Search Results (136)

Magnesium whitlockite (Mg-WH) has emerged as a promising biomaterial for bone regeneration due to its compositional similarity to natural bone minerals. This study aimed to systematically modify a dissolution–precipitation synthesis method to produce Mg-WH granules with tailored morphologies and controlled phase compositions for possible use in bone regeneration applications. Three distinct precursor granules were prepared by mixing varying amounts of ammonium dihydrogen phosphate and magnesium hydrogen phosphate with calcium sulfate. The precursors were then transformed into biphasic and single-phase Mg-WH granules by means of immersion in magnesium- and phosphate-containing solutions under controlled conditions. The X-ray diffraction results demonstrated that biphasic materials containing Mg-WH and either calcium-deficient hydroxyapatite (CDHA) or dicalcium phosphate anhydrous (DCPA) formed after 24 h of synthesis, depending on the synthesis conditions. Prolonging the reaction time to 48 h resulted in complete transformation into single-phase Mg-WH granules. Fourier-transform infrared spectroscopy confirmed the presence of functional groups characteristic of Mg-WH, CDHA, and DCPA in the intermediate products. The spectra also indicated the absence of precursor phases and the progressive elimination of secondary phases as the reaction time increased. Scanning electron microscopy analyses revealed notable morphological transformations from the raw granules to the product granules, with the latter exhibiting interlocked spherical and rod-like particles composed of fine Mg-WH rhombohedral crystals. N₂ adsorption–desorption analyses exposed significant differences in the surface properties of the synthesized granules. By varying precursor, reaction solution compositions, and reaction times, the study elucidated the phase evolution mechanisms and demonstrated their impact on the structural, morphological, and surface properties of Mg-WH granules. Full article

Rice paddy fields are sustainable agricultural systems as soil microorganisms help maintain nitrogen fertility through generating ammonium. In these soils, dissimilatory nitrate reduction to ammonium (DNRA), nitrogen fixation, and denitrification are closely linked. DNRA and denitrification share the same initial steps and nitrogen gas, the end product of denitrification, can serve as a substrate for nitrogen fixation. However, the microorganisms responsible for these three reductive nitrogen transformations, particularly those focused on ammonium generation, have not been comprehensively characterized. In this study, we used stable isotope probing with ¹⁵NO₃⁻, ¹⁵N₂O, and ¹⁵N₂, combined with 16S rRNA high-throughput sequencing and metatranscriptomics, to identify ammonium-generating microbial consortia in paddy soils. Our results revealed that several bacterial families actively contribute to ammonium generation under different nitrogen substrate conditions. Specifically, Geobacteraceae (N₂O and +N₂), Bacillaceae (+NO₃⁻ and +N₂), Rhodocyclaceae (+N₂O and +N₂), Anaeromyxobacteraceae (+NO₃⁻ and +N₂O), and Clostridiaceae (+NO₃⁻ and +N₂) were involved. Many of these bacteria participate in key ecological processes typical of paddy environments, including iron or sulfate reduction and rice straw decomposition. This study revealed the ammonium-generating microbial consortia in paddy soil that contain several key bacterial drivers of multiple reductive nitrogen transformations and suggested their diverse functions in paddy soil metabolism. Full article

Ammonia (NH₃) is a significant air pollutant with major environmental and health impacts, largely attributed to agriculture. Pig production is a major contributor, accounting for 25% of livestock NH₃ emissions. This study developed a new system based on gas-permeable membranes (GPM) technology for NH₃ recovery from the atmosphere obtaining a solution of ammonium sulfate as the resulting fertilizer product. Various experimental configurations were evaluated in the novel system using a synthetic NH₃-emitting solution. The optimal arrangement was a GPM system with recirculation of the generated NH₃ and without recirculation of the acidic trapping solution, yielding a nitrogen (N) recovery rate of up to 237 g m⁻² d⁻¹. Subsequent tests using pig manure (PM) at varying durations achieved rates of up to 73 g m⁻² d⁻¹, representing a four-fold increase in N capture efficiency compared to previous research. The influence of manure temperature on NH₃ emission and capture were analyzed, simulating the possible differences between seasons (summer and winter), and revealing higher N recovery rates at elevated temperatures. At 21.5 °C, the recovery rate was 7.7 g m⁻² d⁻¹, while increased temperatures of 38.8 °C and 49.3 °C yielded rates of 15.9 and 27.2 g m⁻² d⁻¹, respectively. Full article

