Elemental Phosphorus Research Articles

Respon Pertumbuhan dan Hasil Terong (Solanum melongena L.) Akibat Perbedaan Waktu Pemberian Pupuk Mikoriza

Eggplant is a horticultural crop that contains vitamins and nutrients such as vitamin A, vitamin C, potassium, phosphorus, iron, protein and carbohydrates. Optimizing eggplant productivity can be supported by the application of mycorrhizal fertilizers as a provider of phosphorus elements and maintaining soil moisture. The aim of this study was to distinguish the timing of mycorrhizal fertilizer application in supporting eggplant productivity. The treatment was divided into three, namely P1: fertilizing two weeks before planting at a dose of 5 kg/ha; P2: fertilizing one week before planting at a dose of 5 kg/ha; and P3: fertilization at planting time of 5 kg/ha. Completely randomized design with 3 replications was tested in this study. The results of the study were that mycorrhizal fertilizers on vegetative observations tended to be better on the treatment at planting time compared to the other two treatments, but on vegetative observations at plant height at the age of 21 DAT the treatment 1 week before planting turned out to be superior to the other two treatments. Generative observations tended to have better results in the treatment 1 week before planting than the treatment at planting time which tended to have lower yields where the fresh weight of the fruit only weighed 150,35 grams while the treatment 2 weeks before planting had a fresh weight of 161,35 grams . The length of the treated fruit 1 week before planting was 27,35 cm far above the treatment at planting with a length of only 24,26 cm.

Assessment of Hexavalent Chromium Accumulation of Beta Vulgaris L. Var. Cicla and the Change of Its Antibacterial Activity

ABSTRACT Hexavalent chromium (Cr(VI)) is a frequently encountered heavy metal contaminant in agricultural soil and water sources resulting from industrial and agricultural applications, traffic, and urbanization. It is the most toxic form of chromium (Cr), which causes severe health problems. The accumulation capacity of Swiss chard (Beta vulgaris L. var. cicla) for hexavalent chromium and the effect of heavy metal accumulation on the antibacterial activity of plant extracts were evaluated in a pot experiment. The soil was treated with 10 mg kg−1 hexavalent chromium, 30 days prior to planting Swiss chard seedlings. After the harvest, macro- and micronutrient elements and Cr were measured using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-OES). Moreover, plant extracts were obtained by maceration in methanol and the extracts were tested against Gram-positive and Gram-negative bacteria. Cr was found to be uptaken and accumulated with a high concentration (54.7 ± 0.23 mg kg−1) in the aerial parts (transfer factor = 74.95). Cr toxicity reduced plant development and the macronutrient elements phosphorus and potassium in Swiss chard. The micronutrient elements iron and boron were found to be significantly increased in plant upon chromium in a synergistic manner with Cr. Additionally, the antibacterial activity of the extract of Swiss chard decreased against Staphylococcus aureus and Enterococcus faecalis around 50%. Moreover, the number of culturable bacteria decreased about 40% in soil after chromium treatment. The results suggested that this plant can accumulate a high amount of Cr in its aerial parts, which may decrease the health effects of the extracts.

Analysis of the process and factors influencing microbial phosphine production.

The process of phosphine production by phosphate-reducing bacteria Pseudescherichia sp. SFM4 has been well studied. Phosphine originates from the biochemical stage of functional bacteria that synthesize pyruvate. Stirring the aggregated bacterial mass and supplying pure hydrogen could lead to an increase of 40 and 44% phosphine production, respectively. Phosphine was produced when bacterial cells agglomerated in the reactor. Extracellular polymeric substances secreted on microbial aggregates promoted the formation of phosphine due to the presence of groups containing phosphorus element. Phosphorus metabolism gene and phosphorus source analysis implied that functional bacteria used anabolic organic phosphorus, especially containing carbon-phosphorus bonds, as a source with [H] as electron donor to produce phosphine.

