Diammonium Phosphate Research Articles

Ammonium polyphosphate combined with potassium nitrate was used to modify the anti-caking property of nitro-compound fertilizer

Objective Although increasing the amount of inert hydrophobic material can improve the anti-caking performance of compound fertilizer, carrying inert hydrophobic material hinders the applicability of compound fertilizer in mechanized fertilization and the integrated technology of water and fertilizer. In order to reduce the amount of inert hydrophobic material applied to the outer surface of the compound fertilizer particles, in this article, the type and proportion of nitrogen salt, phosphorus salt, and potassium salt were limited so as to increase the anti-caking performance of the particles. Methods The anti-caking performance of 17-17-17SOP nitro-compound fertilizer granules (AN-NPK) was modified by the following three measures: (1) APP (ammonium polyphosphate) was used to replace some inorganic phosphates; (2) reducing the mass fraction of AN (ammonium nitrate) and introducing KN (potassium nitrate) to supplement the nitrate nitrogen in the compound fertilizer, and maintain the same ratio of nitrate nitrogen and ammonium nitrogen in AN-NPK; (3) reduce the mass fraction of KS (potassium sulfate), and shift the molar ratio of NO3/SO4 away from 2.0. The AN modified by APP and KN was characterized by X-ray diffraction and differential scanning calorimetry. The mechanism of improving the anti-caking performance of AN-NPK was demonstrated. Results The results showed that when the mass fraction of APP in the formula was 0%, 8%, 16%, and 21%, the anti-caking performance of AN-NPK is gradually increased, the transverse shear force of the agglomerates decreased from 135.65 N to 94.02, 67.45, and 60.32 N. When 10% KN and 12% APP were added to AN-NPK, the transverse shear force continued to decrease to 33.25 N. Conclusion The mechanism of improving anti-caking performance of AN-NPK is as follows:(1) APP with oligomeric degree has higher solubility and mobility than monoammonium phosphate and diammonium phosphate, resulting in higher enrichment on the surface of AN-NPK; (2) at the granulation temperature of 80 °C, KN releases more potassium ions than KS, and more AN was modified in the granulation process of AN-NPK. In summary, APP combined with KN weakens the phase transition effect of AN and reduces the salt ion concentration on the surface of AN-NPK.

Effect of mechanochemically modified MoO3–ZnO on Mo supply to plants when co-granulated with macronutrient fertilizers

Molybdenum (Mo) is an essential micronutrient required for plant growth but is prone to leaching from neutral and alkaline soils. The use of slow-release Mo sources could potentially reduce leaching losses from soils and increase crop yields. In this study, we assessed mechanochemistry as a green method to produce slow-release Mo sources. Molybdenum compounds (MoO3 or (NH4)6Mo7O24·4H2O) were mechanochemically (MC) treated with ZnO to synthesize compounds with a Mo content of 1–36%. Reduced Mo solubility after MC treatment, compared to the initial Mo source, was obtained with the MoO3 source and these composites were used for co-compaction with macronutrient fertilizers. Macronutrient pellets with 0.2% Mo were compacted using the 4% Mo and 36% Mo (characterized as ZnMoO4) compounds. A column dissolution test showed that the 4% Mo compound in a macronutrient carrier (DAP and MAP) only released around 40% of the total Mo compared to 80% for a non-MC treated control over 72 h. Column leaching using two soils revealed that the release behavior of Mo was strongly related to the pH of the leachate, which was affected by both the soil pH and the macronutrient carrier. More Mo was released when the MC-treated compound was co-compacted with diammonium phosphate (DAP) compared to monoammonium phosphate (MAP). The MC-treated compound with 4% Mo showed significantly less leaching than the control without ball milling when co-compacted with both MAP and DAP. In a pot trial with simulated leaching, the uptake of Mo was greater for the MC-treated 4% Mo compound co-compacted into DAP than for the other Mo sources. Overall, our results indicate that MC-treated MoO3–ZnO could be used as a slow-release Mo source in high-rainfall areas.Graphical

Enhancing maize phosphorus uptake with optimal blends of high and low-concentration phosphorus fertilizers.

