Commercial Phosphorus Research Articles

Leather Waste Hydrolysation, Carbonization, and Microbial Treatment for Nitrogen Recovery by Ryegrass Cultivation.

Leather waste contains up to 10% nitrogen (N); thus, combustion or gasification only for the energy recovery would not be rational, if safety standards are met. On the other hand, the chromium (Cr) content exceeding 5% in half of the waste stream (w/w) is too significant to be applied in agriculture. In this work, four acid hydrolysates from leather waste shavings, both wet-white free of Cr and wet-blue with Cr, were used: two with a mixture of acids and supplemented with Cu, Mn, and Zn, and the other two as semi-products from collagen extraction using hydrochloric acid. Additionally wet-green leather waste shavings, e.g., impregnated with olive extract, were used followed by the two treatments: amendment with a biochar from "wet white" leather waste shavings and amendment with this biochar incubated with the commercial phosphorus stimulating microbial consortia BactoFos. They were applied as organic nitrogen-based fertilizers in a glasshouse experiment, consisting of 4-5 subsequent harvests every 30 days, under spring-autumn conditions in northern Poland. Biochar-amended wet-greens provided the highest nitrogen use efficiencies, exceeding 100% after 4 months of growth (for 20 kg N/ha) and varying from 17% to 37% in particular months. This is backed up by another parameter (relative agronomic effectiveness) that for these materials exceeded 150% for a single month and in total was around 33%. Biochar amendments significantly increased agronomic parameters for wet-greens, and their microbial treatment enhanced them even further. Recycling this type of waste can replace inorganic fertilizers, reducing greenhouse gas emissions and carbon footprint.

Phosphorus‑carbon based hybrid electrodes for sodium ion batteries

In this study, commercial phosphorus powders were first subjected to mechanical ball-milling at varying times and reinforced with graphene oxide and multiwall carbon nanotubes to improve their electrochemical performances. All these processes were carried out by ball milling method to provide mechanical alloying of phosphorus. Subsequently, the crystallinity of the samples was analyzed by X-ray diffraction method, while the morphology of the samples was examined by field emission scanning electron microscopy. The main obstacles that inhibit the reversibility and the cyclic stability of red phosphorus are low electronic conductivity and huge volumetric expansion. Reinforcing amorphized phosphorous with multi-walled carbon nanotube and graphene oxide composites has presented similar initial capacity of 2100 mAh g−1. In addition, reversible capacity of multi-walled carbon nanotube and graphene oxide reinforced samples presented 370 mAh g−1 and 507 mAh g−1 after 250 cycles, respectively. Our results have shown that graphene oxide reinforced composites could be an alternative electrode material for sodium ion battery applications.

The cryoprotective activity of tilapia skin collagen hydrolysate and the structure elucidation of its antifreeze peptide

Antifreeze peptides from fish byproducts have the potential to act as suitable and safe cryoprotectants, replacing synthetic additives currently utilized in the food industry. The main focus of this study was to explore the cryoprotective activity of antifreeze peptides from collagen hydrolysate of tilapia (Oreochromis niloticus) skin and deduce the relationship between its physio-chemical characteristics and antifreeze activity. Our results showed that the antifreeze peptides from tilapia skin collagen hydrolysate (TSCP) by alcalase had a lower molecular weight of <2500 Da, higher content of hydrophilic amino acids, and thermal hysteresis activity was 0.50 °C. TSCP33, the identified novel cryoprotectant peptide with a molecular weight of 454.26 Da, and the amino acid sequence -NHGK showed remarkable thermal hysteresis activity (THA) of 2.63 °C. Frozen scallop muscles treated with 3 g/100g TSCP exhibited higher salt soluble protein concentration, total sulfhydryl content, Ca2+-ATPase activity, and water-holding capacity during the 8 weeks storage period. The cryoprotective effect of 3 g/100g TSCP was equivalent to that of the commercial phosphorus antifreeze. Our findings provide a theoretical basis for developing safe peptide-based cryoprotectants which will maintain and improve the quality of frozen foods.

Stabilized Molecular Diphosphorus Pentoxide, P2O5L2 (L = N-Donor Base), in the Synthesis of Condensed Phosphate–Organic Molecule Conjugates

Commercial phosphorus pentoxide reacts with some N-donor bases to give the adducts P2O5L2 and P4O10L3 (L = DABCO, pyridine, 4-tert-butylpyridine). The DABCO adducts were structurally characterized by single-crystal X-ray diffraction. It is proposed that P2O5L2 and P4O10L3 undergo interconversion through a "phosphate-walk" mechanism, which was evaluated using DFT calculations. P2O5(pyridine)2 (1) efficiently transfers monomeric diphosphorus pentoxide to phosphorus oxyanion nucleophiles, yielding substituted trimetaphosphates and cyclo-phosphonate-diphosphates (P3O8R)2- (R1 = nucleosidyl, phosphoryl, alkyl, aryl, vinyl, alkynyl, H, F). Hydrolytic ring-opening of these compounds forms linear derivatives [R1(PO3)2PO3H]3-, and nucleophilic ring-opening gives linear disubstituted [R1(PO3)2PO2R2]3- compounds.

