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Green liquor dregs (GLD) is an alkaline by-product from the pulp and paper industry with a pH between 10 and 14. Today most of the produced GLD in Sweden is landfilled. As a fine-grained alkaline material, it might be possible to use it for acid-generating mining waste remediation. To increase the utilization, quality characteristics and environmental performance need to be determined. In this study samples were collected 5 times from 16 mills during a period of 2.5 years, and were characterized by analyzing dry matter content, loss on ignition (LOI) 550 °C and LOI 950 °C, elemental analysis, pH, electrical conductivity, and calorific value. The results were then evaluated using multivariate statistics (PCA) as well as being compared to other studies and Swedish till. The results show that even if GLD is heterogenous (both within a mill and between different mills) trends can be seen for samples from most mills. When samples do stand out, it is predominately related to the same four mills. Most of the studied parameters showed characteristics favorable for use as a remediant; however, TOC, sulfur, and some of the elements require further study. In general, this study concludes that GLD can be a viable option for the remediation of small orphaned sulfidic mining sites and thus worthy of further studies on the interaction between GLD and acidic mining waste.Overall, GLD can be a good alternative for cost-effective remediation of smaller orphaned mining sites. It is readily available in large quantities, has the qualities needed for remediation of many orphaned acidic mining sites, and can often be locally sourced near the mining site. The use of GLD for mining site remediation is likely also a more sustainable method compared to traditional remediation methods., (© 2024. The Author(s).)

Paper mill sludge (PMS) is featured with a high content of cellulose and hemicellulose, and using its characteristics to make paperboard can achieve a high-value utilization of PMS, which has attracted growing interest. In this study, currently prevalent landfill, incineration technologies (generating heat and electricity by incineration), and three paperboard technologies (medium density fiberboard, pulp board, and corrugated paper) were evaluated and compared via life cycle assessment (LCA) and life cycle costing (LCC) methods. LCA results show that the PMS-to-pulp board outperforms others with an energy conservation and emission reduction (ECER) value of - 2.86 × 10 -8 , while the landfill exhibits the highest overall environmental impact with an ECER value of 4.80 × 10 -9 . LCC results reveal that the PMS-to-pulp board delivers the highest economic profit with $257.357, while the landfill is the lowest with $ - 35.63. The PMS paperboard technologies are more economically friendly than the incineration technologies due to additional electricity/steam consumption during the PMS pre-drying process in incineration. In addition, different scenarios were set up to explore national GHG emission reduction potential by increasing paperboard technologies application rate and reducing the proportion of landfill and incineration. The scenario analysis suggests that replacing 90% of landfill and incineration ratio with PMS paperboard technologies could tremendously improve the overall emission reduction performance with - 9.08 × 10 10 kg CO 2 eq. This result indicates that the PMS treatment technology transformation has a significant favorable impact on the achievement of the "carbon neutrality" target., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

To overcome the human and animal survivability risk, sustainable development is the only option on earth that can be achieved through the maximum use of renewable environmental resources. Recycling of waste paper is an emerging waste management approach to conserve natural resources. Herein, we studied enzyme-mediated process to recycle the xerographic paper by using the crude fungal extract from indigenously isolated fungi identified as Aspergillus assiutensis. The fungal enzyme cocktail has been characterized for the production of multiple enzymes namely cellulase, amylase, xylanase, pectinase, and protease. All these enzymes have pH optima in the acidic range and except cellulase and all the enzymes are stable from 10 to 80 C. In the zymogram analysis, pectinase, xylanase, amylase, and cellulase were detected at 68 kDa, ~ 54 kDa, 38 kDa, and 30 kDa, respectively. Also, the presence of protease was confirmed by the clear zone at 68, 31, and 16 kDa. A 26% decrease in the kappa number and reduction in Hex A of the pulp was observed on the treatment of the pulp with enzyme as compared to the control pulp without any treatment. The physical and chemical properties of the pulp were also improved by enzyme-mediated pulping as compared to the control The physiochemical parameter of the effluent like TDS was reduced (397 ppm) significantly in comparison to chemical deinking process and it was within the permissible limit. BOD and alkalinity were reduced when the enzymes and chemical dosage were used in combination. These results indicate that chemi-enzymatic deinking is most promising to reduce or remove the pollution parameters including ink and this approach can be used in the paper and pulp industry for sustainable development., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

To ensure the safety of food contact materials, a liquid chromatography method was established to determine the migration of formaldehyde in paper packaging with various food simulants (10%, 25%, 50%, 75%, and 95% ethanol by volume) and to investigate the migration behavior of formaldehyde after various durations and with various materials. The results showed that the method has good linearity with a correlation coefficient of R 2  > 0.9990, a detection limit of 0.0011 ~ 0.0027 mg L -1 , and a spiked recovery of 89.7 ~ 103.2% in the range of formaldehyde determination; the migration of formaldehyde in all six paper contact materials showed a trend of gradual increase with time until equilibrium was reached. At the same time and temperature, the migration of formaldehyde in paper packaging was the highest in low-concentration ethanol. With the same food simulants and materials, the maximum migration of formaldehyde in printed materials was greater than that in nonprinted materials; with different materials and the same food simulant, the thickness value was higher, with the use of water-based ink as a printing material, and the maximum migration value of formaldehyde by offset printing technology was low., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Globally, per- and polyfluoroalkyl substances (PFAS)-related research on paper products has focused on food packaging with less consideration on the presence of PFAS at different stages of the paper recycling chain. This study analysed the prevalence of PFAS in paper grades used for the manufacture of recycled paperboard. The presence of PFAS was attributed to the use of PFAS-containing additives, consumer usage, exposure to packed goods as well as contamination during mingling, sorting, collection, and recovery of paper recycling material. Q Orbitrap mass spectrometry was used to analyse the paper samples after accelerated solvent extraction and solid phase extraction. The distribution and possible propagation of 22 PFAS were determined in pre-consumer, retail and post-consumer paper products. Post-consumer samples had the highest combined average concentration (ΣPFAS) at 213 ng/g, while the ΣPFAS in retail (159 ng/g) and pre-consumer samples (121 ng/g) was detected at lower concentrations. This study showed that waste collection and recycling protocols may influence PFAS propagation and that measures must be developed to minimise and possibly eliminate exposure opportunities., (© 2024. The Author(s).)

China's pulp and paper industry (CPPI) has been always the main carbon emission source in recent years. However, the analysis on influencing factors of carbon emissions from this industry is insufficient. To address the issue, the CO 2 emissions from CPPI are estimated in the period of 2005-2019, the driving factors of CO 2 emissions are investigated by the logarithmic mean Divisia index (LMDI) method, the decoupling state of economic growth and CO 2 emissions is determined by Tapio decoupling model, and finally, future CO 2 emissions are predicted under four scenarios by the STIRPAT model to explore the potential of carbon peaking. The results show that CPPI exhibits a rapid increase and a fluctuating downward trend in CO 2 emissions during the period of 2005-2013 and 2014-2019, respectively. The main promoting and inhibiting factors to the increase of CO 2 emission are per capita industrial output value and energy intensity, respectively. There are five decoupling states of CO 2 emissions and economic growth during the study period, and the CO 2 emissions exhibit a weak decoupling state with the industrial output value growth in most years of the study period. It is very difficult to realize the carbon peaking goal by 2030 under the baseline and fast development scenarios. Therefore, efficient low carbon and strong low-carbon development policies are necessary and urgent for the realization of carbon peaking goal and the sustainable development of CPPI., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The production of paper is a key component for global civilization. Around 300 million tonnes of paper are produced every day globally, with matured pulpwood being the major contributor. Due to rising demand for paper and the depletion of available wood resources, researchers are now focused on finding alternative non-wood resources that are suitable for pulp and paper production. The current study aims to produce eco-friendly and biodegradable paper using a combination of Eichhornia crassipes (water hyacinth) and dried flowers. Water hyacinth is considered as a lignocellulose plant which contains 57% lignocellulose, and dried flower contains 40% cellulose, which is the prime source for paper production. Various sections of water hyacinth, including wet and dry petiole, leaves, and root, were blended with dried flowers through the soda process. Then, the physical properties and FTIR analysis was carried out to identify the quality of the paper produced. The paper produced from root and dried petiole has a lower thickness (1.0 mm and 0.5 mm) than other mix proportions. The opacity of the leaves was found to be 0.5% (light passing) and for the root 0.7% (light passing). Also, the dry petiole and root paper have a good dry tensile strength of 1.30Kpa and 1.20Kpa, respectively. Hence, paper made from dry petiole and root was found to be efficient and suitable for the paper industry., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

