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The use of household waste-derived materials for wastewater treatment has double environmental benefit due to the availability of simultaneous disposal of household waste and wastewater. In this work, we report the facile production of phosphorus-rich carbon from waste paper as a potential adsorbent for the disposal of uranium (VI)-containing nuclear wastewater. A simple phosphoric acid activation-carbonization strategy is developed to effectively transform waste paper into carbon. The phosphorus content of the obtained carbon reaches 8.55 at% and large pores with sizes ranging from 2 to 100 nm are observed. Batch and column adsorption experiments verify that waste paper-derived carbon can efficiently adsorb uranium (VI) from aqueous solution under weakly acidic conditions. The maximum amount of uranium adsorption on the carbon attains 492 mg g−1 at pH 4.6, and adsorption of uranium (VI) on the carbon quickly reaches the equilibrium within 20 minutes. The distribution coefficient of uranium (VI) on waste paper-derived carbon is as high as 128 L g−1. The carbon can be reused for five times with uranium (VI) adsorption efficiencies above 89% and can be used for dynamic adsorption of uranium (VI) in a fix-bed column. Kinetics, thermodynamics and DFT calculations reveal a surface complexation mechanism between uranium (VI) ion and ionized phosphoric acid group. Moreover, to avoid the generation of secondary polluted water during the treatment of uranium-containing nuclear wastewater, a water-saving method is developed for the adsorption preparation and a water-free combustion method is employed for the disposal of uranium-containing spent adsorbent instead of recycling. This study demonstrates the good application potential of household waste-derived materials in wastewater treatment and provides more clues for the amalgamation of multifold subjects. [Display omitted] • The integration of wastes recycling and wastewater treatment. • Facile production of phosphorus-rich carbon from waste paper. • High uranium adsorption efficiency and good selectivity. • Investigation of the mechanism based on DFT calculation. [ABSTRACT FROM AUTHOR]

The terrible shuttling of lithium polysulfides (LiPSs) is a major obstacle for commercializing lithium–sulfur (Li–S) batteries as high‐performance energy storage systems. In this study, a carbon‐based interlayer with effective suppression capability on the shuttle effect is developed by simply coating a well‐dispersed mixture of soybean protein isolate/MXene onto the acidified carbon paper (ACP). The resultant composite interlayer (SM@ACP) is able to synergistically diminish the shuttle effect through chemical adsorption and physical blocking. Meanwhile, this interlayer displays excellent conductivity and facilitates the diffusion of Li ions due to the composite coating to promote both electron/ion conduction as well as the porous structure of ACP. Benefiting from the unique properties of the composite interlayer, the as‐assembled Li–S batteries with SM@ACP interlayers show a great improvement in the cycling stability and rate performance, delivering a very low‐capacity decay rate of 0.071% per cycle at 0.5 C even after 800 cycles. This work provides a feasible route to realize rational design and commercial mass production of desirable interlayers for promoting the commercialization of Li–S batteries. [ABSTRACT FROM AUTHOR]

Cellulose aerogels (CA) were widely used in the adsorption field due to high porosity, ultra-light quality, high-proportioned surface area. This article used a 3D La-CA-based adsorbent to improve wastewater eutrophication. Filter paper as cellulose source was applied and lanthanum was doped. Batch adsorption experiments showed that the maximum phosphate adsorption capacity could reach 54.377 mg g−1 (pH = 3.0). At the same time, the leaching of the lanthanum of the adsorbent was negligible, which proves good stability. In particular, the 3D La-CA presented an overall cylindrical monolith and would be easily separated from water compared with the powdery adsorbent. The adsorption performance of La-CA was not significantly affected by the competitive ions (F−, SO42−, Cl−, NO3−) and could still maintain 84.8% after 5 cycles. And mechanism analysis suggested that the 3D La-CA had a specific affinity with phosphates, through electrostatic attraction and inner-sphere complexation. In general, these 3D La-doped cellulose aerogels would provide new possibilities for the practical application of adsorbents in phosphate adsorption. [ABSTRACT FROM AUTHOR]

The use of paper dry strength additives is one of the methods for producing packaging boards with a lower grammage while maintaining mechanical properties. In the present work, papers were formed using dissolving grade kraft fibres, kraft fibres and carboxymethylated cellulose (CMC) modified kraft fibres (C-kraft fibres), with either cationic starch (CS), anionic polyacrylamide (APAM) or anionic polyelectrolyte complexes (PECs). Fibres and sheets were characterized to evaluate how the saturation adsorption of the different strength additives influences the properties of the treated fibres and the final handsheets. The tensile index of papers made from C-kraft fibres was the highest due to the highest adsorption capacity of strength additives. Moreover, the strength additives increased the tensile index by 33–84 %, while z-directional tensile strength was increased dramatically by 46–139 %. Bending stiffness was improved by 2.6–25 %, and the combination of CS and APAM or PECs resulted in a significant improvement in bending stiffness compared to the addition of CS alone. Importantly, the strength improvement did not sacrifice the density significantly. In summary, the knowledge gained from the current study expands the understanding of strength additives and their relationship with fibres of different surface charge and the overall paper properties. [ABSTRACT FROM AUTHOR]

The discharge of Esparto paper industrial wastewater (EPIW) of SNCPA Company of Kasserine – Tunisia in nature without any treatment can cause harmful effects to the environment. To reduce this danger, several treatment processes have been implemented, in particular, the adsorption technique. The present original study consists of using powdered activated carbon (PAC) to treat EPIW. The tests were carried out on different chemical oxygen demand (COD) concentration of EPIW ranging from 2 to 20 g/L. The influence of initial COD concentration, adsorbent dose, pH and contact time were investigated at temperature of 25 ± 2°C. The equilibrium results were modelled and assessed via Freundlich, Langmuir, Temkin and Dubunin–Radushkevich isotherms models. The error analysis was evaluated by three error functions: the average relative error deviation, the Marquardt's percent standard error deviation and the Sum of the squares of the errors. The results showed that COD removal efficiency, maximum adsorption capacity and colour removal rate were 94%, 190 mg/g and 90%, respectively, for pH = 6, an adsorbent dose of 75 g/L, initial COD concentration of 9.3 g/L and contact time of 60 min. Besides, the main characteristics values of treated EPIW (BOD, TCOD, pH and Salinity) at natural conditions were 200 ± 30 mg O2/L, 1300 ± 50 mg O2/L, 7.2 ± 0.1 and 1.7 g/L ± 0.1, respectively, which were below the ISO-14,000 standards conditions for release in public sewerage system. Furthermore, both the higher value of correlation coefficients (R2) and the lower value of SSE have shown that Freundlich model provided the best fits to adsorption experimental results. [ABSTRACT FROM AUTHOR]