Effects of 24 Years Different Straw Return on Soil Carbon, Nitrogen, Phosphorus, and Extracellular Enzymatic Stoichiometry in Dryland of the Loess Plateau, China

Exploring the biogeochemical cycle characteristics of soil carbon, nitrogen, and phosphorus in farmland in the dryland of the loess plateau can provide scientific basis and technical support for efficient crop production and sustainable land use. Here, based on a long-term (24 year) straw return field experiment in Shouyang, Shanxi province, the effects of different straw return regimes, i.e., straw mulching (SM), direct straw return (DS), animal-digested straw return (AS), and non-straw return (CK), on the stoichiometric ratio of soil elements and extracellular enzyme activities were studied. The vector angle and length were calculated to indicate the resource constraints faced by microorganisms. The vector angle was greater than 45° and less than 45°, indicating that microorganisms were limited by phosphorus and nitrogen, respectively. The greater the deviation from 45°, the greater the degree of limitation, and the longer the vector length, the more severely limited by carbon. The results showed that ① the soil C/N and C/P of long-term straw returning ranged from 9.81 to 14.28 and from 14.58 to 21.92, with the mean values of 12.36 and 17.51, respectively, which were 6.0% and 4.2% lower than that at the initial stage of the experiment. The soil N/P was distributed between 1.27 and 1.57, with an average of 1.42, which was 2.2% higher than that in the initial stage. The soil C/N and C/P ratios showed a trend of first decreasing and then increasing, the soil N/P ratio basically showed a flat trend, and there was no significant difference in soil element metering ratios between different straw returning treatments. ② Compared with the 24-year long-term non-straw return treatment, the activities of β-1,4-glucosidase (BG) and β-1,4-N-acetylglucosaminidase (NAG) in the soil of the long-term straw mulching treatment increased by 134.4% and 107.5% (P<0.05), the activities of BG and alkaline phosphatase (AP) in the soil of the long-term straw mulching treatment decreased by 59.3% and 59.5% (P<0.05), respectively, and the activities of NAG in the soil of the long-term straw mulching treatment increased by 102.8% (P<0.05). Under the long-term straw returning treatment, soil microorganisms were faced with carbon and phosphorus limitation as a whole. Long-term straw mulching aggravated microbial carbon limitation, and animal-digested straw return could alleviate the degree of carbon limitation. Compared with that in the 24-year long-term non-straw return treatment, soil EEAC/N could be significantly reduced by the animal-digested straw return treatment, and soil EEAC/P could be increased by the direct straw return treatment. The three straw returning methods had no significant indigenous effect on soil EEAN/P. The overall vector angle was greater than 45°, and the vector length increased by 3.8%-20.1% compared with that in the initial stage. ③ Correlation analysis showed that C and N inputs were significantly negatively correlated with BG activity; available nitrogen was significantly correlated with NAG activity, AP activity, and EEAC/N; C/P was significantly positively correlated with EEAC/N; there were significant correlations between N/P and NAG activity, AP activity, EEAC/N, and EEAC/P; and there was no significant correlation between EEAN/P and any environmental factors. In conclusion, the availability of soil nitrogen and phosphorus elements and N/P ratio had significant effects on soil extracellular enzyme activity and stoichiometric characteristics under different long-term straw returning treatments. In the future, more attention should be paid to the improvement of organic carbon and the promotion of nitrogen and phosphorus availability in farmland soil in soil-efficient cultivation and agricultural production activities.

Nanostructured N, S, and P-Doped Elaeagnus Angustifolia Gum-Derived Porous Carbon with Electrodeposited Silver for Enhanced Electrochemical Sensing of Acetaminophen.

