Search Results (747)

Plating on Plastics (PoP) requires specific surface pre-treatment steps to enable metallization. The conventional PoP industry utilizes hexavalent chromium (toxic, carcinogenic) and palladium (critical raw material) for surface etching and activation, respectively, raising significant health, environmental, and economic concerns. This work is based on a new Cr⁶⁺-free and Pd-free PoP technology that uses piranha (H₂O₂-H₂SO₄) solutions for surface etching, nickel salts for activation, and NaBH₄ for reduction, ultimately forming metallic nucleation sites for downstream electroless plating and electroplating. A comprehensive modeling approach was developed to simulate and predict unit operation performance (reaction kinetics and yields) and material properties (contact angle and adhesion) across processing stages of the new technology. State-of-the-art and data-driven modeling revealed the combinatorial relationships among process performance, the achieved properties and the different settings of process operating conditions. The results also highlighted capabilities for tuning all processes over a range of conditions, reaching desired product specifications (adhesion and thickness). The models were constructed as a Decision Support Tool (DST) serving economic, environmental, safety and Safe and Sustainable by Design (SSbD) objectives. The DST can be used through a user-friendly interface that enables the insertion of user-defined inputs and monitoring of optimization results. Full article

This work is devoted to the synthesis and comprehensive study of activated carbons (ACs) obtained from agricultural wastes—specifically corn cob (C) and onion (O)—for the effective removal of paracetamol (PCM) and sulfamethoxazole (SMX) from aqueous media. The synthesis was carried out by chemical activation using H₃PO₄, HNO₃, and NaOH as activating agents, which made it possible to obtain materials with a clearly defined microporous structure (microporous fraction V_micro/V_total = 0.75–0.81) and specific surface chemistry. Particular attention was paid to studying the kinetics and equilibrium of adsorption in both single-component and binary (two-pollutant) systems. It was established that the equilibrium time is 8 h, and the experimental data are best described by a pseudo-second-order kinetic model. During binary adsorption tests, the competitive behavior was observed for certain materials, such as the corn-derived carbon activated with HNO₃ (AC-CN) and the onion-derived carbon activated with HNO₃ (AC-ON), where molecules compete for active sites. Conversely, synergistic effects were identified in other systems, controlled by specific surface-functional groups and hydration effects. The maximum adsorption capacity was found to be 29.4 mg∙g⁻¹ for PCM on the AC-CN sample. Adsorption mechanisms, including multilayer isotherm profiles and the competition between pollutant and water molecules, were interpreted using quantum chemical calculations within the framework of Density Functional Theory (DFT). These calculations revealed that partial deprotonation and intense solvation of SMX molecules at natural pH reduce their adsorption capacity. In contrast, the PCM structure favors π-π interactions and the formation of strong hydrogen bonds with oxygen-containing groups on the carbon surface. These results demonstrate the high potential of using agro-industrial waste to create a new generation of selective adsorbents with tailored surface properties. Full article

The Sanjiang Plain is a key black soil agricultural zone in Northeast China. The conversion of dry-lands (DL) to paddy fields (PF) alters soil aggregate phosphorus (P) fractions and microbial diversity, yet the underlying mechanisms are unclear. This study compared DL and PF (converted from DL) soils. The results showed that electrical conductivity (EC) and soil organic carbon (SOC) increased significantly after the dryland-to-paddy conversion (p < 0.05). The proportions of macroaggregates and microaggregates increased, while the silt+clay fraction declined (p < 0.05), indicating enhanced aggregate stability. Soil total P increased by 16.04%, of which 83.81%, was attributed to macroaggregate-associated P. The dominant P fractions shifted from NaOH-Po to NaOH-Pi and HCl-Pi. The land-use change also markedly altered the soil microbial community structure, leading to increased abundances of Bradyrhizobium and Pseudomonas and decreased abundances of Streptomyces and Mesorhizobium, collectively driving the transformation of P fractions. The key functional genes identified were gcd, phoD, and phnA. However, this study did not capture the temporal dynamics of P forms and microbial community structure across different stages of land-use conversion. Future research should track these dynamics throughout the conversion process to clarify the mechanisms of P evolution. Full article

