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EN
Due to urban sprawl, the demand for land has increased for the purpose of construction. It is unlikely that soil available at different construction sites will be suitable for designed structures. For improving the load-bearing capacity of the soil, different soil binders are used, which are present in distinct states. In this review, the authors have collected details about various binders, which are generally used in the soil stabilization, and their effect as a binding agent on the soil. In this article, the authors tried to review different traditional binders. After studying various research articles, the authors found that lime, ground-granulated blast slag (GGBS) polypropylene, polyurethane grouting, and asphalt mix are frequently used binders. However, the authors also gathered information about the negative environmental impact of these traditional soil binders, which led to the need for alternatives to these commonly used soil binders. To diminish this issue, different alternate hydraulic and non-hydraulic binders are discussed. The authors found alternatives to cement and lime with the alkali-activated material consisting of Na2O and silica modulus and belite-calcium sulfoaluminate ferrite, which is also known as "Aether™." According to the research, both alternatives emit 20–30% less CO2 into the environment and also improve the compressive strength of the soil. The various studies promotes bitumen modification. Incorporating 20-mesh crumb rubber and bio-oil into the bitumen reduces its viscosity and improves its fatigue value. When waste oil is mixed with asphalt, it revitalizes the bitumen, improves fatigue resistance, and increases compressive strength. The soil particles treated by Eko soil are held together by enzymes, which give them the same strength as cement. Apart from that, low-carbon binders such as basic oxygen furnace slag, bamboo fiber, enzyme-based soil treatment, zebu manure for stabilization, and lignin-contained biofuels and coproducts are discussed. Replacing these traditional binders helps with energy savings. All waste products are recycled, and energy is saved by not manufacturing traditional binders. Additionally, energy is saved, which is required to avoid the detrimental effects of these conventional binders, making them energy-efficient alternate binders. The authors also summarize the methods used, impacts, and changes that occur in soil properties after using substitutes in place of traditional binders. From the review, the authors determined that different binders have various properties in terms of chemical and physical compositions, and they show different variations in terms of strength when added to soil with low bearing capacity or poor stability.
EN
The article presents considerations regarding the possibility of recovering braking energy of a rail vehicle. The energy parameters obtained during acceleration and braking of the loaded railbus were taken as input data. It was found that over 13 kWh of energy was lost irretrievably in the braking resistors. Due to the speed of the discussed process, capacitors with an original design were proposed for energy recovery. For the purposes of this study, electrodes were fabricated using carbon derived from lignin carbonization at two distinct temperatures: 900°C and 1000°C. Based on the electrochemical tests carried out, it was found that the second proposed solution achieves a significantly better power-to-weight ratio – 13 kW/kg.
EN
Mineral separation relies heavily on the process of flotation. This study explored the feasibility of using organosolv lignin nanoparticles and microparticles (OLP) as a greener alternative to xanthates in the flotation process for mineral separation. Xanthates are widely used but pose environmental and health risks. The efficiency of OLP as collectors was compared to collectorless flotation, resulting in approximately 50% copper recovery, indicating that OLP may not be a suitable replacement for xanthates. Further tests were conducted using a mixture of xanthates and OLP (birch nano and spruce micro) with varying substitution levels (20%, 30%, and 40%). The results demonstrated that increasing the dosage of OLP led to a decrease in flotation efficiency for copper. TOC analysis of the products revealed that high dosages (160 g/t) of birch nano and spruce micro as sole collectors showed beneficiation and selective recovery against copper. While OLPs did not prove effective as collectors, the study highlights their potential as substitutes for maltodextrin in selective flotation of the final concentrate. Two out of four tested OLPs were recommended for pilot scale testing.
EN
Ensuring environmental and human safety is a crucial requirement in modern industrial practices. Consequently, the utilization of natural substances in the tanning industry could serve as a reliable approach to prevent chemical contamination associated with the use of traditional chromium salts during the tanning process. This study aimed to assess the potential application of black liquor derived from rice straw as a tanning agent for leather. The black liquor was prepared using the Kraft method, and a modified version called modified black liquor (MBL) was created by gradually reducing the pH from 13 to 7. Subsequently, MBL was employed in the tanning of pickled sheep pelts using four different concentrations: 10%, 20%, 30%, and 40% of the pelts’ weight. The physical, chemical, and organoleptic properties of the resulting MBL-tanned leathers were compared with those of leathers tanned with quebracho extracts to evaluate the suitability of MBL as a tanning agent. The findings demonstrated that MBL leathers exhibited slightly lower physical and organoleptic properties when compared to the quebracho-tanned leathers. Increasing the concentration of MBL up to 30% was sufficient to enhance the properties of the tanned leathers, while concentrations exceeding this threshold did not yield any significant improvements in the leather’s properties. Consequently, the study recommends the use of MBL in leather tanning either in combination with other tanning agents or as a re-tanning agent to enhance the fullness, smoothness, and overall physical quality of the leather, thereby elevating its overall quality.