The strength of pigmented coatings is crucial in applications such as paints, lithium-ion batteries, and paper coatings. An ongoing challenge that is driven by cost has been to reduce the amount of latex binders in formulations while maintaining the strength in the coatings. This paper describes the development of an all-cationic coating formulation with lower binder content that has comparable strength to coatings made with conventional anionic formulations with higher binder concentration. Adsorption of poly diallyl dimethyl ammonium chloride onto anionic precipitated calcium carbonate (PCC) and styrene-butadiene (SB) latexes produced cationic pigments and latexes. The all-cationic coating with 7 parts per hundred (pph) parts pigment latex levels demonstrated equal coating strength to anionic based coatings with 10 pph latex levels when applied as a coating on paper. The increase in coating strength is due to the impedance of migration of cationic binder at the paper-coating interface due to charge interactions between the cationic binder and the anionic paper fibers. As a result, a second strategy comprising layer-by-layer deposition of all-cationic formulations followed by their anionic equivalent resulted in coatings with lower strength because of failure at the coating layer interface due to lack of interpenetration of the coating components. [ABSTRACT FROM AUTHOR]

Long-term excessive uptake of fluoride through potable water will cause adverse effects on human health. Therefore, it is of great significance to detect and remove excessive fluoride in potable water. Here, we reported a multi-functional Zr-based coordination polymer namely CP-1, which could realize the visual detection and effectively selective adsorption of fluoride. The investigation of fluoride adsorption manifested that the maximum fluoride adsorption capacity of CP-1 could reach 48.78 mg g−1 and selective adsorption capacity kept stable in a wide range of pH. By fluorometric approaches, the detection of limit of F− could achieve 1.55 × 10–6 mol L−1 based on CP-1. Moreover, the fluorescence test paper fabricated by in situ growth of CP-1 onto the surface of filter paper was proved to realize the visual detection of fluoride. [ABSTRACT FROM AUTHOR]

Single-atom catalysts (SACs) are emerging heterogeneous catalysts, which have been shown to be promising for a wide range of applications. Herein, we report the fabrication of single-atom Co sites with regulated Co-N 3 coordination supported on waste paper-derived active carbon (WPAC). The high specific surface area (535.2 m2 g−1) and active Co-N 3 single sites endowed the Co-N 3 /WPAC with high adsorption capacity and excellent catalytic performance. The maximum adsorption capacity of sulfisoxazole (SIZ) onto Co-N 3 /WPAC reached 274.5 mg g−1, and the removal percentage of SIZ reached ∼93.0 % within 1.0 min in the Co-N 3 /WPAC+PS system. The bifunctional properties of Co-N 3 /WPAC led to the efficient preconcentration of organic pollutants from aqueous solution as well as in-situ oxidation of them via the catalytic oxidation process. In addition, the Co-N 3 /WPAC+PS system exhibited a wide operating pH range (3−11), high mineralization capacity (∼89.3 %) and excellent reusability for the degradation of SIZ. Mechanism studies suggested that the Co-N 3 active sites were responsible for enhanced generation of the reactive oxygen species via PS activation, and both radical and non-radical processes contributed to the oxidation of SIZ. This work provides new insights into the resourceful disposal of waste paper and the application of SACs for environmental remediation. • The waste paper-derived active carbon (WPAC) supported Co-N 3 single sites were fabricated. • Co-N 3 /WPAC exhibited high SIZ removal efficiency via adsorption and catalytic degradation. • Co-N 3 /WPAC/PS system had a satisfactory adaptability, stability, and reusability. • Radical pathway and non-radical pathway were proposed in Co-N 3 /WPAC/PS system. • The introduction of Co-N 3 sites accelerated the electron transfer process for PS activation. [ABSTRACT FROM AUTHOR]

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]

This study investigates the process conditions of the adsorption of copper (II) ion onto paper mill sludge (PMS) in a batch process. These conditions are: concentration of initial solution, contact time, temperature and quantity of the adsorbent. Characteristic properties of PMS employed as an adsorbent in the experiments were defined using Fourier transform infrared spectroscopy (FT-IR) scanning electron microscopy (SEM) and elemental analyses. According to the obtained results, while the amount of removed copper (II) ion increased with an increase in the rate of the adsorbent and contact time, it decreased as a result of an increase in the temperature and initial solution concentration. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherms were implemented for the determination of the most appropriate isotherm model for the experimental data, and it was found that the process is in concordance with Langmuir equation. The maximum adsorption capacity of PMS was calculated as 114.42 mg g-1. In kinetic studies, the adsorption process of copper (II) ion onto PMS was controlled by the pseudo-second-order kinetic model. The calculated activation value (Ea) was 38.61 kJ mol-1 and demonstrates that the process occurred by physical adsorption mechanism. The values of the thermodynamic parameters such as enthalpy (ΔHO)(-21.19kJmol-1), free energy (ΔGO) (−8.883 kJ mol-1) and entropy (ΔSO) (0.101 kJ mol-1 K-1) changes were determined to estimate the nature of the process. The results clearly showed that the process was of exothermic and spontaneous nature and that PMS could be utilized as an adsorbent for the removal of copper (II) ion from wastewater. [ABSTRACT FROM AUTHOR]

