Paper Industry Waste Research Articles

Research of physical and chemical characteristics of alternative fuel containing synthetic polymers

RELEVANCE. This paper presents the research of physical and chemical characteristics of combined fuel briquettes consisting of solid wood waste and laminated paper production waste obtained by innovative technology. THE GOAL of the research is to develop a technology for processing and utilization of pulp and paper industry waste containing synthetic polymers by their joint use in the form of combined fuel briquettes of the 2nd generation, consisting of solid wood waste and laminated paper production waste, with subsequent utilization in a boiler plant with a low-temperature vortex furnace. Minimizing harm to the environmental component and maximizing energy and economic efficiency. METHODS. To realize the set goal, the following research methods were used in the work: study of thermoplasticity of synthetic polymers and moisture plasticity of polymeric components of wood in the process of briquette formation, determination empirically of the optimal composition of the combined briquette to obtain high calorific value of fuel, low concentration of harmful emissions, high strength and density of the finished product, determination of the lower heat of combustion of the obtained briquette with the help of calorimetric installation. RESULTS. The paper presents the results of the conducted research and experiments, in particular, the obtained values of density, strength and calorific value of the obtained briquette at different compositions of feedstock. CONCLUSION. The fuel briquettes obtained in the course of work have high indicators of density, strength and calorific value of fuel. In addition, the innovative technology of processing wood waste and waste packaging laminated paper will minimize the harm to the environmental component and increase the maximum energy and economic efficiency. The use of the obtained fuel and the technology of its production will make it possible to reduce the load on landfills with currently unutilized waste and use the obtained fuel energy for own needs.

Commercial organomineral fertilizer produced through granulation of a blend of monoammonium phosphate and pulp and paper industry waste post-composting

This study investigates a commercial granular organomineral fertilizer (GOF) produced by physically mixing landfill paper and cellulose industry waste composted over a long period with monoammonium phosphate (MAP), focusing on its morphological properties, and phosphate release into the water. The organic base used in the GOF composition is rich in humic and fulvic acids due to its long-term composting, rebalances the soil's organic matter, and eliminates a critical environmental liability. No studies have involved long-term lignocellulosic waste composting as the organic base of organomineral fertilizers. Most GOF and MAP granules range from 2 to 4 mm in size, with rough and macroporous surfaces observed through scanning electron microscopy. The specific surface area values of fertilizers are low compared to other fertilizers with different organic matrices. However, 2–4 mm granules exhibit similar values, indicating uniformity of granules. Infrared spectroscopy reveals bands from mineral and organic bases, with possible clay additives confirmed by the silicon detected in Energy Dispersive Spectroscopy analysis. Thermogravimetric curves exhibit improved thermal stability for GOF over the composted organic base, with a 31 °C increase in the second decomposition stage and delayed completion of the subsequent stages. However, this did not significantly alter the Tonset of the ammonium phosphate decomposition, as GOF presented a similar thermal behavior to MAP. GOF and MAP exhibit similar kinetic profiles, with rapid phosphorus release in the first 4 hours, reaching about 77 % of the available phosphorus. GOF shows an increase in specific surface area 29 times after 240 hours of contact with water, facilitating phosphorus release from the commercial mixture. MAP and GOF exhibit a release rate exceeding 84 %, indicating rapid phosphate availability. These values are comparable to those of other organomineral fertilizers. The results demonstrate that the GOF performs similarly to MAP, with lower phosphorus dosages, rebalance of soil organic matter, and increased nutrient application efficiency.