EN
In response to the trend toward sustainable management of by-products from the pulp and paper industry as well as plant waste, practical and economical methods are being developed to use them in a way that does not pose a threat to the environment. The main aim of the research was to study the possibility of using lignin and plant biomass as biosorbents for the removal of zinc ions from aqueous solutions. The secondary aim was to build an optimal multilayer system made of biosorbents selected during the research in order to obtain the highest sorption efficiency and to determine the best conditions of the sorption process. The effectiveness of zinc ion sorption was assessed using an appropriate combination of sorbents such as lignin, oat bran, rice husk, chitosan, pectin, sodium alginate, pine bark, coconut fiber and activated carbon, selected on the basis of literature data and the preliminary results of tests carried out using FTIR and AAS. The main component of the sorption system was lignin separated from black liquor. Results indicate that the best Zn sorption system was based on coconut fiber, lignin, and pine bark, for which the maximum sorption efficiency was 95%. The research also showed that the increase in the process temperature, the mass of biosorbents used and the alkaline pH are the factors that increase the efficiency of the sorption. It can be concluded that lignin and plant biomass can be used as ecological sorbents of zinc ions from water solutions. They are safe for the environment, produced from renewable sources, and are by-products or waste materials, which is part of the sustainable development and circular economy currently promoted in the EU.
EN
The content of structural carbohydrates and lignin are important assessment criteria of the feed value of meadow plants. It is affected by many independent factors, including among others its development stage during the harvest as well as climatic conditions, especially the amount of rainfall. During the years 2014-2016, plant samples were harvested at weekly intervals, respectively five times from late April to late May. The effect of harvest date on cellulose, hemicelluloses and lignin contents was evaluated. The chemical composition of plants was varied, depending not only on harvest date but also on the year of study. Regardless of the course of meteorological conditions in subsequent growing seasons, the increase of cellulose (from 236.5 to 297.9 g∙kg-1 DM), hemicelluloses (from 159.3 to 210.8 g∙kg-1 DM), and lignin (from 31.5 to 43.1 g∙kg-1 DM) in the following dates of harvest were observed. These parameters were also positively correlated with the total rainfall from the begging of vegetation season to the date of plants sampling (R2 = 0.65, 0.12 and 0.44 for cellulose, hemicelluloses and lignin, respectively), and with the average daily air temperature in the moment of harvest (R2 = 0.66, 0.32 and 0.52 for cellulose, hemicelluloses and lignin, respectively). The cellulose and lignin content, regardless of the harvest date, were significantly higher in the first year of the study (2014), when moisture conditions for plant development were optimal.
EN
Sodium lignosulfonate (NLS), a biomass waste procured from paper and pulp industries as brown colour water soluble powder, is explored in this article as dye for nylon 6 fabrics in aqueous media by the exhaustion method. The fastness and functional properties of the dyed nylon 6 fabrics were studied. The dyeing process parameters were optimised using Box–Behnken response surface design and the ANOVA technique. The NLS treated dyed nylon fabric exhibited an excellent ultraviolet protection factor (UPF), as high as 62.13. The NLS dyed nylon fabrics were characterised using FTIR, FESEM, EDX and instruments. The ultraviolet protection factor (UPF) and colour strength (K/S) values are significantly increased with an increase in the concentration of NLS without any loss of tensile properties and thermal stability. Moreover, NLS treatment has excellent wash fastness. This dyeing process for synthetic fibre like nylon can be a cleaner and more eco-friendly approach by utilising waste biomass of paper from the pulp industries.