A synergistic photocatalytic system based on Fe-based perovskite with persulfate was constructed for alkali lignin (AL) degradation in pulp and paper wastewater. The degradation performance and mechanism on AL were carried out under ambient temperature and pressure, accompanied by visible light irradiation. The results showed that the synergistic photocatalytic system exhibited much better performance on AL degradation than the single catalytic system. The degradation efficiency reached 73.5% under the optimal conditions and was constant at around 65% over the pH range from 2 to 8. A significant escalation of the AL degradation was observed at pH 10, reaching 80.1%. The photogenerated holes, 1 O 2 and SO 4 - ·, generated by the system were involved in the degradation, and the holes played a dominant role. During the degradation process, the efficient promotion of cleavage events in lignin methoxy, β-O-4 bond, and benzene ring was observed. Consequently, the depolymerization process led to the generation of high-value compounds, namely p-hydroxybenzaldehyde and vanillin. Remarkably, the yields of the high-value compounds in the synergistic photocatalytic system were five times larger than those in the control. This study offered a viable method to activate persulfate for alkali lignin degradation and to achieve a mutually beneficial strategy for wastewater treatment and recycling., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Nowadays, the paper industry supplies its required fibers either from primary fibers, including wood and plants, or waste papers, called secondary fibers. One of the most challenging recycling processes is deinking of papers digitally printed with electrophotographic ink. In order to produce optically high-quality paper from recycled waste papers, deinking step is required at the desired levels. In this work, the environmentally friendly green enzymatic deinking of printed paper was modeled and optimized via an innovative approach called artificial intelligence method. The effect of treatment temperature, treatment time, and enzyme dosage on mechanical properties (tensile and burst strengths) as well as optical properties (whiteness and brightness) of handsheet was investigated. The developed code can appropriately learn the non-linear behavior of deinking process, and make decisions according to the pattern constructed intelligently. Finally, multi-objective optimization at the specified treatment temperature, treatment time, and enzyme dosage was performed to identify the best conditions for enzyme-deinked handsheet (maximized mechanical and optical properties)., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Concerns about human health regarding the large use of bisphenol A in thermal papers have led to its replacement by bisphenol S. Analyses of bisphenols require several sample pretreatment steps, which are laborious, expensive, and time-consuming. A paper spray ionization mass spectrometry (PSI-MS) was developed to detect and quantify bisphenol S in three different brands of thermal papers commercially available. Parameters such as paper size, and paper position relative to the mass spectrometer inlet were evaluated. The analyses were performed in selected ion monitoring mode on a linear ion trap mass spectrometer. The developed method presented absolute recovery values ranging from 92.2 to 109.04%, accuracy values from -1.2 to 9.0%, and inter assay precision from 1.8 to 5.6% and enabled LOD as low as 5 ng g -1 . The concentration of bisphenol S in all of the three brands of BPA-free thermal papers evaluated ranged from 1.36 to 6.77 μg g -1 , and the concentrarion of BPA ranged from 6.56 to 16.4 μg g -1 in all samples of thermal paper evaluated. The PSI-MS method described here was comparable to the conventional ones, such as liquid chromatography coupled with mass spectrometry and gas chromatography coupled with mass spectrometry described in the literature. The present study proved to be practical, fast, and efficient for the direct determination of bisphenol S in thermal papers. Furthermore, the methodology here described showed to be a promising alternative to replace the classical methods for determination of bisphenol S, due to its simplicity, and no needing of any sample pretreatment., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Biochar has effect on phosphorus adsorption, release, and transformation. This study compared the influence of biochar derived from animal (AB) and plant (PB) during paper mill sludge composting. Results indicated AB not only accelerated sludge decomposition but also had significantly higher levels of available phosphorus (AP) than PB and CK (no biochar), with AP contents in the order of AB > PB > CK. Compared to CK, AB was found to increase the relative abundance of thermophilic bacteria, and PB diversified the microbial community. Based on Pearson and RDA results, TOC/TN ratio (C/N) and organic matter (OM) explained above 50% of the variance in microbial community and phosphorus fractions. Thermophilic bacteria with high levels of OM and C/N promoted the conversion among labile and moderately labile organic phosphorus, moderately labile inorganic phosphorus, and AP. Biochar could enhance the AP conversion pathway, leading to increased levels of AP., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Apart from protecting the environment from undesired waste impacts, wastewater treatment is a crucial platform for recovery. The exploitation of suitable technology to transform the wastes from pulp and paper industries (PPI) to value-added products is vital from an environmental and socio-economic point of view that will impact everyday life. As the volume and complexity of wastewater increase in a rapidly urbanizing world, the challenge of maintaining efficient wastewater treatment in a cost-effective and environmentally friendly manner must be met. In addition to producing treated water, the wastewater treatment plant (WWTP) has a large amount of paper mill sludge (PMS) daily. Sludge management and disposal are significant problems associated with wastewater treatment plants. Applying the biorefinery concept is necessary for PPI from an environmental point of view and because of the piles of valuables contained therein in the form of waste. This will provide a renewable source for producing valuables and bio-energy and aid in making the overall process more economical and environmentally sustainable. Therefore, it is compulsory to continue inquiry on different applications of wastes, with proper justification of the environmental and economic factors. This review discusses current trends and challenges in wastewater management and the bio-valorization of paper mills. Lignin has been highlighted as a critical component for generating valuables, and its recovery prospects from solid and liquid PPI waste have been suggested., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Paper for recycling has become a promising raw material for the pulp and paper industry due to its low cost and because it is conducive to sustainable development. Unfortunately, recycled paper contains a high volume of printed paper that is difficult to deink, which restricts its applications. Flotation deinking plays an essential role in the product quality and process cost of wastepaper recycling. This study was performed to evaluate the deinkability of environmentally friendly offset inks by flotation deinking. For this purpose, three mineral oil free series of four-color inks, namely, hybrid light emitting diode ultraviolet (LED-UV), LED-UV, and vegetable oil-based inks, were printed on white lightweight coated papers under laboratory conditions. The deinking methodology involves repulping, deinking agent treatment, flotation, hand sheet making, and evaluation of the produced hand sheets. The obtained results indicated that the hybrid LED-UV prints had the best deinkability. After flotation deinking, the deinking efficiency and the whiteness of the hybrid LED-UV ink increased by 58.1% and 47.6%, respectively. LED-UV ink had a 46.9% increase in the deinking efficiency and a 37.0% increase in the whiteness of the hand sheet. The deinking efficiency of the vegetable oil-based ink was the lowest, at 42.1%, and the whiteness of the hand sheet increased only by 23.8%. The particle size distribution analysis demonstrated that the hybrid LED-UV four-color ink exhibited a larger value of the average particle size than the two other. Scanning electron microscopy revealed that the hybrid LED-UV ink particles on the surface of the fibers were the least abundant after deinking. The physical strength properties of the hand sheets, including tensile index, folding resistance, and interlayer bonding strength of the hybrid LED-UV, LED-UV inks, and vegetable oil-based inks, increased., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In this study, TiO 2 nanoparticle (TiO 2 NP)-coated film was produced to protect manuscripts against microorganisms using ecofriendly benign materials. As a result, a simple method was created that uses poultice biofilm made of carboxymethyl cellulose (CMC) and Phytagel plant cell (PGP) loaded with TiO 2 NPs to preserve manuscripts against microbes in an environmentally responsible way. Three volumes (1, 2, 4 mL) of TiO 2 NPs were put into a biofilm combination to produce the poultices known as CMC/PGP/TiO 2 -1, CMC/PGP/TiO 2 -2, and CMC/PGP/TiO 2 -3. The synthesized TiO 2 NPs were nearly spherical in shape, small in size (98 nm), and stable (zeta potential value - 33 mV). The results showed that the unique deposition of TiO 2 NPs on the biofilm surface gave the produced films loaded with TiO 2 NPs a rough structure. The highest values of mechanical characteristics were determined to be in CMC/PGP/TiO 2 -1 with values of 25.4 g, 6.6 MPa, and 11.4%, for tensile strength, elongation at break, and tear strength, respectively. Based on molecular identification, the fungus Aspergillus sydowii and the bacterium Nevskia terrae, with accession numbers MG991624 and AB806800, respectively, were isolated and identified from an antiquated manuscript formed from cellulosic fibers. Before the experiments, the produced cotton paper samples were aged, and then, one group was infected for 6 months by A. sydowii and the second group with N. terrae. Following the preparation of a CMC/PGP biofilm loaded with various volumes of TiO 2 NPs, poultices were applied to infected cotton paper in order to clean it. The infected cotton paper was placed inside the sandwich-like poultices that were created. The poultice CMC/PGP/TiO 2 -2 demonstrated potential for preventing the growth of A. sydowii and N. terrae-infected cotton paper, when the fibers were saved, cleaned, and coated with CMC/PGP/TiO 2 -2 after absorbing the fungus and the bacterium and exhibiting exceptional antimicrobial activities. Finally, the novel biofilms have demonstrated their capacity to lessen microbial contamination of cotton paper. In order to generalize the usage of these poultices, it is also advised that they be produced on a large scale and tested on a variety of organic materials in the future., (© 2023. The Author(s).)