High-concentration phosphorus (P) fertilizers are crucial for crop growth. However, fertilizers with lower P concentrations, such as calcium magnesium phosphate (CMP) and single super phosphate (SSP), can also serve as efficient P sources, especially when blended with high-concentration P fertilizers like diammonium phosphate (DAP) or monoammonium phosphate (MAP). In this study, we conducted a 48-day pot experiment to explore how blending low-P fertilizers could optimize maize P utilization, using CMP to replace DAP in acidic soil, and SSP to replace MAP in alkaline soil, with five SSP+MAP and CMP+DAP mixtures tested. Key metrics such as shoot and root biomass, shoot P uptake, root length, and soil P bioavailability were measured. We found that maize biomass and P uptake with 100% DAP were comparable to those with 50% CMP and 50% DAP in acidic soil. Similar results were observed for 100% MAP compared to 50% SSP and 50% DAP in alkaline soil. Root biomass and length were largest with 100% MAP in acidic soil and at 100% DAP in alkaline soil, with no significant differences at 50% SSP or CMP substitutions for MAP and DAP, respectively. Furthermore, 50% SSP or CMP substitutions for MAP and DAP increased the content and proportion of the labile inorganic P (Pi) pool (H2O-Pi and NaHCO3-Pi), had a direct and positive effect on Olsen-P. Our findings reveal that 1:1 blends of SSP and MAP in acidic soil, and CMP and DAP in alkaline soil, effectively meet maize's P requirements without relying solely on high-concentration P fertilizers. This indicates that strategic blending of fertilizers can optimize P use, which is crucial for sustainable agriculture.

Biomimetic Calcium Phosphate Nanoparticles: Biomineralization Models and Precursors for Composite Materials.

The formation of calcium phosphate under the control of water-soluble polymers is important for understanding bone growth in living organisms. These experiments also have spin-offs in the creation of composite materials, including for regenerative medicine applications. The formation of calcium phosphate (hydroxyapatite) from calcium chloride and diammonium phosphate was studied in the presence of polymers containing carboxyl, amine, and imidazole groups. Depending on the polymer composition, solid products and stable dispersions of positively or negatively charged nanoparticles were obtained. Oppositely charged nanoparticles can interact with each other to form a macroporous composite material, which holds promise as a filler for bone defects. The formation of a calcium phosphate layer around a living cell (dinoflagellate Gymnodinium corollarium A. M. Sundström, Kremp et Daugbjerg) using positive composite nanoparticles is a one-step approach to cell mineralization.

Optimizing co-application of starter ammoniacal-N and K-containing fertilizers for barley in the seed-furrow

It is unclear how seed-placed starter ammoniacal-N-and-K fertilizers influence barley (Hordeum vulgare L.) seed-crop emergence, and its early establishment, due to salt injury and potential ammonia production and toxicity within the soil profile under different placement rates. Keeping in this view, the study was undertaken to experiment the effects of different fertilizer types, and rates using three different soil types characterized by fine (G1), medium (G2), and coarse (G3) textures when simultaneously placed with barley seed and establish safe-starter fertilizer recommendation models. The fertilizers were applied at varying rates from 0 to 60 kg N ha−1 and 0 to 74 kg K ha−1 alongside barley seeding. Maximum predicted safe starter ammoniacal-N-fertilizer rates were as follows: urea = 15, 35 and 26 kg N ha−1 is safe for G1, G2 and G3 soils, respectively. DAP (Diammonium phosphate), 52 kg N ha−1 is safe for fine textures whilst 12 and 37 kg N ha−1 for medium and coarse textures. MAP (Monoammonium phosphate) is safely placed at 55, 11 and ≥60 kg N ha−1 for G1 – G3 soils. For MOP (Muriate of Potash) and SOP (Sulfate of Potash), 67 and ≥74 kg K ha−1 were ideal for improved barley emergence across all the soil types. Visual appearances including delayed seed emergence, leaf chlorosis, and stubby coleoptiles were observed at varying seed-placed N and K rates. Intricate relationships among various emergence parameters, root architecture, aboveground and root biomass, chlorophyll content, all showing significant interrelationships. Data indicate that cubic model could be used for predicting seed-safe rates for multiple fertilizer types.