Utilization of waste from paper industry as a heterogeneous base catalyst for the synthesis of biodiesel

AbstractTo meet the pressing demand for alternative biofuel in the contemporary world, the production cost of biodiesel has to be decreased. Hence, this work addresses the usage of CaCO3‐rich industrial waste produced in a local paper industry in Assam, India for the synthesis of a heterogeneous catalyst for biodiesel synthesis. The collected lime sludge waste was subjected to calcination at 800°C for 3 h producing a CaO‐rich catalyst which was then employed in the transesterification of cottonseed oil. The optimized reaction conditions obtained were 5 wt% catalyst concentration, oil to methanol molar ratio of 1:12 at 65°C temperature, and 3 h of reaction time. The catalyst's reusability was evaluated up to four cycles. Besides, the prepared catalyst has been characterized using Fourier transfer infrared spectroscopy (FTIR), powder X‐ray Diffraction (p‐XRD), Scanning Electron Microscope (SEM), Energy Dispersive X‐ray analysis (EDX), and Brunauer–Emmett–Teller (BET) techniques and its basicity was measured using Hammett indicators. Moreover, the biodiesel obtained was characterized with 1H‐nuclear magnetic resonance (NMR), 13C‐NMR, Gas Chromatography‐ Mass Spectrometry (GC–MS), and FTIR techniques. A biodiesel yield of 98.03% was achieved and the quality of biodiesel formed during the transesterification of CSO also conforms to EN 14214 and ASTM D 6751 standards. Thus, our study highlights the sustainability and the potential for future industrial application of paper industrial waste in the production of biodiesel.

Applicability of Paper and Pulp Industry Waste for Manufacturing Mycelium-Based Materials for Thermoacoustic Insulation

Applicability of Paper and Pulp Industry Waste for Manufacturing Mycelium-Based Materials for Thermoacoustic Insulation

Technosol Development Based on Residual Fraction of Coal Tailings Processing, Agro-Industrial Waste, and Paper Industry Waste

Technosol Development Based on Residual Fraction of Coal Tailings Processing, Agro-Industrial Waste, and Paper Industry Waste

Development of PLA-Waste Paper Biocomposites with High Cellulose Content.

In this study, the integration of paper industry waste with high cellulose content into biocomposites of polylactic acid (PLA), a widely used biobased polymer material, was investigated. The PLA/waste biocomposite samples (0-25 wt.%) were manufactured using the extrusion and injection moulding techniques. The mechanical test results showed improvements in terms of tensile properties and a decrease in impact strength as the percentage of residue increased. The melting temperature decreased, and the crystallinity increased in all biocomposites according to the Differential Scanning Calorimetry (DSC) analysis. Water absorption increased proportionally with the percentage of residue, attributed to the higher cellulose content in the biocomposites, determined by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques. The scanning electron microscopy (SEM) fracture analysis demonstrated effective reinforcement-matrix cohesion, supporting the previously observed behaviour of the analysed materials. This work highlights the potential of using waste from the paper industry as reinforcement in PLA matrices, opening new perspectives for sustainable applications in the framework of the manufacture of composite materials.

Sustainability Evaluation of a Paper and Pulp Industrial Waste Incorporation in Bituminous Pavements

The valorization of wastes as an alternative or secondary raw material in various products and processes has been a solution for the implementation of sustainability, a safer environment, and the concept of circular economy in the efficient use and management of natural resources. To promote sustainability through a circular economy approach, this work tries to demonstrate the environmental gains that are obtained by bringing together, in an industrial symbiosis action, two large industrial sectors (the pulp and paper and the road pavement sectors) responsible for generating large amounts of wastes. A sustainability assessment, based on a life cycle and circular economy approach, is presented here, and discussed using a simple case study carried out on a real scale. Two wastes (dregs and grits) from the pulp and paper industry (PPI) were used to partially replace natural fine aggregates in the production of bituminous mixtures used on the top surface of road pavements. The impacts at a technical, environmental, economic, and social level were assessed and it was shown that this simple waste valorization action is not only positive for the final product from a technical point of view, but also for the environment, causing positive impacts on the different sustainability dimensions that were evaluated.

