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Flotation deinking is one of the most widely used techniques for the separation of ink particles from cellulose fibers during the process of paper recycling. It is a complex process influenced by a variety of factors, and is difficult to represent and usually results in models that are inconvenient to implement and/or interpret. In this paper, a comprehensive study of several machine learning methods for the prediction of flotation deinking performance is carried out, including support vector regression, regression tree ensembles (random forests and boosting) and Gaussian process regression. The prediction relies on the development of a limited dataset that assumes representative data samples obtained under a variety of laboratory conditions, including different reagents, pH values and flotation residence times. The results obtained in this paper confirm that the machine learning methods enable the accurate prediction of flotation deinking performance even when the dataset used for training the model is limited, thus enabling the determination of optimal conditions for the paper recycling process, with only minimal costs and effort. Considering the low complexity of the Gaussian process regression compared to the aforementioned ensemble models, it should be emphasized that the Gaussian process regression gave the best performance in estimating fiber recovery (R2 = 97.77%) and a reasonable performance in estimating the toner recovery (R2 = 86.31%). [ABSTRACT FROM AUTHOR]

The need for a biological replacement in the deinking process, instead of chemical alkaline, which creates maximum pollution to the environment, has thrust all researchers to search for a better possible compound to treat printed paper, possibly from waste. The present study focused on screening lipase-producing bacteria from the food industry waste and using it to deink waste printed paper. A bacterial colony showing lipolytic activity was screened, identified, and used for further analysis. The isolated microbe was identified as Priestia endophytica SSP strain by molecular characterization using 16 s RNA sequencing. The microbial lipase production from Priestia endophytica SSP was optimized for medium components in lipase production using PB and RSM design. The optimized condition was found to be 4.37% peptone and 1.68% cottonseed oil, incubated at 35.3 °C for 134.76 h to reach its optimum lipase activity (188.51 IU/ml). The crude lipase was also characterized using FTIR, H-NMR, and XRD for functional and structural elucidation. Lipase produced at the optimum condition was separated and applied as a crude enzyme for microbial deinking of printed waste papers. It shows 69.61% deinking efficiency at 3% w/v of pulp. SEM analysis was carried out to study the structural changes in the deinked pulp material, showing good performance without affecting the pulp character. UV analysis of the deinked effluent revealed that the effluent is less toxic. [ABSTRACT FROM AUTHOR]

Biofuels are the cheapest source of energy, and the continuous decline of traditional sources of energy with the increasing population leads to looking for alternatives to reduce the consumption of traditional sources of energy. Bioethanol production from lignocellulosic wastes and cellulosic wastes is not a new approach for fuel production but a cheap and accessible way for the production of fuel. Bacillus is one of the major species that can act as a source of diversified enzymes. In this study, it was emphasized on screening and isolation of a novel, characterization, and best catalytic action on both celluloses and proteins in the presence of different carbon and nitrogen sources. It was observed the effective catalytic breakdown of cellulose with the crude enzyme to glucose allowed fur for fermentation with Saccharomyces, ultimately leading to the generation of alcohol. The study aims to isolate the microbes that can produce cellulases and enzymes and could be used for biodegradation to produce ethanol in the reaction. The maximum enzyme activity was achieved at 3.112 UI with optimized pH and temperature, and the maximum conversion of sugars into alcohol was about 70% in the newspaper, cartons, colored paper, and disposable paper cups. An essential observation was the decolorization of the origami craft paper within 24 hours. The study was involved in enhancing the maximum Enzyme activity of cellulases from different cellulosic raw materials. Hence, it was achieved by JCB strain, optimization of pH, temperature, and acids for the biodegradation. The presence of peaks at 3200 and 2900 was a confirmation of ethanol bonds in the biodegradation reaction mixtures. [ABSTRACT FROM AUTHOR]

Self-powered electronic equipment has rapidly developed in the fields of sensing, motion monitoring, and energy collection, posing a greater challenge to triboelectric materials. Triboelectric materials need to enhance their electrical conductivity and mechanical strength to address the increasing demand for stability and to mitigate unpredictable physical damage. In this study, polyaniline-modified cellulose was prepared by means of in situ polymerization and compounded with polydimethylsiloxane, resulting in a triboelectric material with enhanced strength and conductivity. The material was fabricated into a tubular triboelectric nanogenerator (TENG) (G-TENG), and an electrocatalytic pretreatment of mixed office waste paper (MOW) pulp was performed using papermaking white water as the flowing liquid to improve the deinking performance. The electrical output performance of G-TENG is highest at a flow rate of 400 mL/min, producing a voltage of 22.76 V and a current of 1.024 μA. Moreover, the deinking effect of MOW was enhanced after the electrical pretreatment. This study explores the potential application of G-TENG as a self-powered sensor power supply and emphasizes its prospect as an energy collection device. [ABSTRACT FROM AUTHOR]