Nitrogen Availability and Utilisation of Oligopeptides by Yeast in Industrial Scotch Grain Whisky Fermentation

Scotch grain whisky is produced with a substantial proportion of unmalted grains, which can result in nitrogen deficiency for yeast in the fermentable grain mash. This study examined nitrogen source availability and utilisation by three commercial whisky strains (Saccharomyces cerevisiae) during Scotch grain whisky fermentation, focusing on oligopeptides. Peptide uptake kinetics in synthetic whisky mash with defined peptides showed that oligopeptides of up to nine amino acids were taken up by the strains, albeit with some variability between the strains. The study found that peptides with appropriate molecular weights could replace free amino acids without negatively affecting fermentation kinetics. Moreover, fermentation performance improved when additional nitrogen was provided via peptides rather than diammonium phosphate. Analysis of industrial grain mash indicated that despite low initial yeast assimilable nitrogen, residual proteolytic activity from malt increased nitrogen availability during fermentation. Approximately 30% of the nitrogen consumed by yeast during grain mash fermentation was derived from peptides. LC-HRMS peptide analysis revealed complex dynamics of peptide formation, degradation, and utilisation. This study highlights the importance of oligopeptides in ensuring optimal fermentation efficiency in Scotch grain mash and similar substrates.

Preparation and research of high electromagnetic wave transmission type concrete in 5G frequency band

In urban areas with many buildings, the transmission of 5 G signals can be greatly absorbed or reflected, leading to decreased effectiveness of transmission. To address the issues mentioned above, the functional admixture formed by the mixture of nanocrystalline cellulose (NCC) and diammonium hydrogen phosphate (DAP) is added into concrete in this study, the electromagnetic transmission performance (ETP) and mechanical properties of concrete are enhanced simultaneously for the first time, and the electromagnetic transmission coefficient of concrete is doubled. When NCC and DAP are mixed, the electromagnetic transmission coefficient of concrete improved by 117.65 %-124.35 %, among which, when 0.5 wt% DAP and 4 wt% NCC are mixed, the electromagnetic transmission coefficient of concrete is the highest, and some frequency bands are as high as 70 %, meeting the requirements of electromagnetic wave transmitting materials. In addition, the compressive strength of concrete containing 4 wt% NCC and 0.5 wt% DAP increases by 24.3 % compared to concrete containing only 4 wt% NCC.

CoNi-N/P-Doped Carbon Nanotubes as Catalysts for Efficient Oxygen Reduction Reaction.

Transition metals (TMs) supported by heteroatom-doped carbon materials are considered to be the potential alternatives to the Pt/C catalyst owing to their low cost, outstanding electrocatalytic efficiency, and excellent electrochemical durability. In this paper, N/P-doped carbon nanotube (CNT) (N/P-CNT)-supported monometallic (Co, Ni) and bimetallic (CoNi) catalysts were synthesized by one-step pyrolysis using diammonium hydrogen phosphate, 2-methylimidazole and organometallic salts as precursors, and the CNT as the catalyst carrier; the effects of transition TM types and pyrolysis temperature (Tp) on the microstructure and electrochemical properties were explored. The analysis exhibited that the CoNi bimetallic catalyst was superior to both Co and Ni monometallic catalysts, and the catalysts pyrolyzed at 900 °C exhibited a better graphitization degree. The optimal CoNi-N/P-CNT-900 displayed remarkable oxygen reduction reaction electrocatalytic performance with a half-wave potential (E1/2) of 0.86 V and excellent methanol tolerance and stability. Moreover, the Zn-air battery coated with CoNi-N/P-CNT-900 demonstrated a larger open circuit voltage of 1.577 V, a larger peak power density of 212.89 mW cm-2 at 357.8 mA cm-2, as well as a higher specific capacity of 799 mA h gZn-1, superior to that of the Pt/C catalyst (1.492 V, 96.04 mW cm-2 at 216.8 mA cm-2, 735 mA h gZn-1), showing outstanding practical value. This study is expected to promote the commercialization of the electrocatalysts.