Toilet paper has been reported as one of the major insoluble pollutant components in the influent of wastewater treatment plants. Toilet paper fibers contribute to a large production of sewage sludge, resulting in a high treatment cost and high energy consumption. To find energy-efficient, cost-effective, and environment-friendly technologies for fiber removal and resource recovery from wastewater, a life-cycle assessment (LCA) was performed to analyze the wastewater treatment processes, including a sieving process for removing and recovering suspended solids before the biodegradation units. Based on the LCA results, it was estimated that the sieve screening process saved 8.57% of energy consumption. The construction phase of sieving consumed 1.31% energy cost compared with the operation phase. Environmental impact analysis showed that sieving reduced the impacts of climate change, human toxicity, fossil depletion, and particulate matter formation, which reduced the total normalized environmental impacts by 9.46%. The life-cycle analysis of the removal of toilet paper fibers from wastewater revealed the need to use more efficient methods to enhance the recovery of cellulose fibers., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The potential of alkaline cellulo-xylanolytic enzymes from non-pathogenic Bacillus subtilis strain was tested for deinking of photocopier waste paper. Cellulase and xylanase play a crucial role in deinking of different types of waste paper. Partial purification of cellulo-xylanolytic enzymes was carried out using ultrafiltration followed by ammonium sulfate precipitation. The ultrafiltered enzyme was used for deinking the photocopier waste paper along with chemical deinking. An enzyme dose of 0.6 IU/g and reaction time of 60 min for ultrafiltered cellulo-xylanolytic enzyme significantly increased deinking efficiency, tear index (9.52%) and folding endurance (5±2%) as compared to chemical deinking. There was improvement in strength properties such as tear index and double-fold along with freeness of pulp (18%). There was slight decrease in tensile index (0.6%) and burst index (16%) while ISO brightness remained unaffected. Enzymatic deinking (74.3%) by ultrafiltered cellulo-xylanolytic from Bacillus subtilis was found significant over conventional chemical deinking., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Recycled paper pulping wastewater (RPPW) will cause serious environmental problems due to the high loads of dissolved organic matter (DOM) and toxic components. In the present work, the degradation of DOM in the biologically treated RPPWs (cardboard wastewater (CW) and corrugated container wastewater (CCW)) by a combined coagulation and ozonation process was investigated. The optimal chemical oxygen demand (COD) removal of CW reached 73.64% at aluminum sulfate (Al 2 (SO 4 ) 3 ) dosage of 800 mg/l, aeration aperture of 10 μm, pH of 9, hydrogen peroxide (H 2 O 2 ) dosage of 100 mg/l, and reaction time of 70 min. The optimal COD removal of CCW reached 55.76% at a poly-aluminum chloride (PAC) dosage of 700 mg/l, H 2 O 2 dosage of 140 mg/l, and reaction time of 50 min. This study provided some insights into the change of DOM during the combined treatment through the use of UV-Vis spectroscopy and excitation-emission matrix spectroscopy (EEM). PAC and Al 2 (SO 4 ) 3 removed high molecular weight organic such as lignin and lignin-derived compounds to improve the biodegradability of the wastewater. Ozone oxidized high molecular weight organic with complex functional groups to low molecular weight organic with simple functional groups and even mineralization, and this phenomenon resulted in the COD of ozonation effluent significantly reduced. Thus, the results presented in this study support the application of the combined coagulation and ozonation process in treating RPPW., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The environmental and energy impacts of ICT were identified using a comparative life cycle assessment (CompLCA) focused on business invoicing processes comparing online to paper processes. There were net energy benefits from online billing. The potential impact across the economy and society is large, particularly as COVID-19 has forced many businesses and government services to shift to online service provision. For one million bills produced electronically and received by customers instead of a paper bill, 18.9 t CO 2 e is avoided, which translates to a national saving of 22,680 tCO 2 e, assuming 1.2 billion annual invoicing transactions. The impacts of CO 2 are sensitive, however, to several assumptions. The study's originality was to show the range of invoicing variables that impact energy and the environment and to highlight which ones can be influenced. For example, the number of online bills produced was the most sensitive. However, the results are reversed under commonly occurring customer use situations. The study demonstrates the positive and negative impacts from the digitalisation of businesses. It suggests remedies based on the main drivers identified under company, contractor and customer control that led to energy consumption and environmental and land use impacts., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

