Search Results (30)

Zinc (Zn) is an essential micronutrient for plant growth, serving as a co-factor in enzymatic processes and pigment biosynthesis. In horticultural crops such as lettuce, Zn fertilization is increasingly relevant for optimizing yield and nutritional quality. In this study, a greenhouse pot experiment was conducted using Lactuca sativa L. cv. Romana Verano (Ramiro Arnedo) to evaluate the effects of four Zn sources with contrasting physio-chemical properties—ZnSO₄, a synthetic chelate containing DTPA, EDTA, and HEDTA, a Zn–lignosulphonate complex, and ZnO nanoparticles—applied to soil at rates of 15, 30, 60, and 120 mg Zn·kg⁻¹. Morphometric traits, photosynthetic pigmentation, and photosystem performance were assessed to determine differences in plant response. Results showed that low to moderate Zn supply (15–60 mg Zn·kg⁻¹) maintained growth, leaf number, stem diameter, and biomass without significant changes compared to the control. In contrast, the highest dose (120 mg Zn·kg⁻¹), particularly in chelated forms, led to reductions in growth and yield exceeding 80%, reflecting supra-optimal effects. Although lignosulphonate and nanoparticles sources lowered soil Zn availability, they did not affect lettuce growth or yield, indicating their potential as safer agricultural alternatives to conventional Zn fertilizers. Photosynthetic efficiency, measured through chlorophyll fluorescence and electron transport activity, was positively modulated by adequate Zn levels but declined at excessive concentrations. These findings highlight that Zn efficiency strongly depends on its chemical form and applied dose, providing practical insights for optimizing Zn fertilization strategies in lettuce and other horticultural crops. Full article

The novelty of this study lies in the first comparative characterisation of five carbonaceous materials: three monophase carbons (wood charcoal, carbon, graphite) and two ore-derived CM samples from polymetallic sulphide and oxidised lithium ores. The methodology included IR spectroscopy, XPS, acid–base adsorption centres identified by colour indicators, chemical composition analysis, and kinetic flotation tests. Bulk and surface compositions differed significantly: although the ash content of ore-derived CM reached 84.4%, XPS revealed carbon-enriched surfaces with thin films of about 1–2 nm. IR spectra confirmed multiphase structures with carbonate, silica, and aluminosilicate bands, and showed an identical composition of CM from different industrial ore types. Flotation kinetics confirmed high floatability (recoveries 80%–99%, k up to 1.95 min⁻¹). Even with sodium lignosulphonate at 500 mg/L, recovery only decreased from 83.02% to 52.54%, showing the limited efficiency of depressants. These results provide a basis for the preliminary removal of CM prior to rough (bulk) flotation in the processing of different ore types, improving concentrate quality, reducing reagent consumption, and lowering metallurgical losses. Full article

Geopolymer-based grouting materials often have a higher early strength, better durability, and lower environmental impact than those of traditional cement-based grouts. However, existing geopolymer grouts face common challenges such as rapid setting and low compatibility with treated substrates. This study develops a new grouting material using industrial byproducts to overcome these limitations while optimizing performance for reinforcing silty mudstone slopes. The base materials used were ground granulated blast furnace slag (GGBFS) and zeolite powder, with calcium lignosulphonate (CL) serving as the retarding agent and NaOH as the alkali activator. The investigation focused on the effects of the mix ratio and water–binder ratio on the setting time, flowability, bleeding rate, concretion rate, and compressive strength of the new grouting material. Scanning electron microscope (SEM) and X-ray diffraction (XRD) analyses were employed to examine the action mechanism of the material components in the slurry. The one-factor standard deviation method and Grey Relational Analysis (GRA) were used to assess the influence of each material component on the slurry performance indices and the correlation between each performance index and its optimal mix ratio. Subsequently, the optimal mix ratio of the new grouting material was ascertained. The results indicate that the setting time is positively correlated with the zeolite powder and CL dosages and the water–binder ratio, while it is inversely related to the NaOH dosage. The flowability is significantly enhanced with increasing zeolite powder and NaOH dosages, but decreases at a higher CL dosage and water–binder ratio. This insight is crucial for optimizing the workability of the grouting material under various conditions. The optimal ratio of the grout is zeolite powder:GGBFS:CL:NaOH = 30:70:5:7, with a water–binder ratio of 0.6. Compared to existing commercial grouting materials, the compressive strength of this new grout is comparable to that of silty mudstone. This significantly reduces the problem of stress concentration at the grout–rock interface due to strength differences, thus effectively reducing the risk of secondary cracking at the interface. These findings provide a new material solution for grouting and repairing fractured silty mudstone slopes. Full article