In this work, poly‐ (methyl methacrylate) microparticles were effectively adsorbed onto the paper cellulose fiber surfaces during impregnation without crosslinking agents. The adsorption behavior and mechanism of microparticles onto paper cellulose fibers were further examined by physical and chemical property characterization in combination with adsorption kinetic model. We reported that the kinetic adsorption process included three phases: rapid adsorption, saturated adsorption, and equilibrium adsorption. Intermolecular hydrogen bonds which increased gradually with the increase of the mass concentration of PMMA microparticles occurred between the carboxyl group of PMMA microparticles and the hydroxyl group of paper cellulose fibers. Due to the increase of the interaction, the crystallinity‐index of the paper cellulose decreased. Furthermore, the hydrophobic interaction also occurred between PMMA microparticles and the paper fibers, leading to preferential adsorption of the microparticles on the surfaces of the hydrophobic (2 0 0) crystal cellulose. [ABSTRACT FROM AUTHOR]

In this study, paper coated with a polyamide film containing a molecularly imprinted polymer (MIP) of benzalkonium chloride (BKC) is prepared. Its BKC adsorption ability and selectivity for BKC adsorption are investigated. The MIP is prepared by agitating an ethylenediamine solution containing an azo initiator, BKC as a template material, and methacrylic acid (MAA) as the functional monomer. First, filter paper soaked in this mixture is impregnated with a cyclohexane solution of terephthaloyl chloride and a BKC–MAA–MIP‐containing polyamide film is prepared on the surface of the paper. Paper containing BKC–MAA–MIP adsorbs BKC. The paper with the highest BKC removal efficiency is prepared under the following conditions: 4 mL MAA functional monomer, 2.5 w/v% ethylenediamine, and 10 min MIP synthesis time. The paper with BKC–MAA–MIP selectively adsorbs BKC from a solution containing BKC, tetracycline hydrochloride, and caffeine. Thus, a polyamide film containing BKC‐MAA‐MIP formed on paper can effectively and selectively remove BKC from aqueous environments. [ABSTRACT FROM AUTHOR]

In this work, a hierarchical Al2O3carbon fiber (H-Al-CF) was successfully fabricated for application in the removal of iodide ions from water. High yields of Al2O3-coated carbon fiber were prepared by a sol–gel process using waste paper fibers as templates and carbon sources. The H-Al-CF is fabricated by an in-situ growth of AlOOH nanocrystals on the surface of carbon fibers following calcination. The synthesized H-Al-CF exhibits the developed porosity including mesopores and macropores, and has high-specific surface area (348.9 m2 g−1) and iodide ions' adsorption efficiency (92.3%). The in-situ growth process ensures that H-Al-CF has a more stable structure, further promoting higher adsorption efficiency. [ABSTRACT FROM PUBLISHER]

Developing highly efficient adsorbents for the removal of trace thallium(I) (Tl+) is crucial for addressing environmental challenges. In this study, we successfully synthesized cubic Prussian blue (PB) loading on filter papers using an intermediate layer (dopamine/polyethyleneimine) via in-situ methods. The as-prepared PB-modified FP demonstrated outstanding anti-interference properties and light-enhanced adsorption performance for Tl+ (0.5 mg/L) under ultraviolet (UV) irradiation, exhibiting twice the effectiveness compared to dark conditions, even in acidic and coexisting ionic environments. This indicated its suitability for treating complex Tl+-contaminated water. Notably, the removal efficiency for trace Tl+ was almost 100%, with a maximum experimental adsorption capacity of 86.2 mg/g after 1-h photo-promoted adsorption under 365 nm UV. Characterization results supported a proposed photo-driven redox mechanism that elucidated the interaction between Tl+ and PB-modified FP. Specifically, the accelerated Fe(III) to Fe(II) redox reaction facilitated Tl+ accommodation on the surface and/or lattice of PB, enhancing Tl+ adsorption by compensating for missed positive charges. This study provides valuable insights into utilizing PB-based materials to enhance the photo-enhanced Tl+ adsorption capacity in a cost-effective, easy-to-synthesize, and environmentally friendly manner. [Display omitted] • A novel material (PB-modified FP) was facilely fabricated by in-situ method. • PB-modified FP showed enhanced adsorption performance under UV. • Mechanisms of the enhanced Tl+ adsorption under UV irradiation were elucidated. • Our adsorbent had an excellent anti-interference ability from other co-cations. • This study provides a promising solution for efficient trace Tl+ removal. [ABSTRACT FROM AUTHOR]

Precious organic cultural relics are easily affected by temperature, humidity, and harmful gases in the environment, resulting in embrittlement, fading, mildew, moth damage and other aging forms. An energy-saving and environmentally friendly material is needed to stabilize humidity and adsorb harmful gases in the environment. In this paper, with an intelligent adjustment function, functional paper containing sepiolite and tourmaline natural minerals was successfully prepared. The component of 80 % of wingceltis and 20 % of straw in dry pulp as main raw material was conducive to the desorption of water molecules. As favorable structure inside functional paper, the adsorption point and the adsorption contact area increased by the rough surface of fiber bundles, the addition of sepiolite and the ordered molecular chains of copolymers destroyed. So, the relative humidity could be adjusted to 55 % ± 3 within 2 hours and was stable with functional paper. At the same time, 1.11 ppm sulfur dioxide and 2.98 ppm ammonia could be effectively adsorbed in 10 and 12 h, respectively, by 1 g of paper in a 5 L container. The pH of the paper was adjusted to neutral with tourmaline, even if the pH was changed by acidic or alkaline gas absorption. Therefore, for long-term organic cultural relic preservation, preparing a constant-humidity and clean environment is of great significance. This is possible through this paper. [ABSTRACT FROM AUTHOR]