Acetaminophen (N-acetyl-p-aminophenol, APAP) is regularly used for antipyretic and analgesic purposes. Overdose or long-term exposure to APAP could lead to liver damage and hepatotoxicity. In this study, the approach of enhanced electrochemical detection of APAP by nanostructured biomass carbon/silver was developed. Porous biomass carbon derived from Elaeagnus Angustifolia gum was prepared by pyrolysis with co-doping of electron-rich elements of nitrogen, sulfur, and phosphorus. The electrodeposition of silver onto a glassy carbon electrode modified with porous carbon could enhance the sensing signal towards APAP. Two linear ranges from 61 nM to 500 μM were achieved with a limit of detection of 33 nM. The developed GCE sensor has good anti-interference, stability, reproducibility, and human urine sample analysis performance. The silver-enhanced biomass carbon GCE sensor extends the application of biomass carbon, and its facile preparation approach could be used in constructing disposable sensing chips in the future.

Ladder‐like cross‐linked network of epoxy resin through multi‐site interaction: Flame retardancy and mechanical properties

AbstractMost epoxy resins (EP) suffer from sacrificial mechanical properties in flame retardancy applications. Through a facile reaction between N‐aminoethylpiperazine (N‐AEP) and 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO), a novel multi‐site interaction flame retardant, DOPO‐based aminoethylpiperazine (abbreviate as AEPO), was successfully synthesized, which could form a ladder‐like cross‐linked network with EP. EP modified by AEPO (EP‐AEPO) was tested for flame retardancy using the limiting oxygen index (LOI), the vertical burning test (UL‐94), and the cone calorimeter test (CCT). According to the results, EP‐10 (EP with 10 phr of AEPO) could pass UL‐94 V‐0 rating and get a LOI value of 35.5%, the peak heat release rate (PHRR) and total heat release (THR) of EP‐10 were also decreased by 25.2% and 29.8%, respectively, which caused by the synergistic charring effect of phosphorus and nitrogen elements contained in the structure of AEPO. Due to the ladder‐like cross‐linked network formed through multi‐site interaction, the mechanical properties demonstrated a significant improved. This work opened up a new strategy for achieving a comprehensive improvement on multifunctional EP through the design of a novel ladder‐like cross‐linked network with multi‐site interaction.

Seasonal changes in the taxonomical structure and abundance of phytoplankton in the pelagial and littoral zones of Obsterno Lake

We studied the seasonal changes in the taxonomic composition and abundance of phytoplankton in the littoral and pelagial zones of Obsterno Lake. A number of important differences recorded for the littoral and pelagic zones. The abundance in the littoral zone is higher in April, August and December. In other months it is higher in the pelagic zone. In the same months, the species richness in the littoral zone is also higher. These differences were influenced by such factors as biogenic elements (nitrogen and phosphorus), as well as the temperature factor.

Synthetic nano-hydroxyapatite as an alternative phosphorus source for wheat grown under field conditions

The aim of this study was to investigate the effects of nano-hydroxyapatite (nHAP) over conventional phosphorus fertilizer in terms of phosphorus nutrition and other nutrients through which it enhances the growth of wheat plants. The experiment was carried out with wheat plants under real field conditions for two consecutive years. Under laboratory conditions, nHAP was synthesized and characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopes (SEM), and elemental dispersive X-rays (EDX). The substance we synthesized according to the characterization tests mentioned here is nano-hydroxyapatite. The application of nHAP was carried out at decreasing rates (80, 60, 40 kg P2O5 ha−1) before sowing, and their effects were compared with 80 kg P2O5 ha−1 diammonium phosphate (DAP) as a reference treatment. Phosphorus and other mineral element concentrations were determined in all plant samples taken at the beginning of the booting stage. In addition, grain samples were taken at harvest. In the nHAP treatment, the plants’ phosphorus, nitrogen and potassium concentrations increased by approximately 25%, 17% and 10%, respectively. This was compared to the DAP treatment. The concentrations of iron and zinc in grain also increased by 46% and 15%, respectively. These increases in grains are particularly noteworthy for biofortification studies. In conclusion, nHAP can be an alternative to conventional fertilizers by reducing phosphorus consumption. However, more studies are required on different plants and long-term field studies regarding the uptake, translocation and interactions of nHAP with other elements.