A systematic study on the mechanisms of cleansing artificial skin by solutions of widely used in personal care surfactants disodium laureth sulfosuccinate (DSLSS), sodium laureth sulfate (SLES), sodium dodecyl sulfate (SDS), dodecyl trimethyl ammonium bromide (DTAB), and coco glucoside (CG), is presented. The systematic characterization of soil removal from artificial skin revealed two primary cleansing mechanisms: emulsification and roll-up. Emulsification occurs in systems with very low interfacial tension, such as sebum in SLES solutions, while dimethicone soil was only removed by roll-up. The roll-up effectiveness depends on the surfactant’s interfacial activity and its adsorption on the soiled surface. Thus, the strong adsorption of DTAB on the skin leads to dimethicone roll-up at a relatively high interfacial tension of 11 mN/m. The anionic and nonionic surfactants adsorbed less at the artificial skin surface, and the oil/water interfacial tension value lowering below 5 mN/m is necessary for the roll-up to occur. Nonionic CG removed dimethicone at a lower concentration than ionic surfactants. Combining CG with ionic surfactants improved cleaning at lower total concentrations. Surfactant mixtures are used to formulate simple cleansing formulations, whose performance is also investigated by the developed in vitro approach. The results obtained allow for a good rating of the formulations, which correlates well with the performance of the surfactant mixtures and their interfacial activity. Full article

Nitrogen is an essential plant nutrient, but N fertilization contributes to greenhouse gas emissions through its production and application as well as nitrous oxide emissions when applied to soil. Diazotrophic bacteria, known to modify root architecture and increase nutrient uptake, have been proposed as a potential strategy to improve nitrogen use efficiency (NUE) in sugarcane cultivation. The objective of this study was to evaluate the efficiency of N use from ¹⁵N ammonium sulfate applied to different sugarcane varieties inoculated with diazotrophic bacteria. The experiment was conducted in pots filled with soil (100 kg pot⁻¹). The sugarcane varieties tested were RB867515 and RB92579. A commercial diazotrophic bacteria inoculant for sugarcane was used. The experimental design was a randomized block design with four replicates. The treatments were as follows: control without inoculation, inoculation with five strains of bacteria, with or without nitrogen fertilization. The evaluations were performed on different parts of the plant. At 360 days after transplanting, the accumulation of N, fresh mass, dry mass, and the proportion of excess ¹⁵N were determined. In the studied sugarcane varieties, the efficiency of ¹⁵N fertilizer use was 60%, with no influence from inoculation. Full article

A series of 5 wt.% Cr/SiO₂ catalysts were prepared through incipient wet impregnation using different chromium salts as a source of Cr (chromium (III) sulfate, acetylacetonate, nitrate, ammonium dichromate). The obtained catalysts were characterized by SEM-EDX, TEM, DRIFT-CD₃CN spectroscopy, UV-VIS diffuse reflectance spectroscopy, and the N₂ low-temperature adsorption–desorption technique. The catalysts were tested in propane, and isobutane dehydrogenation assisted with CO₂ at 600–750 °C. The highest activity in propane dehydrogenation was observed for the catalyst obtained from chromium acetylacetonate, the yield of propylene was 32% at 750 °C, and in the isobutane dehydrogenation reaction, the catalyst obtained from chromium sulfate was the best one; the yield of isobutene was ~30% at 600 °C. The obtained results show that the type of chromium precursor has a significant effect on the efficiency of the catalyst in the propane and isobutane dehydrogenation with CO₂. Full article

The lone application of ammonium fertilizer is one of the most commonly used measures to supplement soil nutrients. At the same time, it also causes soil acidification and leads to many environmental problems, such as soil degradation and eutrophication. Garlic (Allium sativum L.) stalk (RGS) returning has been widely researched for its benefits related to soil organic carbon (SOC) and crop yields. However, few have researched the effects of the incorporation of RGS mixed with ammonium fertilizer on soil physicochemical properties and the bacterial community composition. We incubated soil with the control (N0); ammonium sulfate (AS); and ammonium sulfate combined with 1%, 2%, 3%, and 5% (rate of the dry soil weight) garlic stalk at 25 °C and 60% water-filled pore spaces (WFPS) for 67 days. We measured the soil properties before and on the last day of the experiment. The results showed that adding RGS increased the contents of soil potassium (K), magnesium (Mg), and total nitrogen (TN), but it significantly decreased soil nitrate (NO₃⁻). In addition, adding RGS increased the relative abundance of r-strategists and the soil r/K ratio. The α diversity of soil bacteria reached the highest value with 3% treatment. Compared to AS, RGS increased the relative abundance of Firmicutes and Actinobacteria but decreased that of Proteobacteria and Acidobacteria. The function genes of Replication_and_Repair and Cell_Motility were enhanced after adding AS, while the function genes of Metabolism_of_Other_Amino_Acids, Enzyme_Families, and Metabolism were enhanced with increased RGS rates. Although SOC increased, NO₃⁻ significantly decreased with the increase in the returning levels, which could be due to the strong decreases in nitrifying bacteria with increases in RGS rates from 3% to 5%. Therefore, adding RGS at 3% is suitable for soil bacterial biodiversity and nutrient balance. Full article