Phenol–formaldehyde (PF) resins remain the preferred adhesive for exterior plywood, as they confer these boards their extreme weather resistance. However, their high price and toxicity has made phenol alternatives, such as technical lignins, increasingly more attractive. While many works report the use of kraft lignin, the most commercially available form are lignosulphonates (LS). However, these lack industrial success and are associated with low moisture resistance. In the current study, lignosulphonate–phenol–formaldehyde (LPF) resoles were synthesized considering a phenol replacement of 30% (w/w). Two LS samples of softwood (SLS) and hardwood (HLS) origin were compared. These samples were previously methylolated to increase their reactivity. The effectiveness of the treatment was confirmed through the Automated Bonding Evaluation System. Plywood was manufactured and tested according to EN 314 class 3 for exterior conditions, which is seldom found in the literature. Although a 35% increase in shear strength is still necessary to comply with the standard, methylolated SLS was the most promising substitute, as it resulted in the highest board performance. Notably, when this sample was used without previous methylolation, the plywood boards suffered delamination during immersion in boiling water prior to shear testing. These results reinforce the need for the methylolation of LS to increase the weather resistance of plywood. Full article

The efficacy of using a synthetic (azoxystrobin + difenoconazole), copper-based (copper oxychloride) and low-content copper compound (copper complexed with gluconate and lignosulphonate) fungicides for controlling Venturia oleaginea, the causal agent of olive spot disease, was evaluated in an olive (cv. Nabali) orchard located in the Kafr Qud area (Palestine) in 2017–2018. Treatments were applied at three different times (February, April, and August). In January 2017, at the beginning of the experiment, about 90% of the leaves grown in 2016 were infected. Defoliation was determined by counting the leaves on the labeled branches initially and then periodically. It increased gradually in both the control and treated trees, but those treated with azoxystrobin + difenoconazole or with copper complexed with gluconate and lignosulphonate showed a slower defoliation rate. During 2017, new shoots grew and new leaves developed. All treatments reduced the drop of new leaves with respect to the control, with positive effects on the reproductive activity (inflorescence growth and yield). Overall, all treatments significantly reduced the disease, thus indicating the possibility of greatly reducing infections if treatments are regularly applied each year, also with traditional (copper-based) fungicides. Due to their capability of penetrating inside the vegetative tissue, azoxystrobin + difenoconazole or copper complexed with gluconate and lignosulphonate reduced/slowed down the drop of infected leaves. The use of these fungicides is therefore particularly recommended when olive leaf spot disease is severe. The use of low-content copper compounds allows the amount of metallic copper used for the treatments against V. oleaginea to be greatly reduced. Full article