The Extended Effect of Top-Dressed Recovered Struvite Fertiliser on Residual Irish Grassland Soil Phosphorus Levels Compared to Commercial Phosphorus Fertiliser

Phosphorus (P) is an essential growth-limiting nutrient that cannot be synthetically produced. Mineral P fertilisers are typically applied to crops to sustain modern farming practice and food production. These fertilisers are generally derived from finite phosphate ore, for which there is much concern over long-term sustainability. To address these concerns, various technologies have been developed to recover P from municipal wastewater treatment plants. One product recovered from these processes is struvite, which is a precipitate formed of magnesium, ammonium, and phosphate. To analyse the fertilisation value of the recovered struvite, field trials were conducted on perennial ryegrass (Lolium perenne) over three growing seasons, analysing the dry matter yield of recovered struvite fertiliser. The trial was based on a three-crop silage system designed to mimic typical Irish agricultural practice. This research highlights that recovered struvite as a fertiliser provides additional benefits including increasing the soil P levels. The struvite test case produced a statistically significantly increased soil P level from the baseline of Morgan’s extractable P content of 6.4 mg/L to the optimum Morgan’s soil P level of 11.13 mg/L. The findings of this research provide insight into the added benefits of recovered struvite fertiliser as a sustainable renewable P fertiliser.

Solution-Doped Polysilicon Passivating Contacts for Silicon Solar Cells.

In this work, we present a simple and efficient solution-doping process for preparing high-quality polycrystalline silicon (poly-Si)-based passivating contacts. Commercial phosphorus or boron-doping solutions are spin-coated on crystalline silicon (c-Si) wafers that feature SiO2/poly-Si layers; the doping process is then activated by thermal annealing at high temperatures in a nitrogen atmosphere. With optimized n- and p-type solution doping and thermal annealing, n- and p-type poly-Si passivating contacts featuring simultaneously a low contact recombination parameter (J0c) of 2.4 and 12 fA/cm2 and a low contact resistivity (ρc) of 29 and 20 mΩ·cm2 are achieved, respectively. Taking advantage of the single-sided nature of these solution-doping processes, c-Si solar cells with poly-Si passivating contacts of opposite polarity on the respective wafer surfaces are fabricated using a simple coannealing process, achieving the best power conversion efficiency (PCE) of 18.5% on a planar substrate. Overall, the solution-doping method is demonstrated to be a simple and promising alternative to gas/ion implantation doping for poly-Si passivating-contact manufacturing.

An initial screening of commercial phosphorus ligands on the recovery of metal ions from red mud

Abstract The manufacturing of alumina from bauxite through the Bayer process generates a large amount of highly alkaline waste called bauxite residue or “Red mud”. The annual generation of bauxite residue throughout the world is around 120 million tons and 2.7 billion tons of it has already been stockpiled. Methods for large scale remediation of red mud are an active area of interest around the world. One of the prime challenges to overcome is to ensure that the remediation process is economically feasible. Red mud is a potential source for various metal oxides (oxides of Al, Fe, Ti, Si, Ca, Na and Mg) and many valuable metal ions (including rare earth and transition metals). Out of the mixture of metal ions rare earth (RE) elements are the most economically and strategically important component. The remediation process can be made economical if the rare earth portion of the mixture can be effectively separated into a product. An economically viable process was developed by the authors for the recovery of scandium as Sc2O3 from Jamaican red mud. Even though the developed process was profitable, since the amount of scandium is too low in the red mud the process couldn’t resolve the remediation in terms of large volume waste management. Herein we are reporting an initial study conducted to develop a solvent extraction method for the selective recovery of the large volume elements as well as the critically important rare earth elements by using commercially available phosphorus ligands from simulated waste liquor.

