity to reduce the energy consumption of this process. Four different industrially relevant cationic starches, varying in source, cationization method and degree of substitution were treated by a steam-jet cooking procedure, comparable to industrially employed starch cooking processes. The influence of the starch properties and cooking parameters on the adsorption behavior of the starches on cellulosic pulp was investigated. The adsorbed amount was affected by the cooking temperature and the type of starch. For some starch grades, a cooking temperature of 115 °C can be employed to achieve sufficient starch retention on the pulp fibers. The energy consumption could further be reduced by cooking at higher starch concentrations without loss of adsorption efficiency. [ABSTRACT FROM AUTHOR]