Structure and Properties of Thermally Stabilized and Ecologically Friendly Organic Cotton Fibers as a New Activated Carbon Fiber Precursor

Organic cotton precursor yarn was impregnated in an aqueous solution consisting of diammonium hydrogen phosphate (DAP), boric acid (BA), and urea (U) mixtures before the thermal stabilization stage and then subjected to heat treatments in an air environment at 245 °C. The effect of chemical pretreatment on organic cotton yarn was examined using methods such as X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and infrared (IR) spectroscopy. The XRD analysis revealed a gradual decrease in the crystalline structure, attributed to the disruption of intermolecular hydrogen bonds. DSC and TGA measurements showed an improved thermal stability due to the formation of pre-graphitic structures with aromatic entities at higher temperatures. For samples chemically impregnated and then stabilized, the char yield values increased from 25% to 68% at 500 °C and 23% to 53% at 1000 °C. Analysis of IR spectra indicated a gradual reduction in both intermolecular and intramolecular hydrogen bonds associated with dehydration and dehydrogenation reactions. The IR spectra also confirmed a decrease in crystallinity with increasing oxidation time, which is consistent with the findings from X-ray diffraction. In addition, the IR spectra showed the presence of C = C bonds, indicating the formation of a crosslinked ladder-like structure. The results showed that DAP-BA-U integration increased the thermal stability of organic cotton fibers and the obtained samples were ready for the next stage, carbonization.Graphical

Co-Application of Coated Phosphate Fertilizer and Humic Acid for Wheat Production and Soil Nutrient Transport

The application of a diammonium phosphate coating effectively mitigates direct contact between the phosphate fertilizer and the soil, thus minimizing phosphorus fixation. Humic acid holds a pivotal role in augmenting soil quality and activating the soil’s phosphorus reserves. Notably, when combined with humic acid, diammonium phosphate significantly enhances the utilization efficiency of phosphate fertilizer. However, there is a paucity of literature exploring the dynamics of nutrient transport in soil when humic acid is paired with coated phosphate fertilizers. To assess the impact of the combined application of coated diammonium phosphate and humic acid on wheat yield enhancement, we conducted pot experiments along with leaching and ammonia volatilization simulation tests, aiming to elucidate the effects of this combination on nutrient transport. The study explored the effects of three distinct treatments: coated diammonium phosphate (CP), coated diammonium phosphate combined with humic acid (PHA), and coated diammonium phosphate combined with humic acid (CPHA). The investigation focused on analyzing their impacts on wheat yield, ammonia volatilization, soil-available phosphorus, nitrate nitrogen, ammonium nitrogen, soil-available potassium, as well as the mobilization and transport of calcium and magnesium in the soil. (1) Compared to the P treatment, the PHA and CP treatments significantly increased grain yield by 17.2% and 13.5%, respectively. The PHA treatment also increased effective panicle number by 12.9%. Overall, the CP, PHA, and CPHA treatments improved grain yield by 13.5%, 17.2%, and 19.1% compared to the P treatment. (2) The CP and PHA treatments reduced available phosphorus by 95.6% and 49.2%, calcium by 2.0% and 67.0%, and magnesium by 11.6% and 46.1% compared to the P treatment. Ammonium nitrogen decreased by 37.0% and 64.3%, while nitrate nitrogen increased by 14.0% in CP and slightly decreased by 0.8% in PHA. In the leaching solution, PHA and CP treatments reduced available phosphorus by 96.7% and 62.5%, increased calcium by 5.0% and 78.9%, decreased ammonium nitrogen by 2.2% and 43.4%, and decreased nitrate nitrogen by 10.6% and 13.0%. The PHA and CPHA treatments increased available phosphorus in the 0–20 cm soil layer by 1.4 times and 25.8%, respectively. (3) The CP treatment reduced ammonia volatilization by 87.0% compared to the P treatment, while the CPHA treatment further reduced it by 87.5% compared to the PHA treatment. The application of coated diammonium phosphate efficiently delays nutrient release and reduces nutrient leaching in the soil. Additionally, the integration of humic acid significantly improves the availability of phosphorus in the soil, minimizing phosphorus loss. Notably, the combined application of humic acid and coated diammonium phosphate leads to a significant increase in soil phosphorus content, subsequently enhancing soil nutrient availability, conserving fertilizer, and ultimately resulting in an improved wheat yield.