Flotation deinking is one of the most widely used techniques for the separation of ink particles from cellulose fibers during the process of paper recycling. It is a complex process influenced by a variety of factors, and is difficult to represent and usually results in models that are inconvenient to implement and/or interpret. In this paper, a comprehensive study of several machine learning methods for the prediction of flotation deinking performance is carried out, including support vector regression, regression tree ensembles (random forests and boosting) and Gaussian process regression. The prediction relies on the development of a limited dataset that assumes representative data samples obtained under a variety of laboratory conditions, including different reagents, pH values and flotation residence times. The results obtained in this paper confirm that the machine learning methods enable the accurate prediction of flotation deinking performance even when the dataset used for training the model is limited, thus enabling the determination of optimal conditions for the paper recycling process, with only minimal costs and effort. Considering the low complexity of the Gaussian process regression compared to the aforementioned ensemble models, it should be emphasized that the Gaussian process regression gave the best performance in estimating fiber recovery (R2 = 97.77%) and a reasonable performance in estimating the toner recovery (R2 = 86.31%).

Rheinheimera sp. laccase was cloned and engineered to truncate domain 3 previously in our laboratory. This engineered laccase was found to deink old newsprint paper (ONP) without the need of any mediator. Response surface methodology (RSM) for statistical optimization of deinking conditions achieved deinking efficiency of 55.66% with enzyme dose of 130 U/g odp (oven-dried pulp), treatment time of 4 h and pulp consistency 5%, irrespective of the presence or absence of mediator (1-hydroxybenzotriazole; HBT). The optimized enzymatic pretreatment for deinking was validated in the R&D setup of Kuantum Papers Ltd., Hoshiarpur, Punjab (India), and an increase of 16.69, 17.18, 11.62 and 25% in brightness, breaking length, tear factor and burst factor, respectively, was achieved in addition to reducing the usage of hazardous chemicals by 50%. These results show the promising application of a greener enzymatic approach for environmentally sustainable paper recycling. [ABSTRACT FROM AUTHOR]

Background The bleach-boosting capability of xylanases is well-known. The use of xylanase pre-treatment before the application of chemical bleach has multiple advantages including (i) lesser use of polluting chemicals of the traditional bleaching process; (ii) less damage to the cellulosic fbers, therefore better recyclability; and (iii) better brightness of chemical bleach. The major impediment in the application is the availability of commercial enzymes that are active at the elevated temperature and pH that exist during the industrial pulping process. In the present paper, xylanase having suitability for application in deinking is reported. Results The xylanase used showed high deinking potential. Optimal deinking was obtained at the xylanase dosing of 20U/g of the dried pulp at 60°C for a treatment time of 1h. It could bring about a 50% reduction in the usage of chemical bleach that was applied after xylanase pre-treatment. The comparison of FTIR spectra showed changes in intensity without signifcant changes in the functional group signatures implying that there is negligible damage to the fber strength in the xylanase pre-treatment process as compared to the chemical bleach process. Conclusion The xylanase used in this study was efective in deinking paper pulp and can be used for bio-bleaching of recycled paper. [ABSTRACT FROM AUTHOR]

Self-powered electronic equipment has rapidly developed in the fields of sensing, motion monitoring, and energy collection, posing a greater challenge to triboelectric materials. Triboelectric materials need to enhance their electrical conductivity and mechanical strength to address the increasing demand for stability and to mitigate unpredictable physical damage. In this study, polyaniline-modified cellulose was prepared by means of in situ polymerization and compounded with polydimethylsiloxane, resulting in a triboelectric material with enhanced strength and conductivity. The material was fabricated into a tubular triboelectric nanogenerator (TENG) (G-TENG), and an electrocatalytic pretreatment of mixed office waste paper (MOW) pulp was performed using papermaking white water as the flowing liquid to improve the deinking performance. The electrical output performance of G-TENG is highest at a flow rate of 400 mL/min, producing a voltage of 22.76 V and a current of 1.024 μA. Moreover, the deinking effect of MOW was enhanced after the electrical pretreatment. This study explores the potential application of G-TENG as a self-powered sensor power supply and emphasizes its prospect as an energy collection device.

The main aim of the present research is to examine the effect of progressive deinking and reprinting on the paper properties of inkjet-printed paper. A typical office copy paper was selected as the base paper and printed using an inkjet printer having at least 50 % ink coverage. Thereafter, it was deinked and reprinted thrice, and its paper properties were measured. The paper properties that were measured were roughness, porosity, opacity, brightness, specular gloss, whiteness, bursting strength, tearing resistance, tensile strength, contact angle, deinkability efficiency, visible dirt area, ink elimination factors, and color differences. The results showed that in comparison to the base paper, the progressively deinked and reprinted paper samples showed an increase in roughness, porosity, opacity, tearing resistance, dirt area, and color difference. On the other hand, there was a decrease in brightness, gloss, whiteness, burst strength, tensile strength, contact angle, deinkability efficiency, and ink elimination factors. The experiment shows that the progressively deinked and reprinted papers can be compared to the base paper in the major paper properties. [ABSTRACT FROM AUTHOR]