One of the paper industry's major focuses is shifting toward eco-friendly paper production. Chemical-based bleaching of pulp, which is widely used in the paper industry, is a highly polluting step. Replacing it with enzymatic biobleaching is the most viable alternative to make the process of papermaking greener. Enzymes such as xylanase, mannanase, and laccase are suitable for the biobleaching of pulp, which involves the removal of hemicelluloses, lignins, and other undesirable components. However, as no single enzyme can achieve this, their application in industry is limited. To overcome these limitations, a cocktail of enzymes is required. A number of strategies have been explored for the production and application of a cocktail of enzymes for pulp biobleaching, but no comprehensive information is available in the literature. The present short communication has summarized, compared, and discussed the various studies in this regard, which will be highly useful to pursue further research in this regard and make the process of papermaking greener., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The objective of this study was to check the potential of crude xylano-pectinolytic enzymes in bleaching of rice straw pulp, in order to reduce the toxic waste load for managing the environmental pollution. The xylano-pectinolytic enzymatic bleaching step for delignification was found to be most effective at pulp consistency 1:10 g/ml, xylanase:pectinase dose of 9:4 IU/ml, pH 8.5 and treatment time 180 min at temperature of 55 °C, and resulted in lowering of kappa number of the rice straw pulp by 15.29%. In subsequent bleaching stages, this enzymatic pre-bleaching treatment also resulted in 30% reduction of active chlorine dioxide dose without any loss of optical properties. Significant improvement in various physical properties of the enzymes treated pulp, tear index (15.43%), breaking length (11.11%), double fold number (25.92%), burst index (9.88%) and viscosity (13.63%), and Gurley porosity (39.86%) was also noticed. This approach resulted in reduction of BOD and COD values by 21.07% and 26.57%, respectively. This is the first study on the use of crude xylano-pectinolytic enzymes for bio-bleaching of rice straw pulp.

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.

In this study, action of ultrafiltered xylano-pectinolytic enzymes from a bacterial strain has been evaluated for bleaching of rice straw soda-anthraquinone pulp. Maximum bio-bleaching effect and release of non-cellulosic impurities were noticed with xylano:pectinolytic enzymes dose of 6.0:2.1-IU/g pulp, treatment time of 180 min at 10% pulp consistency, pH 8.5, and temperature 55 °C. Microscopic images of bio-bleached rice straw pulp also confirmed the efficacy of ultrafiltered enzymes, as bleaching agent. This bio-bleaching treatment resulted in 15.38% and 32% reduction in kappa number and active chlorine dioxide dose, respectively, along with increase in various physical properties, burst index (12.50%), tear index (19.07%), breaking length (14.30%), double fold number (26.31%), Gurley porosity (45.32%) and viscosity (16.17%). This bio-bleaching approach not only improved the pulp quality but also reduced environmental pollution load by decreasing effluent parameters values of BOD and COD by 23.67% and 27.44%, respectively. This study indicates that use of ultrafiltered xylano-pectinolytic synergism for rice straw pulp bleaching will ultimately help in making the process eco-friendly, along with better quality pulp. This is the first report on use of ultrafiltered xylanase and pectinase, produced from a bacterial isolate, for bleaching of rice straw pulp.

This research was carried out with an objective to examine the efficacy of ultrafiltered xylano-pectinolytic enzymes in pulping of sugarcane bagasse. Maximum biopulping was achieved with enzyme dose of xylanase (175 IU / g bagasse) and pectinase (75 IU / g bagasse) at treatment period of 180 min. The temperature, pH, and bagasse to liquid ratio for biopulping experiments were kept constant at 55 o C, 8.5, and 1:10 (g/ml), respectively. The ultrafiltered biopulping improved chemical pulping, resulted in 25.11%, 9.17% increase in brightness, unscreened pulp production and 11.81, 59.50, and 49.14% decrease in total solids, rejections. and kappa number, respectively. The bagasse biopulping also resulted in 15% decrease of alkali load to attain similar kappa number and optical properties as obtained under 100% alkali dosage. Ultrafiltered biopulped-unbleached samples showed significant increase in breaking length (13.55%), burst index (40.21%), tear index (19.04%), double fold (42.5%), Gurley porosity (28.21%) and viscosity (13.37%) in comparison with non-enzymatically treated control pulp samples. In comparison with non biotreated-bleached pulp samples, ultrafiltered biopulped-bleached samples also resulted in higher burst index (56.80%), breaking length (17.38%), double fold (39.58%), tear index (3.38%), viscosity (30.68%), and Gurley porosity (52.50%). This environmentally sustainable ultrafiltered biopulping approach for sugarcane bagasse has the potential to decrease the demand of chemicals, ultimately pollution along with enhance the quality of paper.

Although a significant amount of brewery wastewater (BW) is generated during beer production, the nutrients in the BW could be reused as a potential bio-resource for biohydrogen production. Therefore, improvements in photofermentative biohydrogen production due to a combination of BW and pulp and paper mill effluent (PPME) as a mixed production medium were investigated comprehensively in this study. The experimental results showed that both the biohydrogen yield and the chemical oxygen demand removal were improved through the combination of BW and PPME. The best biohydrogen yield of 0.69 mol H 2 /L medium was obtained using the combination of 10 % BW + 90 % PPME (10B90P), while the reuse of the wastewater alone (100 % BW and 100 % PPME) resulted in 42.3 and 44.0 % less biohydrogen yields than the highest yield, respectively. The greatest light efficiency was 1.97 % and was also achieved using the combination of both wastewaters at 10B90P. This study revealed the potential of reusing and combining two different effluents together, in which the combination of BW and PPME improved the nutrients and light penetration into the mixed production medium.

Phenol and its derivatives are the major environmental pollutants discharged from paper and pulp industries into water bodies. All these compounds and chlorinated phenolic compounds in particular are very toxic to fauna and flora, even at relatively low concentration. This study aimed to investigate the removal rate of phenolic compounds from the effluent of pulp and paper industries using a combination of ozonation and photocatalytic processes. Firstly, a certain volume from the effluent of paper and pulp industries containing certain phenol concentrations was obtained and fed into a prefabricated reactor at laboratory scale. Then, the combined and separate effects of zinc oxide dosage (ZnO), ozone flow rate (O 3 ), and pH under ultra violet radiation for 30 min were evaluated. The concentration of phenolic compounds and the produced ozone gas flow rate were measured by a spectrophotometry and iodometric method, respectively. The results showed that the phenolic removal rate increased at acidic PHs compared with alkaline PHs; it was also decreased with the increase in ZnO dosages. Furthermore, the highest phenolic compound's removal rate was 99% at the optimal condition (pH 5, ZnO dosage of 0.1 g L -1 at the 30 min with UV-C illumination of 125 W). Finally, Daphnia toxicity test showed that treated effluent was safe and met the standards to the extent that it can be discharged into the receiving waters. Graphical abstract ᅟ.

We report a pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) method capable of analyzing traditional East Asian papers. The method proposed is based on rapid and easy single step Py-GC/MS analysis that can be carried out with a minimum amount of matter, in the few microgram range. Three reference papers manufactured from kozo (Broussonetia kazinoki Siebold & Zucc.), mitsumata (Edgeworthia chrysantha Lindl.), and gampi (Wikstroemia sikokiana Franch. & Sav.) with the traditional hand paper making processes were examined. The method allows discrimination between terpenic and steroid compounds, which were revealed as chemical markers of origin of the plant fibers. Each paper investigated was found to have characteristic pyrolysis fingerprints that were unique to the traditional handmade paper, demonstrating the potential for differentiation of these biochemical components of fiber plants on East Asian papers towards identification and conservation of cultural heritage. The investigation on Py-GC/MS was extended to liquid extraction followed by GC/MS analysis to characterize the biochemical components of fiber plants. The main contribution of this study is to provide molecular criteria for discriminating plant species used for traditional East Asian hand papermaking. Py-GC/MS complements efficiently microscope identification especially for adverse cases. A case study of archaeological Chinese paper painting artefacts was thereafter successfully investigated to address informative potential and efficiency of the criteria of identification on ancient and degraded East Asian paperworks.

