Waste Office Paper Research Articles

Biodegradable cellulose nanocrystals hydrogels for removal of acid red 8 dye from aqueous solutions

Biodegradable cellulose nanocrystals hydrogels (CNCsH) were synthesized from cellulose nanocrystals (CNCs) which were prepared from office wastepaper (OWP) by a chemical crosslinking method using epicholorohydrin (ECH) as a cross-linker. CNCsH were tested for their swelling behavior and biodegradability and the point of zero charge had been determined. The ability of CNCsH for removing the Acid Red 8 (AR8) anionic dye from its aqueous solution was evaluated. The different parameters affecting removal of the dye, such as pH, initial concentration of dye, content of CNCs, temperature and adsorbent dosage were investigated. The optimum conditions for 68% removal efficiency were pH = 1, initial concentration of dye = 10 ppm, contact time = 105 min, CNCs content = 5% and CNCsH dosage = 0.5 g at 30 °C. The adsorption isotherms, kinetics, and thermodynamic parameters have been studied. The results showed an appropriate fit for Langmuir adsorption isotherm and pseudo-second order kinetics model with an adsorption capacity of 17.12 mg/g. According to the obtained values of thermodynamic parameters, the removal of Acid red 8 by CNCs hydrogels was exothermic spontaneous process.

High-Solid Loading Enzymatic Hydrolysis of Waste Office Paper for poly-3-hydroxybutyrate Production Through Simultaneous Saccharification and Fermentation

Waste paper holds great potential as a substrate for the microbial production of bioplastic (Poly-3-hydroxybutyrate (PHB)). This study aimed to produce PHB by utilizing office paper as a substrate using Cupriavidus necator through batch and fed-batch simultaneous saccharification and fermentation (SSF) approach. For the batch experiment, different loadings of shredded office paper (3, 5 and 10%) with two different pretreatments H2O2 (OPH) and H2O2 and Triton X-100 (OPTH) were carried out. For the fed-batch experiment, paper loading started with 3% and two more additions were made at 36 and 84 h. Both experiments were conducted at 30 °C, 200 rpm and pH 7 using 55.5 FPU/g of cellulase and 37.5 CBU/g of β-glucosidase with a fixed amount of nitrogen source. High PHB yield was observed with OPH in all loadings, though the OPHT showed a better hydrolysis. Maximum PHB yield (4.27 g/L) was achieved with 10% OP on the sixth day of fermentation in batch SSF. Whereas, maximum PHB yield (4.19 g/L) was obtained within a shorter time (66 h)with OPH in the fed-batch experiment. The extracted PHB showed well-matched characteristic features to the standard PHB. Finally, this study proves the feasibility of employing the SSF process for PHB production using waste paper as an alternative approach to overcome the shortcoming of the separate hydrolysis and fermentation (SHF) process.

X-ray protective materials from barium sulfate/amorphous cellulose/natural rubber composites

In this study, barium sulfate/amorphous cellulose (Ba/AC) was incorporated into natural rubber to produce X-ray shielding materials. Ba/AC was prepared by in-situ regeneration of amorphous cellulose from eucalyptus pulp and office waste paper with barium chloride. The shielding sheets were prepared by mixing vulcanized natural rubber with Ba/AC using both office waste paper (NR-W) and purified eucalyptus pulp (NR-E) and were compared to barium sulfate powder (NR-P) used as a conventional material. NR-W and NR-E exhibited a predominant attenuation property compared to that of NR-P. The amorphous cellulose surrounded by barium sulfate is essential in distributing and reducing the aggregation of barium sulfate particles. This behavior results in most incident X-ray beams being effectively absorbed. Subsequently, prototypes were fabricated using NR-W and NR-E with a thickness of 0.25-mm Pb in accordance with the quality standards of medical diagnostic X-ray machines in Thailand. The head, thyroid, and breast shields were produced to protect from direct X-ray beams. Additionally, a lab coat was prepared to block scattered beams. Finally, the fabricated X-ray shielding prototypes are eco-friendly, cost-effective, and nontoxic.