Membrane contactors have proved to be effective for recovering ammonia from wastewater by absorbing it into a trapping solution. This study compares the performance of sulfuric acid and citric acid as trapping solutions in a pilot-scale plant for recovering ammonia from sludge digestion liquors using membrane contactors in a liquid–liquid configuration operating at pH 10 and a temperature of 37 °C and using ultrafiltration (UF) technology as pretreatment. The performance of the process using sulfuric acid at a lower pH (9.5) and temperature (30 °C) was also studied, as well as the advantage of including a CO₂-stripping module in the process. The ammonia elimination efficiency was 88% and 86% when using sulfuric acid and citric acid, respectively. The nitrogen concentration of the produced ammonium sulfate and ammonium citrate reached 23.2 and 14.7 g NH₃-N·L⁻¹, respectively. The ammonia elimination efficiency when using sulfuric acid decreased to 49% when decreasing the pH to 9.5 and to 85% when decreasing the temperature to 31 °C. UF technology was able to reduce the concentration of suspended solids by 90% and the chemical oxygen demand by 37%. However, the UF membranes for the pretreatment and the membrane contactors for ammonia recovery had to be constantly cleaned with acid due to scaling, which significantly increased maintenance efforts. The CO₂-stripping module reduced the consumption of the caustic soda solution by 23% for increasing the pH level of the treated water. Finally, the specific energy consumption of the plant was 8 kWh·m⁻³. Full article

Common beans are an essential food source worldwide, particularly in developing countries, and are grown in soils poor in selenium (Se), a mineral essential for human health. Adding Se to fertilizers is a promising technique; however, more studies are needed on the efficacy of this technique on common beans. This study aimed to evaluate the biofortification utilizing Se-enriched nitrogen fertilizers on common bean seeds’ agronomic, physiological, and nutritional characteristics. The pot experiment used a randomized block design with five treatments (urea, Se-enriched urea, ammonium sulfate, Se-enriched ammonium sulfate, and without N and Se), four genotypes (BRS Cometa, BRS Estilo, BRSMG Madrepérola and Pérola), and three replicates. The highest seed yield was 28.31 g pot⁻¹ with Pérola genotype fertilized Se-enriched ammonium sulfate. Photosynthetic rates ranged from 30.37 to 39.06 µmol m⁻² s⁻¹ for Pérola and BRSMG Madrepérola, both with Se-enriched ammonium sulfate. The highest seed Se concentration was 11.17 µg g⁻¹, with BRSMG Madrepérola fertilized with Se-enriched urea being 22.02%, 17.64%, and 22.47% higher than BRS Cometa, BRS Estilo, and Pérola, respectively. Se-enriched nitrogen fertilizers boost seed yield and alter physiological responses based on genotypes and Se-fertilizer interactions. Se-enriched fertilizers applied to soil can increase the Se concentration in common beans. Full article