Cellulose nanofibers (CNFs) have great potential to be a layer in packaging materials because of their good barrier properties. When paper is coated with CNFs, they are difficult to distinguish from the base sheet. This issue creates challenges when trying to determine where CNFs migrate relative to the paper fibers during coating and drying. A three-dimensional analysis is possible by using confocal laser scanning microscopy (CLSM) if CNFs can be tagged with fluorescently active groups. In this study, CNFs were fluorescently tagged through adsorption of fluorescent dyes such as fluorescein isothiocyanate (FITC) and thioflavin by mixing with CNFs in their native suspension followed by purification. The adsorbed dye remained attached during typical coating procedures, low pH values, and high ionic strengths, but not for high pH and in contact with acetone. CNFs were also covalently tagged with FITC following methods reported in the literature as a comparison to already established methods for tagging cellulose nanocrystals. Images of never dried samples indicated that covalently tagging CNFs altered the state of the fines dispersion, while dye adsorption did not. Coatings of the adsorbed dye tagged CNFs on paper were successfully imaged by CLSM since the concentration of dye in the water phase was low enough to provide a good contrast between regions of CNFs and paper. With this method, the location and potential migration of CNFs coated on paper were successfully determined for the first time to the best of our knowledge. CNF based coatings with solids larger than 2.8% were found to have a distinct layer of CNFs at the paper surface with little CNFs penetrating into the paper structure, but lower solids result in significant penetration into the paper. [ABSTRACT FROM AUTHOR]

A bio-adsorbent (DAWP-PEI-β-CD) was facilely prepared by introducing polyethylenimine (PEI) and β-cyclodextrin (β-CD) into dialdehyde waste paper (DAWP) via a facile two-step method. The structures, morphologies and compositions of the as-prepared adsorbents were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), solid state nuclear magnetic resonance spectrometry (NMR) and X-ray photoelectron spectroscopy (XPS) techniques. Results showed that the pH values, adsorption temperature and contact time played a vital role in uptake of Eu(III) and Au(III). Meanwhile, the adsorption behavior of Eu(III) and Au(III) could be fitted felicitously with the Langmuir and the pseudo-second-order models, and the maximum adsorption capacities of Eu(III) (pH = 6.0) and Au(III) (pH = 2.0) onto DAWP-PEI-β-CD were 424.2 and 241.3 mg/g, respectively. Further advanced spectroscopy analysis revealed that the elimination of Eu(III) was attributed to host-guest inclusion and surface complexation interaction, while adsorption of Au(III) might stem from a combination of electrostatic attraction, chelation, host-guest inclusion and redox interaction. This study demonstrated that DAWP-PEI-β-CD was a promising environmental functional material to separation and enrichment of Eu(III) and Au(III) from contaminated water. [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]

Light-weight paper products that contain less fibres, but with a maintained bulk and improved strength properties, are highly desirable due to the low cost of raw materials and improved logistics of packaged goods. In this respect, the adsorption capacity of dry strength additives onto fibres, which is affected by the surface charge of said fibres, is very important for the development of these mechanically robust paper products. The influence of the surface charge on the adsorption of strength additives was investigated for, dissolving grade fibres, kraft fibres and kraft fibres modified with carboxymethyl cellulose (CMC) with different surface charge densities, but the same fibre dimensions. The strength additives investigated were cationic starch (CS), anionic polyacrylamide (APAM) and polyelectrolyte complexes (PECs), containing CS and APAM. A linear relationship was found between the surface charge of the fibres and the saturated adsorbed amount of CS. However, when either APAM or PECs adsorbed as secondary layers onto the CS, no correlation between cellulose charge and the saturation adsorption could be observed. The adsorption of APAM was dramatically affected by the pre-adsorbed amount of CS, whereas PECs were less influenced. Moreover, the additives improved the tensile strength (60%) and strain at break (> 100%) of handsheets formed with the kraft fibres and adsorbed APAM. It was also found that CS/APAM increased the sheet density while CS/PECs lowered it. In conclusion, the gained fundamental understanding of these adsorption of additives is of significant importance to facilitate the industrial development of sustainable low-cost high-end packaging products. [ABSTRACT FROM AUTHOR]

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Abstract: A papermaking technique with a dual polyelectrolyte retention system was used for the preparation of NaY zeolite-containing papers, which implied the use of cationic and anionic polymers. Two kinds of fibers were employed, either cellulosic or ceramic ones, and accordingly papers with different characteristics were obtained: those that only contained cellulosic fibers for low temperature applications, cellulosic papers, and those prepared using both cellulosic and ceramic fibers – ceramic papers – for high temperature applications. Although a decrease in their mechanical properties due to calcination was observed, zeolitic ceramic papers resulted easy to handle for practical applications. Zeolite was quantified through BET surface area measurements. SEM images indicated a good dispersion of zeolite particles within the cellulosic paper whereas in the ceramic paper they appeared anchored on ceramic fibers. The zeolitic papers prepared resulted efficient as toluene sorbents, the adsorption capacities of zeolitic ceramic papers being higher than those of zeolitic cellulosic papers. In the case of zeolitic cellulosic papers, the amounts of released toluene were lower than those of adsorbed toluene, implying that the treatment up to 160°C did not completely eliminate the hydrocarbon. Also, TPD profiles showed that toluene is chemically retained up to high temperatures (ca. 420°C) in zeolitic ceramic papers. Toluene adsorption values demonstrate that zeolite dispersed into the cellulose/ceramic matrix is as effective as powder massive zeolite in retaining the hydrocarbon, which highlights the potential application of these zeolitic structures as sorbent materials both for low and high temperatures. [Copyright &y& Elsevier]

The reuse of paper solid waste (PSW) as a low-cost sorbent for Cd removal from aqueous phase was investigated. Batch experiments were conducted to study the effects of pH (3.5, 5.5, 7.5), contact time (10–360 min), PSW dose (2.5–20 g L−1), and Cd concentration (5–50 mg L−1) at an ionic strength of 0.01 M NaNO3on adsorption efficiency and capacity. Cd removal of ∼96% occurred in 20 mg L−1Cd solution at pH 5.5 containing 20 g L−1PSW. Equilibrium was attained after 120 min and the equilibrium adsorption capacity of PSW increased with increasing Cd concentration from 5 to 50 mg L−1. The kinetic process of Cd adsorption obeyed the pseudo-second-order kinetic model. Langmuir and Freundlich models described equally well the experimental data and the maximum adsorption capacity was 4.89 mg g−1. PSW can be used for reducing Cd concentration in Cd-contaminated water systems. [ABSTRACT FROM PUBLISHER]