The use of cellulose fiber from office waste paper to improve the thermal insulation-related property of konjac glucomannan/starch aerogel

The development of eco-friendly thermal insulation material composed of recyclable wastes contributes to enhancing environmental sustainability with less pollution. In this study, polysaccharide-based aerogels with improved thermal insulation property were obtained by using konjac glucomannan, starch, and office waste paper cellulose fiber (WPCF) via sol-gel and freeze-drying method. The obtained aerogels had a bulk density of 30.1–44.9 mg/cm3, a porosity of 95.1–97.0%. Results revealed that increased WPCF addition did not impact the thermal stability, but improved the sol stability, reduced the pore size, strengthened the mechanical property, and lowered the hygroscopicity of the aerogels, benefiting practical application. Although WPCF solids showed a high thermal conductivity, increased WPCF addition at 0.1–0.5 wt% reduced the aerogel thermal conductivity, which was explained by the longer heat path and less heat convention. Further higher WPCF addition at 0.5–1.5 wt% increased the aerogel thermal conductivity as the heat conduction of solid matrix was increased and the heat convection was strengthened. Therefore, the lowest thermal conductivity (0.0335 Wm−1 K−1) of the aerogel was reached at the optimized WPCF addition of 0.5 wt%. This work showed the high potential of the WPCF to be used to strengthen the thermal insulation property of polysaccharide-based aerogels.

Technical feasibility of producing binder-free water hyacinth briquettes for domestic energy use

Production of biomass briquettes of good strength and combustion characteristics usually requires the addition of a binder material to the feedstock. This study was aimed at developing a methodology for producing briquettes from water hyacinth at low compression pressures without using a binder material. Fresh water hyacinth was chopped to a maximum length of 3 cm, sun-dried to a moisture content of about 10%, mixed with shredded waste office paper in four water hyacinth to paper proportions on weight basis (100:0, 90:10, 80:20 and 70:30). The mixtures were soaked in water for three days and briquetted using a 6-cylinder screw briquetting machine. The resulting briquettes were subjected to standard strength and combustion tests. A Completely Randomized Design with four treatments replicated five times was used as the experimental design. Results from the study indicate no significant differences in compressed density, relaxed density, relaxation ratio and calorific value between the briquettes. The results further indicate that briquettes made without a binder material have significantly low but adequate shatter resistance, low ignition time, high burning rate and take a longer time to bring water to boil. It can be concluded that good quality water hyacinth briquettes can be produced at low compression pressures without using a binder material. This methodology can potentially increase adoption of water hyacinth briquettes in areas with poor access to binder materials. The originality of the research is the development of a water hyacinth briquetting methodology that does not use binder materials.

Scalable Preparation of Cellulose Nanofibers from Office Waste Paper by an Environment-Friendly Method.

Waste paper is often underutilized as a low-value recyclable resource and can be a potential source of cellulose nanofibers (CNFs) due to its rich cellulose content. Three different processes, low acid treatment, alkali treatment and bleaching treatment, were used to pretreat the waste paper in order to investigate the effect of different pretreatments on the prepared CNFs, and CNFs obtained from bleached pulp boards were used as control. All sample fibers were successfully prepared into CNFs by 2,2,6,6-tetramethyl-piperidine-1-oxyl (TEMPO) oxidation. It was quite obvious that the bleached CNFs samples showed dense fibrous structures on a scanning electron microscopy (SEM), while needle-like fibers with width less than 20 nm were observed on a transmission electron microscopy (TEM). Meanwhile, the bleaching treatment resulted in a 13.5% increase in crystallinity and a higher TEMPO yield (e.g., BCNF, 60.88%), but a decrease in thermal stability. All pretreated CNFs samples showed narrow particle size distribution, good dispersion stability (zeta potential less than −29.58 mV), good light transmission (higher than 86.5%) and low haze parameters (lower than 3.92%). This provides a good process option and pathway for scalable production of CNFs from waste papers.