One-Step Multifunctionalization of Flax Fabrics for Simultaneous Flame-Retardant and Hydro-Oleophobic Properties Using Radiation-Induced Graft Polymerization.

This study concerns the one-step radiografting of flax fabrics with phosphonated and fluorinated polymer chains using (meth)acrylic monomers: dimethyl(methacryloxy)methyl phosphonate (MAPC1), 2-(perfluorobutyl)ethyl methacrylate (M4), 1H,1H,2H,2H-perfluorooctyl acrylate (AC6) and 1H,1H,2H,2H-perfluorodecyl methacrylate (M8). The multifunctionalization of flax fabrics using a pre-irradiation procedure at 20 and 100 kGy allows simultaneously providing them with flame retardancy and hydro- and oleophobicity properties. The successful grafting of flax fibers is first confirmed by FTIR spectroscopy. The morphology of the treated fabrics, the regioselectivity of grafting and the distribution of the fluorine and phosphorus elements are assessed by scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (SEM-EDX). The flame retardancy is evaluated using pyrolysis combustion flow calorimetry (PCFC) and cone calorimetry. The hydro- and oleophobicity and water repellency of the treated fabrics is established by contact angle and sliding angle measurements, respectively. The grafting treatment of flax irradiated at 100 KGy, using M8 and MAPC1 monomers (50:50) for 24 h, allows achieving fluorine and phosphorus contents of 8.04 wt% and 0.77 wt%, respectively. The modified fabrics display excellent hydro-oleophobic and flame-retardant properties with water and diiodomethane contact angles of 151° and 131°, respectively, and a large decrease in peak of heat release rate (pHRR) compared to pristine flax (from 230 W/g to 53 W/g). Relevant results are also obtained for M4 and AC6 monomers in combination with MAPC1. For the flame retardancy feature, the presence of fluorinated groups does not disturb the effect of phosphorus.

Unlocking Deep and Fast Potassium-Ion Storage through Phosphorus Heterostructure.

Potassium-ion battery represents a promising alternative of conventional lithium-ion batteries in sustainable and grid-scale energy storage. Among various anode materials, elemental phosphorus (P) has been actively pursued owing to the ideal natural abundance, theoretical capacity, and electrode potential. However, the sluggish redox kinetics of elemental P has hindered fast and deep potassiation process toward the formation of final potassiation product (K3 P), which leads to inferior reversible capacity and rate performance. Here, it is shown that rational design on black/red P heterostructure can significantly improve K-ion adsorption, injection and immigration, thus for the first time unlocking K3 P as the reversible potassiation product for elemental P anodes. Density functional theory calculations reveal the fast adsorption and diffusion kinetics of K-ion at the heterostructure interface, which delivers a highly reversible specific capacity of 923 mAh g-1 at 0.05 A g-1 , excellent rate capability (335 mAh g-1 at 1 A g-1 ), and cycling performance (83.3% capacity retention at 0.8 A g-1 after 300 cycles). These results can unlock other sluggish and irreversible battery chemistries toward sustainable and high-performing energy storage.

Threads of microbial activity on quasi-anoxic environments: Case studies from Oligocene to Miocene of the Central Paratethys

Microbial activity can be expressed in a wide range of products and forms including boring structures, biofilm-like subproducts, and framboidal pyrite precipitates. Microendolithic structures, in particular, are found in carbonate hardgrounds including tests of planktonic and benthic foraminifera and their traces can provide an extra paleoenvironmental marker of relative paleobathymetry, oxygenation, and environmental stress. Variegated traces of microbial activity including microborings, framboidal pyrite bacterial subproducts, and probable biofilms were herein studied in tests of benthic foraminifera from dysphotic to aphotic, shelf to an upper bathyal hypoxic environment. Collected material is from 6 localities in the Central Paratethys area, the Czech Republic (LOM-1 Mikulov, Hevlín), Slovakia (DNV, LKŠ-1), and Hungary (Rozalia), ranging from Rupelian to Serravalian. Microendolithic morphology was examined from resin casts obtained from the tests resulting in a total of ten ichnospecies and four other forms for which it was only possible to establish affinity on higher ranks. Levels of oxygen depletion were estimated from Benthic Foraminifera Oxygen index (BFOI). The bacterial origin of pyrite was inferred by morphology, grain size, and ẟS34 values. The number of observed microboring structures gradually reduce with the decrease of oxygen content, while the precipitation of framboidal pyrite were increasing at the same time. Biofilm-like structures, apart from the suggestive morphology, also showed an enriched content of elemental iron, sulfur, and phosphorus. Raman spectroscopy shows similarities with organic pigment spectra and is still under investigation.