On the market there are increased quantities of laminated cardboard packaging with glossy surface. Laminated packaging is being used for its appealing appearance. However, laminated paper treatment creates additional problems in the process of recycling of used product. Adhesives and foil are a specific issue in the separation of impurities in recycled paper. It is crucial that the paper packaging products contained in the paper for recycling are repulpable within standard operating time and equipment. In this research three methods (without chemicals, INGEDE 11 and their combination) of removing impurities from paper pulp are compared and their efficiencies are determined to gain deeper insight into the recycling process. The procedures determine the recyclability of existing printed material, as well as the possible adhesive and material improvements. A specific issue in the separation of impurities was the presence of adhesives as well as silver foil (BOPET metallized film) for lamination. All three applied procedures successfully separate impurity particles from paper pulp and printed laminated boxes in a more sustainable manner, without the use of chemical agents.

The present study develops an effective and sustainable catalytic system using mesoporous (KIT-6 and NbKIT-6) and microporous catalysts (ZIF-8) for the conversion of newspaper waste to value-added products such as TRS (Total reducing sugars) and 5-HMF (5-Hydroxymethyl furfural). The bio-based products were produced using green and biodegradable solvent Choline chloride in presence of sustainable catalysts under mild operating conditions at 1 atm pressure. The study demonstrated the potential of monophasic (Choline chloride and Catalyst) and biphasic (Choline chloride, Catalyst and Extracting solvent) system and revealed their comparative insights. It was observed that both the systems were highly effective but the purity and stability of products were higher in the biphasic system compared to the monophasic system. The synthesised catalysts possess high surface area 588.528, 534.414 and 351.85 m2/g with pore volume 0.7587, 0.3574 and 0.2362 cc/g for KIT-6, NbKIT-6 and ZIF respectively. The selected extracting solvents were found to be promising and the maximum 5-HMF yield was found to be 62.12%, 73.45% and 79.66% in DMSO medium using KIT-6 (160 °C, 135 min), NbKIT-6 (140 °C, 90 min) and ZIF-8 (140 °C, 105 min) catalysts respectively. Also, all the catalysts are reusable for up to five runs with minimal loss in catalyst activity. The proposed catalytic system will help to resolve the challenges associated with biorefineries in terms of product separation and recyclability of catalysts.

The primary aim of this study is to determine the effectiveness of separating ink particles which are adherent to cellulose fibers from cellulose fibers after recycling. In addition, after recycling, physical and optical changes in cellulose fibers are observed and inkjet and laserjet printing properties are investigated in some parameters. Initially, the reference papers are recycled according to the 11p standard. After this stage, the pulps are subjected to double stage bleaching (0.4% FAS + H2O2). Then, color scales are printed with inkjet and laserjet printers, and color measurements are made with X-Rite Exact spectrophotometer. These papers are again recycled according to the INGEDE 11p standard. As a result of the calculations, it is observed that there is an accurate ratio between the number of recyclings and the detachability of ink particles from cellulose fibers. In addition, it is determined that the resistance properties of the papers subjected to the second recycling stage are weakened and the porosity increased according to the obtained data. After the second recycling stage, it is determined that the cellulose peak values obtained in the FTIR spectrum became more pronounced and the results overlapped when compared with the ERIC values. In the SEM images, it can be said that after the second recycling stage, the fringing of the fibers increases with hornification and the fiber surface area began to expand. [ABSTRACT FROM AUTHOR]

Recycling technology contributes to sustainability and has received considerable interest in fulfilling consumable products’ social demands, including papers. Recycled fibers are the primary source of the papermaking industry. Papers, valuable daily used materials, can be further recycled for further implementation. Here, we report a simple method for recycling waste papers for further use. Our method includes re-pulping, deinking, bleaching, and papermaking. The sample and the recycled papers were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). XRD data shows the presence of cellulose and filler minerals in the sample and the recycled papers. FTIR analysis confirmed the presence of hydroxyl, carbonyl, and methyl functional groups in the recycled papers suggesting that the deinking and bleaching did not cause any structural changes. The fibrous structures were also sustained after recycling, as confirmed by SEM studies demonstrating that the recycling was successful and the papers can be further used and recycled. EDS analysis further confirmed the filler minerals in the sample paper with a trace amount of lead, which decreased upon bleaching the paper. The structure and properties of the sample and the recycled papers were quite similar, inferring that waste papers can be recycled again and different products from low to higher grade papers can be fabricated. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cellulose nanocrystals (CNC) were successfully prepared from waste newspapers through a simple pretreatment and hydrolysis process. The Fourier transform infrared spectroscopy (FTIR) result for the CNC suggested that no new chemical bonds were formed during the preparation of CNC. X-ray diffraction results indicated that the crystallinities of the deinked and untreated waste newspapers were 66% and 73.8%, respectively. Greater smoothness of the deinked waste newspapers fibers could be clearly observed by scanning electron microscope (SEM), which was attributed to the removal of ink from the chemical treatment. The transmission electron microscopy (TEM) and atomic force microscopy (AFM) results of the CNC revealed a needle-like natural fiber with a length of 300 nm to 600 nm, a diameter of 10 nm to 30 nm, and an aspect ratio in the 10 to 60 range. The obtained CNC particles were found to improve the physical properties of paper sheets, specifically that of the tear, tensile, and burst indices. The maximum increase in the physical properties was achieved with a 5.5% CNC addition.