Moisture adsorption and diffusion were examined in 17 samples of historical and modern papers and cardboards, differing in the time of production and the pulping process. The moisture adsorption data for paper materials made of rags, gelatin-sized were close to each other whereas wood-pulp papers showed higher intra-group variability due to varying contents of lignin and rosin sizing. The average adsorption curve for all specimens was close to that of pure cellulose. In-plane diffusivities along the paper sheets in a stack, primary direction of uptake and release moisture by library objects, were determined as a function of relative humidity and paper compression. Typically, the in-plane diffusivities fell within the range of 6 × 10−6-1.7 × 10−5 m2/s and were significantly affected by the paper fraction in the specimens which were combination of paper sheets and thin air layers or pockets between the sheets. The external mass transfer coefficient at the surface of the paper objects perpendicular to the paper sheets exceeded 2 × 10−3 m/s and significantly depended on the intensity of air motion in typical environments. Effective use of the adsorption and diffusion information obtained was demonstrated in modelling buffering capacities of books. [ABSTRACT FROM AUTHOR]

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]

• 1. A paper-based material with multitasking application is synthesized. • 2. Conjugated polymers and dopped Fe synergistically promote electron transfer. • 3. Self-cycled Fenton and PDA coating are constructed for enhanced photodegradation. • 4. Dynamic-static adjustable adsorption satisfies multi-scenario application. • 5. This composite shows high removal efficiency for organic pollutants and Cr (VI). Environmental remediation with the introduction of multiple driving forces has attracted much attention. Reasonable design of advanced paper-based materials with enhanced degradation capability, switchable adsorption process and excellent operation efficiency for wastewater remediation is desirable but challenging. In this work, by flexibly utilizing oxidative polymerization and self-assembly layer-by-layer strategy, a hierarchical cellulose paper-based material containing rough reactive top layer and photocatalytic bottom layer was successfully fabricated for multitasking wastewater repairing activities. A synergistic mechanism between the modified conjugated polymer and doped Fe was developed, achieving the rapid transfer of electrons through "two-channel" effect, thus sensitizing material. Through the introduction of self-cyclic Fenton system, enhanced photodegradation capability (98.3%) for organic pollutants was realized. The amino-rich polymer was introduced on the composites to develop the multitasking application, which successfully endowed material with the characteristic of high adsorption capacity (167.79 mg·g−1), rapid adsorption rate (50 min) and dynamic-static adjustable adsorption. Benefiting from such peculiarities, effective and low-cost treatment of complex and high toxic industrial wastewater prior to discharge was achieved. The reported material was facile-prepared and demonstrated cost-effective application, operation flexibility and stable regeneration advantages, is promising to achieve real-world applications. This work significantly contributed to the development of advanced paper-based materials for multitasking environmental remediation. [ABSTRACT FROM AUTHOR]

Cationic paper was prepared by reaction of paper with 2,3-epoxypropyltrimethylammonium chloride in aqueous suspension, and tested as low-cost adsorbent for wastewater treatment. The experimental results revealed that anionic dyes (Acid Orange 7, Acid Red 18, and Acid Blue 92) were adsorbed on the cationic paper nicely. The maximum amount of dye Acid Orange 7 adsorbed on cationic paper was 337.2 mg/g in experimental conditions. The effects of initial dye concentration, temperature, and initial pH of dye solution on adsorption capacity of cationic paper were studied. The pseudo-first-order and pseudo-second-order kinetic models were applied to describe the kinetic data. The Freundlich and Langmuir adsorption models were used to describe adsorption equilibrium. The thermodynamic data indicated that the adsorption process of dye on cationic paper occurred spontaneously [ABSTRACT FROM AUTHOR]

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]

Nowadays, biologically treated effluents (BTW) from pulp and paper industry still contain a significant organic load, which makes it unsuitable to discharge directly into the waterway. Therefore, a tertiary treatment by activated carbon adsorption was investigated. To improve the treatment efficiency of BTW in the pulp and paper industry, wood-based activated carbon (WAC) was modified by microwave irradiation (MWAC). WAC and MWAC were characterized by scanning electron microscopy, N2 adsorption, elemental analysis, Fourier transform infrared and X-ray photoelectron spectroscopy. Compared with WAC, MWAC has a higher surface area and lower oxygen-containing groups. The BTW adsorption capacity of MWAC is higher than that of WAC. WAC and MWAC were used to remove chemical oxygen demand (COD) in BTW and the effects of adsorbent dosage, contact time, pH and temperature on the removal of COD in BTW were studied. The adsorption isotherms of WAC and MWAC revealed that the Langmuir models applied to the adsorption process. Molecular weight analysis showed that 1,531 Da was the main component in untreated and treated BTW. MWAC seemed to be more effective in adsorbing small molecular organics due to more micropores. The result indicated that microwave radiation was an efficient method to modify activated carbon for BTW tertiary treatment. [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]

In this work, two pulps, bleached (BP) and raw pulp (RP), derived from the paper production process, were used as precursors of non-activated and activated carbons (ACs). In the case of non-ACs, the production involved either pyrolysis or pyrolysis followed by acid washing. For ACs production, the pulps were impregnated with K 2 CO 3 or H 3 PO 4 , and then pyrolysed and acid washed. After production, the materials were physically and chemically characterized. Then, batch adsorption tests on the removal of two pharmaceuticals (the anti-epileptic carbamazepine (CBZ) and the antibiotic sulfamethoxazole (SMX)) from ultra-pure water and from Waste Water Treatment Plant (WWTP) effluents were performed. In ultra-pure water, non-ACs were not able to adsorb CBZ or SMX while ACs showed good adsorption capacities. In WWTP effluents, although ACs satisfactorily adsorbed CBZ and SMX, they showed lower adsorption capacities for the latter. Tests with WWTP effluents revealed that the best adsorption capacities were achieved by carbons produced from BP and activated with H 3 PO 4 : 92 ± 19 mg g −1 for CBZ and 13.0 ± 0.6 mg g −1 for SMX. These results indicate the potential of paper pulps as precursors for ACs that can be applied in wastewater treatment. [ABSTRACT FROM AUTHOR]