The environmental acceptability of geotechnical composites made of treated municipal sewage sludge (SwS) and paper ash (PA) after two different curing periods has been investigated. The mineral composition of such composites, including their content of major oxides, is mainly influenced by the PA. The content of potentially toxic elements (PTEs) in the initial materials and in the composites varies considerably. In the SwS the Ba, Cd, Cr, Cu, Hg, Ni and Zn contents are above the legally permitted limits. The PTE content of PA are lower, but still somewhat above the permitted values for Ba and Cu. Mixing these two materials together resulted in a decrease in the PTE, but the Ba, Cu and Zn contents are still too high for agricultural application. However, leachates from composites that had been cured for 28 days are highly alkaline, and the As, Ba, Cd, Cr, Hg, Mo, Ni, Pb and Zn contents in them are well below the permitted values. The Cu contents (2.4 to 5.4 mg/kg) are above the permitted limit for inert material, but inside the range for non-hazardous material. In a leachate of composite which was prepared with fresh PA and a lower PA to SwS ratio, the Cu content was 1.4 mg/kg, since fresh PA is more reactive and therefore has a higher ability to immobilise Cu. Therefore, such mixtures can be utilised for covers and liners for sanitary landfills.

Microorganisms are a promising source of colorants with large economic potential. Owing to better bio-degradability and higher eco-compatibility, microbial pigments propose promising avenues and can thus be a smart substitute for artificial pigments. The present work focused on the screening, isolation, and extraction of a blue-green pigment produced by soil microorganisms. The pigment-producing microorganism was identified as Pseudomonas aeruginosa on the basis of standard biochemical tests and by 16S rRNA sequencing. The purified blue pigment was characterized by high-performance liquid chromatography and gas chromatography-mass spectrometry. The antimicrobial activity of the microbial biocolor (3 × 10 8  CFU/ml) was studied, and the zone of inhibition was found to be 10 mm, 13 mm, 9 mm, and 7 mm for E. coli, S. aureus, B. subtilis, and S. typhi, respectively. The evaluation of the biocolor as a dye was executed on different types of textiles and paper. The dyed fabrics were checked for washing, rubbing, and light and temperature fastness. Standard fabric properties of the fabrics dyed with the extracted microbial pigment were also assessed. The dyed fabrics were finally subjected to a patch test to check for any kind of allergic or hypersensitivity on human skin. The extracted pigment from Pseudomonas aeruginosa exhibited remarkable dyeing properties, indicating the scope for utilization of the pigment as a colorant on different types of textile and paper materials. The present study highlights the application of a bacterial pigment as a dyeing agent, which may raise its market value and probably replace toxic synthetic dyes due to its nontoxic nature, compatibility with various textiles, and cost-effectiveness., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In this study, suitability of xylano-pectinolytic enzymes in pulping of wheat straw has been explored. The suitable biopulping conditions were optimized, with xylanase dose of 400 and pectinase dose of 120 IU/g wheat straw, 1:10 (g/ml) material to liquid ratio, 55 °C temperature, 3 h treatment time, 0.75% Tween 80 and pH 8.5. Enzymatic pretreatment efficiently increased the pulpability of wheat straw, generated pulp with higher yield, lower kappa number (15.67%) and rejections (59.65%) in comparison with chemical pulp. The brightness of pretreated wheat straw pulp with enzyme was 16.04% higher than that of the non-enzyme treated wheat straw pulp. The biopulping resulted in 12% reduction of pulping chemicals along with more residual alkali content, in order to achieve similar optical and chemical properties as obtained by 100% chemically treated pulp. Physical properties of pulp also improved after enzymatic pretreatment, increasing burst index (26.50%), tear index (18.22%) and breaking length (5.56%). The enzyme plus chemical (88% pulping chemicals) treated pulp showed improvement in brightness and whiteness, with reduction in yellowness at all bleaching stages. In comparison with chemically bleached pulp, biopulp with reduced alkali dose (88%) had higher breaking length (6.63%), double fold number (51.28%), tear index (2.83%), burst index (24.31%), along with increased viscosity (6.12%) and Gurley porosity (27.50%). These results clearly suggest that biopulping of wheat straw with xylano-pectinolytic enzymes can reduce chemical loading during soda-anthraquinone pulping and also improve the quality of paper. This is the first report demonstrating the biopulping of wheat straw using crude xylano-pectinolytic enzymes.

Lipase enzyme has a critical role in deinking process along with other lignocellulosic enzymes. In this paper, we try to demonstrate the role of lipase in the enzyme cocktail used for enzymatic deinking. For this, we identified a potential lipolytic bacterium, Pseudomonas mendocina ED9 isolated from elephant dung with a molecular weight of 35 kDa. During the Box-Benhken model optimization, a maximum lipase activity of 105.12 U/g, which was 12.36-fold higher than the initial enzyme activity and 1.3-fold higher than the activity obtained during the Plackett Burman design, was achieved. A maximum lipase activity of 105.12 U/g was obtained after optimization. Ammonium sulphate (60%) precipitation resulted in a specific activity of 68.19 U/mg with a 1.4-fold purification and yield of 64%. Lipase from P. mendocina ED9 exhibited a Km of 0.5306 mM and Vmax of 25.0237 μmol/min/mg. A Δ brightness of approximately 14.5% were achieved during the enzymatic deinking using cocktail comprised of cellulase, xylanase and lipase. This reports the significant role and efficacy of lipase in enzyme cocktails for deinking applications. This formulation will reduce the pollution and environmental toxicity of conventional chemical deinking.