Novel and practical low-temperature 3D printing technology composed of a low-temperature 3D printing machine and optimized low-temperature 3D printing parameters was successfully developed. Under a low-temperature environment of 0–−20 °C, poly (vinyl alcohol) (PVA) matrix hydrogels including PVA-sodium lignosulphonate (PVA-LS) hydrogel and PVA-sodium carboxymethylcellulose (PVA-CMC) hydrogel exhibited specific low-temperature rheology properties, building theoretical low-temperature 3D printable bases. The self-made low-temperature 3D printing machine realized a machinery foundation for low-temperature 3D printing technology. Combined with ancillary path and strut members, simple and complicated structures were constructed with high precision. Based on self-compiling G-codes of path structures, layered variable-angle structures with high structure strength were also realized. After low-temperature 3D printing of path structures, excellent electrical sensing functions can be constructed on PVA matrix hydrogel surfaces via monoplasmatic silver particles which can be obtained from reduced reactions. Under the premise of maintaining original material function attributes, low-temperature 3D printing technology realized functionalization of path structures. Based on “3D printing first and then functionalization” logic, low-temperature 3D printing technology innovatively combined structure–strength design, 3D printable ability and electrical sensing functions of PVA matrix hydrogels. Full article

Sodium lignosulphonate (NaLS) from spent sulfite liquor was purified by ultrafiltration, and the structure was confirmed by FTIR analysis. NaLS decreases water surface tension from 72.44 mN/m to 65.36 mN/m when its concentration increases from 0% to 1%. The critical aggregation concentration was determined using UV-Vis spectroscopy, and a value of 0.035% was obtained. NaLS (0.1%) was used as a cosurfactant in an oil-in-water emulsion prepared by a phase inversion method to encapsulate thyme essential oil. The formulation was stable for 24 h, with a droplet size of 154 nm and a polydispersity index value of 0.12. Full article

In this study, Ag-CaCO₃ nanocomposites were synthesized using silver nitrate as the precursor solution based on calcium carbonate nanoparticles (CaCO₃ NPs). The synthesis involved the reaction of calcium lignosulphonate and sodium bicarbonate. The properties of Ag-CaCO₃ nanocomposites were studied by various technologies, including an ultraviolet–visible spectrophotometer, a transmission electron microscope, and a Raman spectrometer. The results showed that Ag-CaCO₃ nanocomposites exhibited a maximum UV absorption peak at 430 nm, the surface-enhanced Raman spectroscopy (SERS) activity of Ag-CaCO₃ nanocomposites was evaluated using mercaptobenzoic acid (MBA) as the marker molecule, resulting in an enhancement factor of 6.5 × 10⁴. Additionally, Ag-CaCO₃ nanocomposites were utilized for the detection of forchlorfenuron. The results demonstrated a linear relationship in the concentration range of 0.01 mg/mL to 2 mg/mL, described by the equation y = 290.02x + 1598.8. The correlation coefficient was calculated to be 0.9772, and the limit of detection (LOD) was determined to be 0.001 mg/mL. These findings highlight the relatively high SERS activity of Ag-CaCO₃ nanocomposites, making them suitable for analyzing pesticide residues and detecting toxic and harmful molecules, thereby contributing to environmental protection. Full article

The article presents the impact of Zn and Pb ore mining and land use on ecohydrological changes in the area of the Biała Przemsza valley in the historical aspect, with particular emphasis on the period 1941–2021. GIS was used to analyse the maps to identify spatial and temporal changes in land use. The following trends could be observed in the spatial development of the Biała Przemsza valley: rapid urbanisation and industrialisation in the 21st century, marked reduction in the surface area of arable land and sands, and dynamics of the increase in the surface area occupied by forests. Notable changes occurred in the plant ecosystems between 1941 and 2021 due to land management. Groundwater level lowering due to mining activity resulted in the change from wet meadows to fresh or dry xerothermic grasslands, while forest cover increased by 4% within the catchment area. The hydrographic network evolved. After the commissioning of the Zn-Pb ore mines Olkusz and Pomorzany in the 1960s and 1970s, a regional depression cone with an area of 400 km² was formed, while the maximum groundwater inflows to the mines reached 360 m³/min. Changes in the hydrodynamic conditions have resulted in changes in the hydrogeochemical regime of the Triassic aquifer manifested by increased levels of, e.g., SO₄ and Cl. Wastewater with lignosulphonate compounds from the paper factory caused periodic degradation of some of the water flowing into the Pomorzany mine. As a result of mining activity, the character of some sections of the Biała Przemsza river changed to an infiltrating one, the quantitative depletion of groundwater resources within the range of the mine drainage cone occurred, river springs disappeared, and the flow in the river decreased. At the same time, mine water was discharged to the tributaries of the Biała Przemsza. A radical reduction in the flow of the Biała Przemsza and its tributaries occurred after the decommissioning of the Zn-Pb ore mines at the turn of 2021 and 2022. Full article