Dehydration and Environmentally Friendly Thermal Processing of Excess Activated Sludge

Introduction. Currently, there is a problem with the accumulation of large amounts of production waste. One type of this waste is excess activated sludge, which is a waste product from biological wastewater treatment that has a high moisture content. When excess activated sludge is deposited in beds, problems can arise related to changes in the gas-air environment, the release of unpleasant odors, as well as the contamination of groundwater and soil. Prolonged presence of sediment in sludge beds in oxygen-free conditions leads to its decay and deterioration of moisture-yielding properties. For these reasons, the development of new methods for disposing of large volumes of waste generated during wastewater treatment is essential. The aim of this research is to develop a technique for preliminary neutralization and thermal treatment of excess activated sludge using energy waste. Materials and Methods. The work used excess activated sludge with a moisture content of 98.2% (waste of hazard class IV). Water treatment sludge (waste of hazard class V) was used as a reagent to increase moisture yield. For experimental studies on dehydration, a laboratory centrifuge Elmi CM-6M.01 was used. Tests were conducted under various conditions (500, 1 000, and 1 500 revolutions per second for 1, 2, and 3 minutes), and the value of centrifugation was determined as a criterion for moisture yield in the sludge. Fuel pellets were produced by rolling with technical lignosulfonate as a binding agent. Elemental analysis of the samples was conducted to study the possibility of thermal treatment using an EA 3 000 Euro Vector Analyzer. Results. A comprehensive technology has been developed to clean the resulting gas emissions from solid particles formed during the combustion of fuel pellets and remove them from the furnace in the form of fly ash along with the outgoing gases. This technology also removed sulfur oxides, nitrogen oxides, and polychlorinated dibenzodioxins and dibenzofurans, while beneficially utilizing flue gas heat by reducing its temperature from 900–1 200°C to 140°C. Discussion and Conclusion. The approach proposed in this article for the processing and disposal of large volumes of waste allows for the reduction of moisture content of excess activated sludge and the use of this waste as a secondary energy source. This method is environmentally friendly and addresses both technical and environmental challenges, such as the effective recycling of industrial waste and reducing the anthropogenic impact on soil, air, and groundwater. It also provides an opportunity to generate additional electrical and thermal energy through thermal utilization of waste. The results of this work indicate that it is possible to integrate the use of various types of industrial waste (sewage sludge, water treatment waste, and pulp and paper industry waste) as secondary energy sources. These findings have practical implications for enterprises in both the municipal and industrial sectors with wastewater treatment facilities.

Valorisation of Pulp and Paper Industry Wastes—Incorporation in Bituminous Mixtures for Road Construction

Some wastes from the paper pulp production process are still sent to a controlled waste landfill. These materials can constitute alternative resources for constructing road pavements. The study aimed to characterize and explore the sustainable application of two inorganic wastes resulting from the paper pulp process, the dregs (green liquor wastes) and the grits (slaker wastes), in the production of bituminous mixtures by the analysis of samples prepared with 5 and 10% of dregs and 5 and 10% of grits on the baseline reference bituminous mixture AC 14 surf 35/50. Some relevant mechanical properties of the blends were assessed based on Marshall compression, sensitivity to water and wheel-tracking tests. Additionally, water poured on the loose asphalt and compacted slabs’ surface was analysed to determine the portion of harmful chemical compounds leached from the asphalt material. The results show that using dregs presented some technical limitations related to mechanical performance and that the incorporation of grits has an acceptable mechanical behaviour. Moreover, the study shows that the measured leachate resulting from water flow in a reference asphalt mixture and the blends with grits are insignificant. It can be concluded that using grits in asphalt mixtures is a promising technique regarding mechanical behaviour and environmental impacts that need further studies.