Electrochemical Recovery of N and P from Municipal Wastewater

Phosphorus, P, is a vital element of paramount importance for both humans and for the Environment. Wastewater contains often relatively high concentrations of P which can be recovered as crystalline struvite (MgNH4PO4·6H2O, MAP). This option is quite attractive in assisting sustainable development because struvite can be used as a slow-release fertilizer. Domestic wastewater is usually high in P and nitrogen, N, but relatively poor in magnesium, Mg. It is necessary to develop low-cost solutions for the enrichment of wastewater with Mg. In the present work, sacrificial magnesium anodes were used, which dissolve upon anodic polarization, releasing sufficient magnesium for the selective precipitation of MAP. The application of constant current between two electrodes of which the anode is a low-cost magnesium cylindrical rod (4 cm2 exposed surface area) and the other a platinum cathode electrode, both immersed in ammonium phosphate solutions, without adjustment of the solution pH, was investigated. Constant current density over the range 10–100 A·m−2, between the Mg- Pt electrodes immersed in solutions of ammonium hydrogen phosphate of exactly known initial concentration, was applied using a potentiostat. In the presence of sodium chloride solutions, on the magnesium anode and in the bulk solution, Mg(OH)2 (brucite) formed because of the passivation of the Mg electrode. In dilute ammonium hydrogen phosphate solutions, the magnesium anode dissolution resulted in struvite precipitation, even at a low applied current (10 mA). Struvite crystals with an average size of 20 μm were precipitated. The behavior of the cell for the electrolyte solutions used was Faradaic as long as the surface coverage of the anode was relatively low. The anodic dissolution of Mg resulted in high pH values (pH 11) eliminating the need for alkali addition.

Assessing the impacts of experimental mid-rotation forest fertiliser treatments on water quality

Background: Planted forests face on-going challenges to increase productivity while remaining within sustainable limits. Forest management activities that potentially impact on water quality are under increasing public scrutiny and regulatory controls. New Zealand’s forest industry is experimenting with aerially applied, mid-rotation fertiliser treatments as a sustainable option to increase productivity from planted forests. However, the effect of such applications on water quality requires investigation. Methods: Field trials were established to assess the effects of two conventional fertiliser applications (either granular di-ammonium phosphate (DAP) or granular urea) and a new-to-forestry liquid foliar fertiliser blend, on nitrogen and phosphorus concentrations in stream water of three planted forest sites representing a range of New Zealand climatic and soil environments. Results: Overall, the liquid foliar fertiliser treatment had the least impact on water quality compared with the two conventional fertiliser treatments. On the day of fertiliser application, when compared with pre-treatment in-stream concentrations, the urea treatments resulted in short-term increases in total nitrogen. The DAP treatment increased total phosphorus and dissolved reactive phosphorus concentrations with peak concentrations declining within hours. In the post-application period, any increases in nutrient concentrations in stream water were mainly associated with rainfall events within six months of application and at one site, the resumption of stream flow following a dry spell. Riparian ‘no-spray’ buffers of varying widths assisted in mediating the impacts of fertiliser applications. Conclusions: Initial evidence from these trials indicates that mid-rotation fertiliser treatments have the potential to provide an alternate management option to increase forest productivity or disease resilience with minimal or only short-term effects to water quality. However, further research on their environmental effects would support the development of guidelines specific to mid-rotation fertiliser applications, particularly if mid-rotation fertiliser applications become standard management practice in the forest industry.

Physico-chemical characteristics of Ca/P ratio on the composition and structure of oxygenated apatite