EN
The overproduction of pollutants resulting from the development of industry causes the deposition of large amounts of toxic and carcinogenic substances, including heavy metals, in the aquatic ecosystem and other ecosystems. This is a civilisation problem of the present times, posing a serious threat to the natural environment, including humans. For this reason, it has recently become extremely important to develop effective methods to minimise the concentration of heavy metal ions in the aquatic systems and thus reduce their negative impact on the environment. One such technique is adsorption, which is believed to be an effective method of removing contaminants such as heavy metal ions from aqueous solutions. Looking at the available literaturę of the last few years, it can be concluded that adsorbents of natural origin are becoming more and more important. These are agricultural waste, all kinds of biomass, and waste from various industries. The study attempts to present and evaluate the sorption capacity of materials of natural origin, including oat bran, chitosan, alginate, tree bark, coconut fibre, and lignin. The use of such biosorbents is more friendly for the environment compared to their synthetic counterparts and perfectly fits the concept of sustainable development and the circular economy.
EN
Urea fertilizers in agricultural operations usually tend to produce large amounts of ammonia due to hydrolysis, therefore contribute to the air pollution. The purpose of this study was to study the potential black liquor from pulp industry as urease inhibitor. Characterization of the black liquor was carried out by Spectrophotometer Fourier Transform Infra-Red (FTIR) and Thermal Gravimetric Analyzer (TGA) instruments. Meanwhile, the determination of ammonia levels was carried out using UV-spectrophotometer. The black liquor used in this process contains OH stretching, C=O stretching, an aromatic ring vibration, ring vibration, and guaiacil ring vibration indicating the presence of lignin. TGA primary weight loss in black liquor occurs above 200 °C. The addition of urease enzymes to urea tends to increase the release of ammonia. Meanwhile, the results showed that black liquor could prevent the nitrogen loss of urea.
EN
The paper is presented results of the technical and economical evaluation of the production of cellulose for the solving the problem of utilization of agricultural residues of lignocellulosic nature. Non-wood was used in this work for pulping. Treatment was proposed to carry out with the application of peracetic acid. Such method allows to obtain cellulose, lignin, furfural and xylose. Spent peracetic solution can be used to precipitate lignin and for regeneration of acetic acid and to recover furfural and xylose. A technological scheme for the processing of plant raw materials by this method has been developed. Economic efficiency was calculated. The sale of by-products can provide additional financial benefit. Such an approach in the processing of significant volumes of agricultural waste is effective from an economic point of view, as well as from an environmental point of view, as it allows to reduce the negative impact on the environment and to ensure its protection.
EN
The research is connected with the solving the problem of rational utilization of agricultural residues by the creation of resource-saving method for their efficient conversion into value-added products. Wheat straw was used in this work in chemical processing. Treatment was carried out with the application of formic/acetic acid mixture. Thus, cellulosic pulp was obtained. The spent solution was used to precipitate lignin. The structure of lignin was investigated. The results indicated that formic/acetic acid treatment was quite effective in isolating cellulose from wheat straw and in recovering lignin. Wheat cellulose is a promising fibrous material for the application in paper industry. Wheat lignin can be considered as a material for biosorbent preparation.
EN
Polymers of natural origin have been gaining increasing significance in sciences, as well as the industry. Owing to their renewable nature, unique properties and wide availability, they are components that can be used for numerous advanced applications. Lignin, a biopolymer, which is a waste product separated from the widely understood biomass, most usually generated in the pulp and paper industry, falls in line with this trend. In this context, the importance of cellulose, which is used in the production of paper and by-products is greater. Whereas lignin, in the vast majority, i.e. approx. 95-98%, constitutes an energy source generated as a result of its combustion. However, nowadays, due to the huge potential arising from the specific structure of lignin and its properties, attempts are being made at using this material in many different applications within the so-called high added value. Lignin, as a commonly used polymer of unique chemical structure and properties, has recently become a source of many studies utilizing its potential in the preparation of functional materials and/or biomaterials, including hybrid ones. Such systems consist of appropriate inorganic and organic elements, which as a whole constitute a functional product with special properties, not exhibited by individual components. This provides unlimited possibilities in terms of engineering, shaping and practical application in newly developed systems. The huge interest in hybrid materials and/or biomaterials results from their potential applications, namely, in medicine, electronics, optics, electrochemistry, energy storage etc. Therefore, it nowadays becomes justified and important to try and develop new, functional systems, which owing to their specific properties could result in interesting application-wise possibilities in everyday life. Therefore, the attempt to use lignin as a source of many attractive and prospective possibilities is not without significance.