In reclaimed and poorly drained soils, combined salinity–waterlogging stress markedly inhibits the early vegetative growth of maize. In this study, maize seedlings at 12 days after sowing (DAS) were subjected to combined stress by immersing the entire root system in 200 mM NaCl for 7 d (stress; ST), then transferred to recovery conditions and supplied potassium at equivalent activity (5 mM K⁺; soil drench) as KH₂PO₄ (ST + K + P), K₂SO₄ (ST + K + S), and potassium silicate (ST + K + Si) at 0 and 5 days after treatment (DAT). Morphological traits, chlorophyll fluorescence, and gas-exchange parameters were measured at PreTR (immediately after stress termination), 5 DAT, and 10 DAT. Phytohormone, mineral nutrient profiles, oxidative stress markers and redox status, osmotic and metabolic parameters, and the expression patterns of key ion transport and stress-responsive genes were quantified at 0 and 10 DAT. The effects of K supplementation were evident across the growth- and photosynthesis-related indicators. Treatment groups (ST + K + Si, ST + K + S, and ST + K + P) exhibited significantly higher carbon fixation capacity than ST at 10 DAT. The Na/K ratio was also notably reduced in all K-supplemented groups, indicating that ionic homeostasis was restored with K supplementation through improvements in various stress response indicators such as phytohormones, osmotic adjustment, and antioxidant responses. The potassium- and silicon-treated group showed the greatest recovery effect, which may reflect the physiological characteristics of cereal species. Overall, these findings provide foundational data for the development of cultivation technology to expand the cultivation area of maize. Full article

The influence of phosphoric acid (H₃PO₄) and sodium hydroxide (NaOH) impregnation on the pyrolysis and CO₂ gasification behavior of dairy manure was evaluated using thermogravimetric analysis (TGA), with kinetic parameters assessed through iso-conversional kinetic analysis (Frieman method). H₃PO₄ pretreatment altered early decomposition by partially removing hemicellulose and promoting the formation of thermally stable, condensed char structures. The resulting chars exhibited reduced CO₂ reactivity, as evidenced by higher gasification temperatures, lower syngas yields, and elevated activation energies, indicating hindered CO₂ diffusion and slower Boudouard reaction kinetics. In contrast, NaOH pretreatment caused only minor changes in both pyrolysis and gasification behavior. A slight reduction in pyrolysis activation energy suggested Na⁺ catalyzed bond-cleavage reactions; however, this effect did not enhance CO₂ gasification reactivity. Chars produced from NaOH-treated manure exhibited slightly higher activation energies during CO₂ gasification and syngas yields, which remained close to or slightly above those of raw manure, attributed to complex mineral interactions that diminish the catalytic influence of sodium. Overall, these findings clarify how acid and base chemical pretreatments govern char evolution and carbon-CO₂ reactivity, providing a foundation for optimizing pretreatment strategies and reactor conditions for manure conversion in CO₂-based pyrolysis and gasification systems. Full article

Montane forests are commonly limited by phosphorus (P) scarcity, yet Rhododendron species persist via specialized P-acquisition strategies. However, the microbial processes governing P utilization among wild Rhododendron species remain unclear. We collected soil and root samples from three wild Rhododendron species—Rhododendron latoucheae Franch. (R. latoucheae), Rhododendron fortunei Lindl. (R. fortunei) and Rhododendron simsii Planch. (R. simsii)—in a montane forest and analyzed soil P fractions, acid phosphatase activity, and fungal community traits to investigate their relationships with P cycling. The results showed significant differences in P fraction contents between non-rhizosphere and rhizosphere soils among the three species. In R. fortunei, rhizospheric NaOH-Po decreased tenfold while H₂O-Pi increased by 9.13 mg/kg, indicating a shift toward labile P. In contrast, R. latoucheae and R. simsii showed increases in moderately labile P by 32.54% and 22.09%, respectively. R. latoucheae exhibited the lowest acid phosphatase activity in non-rhizosphere soil (4.810 ± 0.560 μmol/d/g), which increased significantly in the rhizosphere. Fungal community analysis revealed a significant enrichment of Podila in the rhizosphere of R. latoucheae (10.84%) and R. simsii (9.17%), while Penicillium (6.80%), Trichoderma (3.65%) and Mortierella (5.83%) were dominant in the R. fortunei rhizosphere. R. latoucheae mineralized organic P through acid phosphatase hydrolysis driven by nutrient scarcity. R. fortunei likely mobilizes inorganic P through ericoid mycorrhizal-associated secretion of organic acids and the activity of specialized phosphate-solubilizing fungi facilitated by high substrate availability. Soil nutrients (SOC, TN, $\mathrm{N}{\mathrm{O}}_3^{-}$-N) influenced fungal abundances and indirectly shaped soil P fractions, whereas fungal taxa abundance in the rhizosphere directly drove P turnover. Our results confirm that different wild Rhododendron species employ distinct P-acquisition strategies mediated by rhizosphere fungi and enzyme activities, and provide new insights into microbial-driven P cycling in montane forests. Full article