Abstract: The results of assays carried out on plates used in the construction industry, manufactured entirely with solid wastes of a recycled paper plant, are presented and compared with the results obtained using agglomerated wood and plywood plates. Previous results had shown that wastes are composed essentially of polymers when these wastes are generated by recycled paper produced with the “waved type II” shavings. These solid wastes were placed in a mold that was heated and pressed with a hydraulic press in order to obtain the plates. The waste-produced plates were submitted to tests for humidity, swelling, water absorption, density, modulus of rupture-static bending, modulus of elasticity and direct screw withdrawal. These same assays had been carried out on two types of commercial wood plates, agglomerated wood and plywood, in order to compare the results with those obtained with the waste plate. Waste plates had similar behavior to the agglomerated wood plate, but it was possible to distinguish greater flexibility in the waste-produced plate and a significant difference in the tests for swelling and water absorption which showed the waste plate had a better performance than the agglomerated wood and plywood plates. [Copyright &y& Elsevier]

One of the surface treatments of paper is surface sizing. In this operation, hydrophobic polymers are added to paper in a size press, usually dissolved in an aqueous starch solution. We investigated the penetration of starch solutions in paper in a puddle size press. Starch penetration in paper was followed by x-ray microscopy. A mathematical model was developed, which explains the observed penetration depths. The model is an extension of the classical Lucas–Washburn theory, modified by a build-up of pressure inside the sheet during liquid penetration. The model predicts liquid penetration as a function of paper speed, nip load, viscosity of sizing solution and porosity, and surface chemistry of paper. [ABSTRACT FROM AUTHOR]

Waste newsprint paper was modified with dimethylamine (DMA) to obtain a tertiary amine type adsorption gel called DMA-paper gel. This new derivative was investigated for adsorption, from hydrochloric acid medium, of gold, palladium, and platinum as well as some base metals. The gel exhibited selectivity only for precious metals with a remarkably high capacity for Au(III), i.e., 4.6 mol/kg dry gel and comparable capacities, i.e., 2.1 and 0.9 mol/kg for Pd(II) and Pt(IV), respectively. Also, Au(III) was reduced to the elemental form during adsorption. Furthermore, column adsorption and subsequent elution of the adsorbed metal ions by acidic thiourea revealed encouraging recoveries (approximately 90%), thus enhancing the scope of the gel for effective preconcentration, separation, and recovery of precious metals. The effectiveness of recovery of precious metals from real industrial liquor was also tested, and it showed highly encouraging results with respect to the stability of the gel in the harsh medium, and selectivity for the targeted metal ions in the presence of excess of other metal ions. [ABSTRACT FROM AUTHOR]

This study concerns with the utilization of waste paper sludge, which contains mainly cellulose fibers and inorganic fillers together with coating materials such as calcite, kaolinite and talc. Paper sludge was fired at 500-900°C for 6 h. The crystalline phases originally present decomposed at increasing temperatures (up to 800°C) in the order kaolinite < calcite < talc. Gehlenite was formed at 800°C in increasing amounts above this temperature together with small amounts of magnesium aluminum silicate and anorthite. The uptake of these fired samples of Ni2+, PO43- and NH4+ was investigated at room temperature. Paper sludge fired at 700°C showed the highest uptake of Ni2+, PO43- and NH4+ (3.93, 1.28 and 0.49 mmol/g, respectively). The main process responsible for the sorption of these ions is the ion change along with precipitation with higher solution pH. From an economic point of view, paper sludge is the cheapest raw material for preparing adsorbents with high uptake ability for heavy metal, phosphate and ammonium ions. [ABSTRACT FROM AUTHOR]

Waste papers, although known as a potential global concern, could be used as an adsorbent for removal of lead ions from the aqueous medium, following some degrees of modifications. The present study deals with the adsorption of Pb(II) ion from aqueous solution by using phosphate-functionalized treated waste papers (PF-TWPs). Batch adsorption study was performed based on contact time, pH, adsorbent dose, and temperature. There was logical coordination of experimental data with Freundlich and Langmuir isotherms. The results of this study showed that the percentage of Pb(II) adsorption on the PF-TWPs increased with increasing pH of approximately 5.5, higher or lower pHs showed no remarkable variation in adsorption capacity. The kinetics analysis showed a substantial correlation between the experimental adsorption data with the pseudo-second-order model. Besides, thermodynamic studies were conducted to explore the adsorption of Pb(II) onto PF-TWPs, regarding the influence of temperature on this process. The spontaneity and endothermicity of the Pb(II) adsorption process were identified based on the negative free energy value and positive enthalpy change. The result of the present study showed that the PF-TWPs could be used as a cost-effective adsorbent for Pb(II) removal from industrial effluent. [ABSTRACT FROM AUTHOR]

comparison between activated charcoal and heat-treated coal for decolourization of pulp and paper mill waste water was studied. The heat-treated coal was prepared in an inert atmosphere at 800°C. The adsorption dynamics that include batch contact–time study, kinetics along with adsorption isotherms were carried out. The study shows that heat-treated coal is a suitable adsorbent and can be used for the decolourization of pulp and paper mill effluent streams. The maximum removal was achieved at the initial stages of contact, and the overall adsorption was a slow process. However, the equilibrium concentration in the case of both the adsorbents reaches at almost same time. The linear plot of the Lagergren model shows its applicability and first-order kinetics. [ABSTRACT FROM AUTHOR]

The described analytical method for histamine determination in fish and seafood consists of sample extraction, adsorption onto a paper disc, application of the paper disc onto electrophoresis paper, electrophoresis for only 10 min, drying, and color developing by Pauly’s reagent. Histamine can be satisfactorily detected and completely separated from histidine, carnosine and other Pauly reagent-positive compounds. This method does not require expensive instrumentation and any tedious pretreatment to eliminate potential interference by other imidazole compounds, such as histidine or carnosine. This method can be used to detect histamine in multiple fish and seafood samples simultaneously that contain as little as 15 p.p.m. histamine (1.5 mg/100 g). [ABSTRACT FROM AUTHOR]