Up-cycling of waste paper for increased photo-catalytic hydrogen generation of graphitic carbon nitride under visible light exposure

BackgroundUp-cycling of waste papers to value-added carbon products has significant environmental and economic benefits in real life. This work aims to recycle the waste papers to construct amorphous carbon modified graphitic carbon nitride composite photocatalysts for efficient photocatalytic hydrogen generation from water under visible light. MethodsAmorphous carbon (labeled as a-C) was yielded from the office waste papers by simple sulphuric-acid treatment and then combined with graphitic carbon nitride (g-CN) to form the g-CN/a-C composite photocatalysts by the thermolysis of a-C and melamine mixture. Significant FindingsThe addition of a-C enlarges the surface area of g-CN from 11.52 m2 g−1 of pristine g-CN to 28.12 m2 g−1 of g-CN/a-C-100. In addition, the a-C incorporation can significantly separate the electrons from the photoexcited g-CN owing to the excellent conductivity of a-C. As a result, an increased photocatalytic H2 generation was realized under visible light exposure. The g-CN/a-C-100 sample with optimized a-C contents offers the highest photocatalytic H2 generation rate of up to 17.1 μmol h−1, which is ∼12 times higher than that of pristine g-CN under the same condition. The present study manifests the great potential of the recycling of office waste papers for increased photocatalytic H2 generation.

Management of Bio-Waste by the Paper Mulch

Mulch is a type of protective covering placed on or spread over the soil surface that helps to conserve soil moisture, suppress weed growth and enrich the soil. The paper mulch is the most complete mulch and has numerous beneficial effects upon the soil and plants. This mulch which is produced from office waste paper, newspaper and wrapping papers, conserves soil moisture, is effective at suppressing and inhibiting weed growth, enhances agro-ecosystem health by improving the air and water movement through the soil; providing moist conditions thereby promoting micro-organisms and worm populations; promoting plant growth and product, promoting leaf litter build up and helping to improve the pH balance in the soil.

Waste office paper filled polylactic acid composite filaments for 3D printing

Developing 3D printable waste paper based biocomposites is a potentially greener alternative to traditional waste paper recycling methods. In this paper, waste office paper (WOP) filled polylactide acid (PLA) biocomposites were prepared as filaments for Fused Filament Fabrication (FFF). The morphology, rheology, thermal properties, and physical properties of PLA-WOP composites were investigated. Results revealed that the addition of WOP improved the composites’ melt flow abilities. The Tg and Tm of composites remained similar to the neat PLA. However, tensile strengths of the prints decreased with the increase of WOP content, which could be attributed to the heterogeneous dispersion and aggregation caused by the abundance of WOP in the system. When 5% WOP was used, the elongation at break increased in comparison with pure PLA specimens. Nonetheless, when the WOP content was increased to 15%, the elongation at break decreased. To improve the mechanical properties of the prints, a silane coupling agent (γ-methacryloxypropyltrimethoxylsilane, KH570) was used to modify WOP granules. The mechanical properties were clearly enhanced post KH570 treatment. Furthermore, FTIR analyses demonstrated that the hydrogen bonding improved interfacial adhesion between WOP fillers and the PLA matrix. Thermal decomposition showed that the PLA-WOP composites had virtually no degradation below 260 °C, indicating that the composite filaments are safe for indoor 3D printing.

A comparative study of conventional chemical deinking and environment-friendly bio-deinking of mixed office wastepaper

Bio-deinking is an environmentally friendly process that improves the pulp and paper properties and reduces chemical consumption during the recycling of waste paper. This study was performed to evaluate the efficacy of enzyme by Penicillium sp. AKB-24. Chemical deinking of MOW showed freeness (CSF), pulp brightness (ISO), deinking efficiency, and dirt count by 426±4 ml, 75.55±0.1%, 82.13±0.7%, and 733±24 mm2/m2 respectively at optimum repulping parameters. The physical strength properties including burst index, tear index, tensile index and double fold numbers were found 2.97±0.14 kPa.m2/g, 11.14±0.61 mN.m2/g, 46.60±1.99 N.m/g, and 36±2 respectively during chemical deinking of MOW. The deinking chemicals including NaOH, Na2SiO3, and H2O2 were replaced with crude enzyme by Penicillium sp. AKB-24 during enzymatic deinking of MOW. Enzymatic deinking of MOW resulted in an improvement in pulp freeness by 18.30% compared to chemical deinking while the dirt count value decreased by 32.60% during enzymatic deinking of MOW. Physical strength properties such as burst index, tensile index, and double fold numbers were improved by 16.07%, 14.54% and 8.57% respectively while tear index was decreased by 11.61% during enzymatic deinking of MOW compared to chemical deinking.