Biotechnological Basis of the Pulp and Paper Industry Circular Economic System

To ensure development sustainability, the linear economic approach is being transformed into a cyclical model. For the pulp and paper industry (PPI), which occupies a significant place in the Russian economy, the shift of circular principles to the field of bioeconomics is becoming more important. This requires the development of basic biotechnological approaches implemented in closed cycles (biorefining). The aim of this study was to develop the biotechnological foundations of the circular economic system of the pulp and paper industry. To achieve the goal, the factors for the implementation of the circular mechanism in the pulp and paper industry were established. The composition of pulp and paper waste was systematized, taking into account the places of their occurrence; the directions and forms of the biorefining of pulp and paper secondary renewable resources were determined; and the principal possibility of obtaining bioethanol, based on the whole complex of sugars from cellulose production wastes, is shown. A wide range of general scientific methods was involved (analysis, synthesis, classification, modeling, etc.). Statistical methods were used to process experimental results in the field of pulp and paper waste bioconversion. The biotechnologies involved included methods of destruction, detoxification, and conversion of useful resources into secondary raw materials and final products. From the standpoint of the environmental approach, there are serious efficiency imbalances in the pulp and paper industry, which justify the implementation of circular mechanisms for organizing economic systems. The overall efficiency is ensured by the use of renewable resources and obtaining environmental effects. Algorithms and parameters of green biotechnological regulations for pulp and paper industry waste recycling provide the possibility of microbiological production of a complex of products: biocomposites, bioplastics, medical products, fertilizers, feed additives, vitamin supplements, and bioenergy resources. A strategy for the efficient biochemical processing of pulp and paper waste into green ethanol was determined. The possibility of increasing the efficiency of alcoholic fermentation using various biocatalysts was experimentally confirmed. The technological features of this method, associated with the need for microaerobic fermentation modes, were determined.

Performance evaluation and microbial profiling of integrated vertical flow constructed wetland (IVFCW) for simultaneous treatment of domestic and pulp and paper industry waste water

The present study demonstrates the potential of an integrated vertical flow-constructed wetland (IVFCW) for simultaneously treating black liquor and domestic wastewater. IVFCW was operated and monitored for 12 samples with the frequency of one sample per week with the following specifications viz,4 L of wastewater, a blend of 1:1 of pulp and paper industry effluent (black liquor BL), and domestic wastewater, was fed daily in a continuous mode with organic loading rate (OLR) of 1230 mg COD/L-Day, at a temperature range of 40-45℃ (natural temperature of the workstation). Valves controlled each chamber's hydraulic retention time (HRT) of 3 days and flow rate of 10 mL/minute. The IVFCW showed remarkable efficiency in removing various pollutants, including total suspended solids (TSS) and total dissolved solids (TDS), by 100 % and 83 %, respectively, and organic contaminants such as chemical oxygen demand (COD) and biological oxygen demand (BOD) by 80 % and 81 %, respectively. Moreover, the IVFCW efficiently reduced nutrients such as sulfates (SO₄-2), phosphates (PO₄-3), and total nitrogen by about 81 %, 63 %, and 61 %, respectively. The treatment also led to the reduction of lignin content by 83 %. Microbiological analysis revealed a significant reduction in fecal coliforms, and microbial profiling of Typha latifolia roots confirmed the presence of bacteria involved in lignin degradation. Seed germination and seedling survival were found to be negativelyaffected by untreated wastewater in a phytotoxicity study, suggesting that the wastewater's toxic chemicals could be harmful to plant life.This study highlights the effectiveness of IVFCW as a sustainable, economically viable, and resilient wastewater treatment system for mitigating environmental concerns related to the release of untreated wastewater.

Reclaimed lignosulfonate-modified bamboo fibers prepared via layer-by-layer self-assembly to reinforce poly(3-hydroxybutyrate) biocomposite

Fiber-reinforced poly(3-hydroxybutyrate) (PHB) biocomposites have been increasingly applied in various fields, such as building structures, interior decorations, and product packaging, due to their high strength to weight ratios, low thermal conductivities, low carbon footprints, and biodegradabilities. However, poor compatibility between the hydrophilic natural fibers and the thermoplastic biocomposites limits their mechanical strengths. This work proposes a method based on layer-by-layer self-assembly (LbL) to improve the interfacial compatibility between the PHB and bamboo fibers (BFs). Sodium lignosulfonate (SL) derived from pulp and paper industry waste was used as the raw material. Then, long carbon chains were introduced into the SL via the Mannich reaction. A hydrophobic self-assembled multilayer structure (SMS) was constructed on the surfaces of the BFs. The preparation process was environmentally friendly, controllable and simple. The mechanical properties were improved by the modifications, including the tensile strength (44%), flexural strength (13%), and impact strength (41%). The thermal properties of the fiber-reinforced biocomposites were also enhanced. This study presents a novel strategy for high-value utilization of industrial byproducts and the enhancement of biocomposite interfacial compatibility.