Treatment of dyes in wastewaters is necessary to ensure environmental protection. In this work, sodium alginate (SA) was utilized for modifying filter paper (FP) through Williamson reaction with epichlorohydrin, and its purpose was to meet global needs of sustainable development, while ensuring good mechanical properties of the adsorbent in the aqueous phase and good interaction with the dye molecules. The obtained composites were evaluated for both tensile strength and adsorbability. The results of tensile tests demonstrated that the composites prepared with 4 wt% SA exhibited outstanding wet mechanical performance with the tensile strength and elastic modulus values of 1.84 and 126 MPa, respectively, about 25 times and 10 times higher compared to original FP. Adsorption experiments showed that the maximum adsorption capacity of the composites for methylene blue (MB) was 503.8 mg g−1, compared to only 88.0 mg g−1 for FP. Freundlich and Scatchard model for isothermal study of the composites demonstrated that the MB adsorption occurred on a heterogeneous surface by multilayer sorption, and its kinetic study revealed that the adsorption of MB followed the pseudo-second-order kinetic model. Furthermore, the filtration performances for the composites and original FP showed that the percentage removal of MB on FP was only 36.3%, while that of the composite was 93.9%. The above results suggested that the prepared composites not only had good mechanical properties but could also adsorb the MB molecules efficiently from the aqueous phase. Therefore, the preparation of this bioadsorbent would be useful for environmental protection and sustainable development of resources. [ABSTRACT FROM AUTHOR]

The preparation and application of heteroatom doped carbons have attracted lots of attention in the past years. In the current work, a facile synthesis of nitrogen doped carbon with filter paper as the carbon source and urea as the nitrogen source was presented. Filter paper was first impregnated with urea solution, and was then carbonized and activated. The carbons' physical and chemical properties were studied. For the application in CO 2 adsorption, impacts from porous characteristics and nitrogen doping were discussed and differentiated. The results suggested that nitrogen doping was beneficial to the improvement of CO 2 uptake, but suitable porous properties were the most important factors. Nitrogen doping showed more significant effects on enhancing the adsorption heat and selectivity. The research of carbonaceous CO 2 adsorbent should focus on nitrogen doped carbons with high porosity. • Urea loaded filter paper is used as starting material for nitrogen doped carbon. • Effects of nitrogen doping and porous structure on CO 2 adsorption are studied. • CO 2 uptake at 273 K and 1 bar reaches 5.12 mmol/g. • Nitrogen doping has obvious effects on CO 2 adsorption heat and selectivity. [ABSTRACT FROM AUTHOR]

In this study, we report for the first time few-layered MoS2 nanosheets grown onto graphene dipped cellulose filter paper (M-G-CFP) using a simple hydrothermal method towards efficient adsorption of cationic methylene blue (MB) dye. Detailed morphological and chemical characterization studies of M-G-CFP are performed using FESEM, TEM, XRD and Raman spectroscopy that reveal micro flower-like MoS2 grown onto graphene modified paper with few layers of MoS2 nanosheets and its high purity nature. Due to electrostatic interactions between cationic dye and the anionic adsorbent surface, the hybrid M-G-CFP exhibits ultrafast removal of MB within 2 min with a maximum adsorption capacity of 485.4 mg g−1 which is superior in comparison to other reported MoS2 based adsorbents. This high adsorption capacity is attributed to large accessible active sites on the surface of the hybrid M-G-CFP structure. The adsorption mechanism of MB dye on the MoS2 nanosheets are well described using kinetic and isotherm models with the effects of parameters like pH, contact time and temperature. The kinetic and isotherm study reveals that the adsorption of MB dye follows a pseudo-second order model, indicating the chemisorption and Langmuir model of monolayer adsorption, respectively. Furthermore, this hybrid structure can be efficiently reused for subsequent dye adsorption without compromising on its dye removal efficiency suggesting it is a feasible and promising material towards wastewater treatment applications. [ABSTRACT FROM AUTHOR]

Adsorption gel was prepared from waste recycled paper by immobilizing iminodiacetic acid (IDA) functional group by chemical modification. The gel exhibited good adsorption behavior for a number of metal ions viz. Cu(II), Pb(II), Fe(III), Ni(II), Cd(II), and Co(II) at acidic pH. The order of selectivity was found to be as follows: Cu(II)>Pb(II)>Fe(III)>Ni(II)∼Cd(II)∼Co(II). From the adsorption isotherms, the maximum adsorption capacity of the gel for both Cu(II) and Pb(II) was found to be 0.47 mol/kg whereas that for Cd(II) was 0.24 mol/kg. A continuous flow experiment for Cd(II) showed that the gel can be useful for pre-concentration and complete removal of Cd(II) from aqueous solution. [ABSTRACT FROM AUTHOR]

Paper clay has several properties that make its use in vertical barriers very promising. In this paper the characteristics of two paper sludges (which will also be referred to as paper clays) one from the Erving Paper Company and one from the International Paper Company are considered. To determine the feasibility of paper clay for heavy metal attenuation, batch tests, column tests, hydraulic conductivity tests, and pressure filtration tests were performed. Batch testing showed that the metal, the distribution coefficient (Kd) ranged from as low as 0.002 L/g for manganese to as high as 6.7 L/g for lead in International paper clay. In the Erving paper clay the Kd ranged from 0.007 L/g for manganese to 1.9 L/g for cadmium, while the International paper clay Kd ranged from 0.002 L/g for manganese to 6.7 L/g for lead. Chemisorption was established as the predominant metal binding mechanism in both clays with the only exceptions being manganese adsorption on International paper clay that indicated a constant partitioning, and copper and lead on Erving paper clay that indicated constant partitioning and cooperative adsorption, respectively. Both hydraulic conductivity and pressure filtration tests revealed permeabilities ranging from 10-5 to 10-7 cm/s. Chloride testing showed that the coefficient of hydrodynamic dispersion (D) within paper clay is on the order of 10-7 cm2/s. [ABSTRACT FROM AUTHOR]