Efficient utilization of waste paper as an inductive feedstock for simultaneous production of cellulase and xylanase by Trichoderma longiflorum

Waste paper, one of the major components of municipal and industrial wastes, has considerable potential as a low-cost inductive feedstock for enzyme production. In this study, four kinds of waste papers were used for simultaneous production of cellulase and xylanase by Trichoderma longiflorum. The highest FPase activities (3.21 IU/mL and 2.97 IU/mL) were achieved using waste office paper (WOP) and corrugated board (CB), respectively, followed by magazine paper (MP, 2.51 IU/mL) and tissue paper (TP, 2.34 IU/mL). The maximum β-glucosidase activities (0.51 IU/mL) and xylanase activities (382.59 IU/mL) were obtained from CB substrates, which were higher than that in the reported literature using waste paper. Correspondingly, the soluble protein concentrations and SDS-PAGE profiles from CB fermentation revealed that more enzymes were secreted during fermentation compared with other waste paper. Moreover, the structural features of different waste paper were characterized by using SEM and XRD technique and revealed that the structural variations were mainly caused by the raw wood sources and papermaking processes, and further affected the fermentation capacity. In addition, a higher β-glucosidase activity of 0.80 IU/mL were obtained from the mixed carbon source of CB and wheat bran (WB), which were significantly improved and increased by 56.86% when compared with the CB as single carbon source. This study confirmed that the waste paper without pretreatment could be efficiently utilized as an inductive feedstock for simultaneous production of cellulase and xylanase by T. longiflorum. Therefore, these findings obtained from this study will provide a more widely insight into investigating the low-cost inductive feedstock for enzyme production, which were of great benefit both for the economy and environment.

The use of unconventional organic waste for vermicomposting in Surgut greenhouses

The paper discusses the use of non-traditional types of organic waste in vermicomposting in greenhouses on the territory of the middle taiga forest zone of Western Siberia. Experimental studies were carried out in the laboratories of the scientific and educational center and the center for collective use of the Institute of Natural and Technical Sciences of Surgut State University in 20012020. The main objects of the study were brewers grains, waste from the production of the Kristal brewing company in Surgut and wastewater sludge from the treatment facilities of the Gorvodokanal in Surgut. Additionally, the composition of complex composts included sand, office waste paper, waste coffee, food waste, leaf and grass litter, bird droppings and the microbiological additive Tamir. The compost worms of the Eisenia foetida Prospector species were used as vermiculture. 10 juveniles were launched in the first series of experiments and 50 juvenile worms were launched in the second series. The resulting vermicomposting is more effective in quality than the original substrates. The use of the hybrid Prospector can be effectively used in the disposal of non-traditional organic waste. Complex composts mature more efficiently when microbiological additives are added. In the studied substrates the content of heavy metals was reduced to MPC norms.

Reinforcing effect of nanocrystalline cellulose and office waste paper fibers on mechanical and thermal properties of poly (lactic acid) composites

AbstractNanocrystalline cellulose (NCC) was prepared from office waste paper (OWP) by sulfuric acid hydrolysis method in this paper and it was used to prepare a series of poly (lactic acid) PLA/NCC composites by using a dissolution method in solvent N, N‐dimethylformamide solution. The results indicated that with the addition of only 3 wt% NCC, the composites exhibited outstanding mechanical property. The tensile, bending and impact properties of the PLA/3NCC composite were improved by 8.2%, 13.1%, and 35.9% than those of pure PLA, respectively. On this basis, office waste paper fibers (OWF) were also used as a physical blended filler to enhance PLA/NCC composites to reduce the preparation cost of PLA composites and the perfect PLA/NCC/OWF sample was easily manufactured by melting–blending and injection molding. According to the crystallization and melting performance table, both NCC and OWF can act as nucleating agent to promote the crystallization properties on composites, while the blends did not have positive effect on thermal stability. Furthermore, the water absorption and degradation properties of PLA composites were also studied. This work not only provided a novel idea for the utilization of office waste paper but also successfully produced environment friendly composites with favorable mechanical properties and crystallization performance.

New Approach for Recycling Office Waste Paper: An Efficient and Recyclable Material for Oily Wastewater Treatment.