Beauveria bassiana is an entomopathogenic fungus widely used as a biopesticide for insect control; it has also been shown to exist as an endophyte, promoting plant growth in many instances. This study highlights an alternative potential of the fungus; in the production of an industrially important biocatalyst, xylanase. In this regard, Beauveria bassiana SAN01 xylanase was purified to homogeneity and subsequently characterized. The purified xylanase was found to have a specific activity of 324.2 U.mg-1 and an estimated molecular mass of ~37 kDa. In addition, it demonstrated optimal activity at pH 6.0 and 45 °C while obeying Michaelis-Menton kinetics towards beechwood xylan with apparent Km, Vmax and kcat of 1.98 mg.mL-1, 6.65 μM.min-1 and 0.62 s-1 respectively. The enzyme activity was strongly inhibited by Ag2+ and Fe3+ while it was significantly enhanced by Co2+ and Mg2+. Furthermore, the xylanase was shown to effectively deink wastepaper at an optimal rate of 106.72% through its enzymatic disassociation of the fiber-ink bonds as demonstrated by scanning electron microscopy and infrared spectroscopy. This is the first study to demonstrate the biotechnological application of a homogeneously purified glycosyl hydrolase from B. bassiana. [ABSTRACT FROM AUTHOR]

To reuse recycled cellulosic fibers in paper production, contaminated particles and other impurities of the fibers can be greatly removed using a de-inking stage which is considered as a supplementary step in waste paper recycling technology. The effect of using ultrasonic pretreatment on the deinking of old newspapers was investigated utilizing the common conventional chemical method across this research work. Experimental design method was served to optimize the amount of ultrasonic bath temperature and sonication time. Therefore, 13 tests were designed using Response Surface Methodology (RSM) and Central Composite Design with Design Expert 7.0.0 Trial software. Ultrasonic bath temperature and sonication time at three different levels (1, 0 and 1+) and two axial points (α + and α-) were used as independent variables, and the optical and mechanical properties of handsheets were used as dependent variables. Response surfaces and contour plots were served to show the interaction between the independent variables and the response variable. ANOVA test showed that the quadratic model is the best model to explain the interaction among the studied variables. The predicted values of the obtained model had much conformity with the experimental results (R2=0.98). According to ANOVA results, it can be concluded that the effect of each of the variables on the optimal properties is significant and the ultrasonic time is the most effective factor on the response. According to the results, the proposed optimum conditions to achieve the highest amount of mechanical and optical properties (43.43) are the ultrasonic bath temperature 47 oC and the ultrasonic time of 31 min.

Bu çalışmada, ofis (A4), kuşe, oluklu mukavva, NSSC (Nötral sülfit yarı kimyasal hamur), gazete ve karışım kâğıtları üzerine hamurlaştırma işlemleri yapılmıştır. Bu işlemin sonunda ise dövme ve ardından mürekkep giderme işlemi yapılmıştır. İşlem sonunda ise elde edilen test kâğıtlarına ise bazı testler yapılmıştır. Çalışmada, kontrol amaçlı standart yüzdürme metoduna göre mürekkep giderme işlemi yapılmıştır. Bu amaçla, sodyum hidroksit, hidrojen peroksit, sodyum silikat, oleik asit ve kalsiyum klorür ingede metoduna göre uyarlanarak kullanılmıştır.

The ozone reactive flotation for deinking recovered cellulosic fibers, recently developed at lab scale, showed interesting results in terms of fiber yield and effluent pollution reduction with classical recovered fibers furnishes made of old magazines and old newspapers. However, deinked pulp yellowing occurred. To further develop the ozone-based deinking process, a deeper investigation was conducted to evaluate the effect of ozone reactivity with the cellulosic fibers, and with soluble contaminants originating from the recovered lignocellulosic fibers. For that purpose, flotation trials with air or ozone/oxygen as the gas flow were conducted on model recovered fiber pulps, free of ink particles and contaminants. Two models have been studied, the first containing 100% bleached Kraft pulp and the second one a mixture of 90% bleached Kraft pulp and 10% unbleached thermomechanical pulp to simulate wood-free lignocellulosic fibers furnishes. Moreover, flotation trials were carried out using tap water to submit only cellulosic fiber to the action of ozone and also using industrial model process water containing classical recovered paper contaminants to evaluate the effect of ozone reactivity with soluble species. It has been shown that the deinked pulp brightness increased when ozone was applied to the flotation of wood-free pulp models. Ozone did not impact the deinked pulp strength properties. These results confirmed that ozone reacts preferentially with soluble contaminants, as the deinked pulp strength properties were preserved, which is driving the strong reduction of effluent soluble COD. Analysis of O3 consumption revealed that ozone self-decomposition into water prevailed as well as the reaction with soluble contaminants or water components. In conclusion, reactive ozone-based flotation appears to be a promising green and efficient deinking process for wood-free recovered lignocellulosic fiber recycling. Abbreviations: ONP: old newspaper; OMG: old magazine; MOW: mixed office waste; ERIC: residual ink concentration; NTP: normal conditions of temperature and pressure. [ABSTRACT FROM AUTHOR]