Nitrogen (N) fertilizer is routinely applied in highbush blueberry (Vaccinium corymbosum L.) production. The recommended N fertilizer rate increases as the plants mature, and is usually determined based on regional growing conditions. However, the effects of N fertilizer rates and application methods over the long term remain poorly understood. In this study, ammonium sulfate was applied as an N source at the recommended rate (100%), which corresponds to a maximum of 155 kg N ha⁻¹ for plants older than eight years, along with higher rates at 150% and 200% of the recommended level, as well as a control treatment of no N. Treatments were applied to the blueberry cultivar ‘Duke’ as either broadcast (BROAD) or fertigation (FERT), and impacts were analyzed after 12 and 13 years of treatment. In the 14th year, the 100% N rate was uniformly applied as BROAD across all plants to separate the effects of different N rates from those caused by long-term soil condition changes. The BROAD treatment at the 100% N rate achieved the highest yield, and the FERT treatment at 200% resulted in the lowest yield in the 12th year, suggesting that excessive N rates can reduce fruit yield. However, no significant yield differences were observed in the 13th year. Higher N rates were associated with reduced titratable acidity in fruits and fewer flower buds. The soil pH declined across all N treatments, with the FERT at 200% showing the most significant reduction. All N treatments generally increased soil electrical conductivity (EC). High N rates also decreased plant accumulation of magnesium, calcium, and copper, with the latter reaching deficiency levels. These findings emphasize the importance of adhering to recommended N application rates and adjusting soil pH and EC to mitigate the adverse effects of prolonged N treatments. Full article

Nitrogen is an essential nutrient for plant functioning, photosynthesis, and metabolic activities. In terrestrial settings, nitrogen is not always sufficiently available because its basic form (N₂) must be fixed into other forms, such as nitrate and ammonium, to be usable by plants. Adding nitrogenous fertilizer to soils may provide a means of increasing forest productivity. Ammoniacal nitrogen (N-NH₃), an effluent produced during gold extraction, requires mining companies to manage its long-distance and costly transportation offsite for disposal. Applying this nitrogenous effluent, in its treated form of ammonium sulfate (ammoniacal nitrogen from mine water was converted into ammonium sulfate locally), to regional forest stands could provide a cost-effective and more environmentally sound means of managing this waste product and enhance forest productivity. Here, we conducted greenhouse- and field-based experiments to evaluate ammonium sulfate fertilization on black spruce (Picea mariana) and jack pine (Pinus banksiana) seedling growth. We assigned five treatments, varying in terms of the fertilizer concentration and presence/absence of biochar, to seedlings in greenhouse trials. We also applied various concentrations of ammonium sulfate to an 8-year-old black spruce plantation in Abitibi-Témiscamingue, Québec. We found that black spruce and jack pine seedlings experienced greater growth than the controls in terms of the stem diameter (32–44%), seedling height (21–49%), and biomass (86–154%). In the field experiment, we observed 37% greater volumetric growth in plots receiving medium-level fertilization than the control. Although nitrogen fertilization lowered the soil pH, essential nutrients increased to favor greater seedling growth. Thus, ammonium sulfate, derived from local mining effluent, appears to offer a suitable alternative for enriching nitrogen-limited boreal soils and increasing tree growth. This application could benefit both regional mining industries and forest management bodies. Full article

Rayon is an extremely valuable cellulosic fiber in the global textile industry. Since cuprammonium rayon is more eco-friendly than other types of rayon fabrics, it was synthesized by regenerating α–cellulose isolated from wastepaper using a novel gaseous-ammoniation injection (GAI) process. This was achieved by preparing tetra–ammine copper hydroxide (cuoxam solution) via reacting copper sulfate and sodium hydroxide to produce copper hydroxide that was, finally, ammoniated by injecting the gas directly to the reaction vessel instead of using ammonium hydroxide applied by prior art. After that, the air-dried cellulose was chemically generated by dissolving it in a freshly prepared cuoxam solution and, subsequently, was regenerated by extruding it within a hardening bath constituted mainly from citric acid, producing the cuprammonium rayon (c. rayon). The properties of the fibrous, structural (XRD and mechanical), physical, and chemical features were investigated. It was found that the rayon was produced in a high yield (90.3%) with accepted properties. The fibrous properties of the rayon staple length, linear density, and fiber diameter were found to be 44 mm, 235 Tex, and 19.4 µm, respectively. In addition, the mechanical properties determined, namely tensile strength, elongation at break, modulus of elasticity, and breaking tenacity, were found to be 218.3 MPa, 14.3 GPa, 16.1%, and 27.53 cN/Tex, respectively. Based on this finding, and upon injecting the ammonia gas through the α–cellulose saturated and immersed in the Cu (OH)₂ to complete producing the cuoxam solvent, we find that theuse of an injection rate of 120 mL/minute to obtain the highest fibers’ tensile strength for the final product of the c. rayon is preferable. Utilization of higher rates will consume more amounts of the ammonia gas without gaining noticeable enhancement in the c. rayon’s mechanical quality. Accordingly, the GAI invention rendered the c. rayon favorable for use in making sustainable semisynthetic floss for either insulation purposes or spun threads for woven and nonwoven textile clothing. Full article