Recycling has attracted great attention in academia, because of the economic and environmental benefits to industry. An eco-friendly strategy for recycling office waste paper (WP) was used to sustainedly separate oil-water mixtures. The hydroxyl groups of cellulose endow WP with superlipophilic and superhydrophilic properties in air and superoleophobic features under water. WP could separate various oils from oil-water mixtures, with separation efficiencies exceeding 99%. Importantly, the superhydrophilic WP could separate oil-water mixtures containing HCl, NaOH, and NaCl with separation efficiency above 98.9% for at least 30 cycles. The superoleophobicity of WP was maintained in solutions of different pH values for at least 24 h, suggesting good durability and stability. This green method is renewable, clean, cost-effective, and environmentally friendly. More importantly, the recycled office waste paper not only removes oil from oily wastewater (such as in oil spills) but also realizes the recycling of WP. This method could provide new insights into resource recycling.

Bacterial cellulose as reinforcement in paper made from recycled office waste pulp

Bacterial cellulose, produced during fermentation of Kombucha tea, was investigated relative to its ability to modify the characteristics of pulp from recycled office wastepaper. The produced bacterial cellulose wet films were dispersed and added rates of 5%, 10%, and 15% to the recycled office wastepaper. The Fourier-transform infrared spectroscopy analyses, scanning electron microscopy images and thermogravimetric analysis values were determined in order to characterize the pulp samples. The results of these analyses showed similar changes as the amount of added bacterial cellulose increased, which also meant an increased amount of filler attaching to the fiber matrix. The burst index and tensile index values were protected while the tear index value partially decreased as the amount of added bacterial cellulose increased. The brightness values of the bacterial cellulose reinforced papers did not change after thermal aging, while the changes in the yellowness values were quite limited. Higher water absorption rates, and lower air permeability values were obtained from bacterial cellulose reinforced recycled office wastepaper sheets, which corresponded to the addition of increased bacterial cellulose amounts. Considering the mechanical and physical properties of the reinforced paper, bacterial cellulose represents a promising alternative for the reinforcement of office wastepaper.

A pollution reducing enzymatic deinking approach for recycling of mixed office waste paper.

The efficiency of xylano-pectinolytic enzymes, co-produced by a single microbial strain Bacillus pumilus, was analysed for the recycling of mixed office waste paper through deinking and compared with the alkaline chemical deinking method. Enzymes showed maximum deinking at pH 8.5, pulp consistency of 10%, xylanase-pectinase dose of 12 and 4 IU per gram pulp, respectively, after 120 min of deinking period, and temperature at 50 °C. A chemi-enzymatic approach was employed with xylano-pectinolytic enzymes and various concentrations of deinking chemicals, which showed that enzyme-treated mixed office waste pulp requires only 40% chemicals for deinking, in order to get the almost same level of various handsheets properties, as obtained by the chemical method with 100% chemicals. Similarly, the effluent load of BOD and COD contents was also decreased by 17.90 and 19.75%. This combinational approach of deinking significantly improved the various properties of the handsheets and resulted in gain of 7.5, 9.38, 6.33 and 11.65% in tear factor, burst factor, breaking length and viscosity of the handsheets, while the effective residual ink concentration analysis of deinked handsheets of mixed office waste paper showed deinking efficiency of 22.45%, which revealed the removal of ink particles during enzymatic deinking steps.

Study on the mechanical and thermal properties of poly(lactic acid)/office waste paper fiber composites

AbstractEnvironment friendly composites with favorable mechanical properties and low water absorption performance were successfully produced from poly(lactic acid) (PLA), office waste paper fiber (OWF), and coupling agents. The perfect sample was easily manufactured by melting–blending and injection molding. The PLA/OWF composites were comparable with other PLA/plant fiber composites, and the results indicated that the PLA/OWF composites show better performance than PLA/wheat straw fiber composites and PLA/bamboo fiber composites. On this basis, influence of modification of OWF on the properties of composites was investigated. The infrared results show that the OWF modification by different coupling agents was successful, and the scanning electron microscopy indicates that prepared composites exhibit good interfacial compatibility due to preferable binding force between fiber and matrix. With addition of 2 wt% γ‐(2,3‐propylene oxides)propyl trimethylsilane, the composite exhibits high tensile strength of 58.96 MPa, reflecting increase of 14% than the pure PLA. According to the crystallization and melting performance table, OWF can act as nucleating agent to promote the crystallization properties on composites, while the coupling agents have little effect on thermal stability. This article confirmed that the OWF has appropriate properties and is suitable for preparing composite materials and this work provides a novel idea for the utilization of office waste paper.