STUDY OF THE INFLUENCE OF ENVIRONMENTAL FACTORS ON THE GROWTH AND DEVELOPMENT OF THE INSECT SPECIES HERMETIA ILLUCENS (BLACK SOLDIER FLY)

Background. The problem of agricultural waste disposal is currently very relevant. In the Russian Federation, the agro-industrial complex annually produces hundreds of millions of tons of waste that must be disposed of and used rationally. Organic waste from agricultural production and farm animal manure can be effectively disposed of using directed microbiological fermentation and larvae of the insect Hermetia illucens (black soldier fly). As a result of the activity of the enzyme system of black lion larvae and specific microflora, agricultural waste turns into zoohumus with a high content of nitrogen, phosphorus, potassium and trace elements, which can be used as an organic fertilizer that improves the quality of the soil, and the biomass of larvae for animal feed and for obtaining protein concentrate and fat.&#x0D; Purpose. To determine the optimal temperature conditions for the cultivation of the insect species Hermetia illucens (black soldier fly) on various types of substrates, to study the effect of the substrate composition on the production of larval biomass, protein concentrate and fat.&#x0D; Materials and Methods. The research work was carried out in the microbiological laboratory of the Center for Technological Excellence “Advanced Chemical and Biotechnology”, laboratories of the Department of Biology and Technologies of Living Systems, Faculty of Natural Sciences of the Tula State Pedagogical University named after L. N. Tolstoy and insectaria LLC “Lvinka”.&#x0D; To study the effect of the feed composition on the growth and development of the larvae of the insect species Hermetia illucens, substrates from various agricultural, food and animal waste were used. To determine the influence of temperature and humidity on the development of larvae, thermostats and insectarium rooms were used.&#x0D; Results. The study of the effect of various solid organic waste on the biomass of live and dried larvae showed that the larvae of the insect H. illucens grew and developed better on food waste consisting of meat and fish waste, as well as plant food waste. Larvae developed worse on plant residues. This is due to the fact that these wastes contain a large amount of cellulose and much less nutrients in their composition, therefore, on a substrate of this composition, the larvae gained biomass worse. The optimal temperature for the cultivation of insect larvae of the species H. illucens is t-22°C. The ratio of protein and fat in the larvae of the insect H. illucens depends on the composition of the feed. In those types of feed where protein predominates, the content of this component in the larvae is high. For example, when using food meat waste, the content of protein concentrate reaches 595 g/kg, fat only 323 g/ kg, and when using vegetable waste containing a large amount of carbohydrates, more fat and less protein are produced.&#x0D; Concisions. As a result of the research work carried out, it was possible to study the influence of environmental factors on the growth and development of the insect species H. illucens (black soldier fly), and to select favorable conditions for the development of larval biomass. Optimal substrates were selected for the cultivation of larvae of the insect species H. illucens. The most suitable substrates for the production of protein concentrate and fat were also determined.