Porous carbon materials (PCs) were prepared via hydrothermal carbonization from calcium lignosulfonate (CL) based on enzymatic hydrolysis and alkali activation. The effects of enzymatic hydrolysis and different KOH feeding ratios on the structure and electrochemical properties of enzymatic hydrolysis CL (EHCL)-derived PCs were evaluated in detail. The results showed that the EHCL-derived PCs showed a higher SSA than that of CL. When the mass ratio of KOH/EHCL was 3/2, the PCs exhibited a honeycomb-like microscopic morphology with a specific surface area of up to 1771 m²/g and a 3D hierarchical porous structure composed of abundant micropores, mesopores, and macropores. As an electrode in a supercapacitor, the highest specific capacitance was 147 F/g at a current density of 0.25 A/g, and it maintained 78% of the initial value at a high current density of 10 A/g. The excellent electrochemical cycle and structural stability were confirmed on the condition of a higher capacitance retention of 95.2% after 5000 times of galvanostatic charge/discharge. This work provides a potential application of CL in high-performance supercapacitors. Full article

Soil is a composite material of great interest to civil engineers. When the quality of such composite soils is poor, ground improvement techniques must be adopted to withstand the design load of superstructure. Existing soil stabilizers include lime and cement; however, their environmental safety and sustainable use during stabilization have been receiving increasing attention in recent years. This study investigated the use of granite sand (GS) and calcium lignosulphonate (CLS) as sustainable stabilizers that could be blended with clayey soils. The considered dosages of GS were 30%, 40% and 50%, and those of the CLS were 0.25%, 0.5%, 1% and 1.5%. Direct shear and consolidation tests were performed on the GS–CLS blended soil samples that were cured for 7 and 14 days. The amended stabilizers improved the shear parameters and consolidation characteristics at an optimum dosage of 30% GS and 0.5% CLS. Maximum improvements of 84% and 163% were observed in the cohesion and angles of internal friction, respectively. A significant change was also observed in the consolidation characteristics, making them practically applicable. The soil hydraulic conductivity was reduced by 14%, and the coefficient of consolidation increased by 203% for 30% GS and 05% CLS. Carbon footprint analyses were performed on the soil composition that would be best-suited for a typical homogenous earthen dam section. The results showed that the use of GS and CLS together reduced the carbon emissions by 6.57 and 7.7 times, compared to traditional stabilizers, such as cement and lime. Full article

Out of the 50 to 70 million tons of lignin that are produced annually, only 1 to 2% are used for value-added products. Currently, 90% of the total market of this compound corresponds to lignosulphonates (LS). The most successful industrial attempts to use lignin for wood adhesives rely on using it as a partial substitute in phenol–formaldehyde or urea–formaldehyde resins. However, lignin’s aromatic ring presents a low number of reactive sites. Several methods have been proposed to improve its reactivity, such as prior methylolation with formaldehyde. Off-line methods are commonly applied to monitor this reaction’s progress, but this introduces a significant delay in the analysis. This study proposes a new method for in-line monitoring of the methylolation reaction using visible spectroscopy. In order to monitor the reaction progress, principal component analysis was applied to the spectra, and the obtained scores were analyzed. When these results were plotted against those obtained by the off-line methods, a satisfactory regression was obtained at 50 °C (R² = 0.97) and 60 °C (R² = 0.98) for two different LS samples. Therefore, it was concluded that visible spectroscopy is a promising technique for studying lignin methylolation. Full article