Identifying barriers and opportunities for a circular phosphorus economy in the Baltic Sea region

Phosphorus (P) is one of the essential elements needed for global food security. However, the phosphate life cycle is currently predominantly linear, from P-rock mining to fertiliser production, agriculture, and food consumption, with the P excess ending up in soil and runoff. Eutrophication coupled with limited global commercial phosphorus reserves call for increased efforts toward creating a circular economy for P in many populated drainage basins such as the Baltic Sea region. To identify barriers and opportunities for such a transition, we employ an analytical framework that merges an innovation systems perspective with elements from the socio-technical transitions literature. Combining a literature review with key informant interviews, we find that lack of appropriate policy steering and insufficient knowledge on the performance of technologies for reuse remain key obstacles for closing the P loop. There are, however, structural opportunities presented by the new EU Fertilising Products Regulation that are likely to level the playing field between conventional and waste-derived fertilisers and thereby improve the market opportunities for recovered P. However, the system currently appears to be moving towards a narrow focus on a few new technologies for P recovery and reuse which could lead to new lock-ins. Solutions need to address users’ acceptability of the technologies and waste-derived products while the vision of a circular economy needs to be better articulated through government interventions to capture environmental externalities of phosphate mining. The paper further highlights knowledge gaps and proposes recommendations for policy and research related to the circular economy of P.

Improvement in phosphorus nutrition of wheat plants grown in a calcareous sandy soil by incorporating chemical phosphorus fertilizer with some selected organic substances

Established fertilizer recommendations for wheat is urgently required to enhance the application efficiency of commercial phosphorus (P) fertilizers. This study evaluated the effect of inorganic P combined with some organic supplements i.e., citric acid (CA) or pigeon manure juice (PMJ), on alkaline-calcareous soil as well as plant measurements and phosphorus efficiency parameters of wheat (Triticum durum ’Boussalem’). Different concentrations of P in solution i.e., 0.05, 0.10, 0.15, 0.20, and 0.40 mg l−1, were worked out theoretically using the Freundlich model. A greenhouse study was conducted on a permanent layout with three replicates. As a result, phosphorus in the control was 0.493 mg P pot−1. However, in amended pots with organic substances, the averages of P uptake were 0.701 and 0.785 mg P pot−1, respectively for PMJ and CA treatments. A lower P requirement of 0.195 and 0.245 mg P l−1 may be required in CA and PMJ treatments, compared to the control treatments (0.345 mg P l−1). In addition, the phosphorus absorption efficiency (PAE) was higher in the CA and PMJ treatments. So, it is recommended to apply P fertilizers with poultry manure juice as an alternative solution in order to improve the efficiency of inorganic P fertilizers and consequently reduce their application rates in alkaline calcareous soils.

Modeling Global Trade in Phosphate Rock within a Partial Equilibrium Framework

Against the background of combined population and consumption growth, the global sustainable development agenda foresees limits to the expansion of agricultural land. The application of fertilizer is necessary to replenish soil nutrients and keep crop yields high. Phosphate rock (PR) is the main raw material for the production of commercial phosphorus fertilizers. The international PR market is highly concentrated in terms of reserves and supply: a few countries export the major share of all PR traded globally. As many countries are highly dependent on phosphorus import, the modeling of international PR trade and thus exploration of what-if scenarios is of great interest. For modeling purposes, we employ the partial equilibrium framework. The model is driven by a subset of the United Nations (UN) Comtrade database at a yearly time step spanning the period 1997–2016. The only inputs to the model are slope coefficients of demand–supply curves. The transportation costs are internalized by creating a costs ensemble on the basis of historical data. While reasonably sensitive to its inputs, the model fits very well to reported global annual traded quantities and prices and considerably improves per-trade-partner quantity estimates as compared to simple period-averaging approaches. This is the first application of a partial equilibrium approach to global PR market modeling, including validation.

Selective extraction of In(III), Ga(III) and Zn(II) using a novel extractant with phenylphosphinic acid

A new extractant, [N,N-di(2-ethylhexyl)amino]methylphenylphosphinic acid (DEAPP), was synthesized to develop the mutual separation techniques of In(III), Ga(III) and Zn(II). The extraction selectivity for In(III), Ga(III) and Zn(II) with DEAPP was higher than that of the commercial phosphorus acid extractants such as D2EHPA and PC-88A. The extraction selectivity for metal ions in 1mol·L−1 aqueous ammonium nitrate solution with DEAPP was in the following order: In(III)>Ga(III)>Zn(II). These selective extraction behaviors indicate that the amino moiety of DEAPP plays an important role in the mutual separation of In(III), Ga(III) and Zn(II). The extraction equilibria of In(III), Ga(III) and Zn(II) with DEAPP (=HR) were expressed by the following reactions: In3++2HR¯2⇋InR3HR¯+3H+, Ga3++1.5HR¯2+NO3−⇋GaR2HRNO3¯+2H+, and Zn2++2HR¯2⇋ZnR2HR¯2+2H+. The extraction equilibrium constants of In(III), Ga(III) and Zn(II) with DEAPP were determined to be Kex,M=1.7×104 [dm3·mol−1], 4.17 [(dm3·mol−1)0.5], and 1.55 x 10−2 [–], respectively.