The high potential of saliva for use in the non-invasive diagnosis of a number of diseases raises a number of questions regarding the substantiation of normal and abnormal salivary composition criteria. Factors that must be considered when forming patient cohorts include age, hormonal status, and circadian variability. However, the influence of sex remains controversial. The aim of this study was to investigate the influence of sex on the biochemical composition of normal saliva, including amino acid and lipid profiles, cytokine levels, and electrolytes. The study involved 120 healthy volunteers (75 females and 45 males). The amounts of electrolytes (NH₄⁺, K⁺, Na⁺, Mg²⁺, Ca²⁺, Cl⁻, SO₄²⁻, NO₂⁻, NO₃⁻, F⁻, PO₄³⁻), amino acids (Arg, Lys, Tyr, Phe, His, Leu+Ile, Met, Val, Pro, Thr, Ser, Ala, Gly), cytokines (VEGF, MCP-1, TNF-α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-18, INF-α, INF-γ), and biochemical parameters (protein, urea, total content of α-amino acids, imidazole compounds, lipid peroxides) were analyzed. Lipid content was determined based on the intensity of absorption bands at 1396, 1458, 2853, 2923, and 2957 cm⁻¹ in the IR spectra of salivary lipid extracts. A clear sex correlation was found for amino acid and lipid content in saliva. For electrolytes and biochemical parameters, median differences were demonstrated in some cases; however, the range of variation for all parameters overlapped. Although overall cytokine profiles did not show clear multivariate separation, significant differences between sexes were observed for individual cytokines (IL-1β and IL-10). A comprehensive assessment of all parameters (amino acids, lipids, cytokines, etc.) allows for the formation of a sex-associated metabolic profile of saliva. Therefore, it is recommended to avoid the use of mixed cohorts when analyzing the amino acid and lipid profiles of saliva. Full article

Wastewater-based microalgal cultivation enables coupling environmental remediation with the production of sustainable, value-added biomass. In this study, Euglena gracilis was cultivated under non-axenic conditions in a 2% anaerobically digested livestock wastewater (LSWW)-based medium to enhance biomass accumulation, paramylon storage, and biodiesel precursor production, while simultaneously removing residual nitrogen and phosphorus. The LSWW medium was strongly phosphate-limited relative to ammoniacal nitrogen (N:P mass ratio ~39:1), which constrained growth. Adjustment of the N:P ratio to ~10:1 by NaH₂PO₄ supplementation, together with MgSO₄·7H₂O addition, significantly enhanced biomass production, whereas trace metals and CaCl₂ provided minimal benefit. Cultivation at an initial pH of 3 resulted in substantially higher biomass accumulation than at pH 7 under xenic conditions. Under these optimized conditions, total phosphate and ammonia were efficiently removed, decreasing from 5.27 to 0.009 mg/L (99.8%) and from 57.40 to 2.11 mg/L (96.3%), respectively. Although paramylon accumulation was low in LSWW alone (~4% dry weight), short-term ethanol supplementation (0.095%, v/v, 24 h) enhanced paramylon content to ~20% dry weight. Subsequent anaerobic treatment further enhanced lipid conversion, increasing fatty acid methyl ester (FAME) content to ~45% dry weight. Collectively, low-pH non-axenic cultivation of E. gracilis in LSWW, combined with minimal nutrient supplementation, provides an integrated platform for enhanced biomass, paramylon, and biodiesel precursor production with efficient nutrient removal. Full article

Electroless Ni–P coatings are widely used for corrosion and wear protection, yet their ability to deliver water-based superlubricity and the role of phosphorus content remain insufficiently understood. Here, electroless Ni–P coatings with four P contents (3.4, 6.4, 9.0, and 12.4 wt%) were deposited on GCr15 steel with nearly constant thickness and comparable initial roughness, and were tested against Si₃N₄ balls in neutral 0.5 M NaH₂PO₂ solution. Friction measurements, together with surface topography characterization and tribofilm analysis, were used to link P content with tribofilm chemistry and superlubricity. All coatings achieved macroscale superlubricity, exhibiting steady-state friction coefficients below 0.01, while the running-in time decreased markedly as P content increased. During sliding, the wear tracks underwent mechano-chemical polishing to Sa ≈ 11–12 nm and formed phosphate–silicate tribofilms enriched in P–O and Si–O species on both the coating and the counterface. These findings establish a composition–tribofilm–superlubricity relationship in the Ni–P/NaH₂PO₂ system and demonstrate that P-content optimization is an effective internal design lever to accelerate running-in, mitigate wear, and achieve robust superlubricity under neutral aqueous lubrication. Full article