The potential of Rhodosporidium toruloides, Candida oleophila, Metschnikowia pulcherima, and Cryptococcus curvatus species to produce single-cell-oil (SCO) and other valuable metabolites on low-cost media, based on commercial-type xylose, was investigated. Rhodosporidium strains were further evaluated in shake-flasks using different lignosulphonate (LS) concentrations, in media mimicking waste streams derived from the paper and pulp industry. Increasing the LS concentration up to 40 g/L resulted in enhanced dry cell weight (DCW) while SCO production increased up to ~5.0 g/L when R. toruloides NRRL Y-27012 and DSM 4444 were employed. The intra-cellular polysaccharide production ranged from 0.9 to 2.3 g/L in all fermentations. Subsequent fed-batch bioreactor experiments with R. toruloides NRRL Y-27012 using 20 g/L of LS and xylose, led to SCO production of 17.0 g/L with maximum lipids in DCW (Y_L/X) = 57.0% w/w. The fatty acid (FA) profile in cellular lipids showed that oleic (50.3–63.4% w/w) and palmitic acid (23.9–31.0%) were the major FAs. Only SCO from batch trials of R. toruloides strains contained α-linolenic acid. Media that was supplemented with various LS concentrations enhanced the unsaturation profile of SCO from R. toruloides NRRL Y-27012. SCO from R. toruloides strains could replace plant-based commodity oils in oleochemical-operations and/or it could be micro- and nano-encapsulated into novel food-based formulas offering healthier food-products. Full article

All-lignin coating formulations were prepared while combining water-soluble cationic kraft lignin (quaternized LignoBoost^®, CL) and anionic lignosulphonate (LS). The electrostatic attraction between positively charged CL and negatively charged LS led to the formation of insoluble self-organized macromolecule aggregates that align to films. The structures of the formed layers were evaluated by atomic force microscopy (AFM), firstly on glass lamina using dip-coating deposition and then on handsheets and industrial uncoated paper using roll-to-roll coating in a layer-by-layer mode. Coated samples were also characterized by optical microscopy, scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (SEM/EDS), and contact angle measurements. It was suggested that the structure of all-lignin aggregates is the result of the interaction of amphiphilic water-soluble lignin molecules leading to their specifically ordered mutual arrangement depending on the order and the mode of their application on the surface. The all-lignin coating of cellulosic fiber imparts lower air permeability and lower free surface energy to paper, mainly due to a decrease in surface polarity, thus promoting the paper’s hydrophobic properties. Moderate loading of lignin coating formulations (5–6 g m⁻²) did not affect the mechanical strength of the paper. Full article

Lignin derived from black liquor has a lot of potentials, particularly in its thermal stability, for making value-added chemicals. The purpose of this study was to determine the effect of washing frequency during hydrochloric acid lignin isolation on the properties of eucalyptus kraft lignin. To improve its thermal characteristics and enable its usage as an additive flame retardant, the isolated lignin was synthesized into lignosulphonate. The lignin produced by 3× and 5× washing treatments had a purity of 85.88 and 92.85%, respectively. An FTIR analysis indicated that lignosulphonate was successfully synthesized from isolated lignin after 3× and 5× washing treatments, as the S=O bond was detected at around 627 cm⁻¹. The lignosulphonate exhibited a purity of 71.89 and 67.21%, respectively. Thermal gravimetry and differential scanning calorimetry analysis revealed that the lignin and lignosulphonate after 3× and 5× washing treatments had a char residue of 44, 42, 32, and 48%, respectively. Glass transition temperatures (Tg) of 141, 147, 129, and 174 °C were observed. According to the findings, washing frequency increases lignin purity and Tg, thereby improving the thermal properties of lignosulphonate. Furthermore, the flammability of rattan impregnated with lignosulphonate was V-0 in the UL-94 vertical burning test. Full article