Phosphocalcic apatites have osteoconductive and bioactive properties that make them suitable for bone reconstruction. But, they are inactive against pathogenic microorganisms that can infect bone tissue. To overcome this limitation, we synthesized oxygen-doped phosphocalcic apatites that can release molecular oxygen as a bioactive molecule. We investigated how the calcium-to-phosphorus ratio (Ca/P) gave impacts on the chemical and structural composition of the oxygen-doped phosphocalcic apatites. We here used the double decomposition method, which involved mixing calcium nitrate and diammonium phosphate solutions in an ammonia buffer. We then characterized the products using several analysis, including infrared absorption spectroscopy, X-ray diffraction, thermal analysis, nitrogen adsorption-desorption, and elemental chemical analysis. It was found that the oxygen-doped phosphocalcic apatites were calcium-deficient and had a well-defined crystallinity at room temperature. After calcination at 900°C, the crystallinity improved further. The thermal analysis showed two mass losses: one at 50°C due to water adsorption and another at 450°C due to CO2 release. The specific surface area was about 100 ± 2 m2/g without any change with the Ca/P ratio. The quantity of molecular oxygen increased with the Ca/P ratio and reached an optimal value of the order of 3.6 ×10-4 mol for Ca/P=1/65 with the chemical formula of Ca9.9(PO4)6(OH)1.25(O2)0.74(CO3)0.01. It is important to make further analysis to know more about the properties of oxygenated apatite, and to combine this apatite with polymers purposely to have biomedical composites. It then can be concluded that the oxygen-doped phosphocalcic apatites could be a promising biomaterial for bone infection prevention and treatment. This research highlights an oxygenation treatment of phosphocalcic apatite and brings new ideas and possibilities for future research and development to get better understanding of the behavior of these biomaterials to be more effective, especially in the biological field. As a perspective, improving the biological properties in these biomaterials needs to be further explored, including experimental parameters for the obtainment of more conclusive results.

Response of tomato to innovative organo-mineral fertilizers

Organo-mineral fertilizers (OMFs) with low organic carbon (Corg) content have been associated with higher mineral fraction nutrient use efficiency. However, the extraction of peat, which is typically used in these OMFs, from endangered ecosystems causes long-time stored Corg to mineralize and to be released back into the atmosphere as carbon dioxide (CO2). This study analyzes the replacement of peat in OMFs with biowaste materials. These materials, considered organic byproducts that microorganisms and other living things can decompose through composting and aerobic or anaerobic digestion, offer a viable opportunity. This study investigated three stabilized biowastes—green compost (GC) from pruning residues, municipal solid waste compost (MSWC), and manure-based vermicompost (VC)—as the organic matrices for granular OMFs. These matrices were impregnated with dissolved ammonium sulfate and urea and used to coat diammonium phosphate granules. Each biowaste OMF contained 7.5% Corg, 20% mineral N, and 10% mineral P2O5 (OMF20 − 10). Fertilizers with high nutrient concentrations have the advantage of requiring low application volumes, facilitating their application in the field. Biowaste OMFs were compared with peat OMFs with the same Corg-N-P2O5 concentration. Peat and MSWC were also used to create OMFs containing 7.5% Corg, 10% mineral N, and 5% mineral P2O5 (OMF10 − 5). A 75-day tunnel trial was conducted under semi-controlled conditions using tomato plants (Solanum lycopersicum L.) fertilized to an equivalent of 81 mg N kg−1 soil and 18 mg P kg−1 soil. Controls included no fertilization (N0P0) and mineral N and P fertilization (MFNP). The Soil Plant Analysis Development (SPAD) chlorophyll meter and the BBCH (from German Biologische Bundesanstalt, Bundessortenamt und CHemische Industrie) scale as well as the number of shoots were measured over time, as berry and total aboveground yield, N and P uptakes, and N and P use efficiencies (NUE and PUE, respectively) were calculated at harvest. All treatments outperformed the control N0P0 in most indicators. Peat20 − 10 did not have more berry yield than other OMF20 − 10; however, the higher number of shoots indicated a higher potential yield in the event of prolonging the experiment. At the end of 75 days, VC20 − 10 and MSWC20 − 10 showed similar PUE to peat, suggesting that those materials can be used as replacements. In the case of OMF10 − 5, MSWC10 − 5 had yield and N and P uptakes like peat OMFs, confirming the potential use of MSWC as peat replacement even at different nutrient concentrations. This research provides reassuring evidence of the effectiveness of biowaste OMFs, offering a positive outlook for sustainable agriculture. However, their use is not recommendable for short growing seasons.

Simultaneous detection of three hypoxia-inducible factor stabilizers-molidustat, roxadustat, and vadadustat-in multiple keratinized matrices and its application in a doping context.