Paracetamol (PAR) and orphenadrine citrate (ORPH) are two active substances commonly used in combination medicinal products, due to the analgesic effect of paracetamol and the muscle relaxant effect of orphenadrine, with a therapeutic indication of mild to moderate acute musculoskeletal pain. The aim of this work is to develop and validate an isocratic HPLC method for the simultaneous determination of PAR and ORPH in tablet formulation. Preliminary experiments showed that an analytical column with a chemically bound phenyl phase was required. A Box–Behnken design (BBD) was utilized to optimize the analytical method for two key responses, PAR asymmetry factor (Asym_PAR) and ORPH capacity factor (k_ORPH), with three numerical factors: percentage of ACN in mobile phase (A); pH (B); and salt concentration in the aqueous solution (C). The optimized method consists of a Pinnacle DB Biphenyl (250 × 4.6 mm) 5 µm column, and a mobile phase of 37%/63% v/v ACN-NaH₂PO4·H₂O in 29 mM aqueous solution, pH = 2.5. The flow rate was set to 1.5 mL/min and detection occurred at 215 nm. After the optimization process the following chromatographic conditions were selected and the method was validated for various ICH parameters covering system suitability, specificity, linearity (R² = 1.00), precision (%RSD ≤ 2), accuracy (98% ≤ %Recovery ≤ 102%), and robustness. Finally, the environmental friendliness of the novel method was assessed by using the Analytical GREEnness (AGREE) metric tool, obtaining a score of 0.67. Full article

The presence of emerging contaminants in water has led to a need for the development of new materials and treatments. Four low-cost adsorbents derived from lignocellulosic biomass waste (pine nut shells and olive stones) were prepared via chemical treatment (with H₃PO₄ or NaOH) followed by thermal activation (at 550 °C under N₂). Characterization of the bioadsorbents was carried out using N₂ adsorption–desorption isotherms, FTIR and Raman spectroscopic analyses, and pHpzc determination. The electrostatic interactions between the adsorbent surface and the dyes were determined, and it was found that the interactions in both adsorbents were attractive for the methylene blue and repulsive for methyl orange, at pH basic or neutral. The performance of the obtained activated carbons was evaluated at lab scale with two dyes (methylene blue and methyl orange), and a comparison was made between both adsorbents and with commercial charcoal. The H₃PO₄-activated adsorbents exhibited higher adsorption capacities (up to 300 mg/g for methylene blue and 285 mg/g for methyl orange), with adsorption efficiencies close to 100%. More than 10 adsorption–desorption cycles were performed, with efficiencies exceeding 85%. The good reusability shown by the H₃PO₄-activated adsorbents suggests significant potential for industrial application; namely, in the removal emerging contaminants from urban wastewater. It should be noted that the adsorption efficiency decreased after the fifth cycle, indicating a gradual reduction in performance over time (although it remained above 85% in the performed experiments). This study aims to achieve the goal of zero waste and contribute to the circular economy through the sustainable use of residual biomass. Full article

The excessive use of chemical fertilizers raised concerns regarding environmental sustainability and soil degradation, prompting increasing interest in biofertilizers as eco-friendly alternatives. Among these, a compound that is effective in stimulating root and plant growth is indole-3-acetic acid (IAA). In our study, we evaluated IAA production by the halotolerant bacterium Vreelandella titanicae under different and varying nutritional conditions, such as tryptophan availability, temperature, pH, salinity, etc. The bacterium showed significant IAA production under a broad range of conditions and a dependence on the presence of tryptophan for IAA biosynthesis. High salinity (1.0 M NaCl), slightly alkaline pH (8.0–9.0), and temperatures of 34 °C increased IAA production, while optimal growth occurred in the absence of NaCl at a range of temperatures of 25–28 °C, suggesting a stress-responsive regulation of its biosynthesis. Easily metabolizable carbon sources, such as glucose and mannitol, enhanced IAA yield again, whereas additions of 1.0 g L⁻¹ NH₄NO₃ and KH₂PO₄ in the basal medium, poor in these salts, inhibited both the growth of the bacterium and IAA production. Notably, V. titanicae produced relevant amounts of IAA in seawater (24.57 ± 11.28 μg⋅mL⁻¹) when used as growth medium and dairy whey (15.68 ± 2.42 μg⋅mL⁻¹), highlighting its suitability for low-cost and circular bioprocessing strategies. In conclusion, V. titanicae is a promising Plant Growth-Promoting Rhizobacterium (PGPR) candidate for sustainable IAA production and potential application in saline or marginal agricultural soils. Its ability to synthesize IAA in different growth media could allow its exploitation in environmentally friendly bioprocesses. Full article