The effects of cellulase enzymes (Trichoderma reesei) in flotation deinking of mixed office wastes (MOW) on the deinking efficiency, physical and optical properties of the papers were investigated. In order to determine the effects of cellulase, conventional chemical deinking was also performed and compared with enzymatic deinking. After deinking processes, the handsheets were produced to determine deinking efficiency and physical and optical properties. Dirt particle analyses, Effective Residual Ink Concentrations (ERIC) and deinking efficiency (IEERIC) were determined to clearly understand effects of cellulase on deinking of MOW. IEERIC values of papers obtained from enzymatic and chemical deinked pulps were 11.9 and 62.0%, respectively. Use of cellulase enzyme by itself was not as effective as conventional deinking. Furthermore, optical properties of enzymatic deinked papers were lower than those of chemical deinked papers. These negations were eliminated by combining enzymatic and chemical deinking processes. Chemical charge used in conventional deinking were reduced by half with using cellulase. Properties of papers obtained from this deinking process were better than both enzymatic and chemical ones. This suggests that using cellulase enzyme in deinking process of MOW have a great potential as an alternative to chemical conventional deinking per se. [ABSTRACT FROM AUTHOR]

Three approaches were examined for the reutilization of cold caustic extraction (CCE) lye. The term CCE lye refers here to the used NaOH solution with relatively high alkali content, which could be wasted if not reused properly. The results showed that CCE lye can be effectively applied in deinking, alkaline hydrogen peroxide bleaching, and oxygen delignification processes. The CCE lye improved the physical strength of the dried sheet of pulp, as the tensile index increased by 17.9% to 40.5%, the tear index increased by 2.9% to 22.2%, and the burst index increased by 10.5% to 41.0%. The results demonstrated the feasibility of integrating the CCE process of dissolving pulp production with regular pulping and bleaching processes. [ABSTRACT FROM AUTHOR]

Recycling paper is worthy alternative to cut down the dependence on trees thereby preventing the hazards like deforestation. Deinking is an important step in the recycling process which involves the removal of ink particles from fiber surface and decolorization of the dislodged ink. Enzymes such as laccases may prove eco-friendly cost effective alternatives to the conventional chemicals methods used for the recycling process. However, the commercial application of this enzyme is limited by insufficient production and less stability. Hence, in this study, the laccase produced by basidiomycetes species, P. ostreatus was evaluated for its potential as a deinking agent. P. ostreatus was able to grow on many cheap substrates and when grown in the medium containing sawdust showed significant laccase production. Addition of 5g/L of Al2O3 microparticles (microparticle enhanced cultivation) improved the production of laccase. The maximum activity of P. ostreatus laccase was observed at pH 3 and at 28°C. Activity was further stabilized by incorporation of Copper ions and immobilization in Ca-alginate beads. The enzyme was capable of decolorizing ink from color printer cartridge and from low quality coloured papers such as bus tickets. The brightness of the handsheets made from pulp was more pronounced than those treated with chemicals. [ABSTRACT FROM AUTHOR]

In this study, first of all, pulping processes were applied on white A4 office paper which was applied laser printing. Then, mixtures were prepared in the proportions determined on the pulped office papers. In this pulping and mixture preparation process, different ratios of chemicals and enzymes were utilized. As chemical substances, oleic acid, sodium hydroxide, sodium silicate, calcium chloride and hydrogen peroxide were used and cellulase, xylanase, amylase and β-gluconase were used as enzyme. Then, ultrasound effect was examined. Finally, the pulp suspension was removed from the inks by flotation. At the end of all these processes, wastewater analysis was performed. [ABSTRACT FROM AUTHOR]

In this study, investigates recycling possibilities of office paper in archive form (stored for at least 5 years). These papers are mostly made by burning. This is to destroy tons of paper raw materials. These papers may be presented with a simple pulping or recycling with small fractionation. This will contribute greatly to the country's economy. The study will also look at the physical and optical properties of these papers. These papers are likely to lose fiber resistance and brightness due to the physical conditions (humidity, temperature) and the mushrooms and insects. In addition, loss of the shine and resistance of the fibers will come to the fore when the ink is removed from these papers. How much of these losses are in the study will be investigated. This will be done in conjunction with a number of applications to compensate for losses. With these operations, tons of waste paper raw materials will be obtained and new waste white office paper will be produced with the desired quality. [ABSTRACT FROM AUTHOR]