In a doping case, a top athlete challenged an anti-doping rule violation, involving molidustat. Molidustat is a stabilizing agent of the hypoxia-inducible factor (HIF) recently developed. It is currently undergoing clinical trials for anemia associated with chronic kidney disease. HIF stabilizers are banned at all times by the World Anti-Doping Agency (class S2). Because of their pharmacological proprieties, these new drugs can enhance athletic performance. The athlete's defense wanted to analyze multiple keratinized matrices as they allow long-term investigations. Requests concerning HIF stabilizers are constantly growing. We have therefore developed a liquid chromatography coupled with tandem mass spectrometry method to identify and quantify three molecules of this class: molidustat, vadadustat, and roxadustat. Thirty milligrams of keratinized matrices were incubated in 1mL of pH8.4 diammonium hydrogen phosphate buffer for 16 h at 40°C with 1ng of testosterone-D3, used as internal standard. After extraction with ethyl acetate/diethyl ether (80/20), the organic phase was evaporated, and the dry residue was reconstituted in 30 μL of initial phase. The method was linear from 5 to 1000 pg/mg for the three analytes. Limits of quantification were 2, 0.5, and 5pg/mg for molidustat, roxadustat, and vadadustat, respectively. The analysis of the athlete's head hair (collected 1 month after the urine test) showed a concentration of molidustat of 135 pg/mg, and his beard hair and his fingernails clippings contained 55 and 40 pg/mg, respectively.

Manipulating geological phosphorus resources for improved production and environmental outcomes during plant establishment

Phosphorus (P) fertilisers are under scrutiny due to resource constraints and environmental impacts. Simple rock phosphate (RP) modifications with acids and co-applied with microbial inoculum could offer sustainable alternative P fertiliser products. We evaluated the effects of acid-treated rock phosphate (RP) in combination with fungal inoculum on plant establishment, environmental impacts (nutrient leaching) and soil quality in a 5-month pot trial. The treatments were evaluated in a clayey Vertisol and a silty Acrisol using cotton (Gossypium hirsutum) as a model plant. The RP treatments – apart from the unmodified and HCl products – were effective in promoting plant establishment with two of the microbial formulations superior to conventional P fertilisers by an average factor of 2 in both soil types (p < 0.05). All RP products restricted P leaching compared with conventional P fertilisers (p < 0.05), by an average factor of 5 for diammonium phosphate (DAP) in both soil types and 3 for the triple superphosphate TSP (only in Acrisol). Nitrate leaching from all treatments was high although much lower from the RP treatments compared with the conventional fertilisers towards the end of the establishment trial, by an average factor of 1.5 (p < 0.05). Ranking analysis revealed that some RP treatments showed evidence for improved ongoing soil quality, including decreased P leaching and soil acidification risks. Microbial analysis showed complex interactions between treatment and soil type. Nonetheless, inoculum persistence at the end of the plant establishment phase was observed for all pots analysed. Our results demonstrate that relatively simple modifications to RP could pave the way for developing sustainable P fertilisers.

An eco-friendly approach harnessing Trichoderma lixii ORT2 for reducing chemical phosphatic fertilizer dependency and groundwater phosphorus management through integrated in silico, in vitro and omic studies

Groundwater pollution has become an escalating global issue, with excessive application of phosphorus (P) fertilizers emerging as a major contaminant. The overuse of chemical phosphatic fertilizers has intensified the problem of P infiltration into water table, compromising soil health and exacerbating groundwater pollution. This underscores the urgent need to explore sustainable alternatives to chemical fertilizers to safeguard groundwater and soil health. The enzyme alkaline phosphatase (ALP) plays important role in efficient P-solubilization achieved by Trichoderma sp. a soil fungus known for its gradual transportation of P from fixed sources to plants. This mechanism not only minimizes P leaching into groundwater but also reduces dependency on fertilizers. To investigate the active role of fungal ALP in P-solubilization, amino acid/gene sequences of enzyme from 20 Trichoderma strains were retrieved from NCBI. Molecular docking revealed strong catalytic interaction (−6.93 kcal/mol) between complex-bound P and the ALP, involving two hydrogen bonds and key residues Gln286 and Arg340. To confirm ALP-mediated P-solubilization, 12 newly isolated Trichoderma spp., were assessed in vitro using media amended with tri-calcium phosphate (TCP), zinc phosphate (Zn3(PO4)2), or ferric phosphate (FePO4) as sole phosphorus source. Trichoderma lixii ORT2 demonstrated highest P-solubilization, yielding 547.40 μg/mL phosphate from TCP, 538.6 μg/mL from Zn3(PO4)2, and 423.45 μg/mL from FePO4, in 72 h. Solubilization was accompanied by simultaneous expression of ALP and siderophore in the same aliquot. TCP induced maximum expression of ALP (9.47 U/mL), followed by Zn3(PO4)2 and FePO4 showing 8.65 and 5.64 U/mL, respectively, in culture filtrates at 72h, that was further confirmed through proteomic analysis. FESEM micrographs confirmed P binding and biosorption into fungal mycelia as P-globules. Furthermore, Cicer arietinum inoculated with Trichoderma lixii ORT2 bio-formulations showed significant enhancement in growth parameters in TCP amended soil as compared to di-ammonium phosphate (DAP). The integrated approach of microbial P-solubilization and further utilization by plants for their growth as major nutrients merges microbial and phyto-remediation to address sustainability issues related to the management of soil health and phosphorus contamination. This strategy aims to substitute chemical phosphatic fertilizers, which are significant contributors to rising dissolved total phosphorus (DTP) in groundwater. This approach directly supports SDG 6 by reducing P leaching and improving groundwater quality, ensuring sustainable water and sanitation management for all.