An eco-friendly process for xylose production from waste of pulp and paper industry with xylanase catalyst

Plentiful waste is generated by pulp and paper industries during different stages of paper production. Current practices being used harm the environment to a large extent and thus, require a sustainable approach to deal with the waste. Thus, present study investigated the effect of xylose production without NaOH and with pre-treated (2% NaOH) waste paper pulp under the effect of temperature; pH and incubation time with the help of xylanase isolated from Bacillus pumilus. A comparative analysis was drawn with three treatments namely enzymatic, xylanase immobilization onto chitosan and microbial treatment. Chitosan being inert, cheap and biocompatible was chosen as carrier and resulted in 94.87% immobilization yield. Optimum parameter for xylose production was found to be temperature 50 °C and pH 6.0. For incubation time, highest xylose production was seen after 12 hrs (enzymatic and chitosan and immobilized) and on 3rd day (microbial). Therefore, treatment of waste paper pulp with xylanase showed significant results for xylose production which later can be used in the production of various value added products such as xylitol.

The impact of pollutant emissions from co-incineration of industrial waste in municipal solid waste incinerators

A large amount of industrial solid waste (including waste plastics, textiles, wood, etc., which are byproducts of industrial production) urgently needs to be treated. Incineration is undoubtedly the most efficient and convenient method. The existing municipal solid waste incineration plants can be transformed to burn such industrial wastes. However, the potential risks associated with high levels of heavy metals in industrial waste and the air pollution caused by co-incineration pose significant challenges to the co-incineration disposal of industrial solid waste. The change of physical and chemical properties of municipal solid waste and the emission characteristics of flue gas pollutants after co-incineration of industrial waste were studied by means of material flow simulation and experiment. In addition, experiments were designed to study the effects of temperature, calcium sulfur ratio and chlorine content on heavy metal emission during the incineration of industrial waste. The results showed that co-incineration of a certain proportion of industrial waste significantly increased the calorific value of municipal solid waste, but excessive mixing of plastic and paper industrial waste would increase the ash content. Co-incineration of plastic industrial waste can significantly increase HCl, and with the increase of temperature, the transformation of Cl to HCl is more thorough. The increase of temperature can promote the migration of Cr, Pb and Se elements to the gas phase. When Cr, Pb, and Se elements are present in the gas phase, they can combine with other gases and aerosols to form particulate matter and toxic substances, causing air pollution. When Ca/S is 1, Ba, Mn, Ni, Zn can effectively reduce the retention rate of elements in the ash. Under certain conditions, chlorine in industrial waste plastics will react with Zn to form tiny particles and low boiling point chlorides, which will increase its volatility. The mineral components in the ash can also be used for making ceramsite and building materials. These results will provide reference for the pollutants controlling during co-incineration of industrial waste and municipal solid waste process.

Performance of resource saving agro-industrial wastes and their utilization in lightweight concrete -A review