The objective of this work was to evaluate thermal paper (TP) tickets used in Argentina as a potential source of bisphenol A (BPA) that could impact humans and the environment. BPA in TP was measured by HPLC ranging from 11.1 to 30.5 mg BPAg -1 . In order to estimate the impact on humans, dermal BPA estimated daily intake was calculated as being 79.3 ± 19.5 μgd -1 for workers and 1.6 ± 0.4 μgd -1 for the general population. To evaluate TP's impact on the environment, BPA migration from TP to water and soil was studied. In the case of water, 99.6% of the BPA tickets content migrated in 30 h, while 78.0% moved into the soil in 96 h. BPA degradation kinetics in soil and water were also carried out; while in soil 61.9% of BPA degraded in 120 h, no degradation was observed up to 120 h in tap or river water.Additionally, ecotoxicological effects of BPA on the earthworm Eisenia andrei, a representative terrestrial indicator, were studied performing bioassays on lethality, avoidance, and reproductive and enzymatic activity. BPA showed to be very toxic to E. andrei (LC 50 value in contact paper test of 17 μgcm -2 , 95% confidence interval 6-46 μgcm -2 , 24 h exposure) and also caused an increase of total cocoons for earthworms exposed to 10 and 50 mg BPA kg -1 soil. Evasion response was observed at a concentration of 50 mg BPA kg -1 soil, while no effect was observed on cholinesterases, carboxylesterases, and glutathione S-transferases activities (1, 10, and 50 mg BPA kg -1 soil). Finally, a simple BPA degradation technology using water peroxide and radish (Raphanus sativus) tissue as catalyst was explored as a simple and domestic potential treatment to avoid BPA migration to the environment., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The quest for cost-effective and thermal efficient structural materials onto beating the high cost of construction is gaining more attention among researchers. This study focused on the blending of cement and sand with waste paper pulp into cost-effective structural materials. The composites were prepared in four mix groups with each containing a fixed amount of sand at 5, 10, 15, and 20 wt.% (by weight of pulp). Cement was varied at 10, 20, 30, and 40 wt.% in each group, and curing was done for 28 days. Properties evaluated are compressive, bending, and splitting strengths. It was observed that increasing cement and sand contents enhanced strengths; howbeit, the blend of 30 wt.% cement/15 wt.% sand resulted in a reduction in bending strength even as 30 wt.% cement/20 wt.% sand engendered a decrease in bending and splitting strength. The microstructural features showed that inherent fibers of the pulp were well bonded with hydration products and sand content yielding good performance in the composites. The optimization procedure carried out depicted a combination of 35.27% cement and 20% sand as the optimum composition. Experimental outcomes were modelled for the purpose of prediction of responses. The models were confirmed statistically fit showing how varying cement content affected strength responses at fixed sand proportion. ANOVA affirmed the significant contribution of cement and sand on the strength responses. Compliance reliability was observed to be dependent on the interactive pattern between cement and sand. Going by the standard prescription for the strength properties, cement and sand content of 35.27 and sand 20 wt.% satisfied all strength requirements for low-cost construction having a compliance reliability of 1.31., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In this work, the effect of using Ag-doped TiO 2 nanopigments on optical, mechanical and antimicrobial properties of coated paper was explored. Furthermore, the long-term antimicrobial activity of the coated paper was examined for up to 25 years. Titanium dioxide (TiO 2 ) nanoparticles have been synthesized and doped with different percentages of Ag nanoparticles (Ag NPs) using a simple wet chemical approach. The Ag@TiO 2 modified nanopigments were in the form of nanorods with an average size of about 20 nm as observed from TEM images. Increasing Ag content from 0.01 to 1.0% showed an increase in the mechanical properties of coated paper in terms of tensile, stretching, tensile energy absorption and burst while preserving the optical properties. Moreover, the antimicrobial inhibition activity increased with increasing the Ag content. The 1% Ag@TiO 2 showed a long-lasting antimicrobial effect against Staphylococcus aureus (S. aureus) Gram-positive bacteria even after 25 years of ageing (93.4% inhibition). Investigation of reactive oxygen species (ROS) generation and reaction mechanism of antimicrobial activity over Ag/TiO 2 under visible light is proposed. These results suggest that Ag/TiO 2 NPs can be potentially used as a disinfection coating for paper and improving its mechanical properties., (© 2022. The Author(s).)

An essential requirement for colorimetric paper-sensor is to allow the target analytes (heavy metal ions) to access the chromophore while maintaining strong chromophore immobilization on the porous substrate surface. This work evaluates the selection of sensitive chromophores (dithizone, 1-(2-pyridylazo) 2-naphthol and 4-(2-pyridylazo)-resorcinol) and their immobilization strategies on paper sensors. Dithizone (DTz) are capable of producing a significant color transition at unadjusted pH, observed by UV-Vis absorption spectroscopy and visible recognition. After immobilizing DTz on a paper substrate (cellulose acetate/chitosan substrate), the DTz-paper sensor showed a distinctive color change from blue-green to peach-pink upon reaction with Pb 2+ ions, and the color intensity was proportional to the metal concentration. Quantitative analysis using RGB (R:Red; G:Green; B:Blue) plots showed that increasing DTz concentration on the CA/CS paper sensor increases the difference in total color intensity (∆I T ) and the difference in red code intensity (∆I R ). This is due to the formation of more DTz-Pb 2+ complexes on the CA/CS paper substrate. The CA/CS paper strips immobilized with 100 ppm DTz showed practical potential for rapid detection of heavy metal ions. The DTz-CA/CS paper sensor showed significant color change when detecting spiked heavy metals ions (0.1 ppm Pb 2+ , 2.0 ppm Zn 2+ , and 0.2 ppm Cu 2+ ) in river water samples that prepared at the maximum permissible limit for industrial effluent in Malaysia., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Phthalate acid esters are widely used as plasticizers to impart plastic flexibility in various industrial applications. In this study, the content of seven phthalates, dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), di-(2-ethylhexyl) adipate (DEHA), di-2-ethylhexyl phthalate (DEHP), di-n-octyl phthalate (DNOP), di-isononyl phthalate (DINP), and di-isodecyl phthalate (DIDP) were determined in paper cups using gas chromatography-mass spectrometry (GC-MS). In addition, the potential migration of these seven phthalates from paper cups into various food stimulants under different conditions was evaluated. The levels of DBP, DEHA, DEHP, and DNOP were in the ranges of 0.07-3.14, 0.16-42.69, 0.45-58.56, and 0.3-2.4 mg/kg, respectively. Meanwhile, BBP, DINP, and DIDP were not detected in most of the tested samples. In the migration test, DEHA was released to 50 % ethanol and n-heptane in a time-dependent manner and the maximum migration levels were 65.62 ± 3.61 and 95.56 ± 19.76 μg/L, respectively. The release of other phthalates was very low or negligible. These results demonstrated that paper cups are not a significant source of phthalate exposure; however, DEHA could be released from paper cups into alcoholic beverages or oily liquid beverages in the human diet.

Low pressure reverse osmosis (LPRO) has been increasingly used in advanced treatment of pulp and paper wastewater (PPWW) for the purpose of water reuse. However, membrane fouling is a major problem encountered by full-scale RO systems due to the organic and inorganic contents of the feedwater. Electrocoagulation (EC) as an effective treatment for foulants removal can be applied in pre-filtration. Therefore, the LPRO membrane fouling mechanism and the membrane fouling control performance by EC treatment were investigated in this study. EC pretreatment could reduce the membrane fouling and improve the membrane flux by 31%, by effectively removing and/or decomposing the organic pollutants in PPWW. Fluorescent spectrometry analyses of the feedwater and the permeate revealed that humic acid-like and fulvic acid-like organics in PPWW were the major foulants for the LPRO membranes. Fourier transformation infrared spectrometry results confirmed that the organic foulants contained benzoic rings and carboxylic groups, which were typical for organic substances. EC effectively removed organic pollutants containing functional groups such as carboxylic acid COH out-of-plane bending, olefin (trans), and NH 3 + symmetrical angle-changing. Moreover, the extended Derjaguin-Landau-Verwey-Overbeek model suggested that the membrane filtered 30-min EC-treated PPWW had the strong repulsion force to foulants due to the higher cohesion energy (12.1 mJ/m 2 ) and the lower critical load, which theoretically explained the reason of EC pretreatment on membrane fouling control., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Peat-based growing media are not ecologically sustainable and peat extraction threatens sensitive peatland ecosystem. In this study, olive-stone waste (OSW) and paper waste (PW) were used in different ratios-as growing media-for ornamental crop production, as peat (P) substitutes. Marigold (Calendula officinalis L.), petunia (Petunia x hybrita L.) and matthiola (Matthiola incana L.) plants were grown in (1) P (100%), (2) P:OSW (90%:10%), (3) P:OSW (70%:30%), and (4) P:OSW:PW (60%:20%:20%). The physicochemical properties of these substrates and the effects on plant growth were determined. The addition of 10-30% OSW into the substrate increased marigold height compared to plants grown in 100% peat. No differences in plant size, plant biomass (leaves and flowers), and dry matter content were found. Adding PW, in combination with OSW, maintained marigold height and total number of flowers produced to similar levels as in plants grown in 100% peat. In matthiola, adding 30% OSW into the substrate reduced plant size and fresh weight, but not plant height. No differences were observed when plants grew in lower OSW (i.e., 10%) content. Petunia's height, its total number of flowers and flower earliness (flower opening) were increased in the presence of OSW compared to the plants grown in 100% peat. The addition of OSW did not affect petunia's size and fresh weight among treatments. The addition of PW suppressed several plant growth-related parameters for both matthiola and petunia. The insertion of OSW did not change leaf chlorophyll content whereas the presence of PW decreased chlorophylls for marigold, petunia, and matthiola. Both OSW and PW altered the content of total phenolics and antioxidant capacity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) in leaves and flowers for marigold and petunia. Both 30% OSW and PW increased antioxidative enzyme metabolism due to the increased damage index and lipid peroxidation observed in plants. Leaf N and P content decreased in PW-based media, while matthiola displayed visual phytotoxicity symptoms when PW was added into the substrate. The present work indicates that up to 30% of OSW can replace peat for marigold and petunia growing and only up to 10% of OSW for matthiola, while the addition of PW on top of OSW is not recommended, so further research is needed.