Characterization of young biofilm morphology, disinfection byproduct formation potential and toxicity of renewed water supply pipelines by phosphorus release from corroded pipes

The deterioration of drinking water quality due to corrosion of the water supply network has become inevitable and regular renewal of pipes has become a common means of doing so. Severely corroded pipes release certain nutrients (e.g., elemental phosphorus), however, little has been reported on the effect of old pipes on the young biofilm of new pipe sections and on ensuring water safety in the early stages of the water supply. The aim of our study was to model the effect of key phosphorus nutrients released from corroded old pipes on the morphological characteristics of young biofilms in new pipe sections, mediated disinfection byproducts (DBPs) production and their combined toxicity. Based on the experimental results, phosphorus showed significant differences in the morphological characteristics, spatial structure of extracellular polymers (EPS), functional abundance, disinfection byproduct formation potential (DBPsFP) and toxicity of young biofilms. Under residual chlorine (1.0 ± 0.2 mg/L) incubation, the functional abundance of young biofilm metabolism was dominant, particularly amino acid metabolism and carbohydrate metabolism. There is a dynamic balance between the trophic and shedding effects of phosphorus, where concentration changes affect young biofilm morphology and DBPFP. Relatively moderate phosphorus concentrations resulted in the highest density of PN/PS organic precursors in EPS and a clear advantage of DBPFP; relatively high phosphorus conditions had limited promotion of young biofilm, while membrane structure shedding was more pronounced, increasing young biofilm-mediated DBPs production. Nitrogen-containing disinfection byproducts (N-DBPs) in young biofilms had a clear toxicity advantage, with HANs and HNMs being key to controlling cytotoxicity and genotoxicity, respectively.

A comparative study of dietary lipid sources on growth performance, body composition, fillet quality, and nutrient retention in juvenile yellow drum (Nibea albiflora)

Vegetable oils (VOs) are promising alternatives for fish oil (FO) in the aquafeed industry. However, high dietary VOs lead to undesirable effects on fish growth performance and health, but little information is known about VOs on fillet quality and nutrient retention. This study compared the impacts of different VOs on fish growth performance, fillet quality, and nutrient retention in juvenile yellow drums (Nibea albiflora). The FO group was used as the control (containing 6% FO), and the other four diets had the same lipid content with 5% FO was substituted by different VOs(soybean oil [SO], linseed oil [LO] rapeseed oil [RO], and palm oil [PO]). Juvenile fish (initial body weight of 5.55 ± 0.02 g) were fed the respective diets for 56 days. Results indicated the replacement of FO by VOs was feasible without affecting the growth performance, body composition, or serum biochemicals. The SO diet significantly increased fillet yield and fillet calcium (Ca) and phosphorus (P) element contents. The PO diet reduced water-holding capacity, and altered fillet texture, but significantly increased fillet n-3 LC-PUFAs retention. This could be attributed to the preferential oxidation of SFAs therefore selectively retained DHA in the fillet. Fillet transcriptome sequencing analysis revealed that compared with the FO group, the upregulated mRNA levels of lipid transport-related genes were found in the SO (fabp4, and cd36) and PO (fabp4, cd36, lcat, acbp, and cav1)groups, whereas lipid synthesis-related (acss, elovl4, acsbg, acsl, and elovl1) and lipolysis-related genes (mgll, hsl, acaa1, abhd5, decr1, acad9, pparα, and cpt1) expression were upregulated in the RO and PO groups, respectively. Weighted gene co-expression network analysis clustered two coexpression modules. One module was significantly and positively correlated with fillet yield (P = 0.01, R = 0.64) and Ca element retention (P = 0.05, R = 0.51), and contained genes related to fillet development (eno3 and tnnt3) and Ca regulation (dhrs7c, mcam, and ocam). The other module included genes related to lipid metabolism (elovl1, scd, tecr, fbn1, thbs1, and mdh1), which was associated with fillet n-3 LC-PUFAs retention. Collectively, these findings demonstrated that SO, LO, RO, and PO can be utilized as alternative lipid sources for FO. Based on transcriptome analysis results, genes related to fillet development, Ca regulation, and lipid metabolism were highlighted. These findings help to understand the relationship between dietary lipid sources and fillet nutrient retention in marine carnivorous fish species.