The high demand for natural aggregates has created opportunities for the use of agro-industrial waste in the building sector brought on by rising urbanization and the disposal issue of agricultural and industrial waste. Numerous agricultural waste and industrial by-products are already employed in concrete in place of cement, fine aggregate, coarse aggregate and reinforcing elements. Furthermore, there is an increase in the use of Lightweight concrete (LWC) in civil structures such as high-rise buildings, off-shore structures, and long-span bridges owing to the need of concrete, lighter than the conventional one. Presence of natural aggregates makes the concrete dense and heavy, hence the use of lightweight aggregates (LWA), such as perlite, paper industry waste, expanded shale, volcanic pumice, slate, wood ash waste, and expanded polystyrene (EPS), in the production of LWC can effectively decrease the self-weight of a structure. In a comparable manner agricultural wastes, like oil palm shell (OPS), coconut shell (CS), rice husk ash (RHA) and industrial waste like fly ash, plastic aggregate, silica fume (SF), metakaolin (MK) have the potential of a LWA. This study reviewed the utilization of oil palm shells (OPS), coconut shells (CS), expanded polystyrene (EPS), and silica fume (SF) in concrete, among the numerous available agro-industrial wastes. For the past decade, research has been ongoing on aggregate processing to meet special concrete requirements such as low density, thermal insulation, and strength. These wastes exhibit similar properties to conventional concrete when used in combination with mineral additives like SF and RHA, among others. The study also highlights the eco-efficiency and functional benefits of using these wastes as lightweight aggregates (LWA).

Utilization of Yellow Shells (Cypraea moneta) in the Treatment of Cadmium Heavy Metal (Cd) Waste

Cadmium (Cd) metal is a heavy metal that can cause environmental pollution if its levels are above the environmental quality standard value. Generally, industrial wastes such as paper industry waste contain heavy metal Cd with levels reaching 0.026 ppm. Meanwhile, the quality standard for Cd metal in the environment is 0.005 ppm. For this reason, it is necessary to process it to reduce the levels of Cd metal in the waste before being discharged into the environment. One way that can be used to reduce the levels of Cd metal is by adsorption method using Cypraea moneta clamshells containing chitin. This study used variations in the particle size of the shellfish adsorbent of 6 and 12 mesh. In addition, the ratio of the amount of adsorbate and adsorbent (mg:mg) is 1 : 0.5x106; 1 : 1x106; and 1 : 1.5x106. Based on the results obtained, it showed that the use of shellfish as an adsorbent was able to reduce Cd metal content up to 89%.

Detoxification Approaches of Bagasse Pith Hydrolysate Affecting Xylitol Production by Rhodotorula mucilaginosa.

In this study, the potential of bagasse pith (the waste of sugar and paper industry) was investigated for bio-xylitol production for the first time. Xylose-rich hydrolysate was prepared using 8% dilute sulfuric acid, at 120 °C for 90 min. Then, the acid-hydrolyzed solution was detoxified by individual overliming (OL), active carbon (AC), and their combination (OL+AC). The amounts of reducing sugars and inhibitors (furfural and hydroxyl methyl furfural) were measured after acid pre-treatment and detoxification process. Thereafter, xylitol was produced from detoxified hydrolysate by Rhodotorula mucilaginosa yeast. Results showed that after acid hydrolysis, the sugar yield was 20%. Detoxification by overliming and active carbon methods increased the reducing sugar content up to 65% and 36% and decreased the concentration of inhibitors to >90% and 16%, respectively. Also, combined detoxification caused an increase in the reducing sugar content (>73%) and a complete removal of inhibitors. The highest productivity of xylitol (0.366 g/g) by yeast was attained after the addition of 100 g/l non-detoxified xylose-rich hydrolysate into fermentation broth after 96 h, while the xylitol productivity enhanced to 0.496 g/g after adding the similar amount of xylose-rich hydrolysate detoxified by combined method (OL+AC2.5%).

Methane yield of paper industry waste in the presence of two compounds from alcohol and aldehyde groups during thermophilic anaerobic digestion