Porous magnesium oxide (MgO) films on carbon fiber paper (CF) have been successfully fabricated in a hydrothermal route at different calcination temperatures. The CF@MgO samples (CF@MgO-300, -400, and -500) show different morphologies with the increasing surface area from 3 for CF to 27 m 2  g -1 for CF@MgO-400. Among the four investigated samples, the CF@MgO-400 exhibits the highest phosphate removal ability (~ 1230 mg g -1 ) with promising applications for the large-scale utilization at low cost.

This study aimed to maximise the amount of CO 2 storage by indirect carbonation using paper sludge ash (PSA), which is an alkaline industrial waste. The properties of the following three types of solvents were considered: acids (acetic acid and hydrochloric acid), ammonium salts (ammonium chloride and ammonium acetate) and others (sodium citrate and water). When carbon dioxide was injected into calcium leachates prepared from PSA using acids, carbonation did not occur, and using ammonium salts as solvent, the carbonation efficiency was low. However, after pH swing of the leachates using sodium hydroxide and ammonia solution for acid and ammonium salt solvents, up to 324 kg CO 2 /(ton PSA) and 175 kg CO 2 /(ton PSA) were stored, respectively. When carbon dioxide was injected into calcium leachates prepared from PSA using sodium citrate or water, solid was initially generated which later dissolved. In order to solve this problem, CO 2 injection was stopped just before the pH of the solution reached 10.5 for sodium citrate and 8.3 for water, resulting in the storage of 136 kg CO 2 /(ton PSA) and 29 kg CO 2 /(ton PSA), respectively. Solids obtained through carbonation were pure calcium carbonate.

This review describes medium and high molecular weight organic material found in wastewaters from pulp and paper industry. The aim is to review the versatile pollutants and the analysis methods for their determination. Among other pollutants, biocides, extractives, and lignin-derived compounds are major contributors to harmful effects, such as toxicity, of industrial wastewaters. Toxicity of wastewaters from pulp and paper mills is briefly evaluated including the methods for toxicity analyses. Traditionally, wastewater purification includes mechanical treatment followed by chemical and/or biological treatment processes. A variety of methods are available for the purification of industrial wastewaters, including aerobic and anaerobic processes. However, some fractions of organic material, such as lignin and its derivatives, are difficult to degrade. Therefore, novel chemical methods, including electrochemical and oxidation processes, have been developed for separate use or in combination with biological treatment processes.

The aim of the present study was to subject the post-consumer waste, namely paper cups for vermicomposting along with cow dung in three different ratios for a period of 90-140 days employing Eisenia fetida. The post-consumer wastes are a menace in many developing countries including India. This waste was provided as feed for earthworms and was converted to vermicompost. Vermicompost prepared with paper cup waste was analyzed for their physicochemical properties. Based on the physicochemical properties, it was evident that the best manure is obtained from type A (paper cup/cow dung in the ratio 1:1) than type B (paper cup/cow dung in the ratio 1.5:0.5) and type C (paper cup/cow dung in the ratio 0.5:1.5). The results showed that earthworms accelerated the rate of mineralization and converted the wastes into compost with needed elements which could support the growth of crop plants. The predominant bacterial strains in the vermicompost were characterized biochemically as well as by 16S ribosomal RNA (rRNA) gene sequencing. The bacterial strains like Bacillus anthracis (KM289159), Bacillus endophyticus (KM289167), Bacillus funiculus (KM289165), Virigibacillius chiquenigi (KM289163), Bacillus thuringiensis (KM289164), Bacillus cereus (KM289160), Bacillus toyonensis (KM289161), Acinetobacter baumanni (KM289162), and Lactobacillus pantheries (KM289166) were isolated and identified from the final compost. The total protein content of E. fetida involved in vermicomposting was extracted, and the banding pattern was analyzed. During final stages of vermicomposting, it was observed that the earthworm did not act on the plastic material coated inside the paper cups and stagnated it around the rim of the tub. Further, the degradation of paper cup waste was confirmed by Fourier transform infrared spectroscopy analysis. Hence, vermicomposting was found to be an effective technology for the conversion of the paper cup waste material into a nutrient-rich manure, a value-added product.

Waste management is the protection of the environment and the health of the population. Paper waste sludge is produced during paper production and sepiolite is a natural clay mineral. The aim of the study was to investigate the usability of sepiolite-added paper waste sludge as a bedding material in the broiler production. Two hundred eighty-eight 1-day old male broiler chicks were divided into the 6 bedding material groups (wood shavings (control), paper waste sludge, sepiolite, mix of 25% paper waste sludge and 75% sepiolite, mix of 50% paper waste sludge and 50% sepiolite, and mix of 75% paper waste sludge and 25% sepiolite) with 6 replicate pens per group. Litter quality, performance, and some welfare parameters of broilers were assessed during the 6 weeks' period. Body weight at 42 days of age and body weight gain from 0 to 42 days of broilers reared on the wood shavings and mix of 50% paper waste sludge and 50% sepiolite were found higher than those of the sepiolite and paper waste sludge groups. Feed consumption and feed to gain ratio from 0 to 42 days, yields of carcass and carcass parts, percentages of organs and abdominal fat, IgG, percentage of bursa Fabricius, burns of foot pad and breast, litter pH and meat properties of broilers reared on the wood shavings, paper waste sludge, and sepiolite litter groups were not found to be statistically different. Litter moisture was found higher in the paper waste sludge group than that in the sepiolite group at the 42 days of rearing. As a conclusion, usage of mix of 50% paper waste sludge and 50% sepiolite as a litter does not have any negative effects on performance, welfare, and litter quality. This result is important in terms of utilizing a waste product., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The paper-making process can produce large amounts of wastewater (WW) with high particulate and dissolved organic loads. Generally, in developed countries, stringent international regulations for environmental protection require pulp and paper mill WW to be treated to reduce the organic load prior to discharge into the receiving environment. This can be achieved by primary and secondary treatments involving both chemical and biological processes. These processes result in complex changes in the nature of the organic material, as some components are mineralised and others are transformed. In this study, changes in the nature of organics through different stages of secondary treatment of pulp and paper mill WW were followed using three advanced characterisation techniques: solid-state (13)C nuclear magnetic resonance (NMR) spectroscopy, pyrolysis-gas chromatography mass spectrometry (py-GCMS) and high-performance size-exclusion chromatography (HPSEC). Each technique provided a different perspective on the changes that occurred. To compare the different chemical perspectives in terms of the degree of similarity/difference between samples, we employed non-metric multidimensional scaling. Results indicate that NMR and HPSEC provided strongly correlated perspectives, with 86 % of the discrimination between the organic samples common to both techniques. Conversely, py-GCMS was found to provide a unique, and thus complementary, perspective.