Contrasting global patterns and trait controls of major mineral elements in leaf

AbstractAimMultiple mineral elements in leaf are the foundation of plant life and regulate many ecosystem functions. However, whether a common mechanism governs the variations of all leaf mineral elements is still unknown.LocationGlobal.Time period1970–2020. 10.Major taxa studied: Plants.MethodsHere, we demonstrate the global‐scale biogeographic patterns of 12 major mineral elements (nitrogen, phosphorus, potassium, calcium, magnesium, sulphur, aluminium, iron, manganese, sodium, zinc and copper) by compiling a global data set including 2710 records of leaf mineral elements for 1073 species and of associated climate and soil indices.ResultsIn general, like nitrogen and phosphorus, elements including potassium, calcium, magnesium, sodium and copper in leaf declined towards the equator, which supported both plant physiological hypothesis and soil substrate age hypotheses developed on the basis of nitrogen and phosphorus. By contrast, other elements responded to latitude in a contrary manner as nitrogen and phosphorus, in line with a competing mechanism, temperature–biogeochemistry hypothesis. Besides, plant functional types intrinsically differed in mineral concentrations, and to a certain extent, shifts of their composition in turn exacerbated the latitudinal patterns of respective elements as predicted by the species composition hypothesis.Main conclusionsThe fundamentally different dynamics and control mechanisms of patterns of some elements compared with those of nitrogen and phosphorus challenge the idea that common hypotheses can predict biogeographic patterns across all mineral elements; thus, current paradigms of element biogeochemical models and ecological plant nutrition require revision.

Synthesis and Properties of Sulfur-Containing Organophosphorus Extractants Based on Red Phosphorus, Alkyl Bromides, and Elemental Sulfur.

In order to obtain sulfur-containing organophosphorus compounds that are promising as extractants of heavy metals, the interaction of elemental phosphorus and sulfur with alkyl bromides catalyzed using strong bases was studied. According to the task, the reaction of non-toxic and non-flammable red phosphorus with alkyl bromides under conditions of phase transfer catalysts (PTC), followed by the introduction of elemental sulfur into the reaction medium, were studied. It is shown that alkyl bromides interact with red phosphorus when heated (95-105 °C, 5-8 h) under conditions of phase transfer catalysts (PTC) in a two-phase system: a 60% aqueous solution of KOH-toluene-benzyltriethylammonium chloride (BTEAC) forming a mixture of organophosphorus compounds along with alkylphosphines (57-60%), are the main reaction products; alkylphosphine oxides are also formed (40-43%). The introduction of elemental sulfur (solution in toluene) at the final stage of the process into the reaction mass cooled to 40-60 °C leads to the expected alkylphosphine sulfides, which are the result of the interaction of alkylphosphines with sulfur. The formation of complex mixtures of products prevents the release of target alkylphosphine sulfides in individual form. However, the synthesized mixture of alkylphosphine sulfides and alkylphosphine oxides without separation into individual components is promising for studying its extraction properties in relation to heavy metals. Testing of the extraction properties of synthesized mixtures of alkylphosphine sulfides and alkylphosphine oxides in relation to heavy metals (Ni, Co, Zn, Pb) and noble metals (Ag) showed that the resulting mixtures of tertiary phosphine oxides and phosphine sulfides are highly effective extractants. The degree of extraction in relation to Ni, Co, Zn, and Pb varies from 99.90 to 99.99%, and for Ag from 99.56 to 99.59%.

Clindamycin-Loaded Nanosized Calcium Phosphates Powders as a Carrier of Active Substances.

Bioactive calcium phosphate ceramics (CaPs) are one of the building components of the inorganic part of bones. Synthetic CaPs are frequently used as materials for filling bone defects in the form of pastes or composites; however, their porous structure allows modification with active substances and, thus, subsequent use as a drug carrier for the controlled release of active substances. In this study, four different ceramic powders were compared: commercial hydroxyapatite (HA), TCP, brushite, as well as HA obtained by wet precipitation methods. The ceramic powders were subjected to physicochemical analysis, including FTIR, XRD, and determination of Ca/P molar ratio or porosity. These techniques confirmed that the materials were phase-pure, and the molar ratios of calcium and phosphorus elements were in accordance with the literature. This confirmed the validity of the selected synthesis methods. CaPs were then modified with the antibiotic clindamycin. Drug release was determined on HPLC, and antimicrobial properties were tested against Staphylococcus aureus. The specific surface area of the ceramic has been demonstrated to be a factor in drug release efficiency.