In this study, effect of two chemical compounds (i.e., 1-octanol and hexanal) respectively from the alcohol and aldehyde groups on thermophilic (55±2 °C) anaerobic process digesting the waste produced at a paper industry was investigated. In this scope, possible inhibition was monitored by the cumulative methane (CH4) yields in the batch reactors digesting the paper waste as the feedstock at concentrations of 0.005%, 0.05%, and 0.5% for each compound. Comparing the effects of the two different groups with the control reactor having only the paper waste as the substrate, the results revealed that adding 1-octanol and hexanal up to 0.05% concentrations had some synergistic effect on biogas yield (i.e., from 3% to 12% enhancement). Accordingly, the highest methane yields were 550 and 567 mL/g-VSfed, respectively on average in the presence of 1-octanol and hexanal at a concentration of 0.05% while the cumulative methane yield was observed as 490 mL/g-VSfed for the control reactor. With the exception of 1-octanol at 0.5%, adding both compounds at each investigated concentration was beneficial for the digestion in the batch process. Therefore, the selected alcohol and aldehyde sources did not cause the expected detrimental effect on the methanogens even at the maximum amounts added in this study. Nevertheless, since the effect of the chemical compounds on methane generation has been generally concentration-dependent, the toxic effects of 1-octanol and hexanal would be better observed at higher concentrations (>0.5%), especially when their threshold levels are exceeded in anaerobic reactors digesting paper wastes.

Utilization of pulp and paper industrial wastewater for production of polyhydroxybutyrate by Bacillus sonorensis NAM5

Given the environmental pollution caused by petroleum-based plastics, finding alternative substitutes for sustainability has become critical. Polyhydroxybutyrate (PHB), a storage food material that is accumulated by several bacteria, is biodegradable, safe, environment friendly and comparable to conventional plastics. However, scale-up is an issue due to high production cost. Substrate replacement using renewable, plentiful, sustainable and low-cost carbon sources derived from industrial waste facilitates waste reduction, while also enabling the synthesis of value-added products. In this context, inexpensive pulp and paper industrial waste as carbon source was exploited for production of PHB by using previously isolated (Source: hot springs of Manikarn, Himachal Pradesh, India) thermophilic bacteria Bacillus sonorensis NAM5 under optimized conditions in a fermenter. Production was done in a fermenter under optimized conditions (72 h of incubation at 50 °C temperature and 7 pH) to enhance the accumulation of PHB. The bacterial strain was able to produce 5.28 ± 0.11 g L−1 after 72 h of growth without any carbon and nitrogen source supplementation to the industrial effluent. The culture accumulated 66% PHB of cell dry weight (CDW). The produced polymer was characterized through FTIR, NMR and TGA. Additionally, bacteria-treated industrial wastewater was used for phytotoxicity assay on agriculturally important crops such as wheat, maize and mung, which exhibited considerable difference in growth parameters.

Nanofibrillar biochar from industrial waste as hosting network for transition metal dichalcogenides. Novel sustainable 1D/2D nanocomposites for electrochemical sensing

Industrial wastes have become elective sustainable sources to obtain materials for electronic/electroanalytical purposes; on the other hand, easy and green strategies to include semiconductor 2D graphene-like materials in conductive networks are highly required.In this work, 1D/2D nanocomposites (NCs) based on nanofibrillar biochar (BH) from paper industry waste and transition metal dichalcogenides (TMDs: MoS2, WS2, MoSe2, and WSe2), were prepared in water via liquid phase exfoliation (LPE) using sodium cholate as bioderived surfactant. The TMD amount in the NCs has been carefully optimized, searching for the best compromise between electron transfer ability and electroanalytical performances. Four different water-dispersed BH-TMD NCs have been selected and comprehensively studied from the electrochemical point of view and morphologically characterized. The BH-TMDs potentiality have been demonstrated in model solutions and real samples towards different analytes of biological and agri-food interest. The most performing NCs have been selected and used for the simultaneous determination of the neurotransmitters dopamine (DP) and serotonin (SR), and the flavonoids quercetin (QR) and rutin (RT), obtaining good linearity (R2 ≥ 0.9956) with limits of detection ranging from 10 to 200 nM. Reproducible quantitative recovery values (90–112%, RSD ≤6%, n = 3) were obtained analyzing simultaneously DP and SR in synthetic biological fluid and drugs, and QR and RT in food supplements, proving the usability of the proposed materials for real analyses.This work proves that BH-nanofibers act as a sustainable conductive hosting network for 2D-TMDs, allowing full exploit their electroanalytical potential. The proposed BH-TMD NCs represent a sustainable, affordable, and captivating opportunity for the electrochemical and (bio)sensoristic field.