Bioethanol production using paper wastes seems a promising approach towards sustainable energy, but mainly hindered by hazardous ink. Therefore, in our experimental plan various methods were applied for the deinking of waste newspapers, laser printed papers and examination papers. A newly designed paper pulper reduced the pulping time from 6 h to 2 h. Cellulase (15 FPU/g) from Aspergillus oryzae MDU-4 was found effective for the deinking of newspapers, whereas laccase isozymes (150 U/g) from Ganoderma lucidum MDU-7 along with 2 mM HOBt was preferred for the ink removal and degradation from the examination papers. Ozonation in the presence of Tween-80 was found to be efficient in the removal of toxic toners used in laser printing papers. The biologically and physically deinked papers, studied with the help of SEM, TEM, FTIR, and XRD analysis revealed significant changes in the chemical and surface structure. Moreover, the saccharification of deinked papers with the help of an enzymatic consortium of Trichoderma citrinoviride MDU-1 resulted in 305 mg/g, 377 mg/g, and 409 mg/g release of sugars from the newspaper, examination paper, and laser printed paper, respectively. Finally, the enzymatic hydrolysates fermented with Saccharomyces cerevisiae NCIM-3640 produced 3.35 g/L ethanol, with 40.85% ethanol yield. Image 1 • Pulping time was reduced from 6 h to 2 h by designing a new pulp maker. • Cellulase and laccase were effective for the deinking of NP and EP, respectively. • Ozonation was found appropriate for the removal of toners from PP. • Optimized deinking methods were comparatively better than chemical process. • Ink free paper hydrolysates resulted in 40.85% ethanol yield using S. cerevisiae. [ABSTRACT FROM AUTHOR]

The deinking of mixed office waste paper by cellulase, M/Las (modification of laccase aspartic acid system), and C-M/Las (cellulase synergistic modification of laccase aspartic acid system) was investigated. The fiber morphology parameters, hydrogen bond patterns, cellulose crystallinity, and fiber microstructure were observed via fiber quality analyzer (FQA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results showed that the effective residual ink concentration of enzyme deinked pulp decreased compared with blank pulp (pulp without enzymatic treatment). The deinking efficiencies of C-M/Las, cellulase, and M/Las were 18.17%, 14.01%, and 12.31%, respectively. FQA analysis indicated that the fiber length and curl index decreased, while the fiber width slightly increased. FTIR analysis revealed that after cellulase, M/Las, and C-M/Las treatment, the content of intermolecular hydrogen bonds increased by 14.65%, 13.37%, and 19.80%, respectively. This indicates that there is a synergistic effect between cellulase and M/Las. XRD showed that the cellulose crystallinity decreased after enzymatic deinking. SEM micrographs of fibers treated with enzymes revealed that the fiber surface became rough and more fibrils appeared. The water retention value was increased after enzymatic deinking. [ABSTRACT FROM AUTHOR]

Beauveria bassiana is an entomopathogenic fungus widely used as a biopesticide for insect control; it has also been shown to exist as an endophyte, promoting plant growth in many instances. This study highlights an alternative potential of the fungus; in the production of an industrially important biocatalyst, xylanase. In this regard, Beauveria bassiana SAN01 xylanase was purified to homogeneity and subsequently characterized. The purified xylanase was found to have a specific activity of 324.2 U·mg−1 and an estimated molecular mass of ~37 kDa. In addition, it demonstrated optimal activity at pH 6.0 and 45 °C while obeying Michaelis–Menton kinetics towards beechwood xylan with apparent Km, Vmax and kcat of 1.98 mg·mL−1, 6.65 μM·min−1 and 0.62 s−1 respectively. The enzyme activity was strongly inhibited by Ag2+ and Fe3+ while it was significantly enhanced by Co2+ and Mg2+. Furthermore, the xylanase was shown to effectively deink wastepaper at an optimal rate of 106.72% through its enzymatic disassociation of the fiber-ink bonds as demonstrated by scanning electron microscopy and infrared spectroscopy. This is the first study to demonstrate the biotechnological application of a homogeneously purified glycosyl hydrolase from B. bassiana.

Continuous efforts have been made in recent year to improve the process of paper recycling, as it is of critical importance for saving the wood, water and energy resources. Flotation deinking is considered to be one of the key methods for separation of ink particles from the cellulose fibres. Attempts to model the flotation deinking process have often resulted in complex models that are difficult to implement and use. In this paper a model for prediction of flotation performance based on Support Vector Regression (SVR), is presented. Representative data samples were created in laboratory, under a variety of practical control variables for the flotation deinking process, including different reagents, pH values and flotation residence time. Predictive model was created that was trained on these data samples, and the flotation performance was assessed showing that Support Vector Regression is a promising method even when dataset used for training the model is limited.