Estonian Phosphate Rock Dissolution in Hydrochloric Acid: Optimization of Acid Dosage and Concentration

The increasing need for phosphorus and rare earth elements (REEs) has initiated the studies of new mineral deposits and new complex processing technologies. Estonian phosphate rock (EPR) resources, which are not in use, are estimated to be more than 3 billion metric tons or 800 million tons of P2O5. The experiments of dissolution of three different EPR samples in hydrochloric acid were carried out with the aim of studying the impact of the chemical and mineralogical composition of EPR on the leaching process. The leaching of P, Ca, Mg, and consumption of H+ ions depend on HCl concentration and dosage. The solubility of fluorine and REEs are also influenced by CaF2 and REEs-phosphates precipitation. Fe solubility depends on the mineralogical composition of EPR but also on particle size, acid dosage, pH, and phosphorus content in the solution. The dissolution of pyrite is much lower than the solubility of carbonate apatite. Dolomite dissolution depends on the acid dosage and the fractional composition of EPR. Dolomite dissolution also rests lower than that of apatite. For all the samples studied, the best regression models that describe P, Mg, and Ca solubility and the optimum concentration of HCl for phosphorus dissolution were found using mathematical modeling.

Formation of a P162- Ink from Elemental Red Phosphorus in a Thiol-Amine Mixture.

A P162- polyphosphide dianion ink was produced by the reaction of red phosphorus with a binary thiol-amine mixture of ethanethiol (ET) and ethylenediamine (en). The polyphosphide was identified by solution 31P NMR spectroscopy and electrospray ionization mass spectrometry. This solute was compared to the reaction products of white phosphorus (P4) and other elemental pnictides in the same solvent system. The reaction of P4 with ET and en gives the same P162- polyphosphide; however, the easier handling and lower reactivity of red phosphorus highlights the novelty of that reaction. Elemental arsenic and antimony both give mononuclear pnictogen-sulfide-thiolate complexes upon reaction with ET and en under otherwise identical conditions, with this difference likely resulting from the greater covalency and tendency of phosphorus to form P-P bonds.

Effects of Phosphorus Addition on the Hydrophobicity and Catalytic Performance in Methane Combustion of θ-Al2O3 Supported Pd Catalysts

A series of xPθ-Al2O3 supports modified with different amounts of phosphorus element were prepared and taken as supports of palladium catalysts for methane catalytic combustion. The impacts of phosphorus additives on the hydrophobicity of Pd/xPθ-Al2O3 and its performance of methane catalytic combustion in the absence of and presence of 8% water were systematically studied. It was found that the hydrophobicity of xPθ-Al2O3 changed with the increase of phosphorus content, which had a significant effect on the activity of methane catalytic combustion. The incorporation of phosphorus replaced the hydroxyl groups on the surface of Al2O3 in the form of phosphates, thus changing the density of hydroxyl groups of Al2O3 support. TGA, NH3-TPD, IR, and XPS were employed to illustrate the process of phosphate replacement. xPθ-Al2O3 with less than 1 wt.% phosphorus content had better hydrophobicity than the unmodified θ-Al2O3 and Pd/xPθ-Al2O3, therefore had better performance for methane catalytic combustion, which was attributed to the substitution of hydroxyl groups on the surface of θ-Al2O3 by PO43− and HPO42−. However, when the phosphorus content of Al2O3 was higher than 1 wt.%, the substitution of H2PO4− began to dominate, which would lead to poorer hydrophobicity and catalytic performance. This work will guide the design of methane catalytic combustion catalysts resistant to water inhibition problem.