Structural-Mechanical Modification of Amorphous Polyethylene Terephthalate and Hybrid Nanocomposite Materials Based on It

Hybrid nanocomposite materials based on polyethylene terephthalate and inorganic flame-retardant diammonium phosphate were prepared according to the fundamental strategy of environmental crazing of polymers. Structural-mechanical modification of the initial amorphous polyethylene terephthalate and the resultant nanocomposite polyethylene terephthalate-based was carried out by rolling at room temperature. The effect of preliminary rolling on the deformation behavior of polyethylene terephthalate during subsequent stretching in air and in physically active liquid media was established.

Carbon Fibers Based on Cellulose–Lignin Hybrid Filaments: Role of Dehydration Catalyst, Temperature, and Tension during Continuous Stabilization and Carbonization

Lignocellulose has served as precursor material for carbon fibers (CFs) before fossil-based polymers were discovered as superior feedstock. To date, CFs made from polyacrylonitrile have dominated the market. In search of low-cost carbon fibers for applications with medium strength requirements, cellulose and lignin, either as individual macromolecule or in combination, have re-gained interest as renewable raw material. In this study, cellulose with 30 wt% lignin was dry-jet wet-spun into a precursor filament for bio-based carbon fibers. The stabilization and carbonization conditions were first tested offline, using stationary ovens. Diammonium sulfate (DAS) and diammonium hydrogen phosphate were tested as catalysts to enhance the stabilization process. Stabilization is critical as the filaments’ strength properties drop in this phase before they rise again at higher temperatures. DAS was identified as a better option and used for subsequent trials on a continuous carbonization line. Carbon fibers with ca. 700 MPa tensile strength and 60–70 GPa tensile modulus were obtained at 1500 °C. Upon further carbonization at 1950 °C, moduli of &gt;100 GPa were achieved.

Bio-solubilization of Rock Phosphate Using Acidophilic Bacteria and Effect of Bio-Organic-Phosphate Composite on the Growth of Wheat

Acidophilic sulfur and iron oxidizing bacteria, such as Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans, play a crucial role in releasing nutrients into the soil. This study utilized a mixture of these bacteria to solubilize phosphorus from phosphate rock. Acidophilic bacteria were enriched from soil samples taken from the collection pond of a coal heap constructed for biodesulfurization studies. Rock phosphate sample was supplemented with elemental sulfur (So) and pyrite (FeS2) as energy substrates for bioleaching of phosphorus. The effect of different pulp densities of the rock phosphate on biosolubilization of phosphorus elucidated that the pulp density and rock phosphate solubilization are negatively correlated. The mixture of acidophilic microorganisms solubilized 40.76% P2O5 at 10 g/L pulp density during 30 days of leaching. A comparative study showed that a two-step process is more effective for the phosphorus leaching from rock phosphate. In pot experiments under net house conditions, the acidophilic bacterial composite increased wheat grain yield by 2% and seed phosphorus content by 3%, while reducing the need for DAP fertilizer by 20%. Treating soil with BOP (a combination of phosphate rock and acidophilic bacteria) proves to be an efficient method for converting frugally soluble phosphorus compounds into readily available forms for plants.