EN
Purpose: of this paper was to review and summarize significant papers related to the development and characterization of lignin-containing adhesives: polyurethane and epoxy types. In the last decades, several efforts have been dedicated on the development of renewable raw materials for polymer synthesis, mainly due to petroleum depletion and sustainability. In this context, lignin emerged as a potential candidate to substitute fossil-based raw materials in adhesive synthesis and formulations. Design/methodology/approach: Recent and other relevant papers were reviewed, aiming to identify the main advantages and limitations involved in lignin incorporation into epoxy and polyurethane adhesives formulations. First, effects of unmodified lignin addition were presented. Afterwards, the main lignin chemical modification methods were presented and discussed, based on thermomechanical results. Findings: Incorporation of unmodified lignin usually is limited to 30 %wt., otherwise mechanical properties are drastically affected as consequence of poor lignin solubility and excessive brittleness. Lignin chemical modification can be used to increase the reactivity of hydroxyl groups and/or add new moieties in its molecular structure, improving solubility and thermomechanical properties of cured adhesives. Practical implications: In the last years, some industrial plants started to operate and produce technical grade lignin at industrial scale, with reproducible properties and controlled molecular structure. Therefore, increasing efforts have been dedicated from researchers and chemists to develop lignin-based technologies, in which this work can directly contribute with. Originality/value: As consequence of the high content of phenol groups in its molecular structure, lignin was mostly applied on the development of phenolic resins applied as wood adhesives. For the first time in the literature, this work summarizes the advances related to synthesis and characterization of polyurethane and epoxy, applied as adhesives. Results can support the development and application of biobased, as well as contribute to the revalorization of this valuable and readily available biomass.
EN
The use of renewable resources as feedstocks to ensure the production of goods and commodities for society has been explored in the last decades to switch off the overexploited and pollutant fossil-based economy. Today there is a strong movement to set bioeconomy as priority, but there are still challenges and technical limitations that must be overcome in the first place, particularly on biomass fractionation. For biomass to be an appellative raw material, an efficient and sustainable separation of its major components must be achieved. On the other hand, the technology development for biomass valorisation must follow green chemistry practices towards eco-friendly processes, otherwise no environmental leverage over traditional petrochemical technologies will be acquired. In this context, the application of green solvents, such as ionic liquids (ILs) and deep eutectic solvents (DES), in biomass fractionation is envisaged as promising technology that encompasses not only efficiency and environmental benefits, but also selectivity, which is a crucial demand to undertake cascade processes at biorefinery level. In particular, this article briefly discusses the disruptive achievements upon the application of ILs and DES in biomass delignification step towards an effective and selective separation of lignin from polysaccharides. The different physicochemical properties of these solvents, their interactions with lignin and their delignification capacity will be scrutinized, while some highlights will be given to the important characteristics of isolated lignin fractions for further valorisation. The advantages and disadvantages between ILs and DES in biomass delignification will be contrasted as well along the article.
PL
Niniejszy artykuł poświęcono zagadnieniu wykrywania włókien zasobnych w ligninę, pobieranych do badań z obiektów o znaczeniu historycznym, dzieł sztuki, które trafiają do pracowni konserwatorskich. Przedstawiono praktyczne metody mikroskopowe badań, pomocne przy wykrywaniu różnych rodzajów włókien pochodzących z takich materiałów, jak: papiery, tektury, wyroby tekstylne. Dokonano wyboru odczynników wybarwiających. Skupiono uwagę głównie na zagadnieniach związanych z badaniem ścieru drzewnego (białego i brązowego) oraz juty. Omówiono także występowanie oraz problematykę badania innych, wybranych rodzajów włókien.
EN
The article discusses identification of fibres rich in lignin, collected for the tests from objects of historical significance, works of art that go to conservation. Practical microscopic testing methods, helpful in identification of various types of fibres from such materials as paper, cardboard and textile products, were presented. Staining reagents were selected. Attention was focused mainly on issues related to wood pulp (white and brown) and jute. The occurrence and problems of testing other selected types of fibres were also discussed.
EN
Lignin was used to study the mechanical properties and thermal stability of polymers. The lignin was blended with three kinds of polymers, and the addition of lignin was 0.5 wt%. Under the condition of thermal oxidation, the thermal stability of lignin/polymer samples varies with the structure of lignin. The effects of lignin on the mechanical properties and thermal stability of the polymers were investigated by oxidation induction time (OIT), rheological properties, mechanical properties and differential scanning calorimetry (DSC). The results show that the effect of lignin on the thermal properties of polymer samples is 2~3oC. It can be inferred that lignin can effectively improve the interaction between polymer molecular chain segments, and improve the crystallization rate and rigidity to a certain extent, so it can be seen that lignin has good compatibility and thermal stability.