This study presents a rapid and efficient laboratory-scale process for removing lead from Pb–Sb alloy melts using a composite H₃PO₄–(NaPO₃)₆ flux. Thermodynamic analysis was combined with experimental investigation to elucidate the influence of key parameters on lead removal behavior. The Wilson equation was employed to describe the non-ideal behavior of the Pb–Sb system, enabling estimation of equilibrium lead contents and providing theoretical support for interpreting experimental trends. Under the investigated conditions (1073 K, H₃PO₄/(NaPO₃)₆ mass ratio of 2:1, and a holding time of 10 min), the Pb mass fraction was reduced from 10.0 wt.% to 0.018 wt.%, corresponding to a lead removal efficiency of 99.86%. Compared with the traditional refining processes, this method shortens the processing time and avoids the use of volatile gas reagents, demonstrating its potential for lead–antimony separation. The results provide thermodynamic and experimental insight into phosphate-based refining of crude antimony. Full article

Li₃PO₄ is a promising raw material for the low-cost synthesis of high-performance LiFePO₄. Reactive crystallization from low-concentration lithium-rich brine is a key process for the efficient preparation of high-quality Li₃PO₄ products. The effect of operating conditions (temperature/supersaturation/impurities/ultrasonic) on the induction time was investigated using a focused beam reflectance measurement. The evaluation of the primary nucleation, growth kinetics, and parameters for the extraction of Li₃PO₄ from low-concentration lithium-rich brine was conducted using an induction time method. The dominant mechanisms at different stages were inferred through online monitoring of the particle size distribution during the Li₃PO₄ crystallization process. Results show that induction time decreases with increasing operating conditions (temperature/supersaturation/ultrasonic frequency), indicating that their increases all promote nucleation. Impurities (NaCl/KCl) did not significantly affect the induction time, whereas Na₂SO₄ and Na₂B₄O₇ significantly increased it, with Na₂B₄O₇ showing the most notable effect. Classical nucleation theory was applied to determine kinetic parameters (nucleation activation energy/interfacial tension/contact angle/critical nucleus size/surface entropy factor). Results indicate that Li₃PO₄ mainly nucleates through heterogeneous nucleation, with a temperature increase weakening the role of heterogeneous nucleation. Fitted models indicate that Li₃PO₄ predominantly follows the secondary nucleation and spiral growth mechanism. Our findings are crucial for crystallization design and control in producing high-quality Li₃PO₄ from lithium-rich brines. Full article

Carbon (C) is crucial for nutrient cycling and the assembly of microbial populations in the soil. However, it is still unclear how the C-source utilization characteristics of microbes in distinct types of soils respond to changes in soil phosphorus (P) activity. This study investigated how the addition of different C sources with different decomposition rates (glucose, hemicellulose, and lignin) affects P transformation in two distinct agricultural soils (i.e., Mollisols and Fluvo-aquic soil). Results revealed that the short-term glucose addition to soil induced rapid acidification and microbial biomass accumulation, thereby significantly increasing labile P (NaHCO₃-P_i, NaOH-P_o) content in Fluvo-aquic soil. Lignin amendment promoted gradual HCl-P release in Mollisols, reflecting differential microbial utilization strategies. Glucose stimulated phosphatase activity (2.5–3.0× control) and phoD gene abundance (4.8×) in Fluvo-aquic soil in the early stage, favoring the growth of Pseudomonas and Burkholderia, whereas lignin sustained the mineralization of fungal-associated P in Mollisols (1.8–2.3× phosphatase activity) by enhancing the abundance of Streptomyces and Bradyrhizobium. Soil type dictated P mobilization efficiency. The Fluvo-aquic soil exhibited rapid but transient P release via bacterial dominance, while Mollisols retained slower yet persistent P availability through specialized microbial consortia. Notably, glucose enhanced organic P mineralization by stimulating C decomposition by microbes, particularly in C-rich Mollisols. Lignin increased P availability in Mollisols via Fe/Al-P desorption. However, in Fluvo-aquic soil, lignin reduced the availability of P through microbial immobilization. These findings highlight that C source degradability and soil properties interactively govern microbial-mediated P cycling in soil. Therefore, organic amendments in contrasting agroecosystems need to be optimized. Full article