Greenhouse gas (GHG) emission in wastewater treatment plants of the pulp-and-paper industry was estimated by using a dynamic mathematical model. Significant variations were shown in the magnitude of GHG generation in response to variations in operating parameters, demonstrating the limited capacity of steady-state models in predicting the time-dependent emissions of these harmful gases. The examined treatment systems used aerobic, anaerobic, and hybrid-anaerobic/aerobic-biological processes along with chemical coagulation/flocculation, anaerobic digester, nitrification and denitrification processes, and biogas recovery. The pertinent operating parameters included the influent substrate concentration, influent flow rate, and temperature. Although the average predictions by the dynamic model were only 10 % different from those of steady-state model during 140 days of operation of the examined systems, the daily variations of GHG emissions were different up to ± 30, ± 19, and ± 17 % in the aerobic, anaerobic, and hybrid systems, respectively. The variations of process variables caused fluctuations in energy generation from biogas recovery by ± 6, ± 7, and ± 4 % in the three examined systems, respectively. The lowest variations were observed in the hybrid system, showing the stability of this particular process design.

The Tibetan Plateau works as an important environmental and ecological barrier for the Asian continent. The researches on Tibetan environment and ecology are becoming extensive, but there is no systematic summary of research hotspots and trends in this field. Here, we analyzed 9180 publications retrieved from the WOS and CNKI during 2000 ~ 2020. The characteristics of publication, keywords with a 5-year interval and co-occurrence analysis were carried out so as to reveal the evolution and development trends of topics. The results show that articles increase dramatically since 2012. Except for common concerns like evolution, climate change, and precipitation, diversity was been studied more by Chinese scholars, while the USA, Germany, UK, and Australia researchers focused more on adaptability, basin western Tibet, lake, barley, and ore-related themes, respectively. Besides, China closely collaborated with the USA, Australia, and Germany in topics of evolution, climate change and degradation, precipitation, and diversity. The institutions located in Chinese different economic regions focused on different research keywords, such as vegetation, growth, trace elements, and geochemistry. The CAS contributed the most articles with 4254, showed advantages both in quantity and quality. Few articles were published by researchers affiliated to Free University of Berlin but with higher citations. It is the only one institute outside of China in the top 20. Main research hotspots include climate change, geology, and diversity. In future researches, ecological management and rehabilitation of mining area and tailings ponds, waste disposal, and changes of soil and water quality are worthy of attention and funding., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The current study investigated the efficiency of poly ferric chloride (PFC) and poly titanium tetrachloride (PTC) in coagulation-flocculation process for treatment of paper and cardboard wastewater. The effect of pH (5-11), coagulant concentrations (100-1000 mg/L), mixing rate (10-60 rpm), mixing time (5-25 min), and settling time (5-30 min) were examined. The results showed that the removal efficiency for turbidity, total suspended solids (TSS), and chemical oxygen demand (COD) by PFC and PTC coagulants increased with pH rising up to 9 for the former and 7 for the latter coagulant. Furthermore, the removal efficiency for the afore-mentioned parameters increased along with a 30 rpm increase in the mixing rate, while the mixing time reached 20 min. It was also found that the best removal efficiencies for turbidity, TSS, and COD by PFC under optimal conditions (pH 9, coagulant dose 800 mg/L, and settling time of 25 min) were 97.11%, 99.1%, and 84.91%, respectively. In addition, the removal efficiencies for PTC (optimal conditions of pH 7, coagulant dose 600 mg/L, and settling time of 15 min) were found to be 98.29%, 99.29%, and 86.42%, respectively. Water recovery and the produced sludge volume by PFC were 80% and 200 cm 3 , respectively, in the settling time of 25 min and for PTC were 81.5% and 185 cm 3 , respectively, in the settling time of 15 min. Costs of the coagulation-flocculation process for treatment 1 m 3 of paper and cardboard wastewater using PTC and PFC were 0.42 $ and 0.32 $, respectively. Finally, it can be concluded that compared to PFC, PTC with higher settling rate has a greater efficiency for treatment of paper and cardboard wastewater.

Introduction: In this study, we explore the identity of a range of polyfluorinated surfactants (PFS) used for food contact materials, primarily to impart oil and water repellency on paper and board. PFS are of interest, as they can be precursors of poly- and perfluorinated alkyl substances (PFAS), of which several are persistent and are found worldwide in human blood and in the environment., Materials and Methods: To determine the elemental composition of PFS, we combined information from patents, chemical suppliers and analyses of industrial blends using ultra performance liquid chromatography-negative electrospray ionisation quadrupole time-of-flight mass spectrometry., Results: At a high pH of 9.7, both non-ionic and anionic PFS were ionised and were recognised by negative mass defects of exact masses, and neutral fragment losses of n × 20 or n × 100 Da. More than 115 molecular structures were found in industrial blends from the EU, US and China, belonging to the groups of polyfluoroalkyl-mono- and di-ester phosphates (monoPAPS, diPAPS and S-diPAPS), -ethoxylates, -acrylates, -amino acids, -sulfonamide phosphates and -thio acids, together with residuals and synthesis byproducts. In addition, a number of starting materials such as perfluorooctane sulfonamide N-alkyl esters were analysed. Di- and trialkylated PAPS and S-diPAPS were found in migrates from European food contact materials., Conclusion: This study highlights the need to monitor for more types of PFS in order to map the sources of PFAS in humans and the environment.

Background, Aim, and Scope: For many years, highly concentrated wastewater generated from the pulp and paper industry has become the focus of much concern worldwide. The objectives of this study were to determine the treatment efficiency of the alkaline peroxide mechanical pulp (APMP) process wastewater using a sequencing batch reactor (SBR) and analyze the microbial dynamics of the wastewater treatment system using the random amplified polymorphic DNA (RAPD) method., Materials and Methods: An SBR was applied to the treatment of APMP pulp and paper process wastewater. The wastewater characteristics and many physicochemical operator indicators in the wastewater treatment process were analyzed and determined according to standard methods. Microbial 16 S rDNA in active sludge was extracted, amplified, and analyzed using the RAPD method for the microbial dynamics of the wastewater treatment system., Results and Discussion: Ten kinds of natural organic compounds of plants such as monoterpene were detected in the APMP pulp and paper process wastewater. With an influent chemical oxygen demand (COD) that varied in the range of 685.7 to 907.5 mg/L, the corresponding effluent COD was 176.5 to 266.1 mg/L and the removal efficiency was 70.3% to 79.8%. An optimal strain (S308: CAGGGGTGGA) was selected to study the population dynamics and diversity of the bacterial community. The RAPD-polymerase chain reaction (PCR) fingerprints showed very high polymorphism of the genetic bands (78-100%). Four groups of species were clustered using the unweighted pair group method with arithmetic (UPGMA) analysis, and the genetic distance was close between the species within each group. The Shannon-Weaver index was high and varied over time with the COD removal., Conclusions: The RAPD-PCR technique can be used to study microbial dynamics, which was shown to vary over time with the removal efficiency of SBR treating APMP pulp and paper process wastewater.