Production of microbial lipids utilizing volatile fatty acids derived from wastepaper: A biorefinery approach for biodiesel production

Volatile fatty acids (VFAs) derived from organic wastes are being considered as low-cost feedstock for microbial lipid production as a valuable alternative to plant derived oils/biodiesel. In this study, VFAs were produced from anaerobic open culture fermentation of wastepaper and subsequently, used as a feedstock for lipid production by Cryptococcus curvatus. Total VFAs, yield and productivity achieved from waste office paper (WOP) and waste newspaper (WNP) were 17.3 and 10.2 g/L, 0.17 and 0.10 g/g TS, and 0.86 and 0.51 g/L/day, respectively. Biomass, lipid content and productivity achieved utilizing VFAs derived from WOP and WNP were 4.3 and 2.9 g/L, 41.2 and 27.7% DCW, and 0.037 and 0.033 g/L/h, respectively. The dominance of fatty acids such as oleic, palmitic, stearic and linoleic acid in the lipids suggests a high level of similarity with plant/vegetable oils used for biodiesel production. Therefore, VFAs derived from wastepaper could be potentially used as feedstock to produce microbial lipids towards cost-effective production of biodiesel.

Green ecofriendly bio-deinking of mixed office waste paper using various enzymes from Rhizopus microsporus AH3: efficiency and characteristics

Mixed office waste paper (MOWP) is a low cost, high quality and easily collected fiber source for the papermaking industry. Unfortunately, limits in the application of traditional deinking are related to the negative environmental impacts of using chemicals during the deinking process. Hence, enzymatic deinking has received growing attention in the last decade. This study investigates the effect of using the effective enzymes produced from Rhizopus microspores AH3 which is grown on watermelon peel waste (WPW) extract, as a bio-deinking method in the deinking of MOWP, which is difficult to recycle because of their ink type and printing process. The methodology involves preparation of samples, impregnation with water, enzymatic treatment, washing, papermaking, evaluation of the produced paper sheets. The evaluation includes determination of the optical and mechanical properties as well as topographic investigation via scanning electron microscope of produced paper sheets. The results showed that there is an improvement in both optical and mechanical properties of all paper sheets produced in this study. The best enhancement was for medium B30 which was extracted by boiling of WPW for 30 min. This treatment gave high enhancement because of the effect of the produced enzymes from Rhizopus microspores AH3, where cellulase, xylanase, lignin peroxidase, poly phenol oxidase and laccase were 1.62, 1.49, 1.38, 1.2 and 1.5 U/ml, respectively. Moreover, the tensile strain (maximum load) increased by about 77% as well as the brightness percentage achieved about 86.78% and the deinking ability was increased approximately 16%.

De-Inking of ONP Paper by using Different Surfactants: In Dissolved Air Flotation Process

Meeting the demand of paper and paper product requirement and at the same time decreasing the availability of fibrous raw materials, keeping an eye on cost effectiveness is challenging. Thus, recycling of paper is an alternative. Corrugated box, old newspapers and office waste papers are the sources of raw materials for paper and paper product industries. Deinking is an important step for recycling of old waste writing, printing and newsprint papers. The efficiency of ink separation in the process of waste paper recycling depends on the ink properties, kind of the additives, surfactants used, age of waste papers, the printing techniques and printing conditions. In general, deinking process consumes a large amount of chemicals which makes this method expensive, pollution intensive and even quality is compromised. In this study the effectiveness of surfactants like benzene dodecyl sulphonate, lauryl benzene sulphonate and sodium carbonate for cost effective deinking process by optimizing the chemical doses has been studied. The physical strength and optical properties of the paper after deinking was also explored. The surfactant better for both physical strength properties and optical properties of paper is identified to be the sodium dodecyl benzene sulfonate.