Laccase has the enormous potential to be implemented as the multitasking biocatalyst in whole process of paper making. The enzyme can utilize effectively for pulping, delignification of pulps as alone or in the combination with other bleaching enzymes. Laccase has been evaluated for the biografting of pulp fibers, decolorize and stabilize the effluent of the paper mills, biotransformation of high molecular weight (HMW) lignins to lower molecular weight (LMW) aromatic compounds. Further this enzyme has the huge possibilities to apply for deinking of old newsprint (ONP) and pitch removal from varieties of the different pulps. There is no doubt on versatility mode of action of laccases in paper industry, but still there is limited commercialization of this enzyme has been possible, because of laccases has the less redox potential (E0) and needs mediators for the oxidation of non phenolic substrates, production of enzyme is cost intensive at large scale. This review is providing the proper updated information on the state of the art of different applications of laccase in paper industry. It also confer the interpretation to the readers about the areas of extensively studied and the field where there is still much left to be done. [ABSTRACT FROM AUTHOR]

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Compared with conventional chemical deinking, enzymatic deinking is a more environmentally compatible alternative for processing recovered paper. In this study, a bacterial isolate identified as Achromobacter xylosoxidans (designated as L2) was found to be a promising candidate for a paper deinking process. It showed endoglucanase, ß-glucosidase, endoxylanases, and filter paper degrading activities (FPase) with the maximal values of 2.60, 2.57, 3.08, and 24.58 U/mL, respectively. The optimal temperature and pH for FPase were determined to be 44 °C and pH 7.6. After two days of incubation with L2 at 130 rpm and 30 °C, the waste newspaper strips (0.5 cm × 5 cm) were disintegrated to debris with the average size of 3.5 mm (while that of the untreated without inoculation of L2 was 5.7 mm). The final brightness of the regenerated handsheets after incubation with L2 increased 3.7 units (31.4% ISO). The isolate and its complete lignocellulosic enzymes could be applied as deinking agents in the recycling of waste paper. [ABSTRACT FROM AUTHOR]

With the utilization of used newspaper into the paper making industry, bleaching has been an area of concern to obtain a balance between desired brightness and the amount of treatment it requires. Motivation of this study was to optimize bleaching of recycled newsprint fibers in terms of five variables namely hydrogen peroxide charge, amount of sodium hydroxide employed, pulp consistency, bleaching temperature, and bleaching time. Experimental work was conducted in the laboratory to simulate bleaching plant and it was found that higher peroxide charge is better for improvement in brightness, but it is uneconomical to increase peroxide charge indefinitely. The amount of hydrogen peroxide is added so that the residual peroxide at the end of the reaction is not less than 10% of the initially added peroxide. Sodium hydroxide provides alkalinity which is very important for making the fibers flexible and softening of ink particles but it also contributes to pulp yellowing if residual hydrogen peroxide contents are lesser than the minimum required value. So, for 16 kg t ^−1 of hydrogen peroxide, 6 kg t ^−1 of sodium hydroxide prevented the brightness reversion in this study. Higher pulp consistency is better but unavailability of very high consistency pulp mixer in the industry is a limiting factor for higher than 30% pulp consistency. Temperature and time are quite interrelated and, with the given bleaching conditions, a temperature of 95 °C with 10 min residence time was found to be optimum for this study. It was also observed that multiple pre-washings increase brightness and save bleaching chemicals.

The effect of changing the sequence of refining and enzymatic treatment on the properties of deinked pulp from mixed office waste paper (MOW) was investigated. The sequences included refining before and after enzymatic treatment. Refining was applied for 700 and 1500 revolutions, and the consistency of pulps during enzymatic treatment was 5, 8, and 13%. Enzymatic treatment was applied for 20, 40, and 60 min. After each of the sequences, the deinking stage was the same. When refining was applied after the enzymatic treatment, the freeness of pulp was greater than that of the pulp on which refining was conducted before the enzymatic treatment, at a constant refining speed. Better strength properties were produced when refining was carried out before the enzymatic treatment. Also, the results of testing the optical properties of deinked pulp showed that brightness and ERIC improved when refining was carried out before the enzymatic treatment.

Bu çalışmada, ofis kâğıtları üzerinde mürekkep giderme işlemi yapılmıştır. Bu işlem için farklı oranlarda kimyasal ve enzimler katılmış ve bunların etkileri analiz edilmiştir. Bu amaçla sodyum hidroksit, hidrojen peroksit sodyum silikat ve oleik asit’de uygun dozlarda kullanılmıştır. Çalışmada ayrıca ultrasonik enerjinin etkiside ayrıca incelenmiştir. Araştırma sonunda ise işlem sonunda elde edilen hamur ve atık çamur üzerinde organik ve anorganik madde analizleri yapılmıştır.