Sorghum is a plant that mainly requires chemical nitrogen fertilization. There are organic fertilizers that can provide nutrients to plants with great benefits to the soil, such as chicken manure. To determine the influence of organic fertilization on nitrate reductase (NR), glutamine synthetase (GS), and the amount of chlorophyll, sorghum plants were grown using the following four treatments: soil (T1), soil + chicken manure 100 kg ha⁻¹ of nitrogen (N) (T2), soil + chicken manure 200 kg ha⁻¹ N (T3), and soil + ammonium sulfate 100 kg ha⁻¹ N (T4). Leaves were sampled in the vegetative stage (VS), the reproductive stage (RS), and the maturation stage (MS). The highest NR activity occurred in plants with T2 and T3 in the VS. The highest GS activity was in T3 and T4 in the RS. The amount of chlorophyll a was the same in all phenological stages. However, the amount of chlorophyll b was influenced by the type of fertilization at different phenological stages. Organic fertilizers (OF) produced the highest NR activity. On the other hand, GS activity was higher with chemical fertilization (T4), which was equal to the second dose of organic fertilization (T3). Finally, chlorophyll a and b were influenced by both types of fertilization, and was different from T1. Full article

As part of the development of alternative and environmentally friendly control against phytopathogenic fungi, Burkholderia cepacia could be a useful species notably via the generation of hydrolytic enzymes like chitinases, which can act as a biological control agent. Here, a Burkholderia contaminans S614 strain exhibiting chitinase activity was isolated from a soil in southern Tunisia. Then, response surface methodology (RSM) with a central composite design (CCD) was used to assess the impact of five factors (colloidal chitin, magnesium sulfate, dipotassium phosphate, yeast extract, and ammonium sulfate) on chitinase activity. B. contaminans strain 614 growing in the optimized medium showed up to a 3-fold higher chitinase activity. This enzyme was identified as beta-N-acetylhexosaminidase (90.1 kDa) based on its peptide sequences, which showed high similarity to those of Burkholderia lata strain 383. Furthermore, this chitinase significantly inhibited the growth of two phytopathogenic fungi: Botrytis cinerea M5 and Phoma medicaginis Ph8. Interestingly, a crude enzyme from strain S614 was effective in reducing P. medicaginis damage on detached leaves of Medicago truncatula. Overall, our data provide strong arguments for the agricultural and biotechnological potential of strain S614 in the context of developing biocontrol approaches. Full article

In this study, polysaccharides were extracted at a rate of 87.5% ± 1.5% from native dandelion roots, and the dandelion root polysaccharides (DRPs) were then chemically modified to obtain sulfated polysaccharides (SDRPs) with a degree of substitution of 1.49 ± 0.07. The effects of modification conditions, physicochemical characterizations, structural characteristics, antioxidant properties, hypoglycemic activity, and proliferative effects on probiotics of DRP derivatives were further investigated. Results showed that the optimum conditions for sulfation of DRPs included esterification reagents (concentrated sulfuric acid: n-butanol) ratio of 3:1, a reaction temperature of 0 °C, a reaction time of 1.5 h, and the involvement of 0.154 g of ammonium sulfate. The DRPs and SDRPs were composed of six monosaccharides, including mannose, glucosamine, rhamnose, glucose, galactose, and arabinose. Based on infrared spectra, the peaks of the characteristic absorption bands of S=O and C-O-S appeared at 1263 cm⁻¹ and 836 cm⁻¹. Compared with DRPs, SDRPs had a significantly lower relative molecular mass and a three-stranded helical structure. NMR analysis showed that sulfated modification mainly occurred on the hydroxyl group at C6. SDRPs underwent a chemical shift to higher field strength, with their characteristic signal peaking in the region of 1.00–1.62 ppm. Scanning electron microscopy (SEM) analysis indicated that the surface morphology of SDRPs was significantly changed. The structure of SDRPs was finer and more fragmented than DRPs. Compared with DRPs, SDRPs showed better free radical scavenging ability, higher Fe²⁺chelating ability, and stronger inhibition of α-glucosidase and α-amylase. In addition, SDRPs had an excellent promotional effect on the growth of Lactobacillus plantarum 10665 and Lactobacillus acidophilus. Therefore, this study could provide a theoretical basis for the development and utilization of DRPs. Full article