The porous metallic iron/carbon (Fe∘/C) ceramsites, with virtues of low cost and 'green' fabrication, were prepared by direct reduction roasting of magnetite, coal, and paper mill sludge. The X-ray diffraction data revealed that Fe∘ was generated in situ by reducing the magnetite at 1,200 °C. Scanning electron microscopy with energy-dispersive X-ray spectroscopy indicated that Fe∘ particles, with a size of <10 μm, were highly dispersed on carbon particles to form an integrated anode (Fe∘) and cathode (C) structure of microelectrolysis filters. The effects of initial solution pH and Fe/C mass ratio on Cu2þ removal were investigated. The extent of Cu2þ removal increased from 93.53% to 99.81% as initial pH rose from 2.5 to 7.0. The residual Cu2þ concentration was as low as <0.2 mg/L. The highest extent of Cu2þ removal was achieved at Fe/C mass ratio of 6.8:1. The pseudo-second-order kinetic model fitted well for Cu2þ removal by the ceramsite, revealing the chemisorption as a limiting step. The Cu2þ adsorption equilibrium datawerewell described by the Langmuir isotherm, with a maximum adsorption capacity of 546.45 mg/g at initial pH 3.0. [ABSTRACT FROM AUTHOR]

Biocellulose or bacterial cellulose (BC) is a biocompatible (nano) material produced with a threedimensional network structure composed of microfibrils having nanometric diameters obtained by the Gluconacetobacter xylinus bacteria. BC membranes present relatively high porosity, allowing the incorporation or synthesis in situ of inorganic nanoparticles for multifunctional applications and have been used as flexible membranes for incorporation of magnetic nanocomposite. In this work, highly stable superparamagnetic iron oxide nanoparticles (SPION), functionalized with polyethylene glycol (PEG), with an average diameter of 5 nm and a saturation magnetization of 41 emu/g at 300K were prepared. PEG-Fe2O3 hybrid was dispersed by mixing a pristine BC membrane in a stable aqueous dispersion of PEG-SPION. The PEG chains at PEG-SPION's surface provide a good permeability and strong affinity between the BC chains and SPION through hydrogen-bonding interactions. PEG-SPION also allow the incorporation of higher content of nanoparticles without compromising the mechanical properties of the nanocomposite. Structural and magnetic properties of the composite have been characterized by XRD, SEM, energy-dispersive X-ray spectroscopy (EDX), magnetization, Raman spectroscopy, and magnetic force microscopy. [ABSTRACT FROM AUTHOR]

Cationic modification of cellulose fibers is an effective strategy to improve the absorptive capacity of anionic dyes and promote wastewater treatment. In this study, cationic cellulose nanofibers (CCNFs) with different degrees of substitution (DS) were prepared by grafting cellulose fibers with 2, 3-epoxypropyltrimethylammonium chloride (EPTMAC) and homogenizing. The synthesized CCNFs were employed in salt-free dyeing of ultra-lightweight paper. It showed that the maximum adsorption capacity of CCNFs for anionic dye was 1281.74 mg/g, and the dye uptake was as high as 90% under mild conditions without NaCl. Dyeing adsorption dynamics and isotherm analyses revealed that the dyeing process was monomolecular chemical adsorption. Moreover, compared with the control group and blank group, the dyed ultra-lightweight paper added with CCNFs not only had better color fixation and dye uptake, but also possessed higher breaking stress. This study fully confirmed the great potential of CCNFs in the salt-free dyeing of cellulose. [ABSTRACT FROM AUTHOR]

This paper deals with the removal of Cu2+ from water using adsorbent materials prepared from paper industry waste materials (one de-inking paper sludge and other sludge from virgin pulp mill). Experimental results showed that de-inking paper sludge leads to mesoporous materials (V mic/V T =0.13 and 0.14), whereas the sludge from virgin pulp mill produces high microporous adsorbents (V mic/V T =0.39 and 0.41). Adsorbent materials were then used for Cu2+ removal from water at acid pH. During water treatment, heavy metals lixiviation from adsorbent materials was not produced. However, important Ca and Mg leaching was observed. Final pH significantly increases after treatment of water with adsorbent materials probably due to their elevated CaCO3 content. In general, highest Cu2+ removal was obtained using adsorbent materials from de-inking paper sludge. This result could be due to their higher content in oxygenated surface groups, high average pore diameter, elevated superficial charge density, high CaCO3 amount and high Ca and Mg exchange content. [Copyright &y& Elsevier]

“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]

Highlights: [•] 9–12h adsorption of CO2 in the 1st cycle increases cyclic CO2 adsorption of APMW. [•] Repeated prolonged adsorptions in cycles are feasible to capture CO2 using APMW. [•] Prolonged adsorption increases pores in 10–100nm of APMW after desorption of CO2. [Copyright &y& Elsevier]

Adsorption isotherms of 3 selected paper-based packaging materials, that is, vegetable parchment (VP) paper, Kraft paper, and solid-bleached-sulfate (SBS) paperboard, were determined at 3 different temperatures (25, 40, and 50 °C). The GAB isotherm model was found to fit adequately for describing experimental adsorption isotherm data for the paper samples. The monolayer moisture content of the paper samples decreased with increase in temperature, which is in the range of 0.0345 to 0.0246, 0.0301 to 0.0238, and 0.0318 to 0.0243 g water/g solid for the MG paper, the Kraft paper, and the SBS paperboard, respectively. The net isosteric heats of sorption ( qst) for the paper samples decreased exponentially with increase in moisture content after reaching the maximum values of 18.51, 27.39, and 26.80 kJ/mol for the VP paper, the Kraft paper, and the SBS paperboard, respectively, at low-moisture content. The differential enthalpy and entropy of 3 paper samples showed compensation phenomenon with the isokinetic temperature of 399.7 K indicating that water vapor had been adsorbed onto the paper samples with the same mechanism. Depending on the paper material, tensile strength of paper samples was affected by moisture content. [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]