Bu çalışmada, yüzdürme metoduna göre mürekkep giderme işlemi uygulanmış baskılı ofis kâğıtları üzerinde taramalı elektron mikroskobu (SEM) ile görüntü analizleri yapılmıştır. Bu işlem için öncelikle bazı kimyasallar ile enzimler kullanılmıştır. Çalışmada ayrıca ultrasonik enerjiden de faydalanılmıştır. Çalışmada baskılı ofis kağıtlarının hamurlaştırma ve ardından uygulanan yüzdürme işlemi sonrası elde edilen numunelerden örnekler alınarak taramalı elektron mikroskobu yardımıyla (SEM) görüntü analizleri yapılmıştır. Bu analizler sayesinde baskılı ofis kağıtlarınına uygulanan ultrasonik, kimyasal katkılı, kimyasalsız ve enzim katkılı işlemler sonucu lif ve tonerde meydana gelen değişimler gözlemlenmiştir.

Bu çalışmada, yüzdürme metoduna göre mürekkep giderme işlemi uygulanmış baskılı ofis kâğıtları üzerinde taramalı elektron mikroskobu (SEM) ile görüntü analizleri yapılmıştır. Bu işlem için öncelikle bazı kimyasallar ile enzimler kullanılmıştır. Çalışmada ayrıca ultrasonik enerjiden de faydalanılmıştır. Çalışmada baskılı ofis kağıtlarının hamurlaştırma ve ardından uygulanan yüzdürme işlemi sonrası elde edilen numunelerden örnekler alınarak taramalı elektron mikroskobu yardımıyla (SEM) görüntü analizleri yapılmıştır. Bu analizler sayesinde baskılı ofis kağıtlarınına uygulanan ultrasonik, kimyasal katkılı, kimyasalsız ve enzim katkılı işlemler sonucu lif ve tonerde meydana gelen değişimler gözlemlenmiştir.Anahtar Kelimeler: Taramalı elektron mikroskobu (SEM), Enzimler, Mürekkep giderme, Ultrases

Bu çalışmada, ofis kâğıtları üzerinde mürekkep giderme işlemi yapılmıştır. Bu işlem için farklı oranlarda kimyasal ve enzimler katılmış ve bunların etkileri analiz edilmiştir. Bu amaçla sodyum hidroksit, hidrojen peroksit sodyum silikat ve oleik asit’de uygun dozlarda kullanılmıştır. Çalışmada ayrıca ultrasonik enerjinin etkiside ayrıca incelenmiştir. Araştırma sonunda ise işlem sonunda elde edilen hamur ve atık çamur üzerinde organik ve anorganik madde analizleri yapılmıştır.Anahtar Kelimeler: Organik madde, Anorganik madde, Mürekkep giderme, Ofis kağıdı

Plastic flexible films are increasingly used in many applications due to their lightness and versatility. In 2014, the amount of plastic films represented 34% of total plastic packaging produced in UK. The flexible film waste generation rises according to the increase in number of applications. Currently, in developed countries, about 50% of plastics in domestic waste are films. Moreover, about 615,000 tonnes of agricultural flexible waste are generated in the EU every year. A review of plastic films recycling has been conducted in order to detect the shortcomings and establish guidelines for future research. This paper reviews plastic films waste management technologies from two different sources: post-industrial and post-consumer. Clean and homogeneous post-industrial waste is recycled through closed-loop or open-loop mechanical processes. The main differences between these methods are the quality and the application of the recycled materials. Further research should be focused on closing the loops to obtain the highest environmental benefits of recycling. This could be accomplished through minimizing the material degradation during mechanical processes. Regarding post-consumer waste, flexible films from agricultural and packaging sectors have been assessed. The agricultural films and commercial and industrial flexible packaging are recycled through open-loop mechanical recycling due to existing selective waste collection routes. Nevertheless, the contamination from the use phase adversely affects the quality of recycled plastics. Therefore, upgrading of current washing lines is required. On the other hand, household flexible packaging shows the lowest recycling rates mainly because of inefficient sorting technologies. Delamination and compatibilization methods should be further developed to ensure the recycling of multilayer films. Finally, Life Cycle Assessment (LCA) studies on waste management have been reviewed. A lack of thorough LCA on plastic films waste management systems was identified. [ABSTRACT FROM AUTHOR]

Abstract: Laccase is a major enzyme used in the paper and pulp industries for bio-bleaching applications. This paper focused on the bio-bleaching property of a potential lignolytic fungus, Fusarium equiseti VKF-2. Optimum conditions for laccase production were tested by statistical models under solid state fermentation using saw dust as substrate. Fusarium equiseti VKF-2 achieved a maximum laccase activity of 305 Ug−1 of substrate. During purification, 67% yield was obtained with 80% ammonium sulphate. The enzyme activity was confirmed through zymogram analysis with 2 active fractions observed at 94 and 75 kDa. Laccase treatment resulted in defibrillations, crack formation and changes in the functional groups of paper pulp. The laccase facilitated the maximum hexenuronic acid release with Kappa number reduction. There was a Δ brightness of 15% following 4 h of enzymatic treatment. Hence, the present laccase was found to be suitable for the bio-bleaching of newspaper waste via an eco-friendly process. Graphical abstract: [ABSTRACT FROM AUTHOR]