17
Content available Heating value of thermally treated wood
EN
Common ash (Fraxinus excelsior L.) wood was heat treated in an oven at the temperatures of 180°C, and 200°C under atmospheric pressure in the presence of air for 3, 6, 9, 12 hours, and the changes in higher heating value (HHV) of wood were studied. For untreated ash wood the value 19.51 MJ·kg-1 was determined. Thermal treatment considerably increased the HHV of wood. The highest value was measured in sample that was thermally treated for 6 h at the temperature of 200°C. In this sample the value 20.78 MJ·kg-1 was determined. Changes in HHV are a consequence of chemical changes in wood during treatment. Strong positive correlation between HHV and the ratio of the sum of lignin and extractives content to holocellulose content was observed.
EN
Due to growing interest in the application of renewable resources in industry, there is a need for new carbon precursors. Lignin is a natural polymer and the main by-product of the paper industry, but its application on an industrial scale is limited. Due to its chemical composition and high aromatic carbon content, combined with a lack of toxicity, it may be a promising candidate for a carbon precursor, as well as – in carbon electrode technology – a carbon binder. The main disadvantage of lignins is the variety of their types, with differing properties. There is a need to establish the relationship between the structure of lignin and its carbon precursor potential. In this work, an attempt was made to find the dependence between the lignin structure and its properties before (chemical composition, structural studies) and after thermal treatment under an inert atmosphere (carbon residue, bonding properties and degree of carbonization and graphitization), using different techniques (FTIR, Raman spectroscopy, XPS, TG, SEM) on two softwood lignins – alkali lignin and kraft lignin. The results proved that both lignins are good candidates for carbon precursors (high mass residue after heat treatment), but only kraft lignin exhibits the bonding properties which are crucial for application as a carbon binder.
EN
Initial studies on the influence of Aspergillus niger on the wood components of Populus sp. An attempt was made to determine the content of structural substances (cellulose, holocellulose, lignin) and non-structural substances in poplar wood (Populus sp.) infected with the mentioned fungus. For this purpose, wood chips were infected with spore suspension and then incubated under sterile and suitable growth conditions. After 7, 14 and 21 days the degree of poplar wood degradation was assessed by determining the substances contained in the wood by performing chemical analyses: Kürschner-Hoffer cellulose, holocellulose by the sodium chlorite method, lignin in accordance with PN-92/P50092 standard and non-structural components. The conducted analyses made it possible to determine the effect of Aspergillus niger’s presence time on the degree of degradation of individual wood components.
PL
Wstępne badania wpływu Aspergillus niger na zawartość składników drewna Polupus sp. W pracy podjęto próbę oznaczenia zawartości substancji strukturalnych (celulozy, holocelulozy, ligniny) oraz substancji niestrukturalnych na drewnie topoli (Populus sp.), zainfekowanym wspomnianym grzybem pleśniowym. W tym celu porażono wióry przy pomocy suspensji zarodnikowej, a następnie w sterylnych i odpowiednich warunkach wzrostowych całość inkubowano. Po 7, 14, 21 dniach określano stopień degradacji drewna topoli przez wyznaczanie substancji zawartych w drewnie, wykonując analizy chemiczne: celulozę Kürschnera-Hoffera, holocelulozę metodą chlorynu sodowego, ligninę według normy PN-92/P50092 oraz składniki niestrukturalne. Przeprowadzone analizy pozwoliły określić wpływ czasu porażenia przez Aspergillus niger na stopień degradacji poszczególnych składników drewna.
EN
A new method of synthesis of polymer biocomposites with lignin using the photopolymerization method has been proposed. Bisphenol A glycerolate (1 glycerol/phenol) diacrylate (BAGDA) was used as a main monomer and 2-ethylhexyl acrylate (EHA) as a reactive diluent. Lignin (L) was applied as an eco-filler. The influence of the increasing lignin content (0; 2.5; 5; 10; 20% w/w) on the properties of the obtained biocomposites was investigated. The chemical structure of biomaterials was investigated by the attenuated total reflectance Fourier transform infrared spectroscopy (ATR/FT-IR) method while the thermal properties were studied by the differential scanning calorimetry (DSC) and thermogravimetric analysis (TG/DTG). Their hardness was measured by the Shore D method. Incorporation of the biopolymer into the structure of polymer composites could be a promising alternative to synthetic materials and would contribute to better lignin utilization. The results of the study are of practical importance in prospective applications of biocomposites with lignin.
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