Advanced treatment of swine wastewater using an agent synthesized from amorphous silica and hydrated lime

Advanced treatment using an agent synthesized from amorphous silica and hydrated lime (M-CSH-lime) was developed and applied to swine wastewater treatment. Biologically treated wastewater and M-CSH-lime (approximately 6 w/v% slurry) were fed continuously into a column-shaped reactor from its bottom. Accumulated M-CSH-lime gradually formed a bed layer. The influent permeated this layer and contacted the M-CSH-lime, and the treatment reaction progressed. Treated liquid overflowing from the top of the reactor was neutralized with CO2 gas bubbling. The colour removal rate approximately exceeded 50% with M-CSH-lime addition rates of>0.15 w/v%. The removal rate of exceeded 80% with the addition of>0.03 w/v% of M-CSH-lime. The removal rates of coliform bacteria and Escherichia coli exceeded 99.9% with>0.1 w/v%. Accumulated M-CSH-lime in the reactor was periodically withdrawn from the upper part of the bed layer. The content of citric-acid-soluble P2O5 in the recovered matter was>15% when the weight ratio of influent to added M-CSH-lime was>0.15. This content was comparable with commercial phosphorus fertilizer. The inhibitory effect of recovered M-CSH-lime on germination and growth of leafy vegetable komatsuna (Brassica rapa var. perviridis) was evaluated by an experiment using the Neubauer's pot. The recovered M-CSH-lime had no negative effect on germination and growth. These results suggest that advanced water treatment with M-CSH-lime was effective for simultaneous removal of colour, and coliform bacteria at an addition rate of 0.03–0.15 w/v%, and that the recovered M-CSH-lime would be suitable as phosphorus fertilizer.

Startup of the First Commercial Phosphorus Recycling Facility in the US at Durham AWWTP

Startup of the First Commercial Phosphorus Recycling Facility in the US at Durham AWWTP

Molybdenum limitation of asymbiotic nitrogen fixation in tropical forest soils

Biological nitrogen fixation limits plant growth and carbon exchange at local to global scales. Long-term nutrient manipulation experiments in forests and short-term manipulation experiments in microcosms suggest that the micronutrient molybdenum, a component of the nitrogen-fixing enzyme nitrogenase, limits nitrogen fixation by asymbiotic bacteria in tropical soils in Panama. Nitrogen fixation, the biological conversion of di-nitrogen to plant-available ammonium, is the primary natural input of nitrogen to ecosystems1, and influences plant growth and carbon exchange at local to global scales2,3,4,5,6. The role of this process in tropical forests is of particular concern, as these ecosystems harbour abundant nitrogen-fixing organisms1,4 and represent one third of terrestrial primary production4,7,8. Here we show that the micronutrient molybdenum, a cofactor in the nitrogen-fixing enzyme nitrogenase, limits nitrogen fixation by free-living heterotrophic bacteria in soils of lowland Panamanian forests. We measured the fixation response to long-term nutrient manipulations in intact forests, and to short-term manipulations in soil microcosms. Nitrogen fixation increased sharply in treatments of molybdenum alone, in micronutrient treatments that included molybdenum by design and in treatments with commercial phosphorus fertilizer, in which molybdenum was a ‘hidden’ contaminant. Fixation did not respond to additions of phosphorus that were not contaminated by molybdenum. Our findings show that molybdenum alone can limit asymbiotic nitrogen fixation in tropical forests and raise new questions about the role of molybdenum and phosphorus in the tropical nitrogen cycle. We suggest that molybdenum limitation may be common in highly weathered acidic soils, and may constrain the ability of some forests to acquire new nitrogen in response to CO2 fertilization9.

Phosphorus allocation in surface soil of two drained peatland forests following wood and peat ash application – why effective adsorption on low sorptive soils?

Fertilization of drained peatland forests with wood ash and different commercial phosphorus fertilizers (calcium phosphates) generally give similar stand growth responses. However, it has been shown that use of calcium phosphate fertilizers generally lead to highly increased P release to recipient water courses. On the other hand, no corresponding release has been reported after ash fertilization. Soil samples from the surface peats from a nutrient poor and a fertile drained peatland site were collected before and 1–4 years after application of five different types of ash products. The changes over time in the different chemical forms of P in the substrate were studied. The results indicated that the reason for the low liability to leaching of ash fertilizers was that significant amounts of P are adsorbed by Al and Fe during weathering of the ash fertilizers. However, further studies are needed to clarify whether the adsorption of P occurs with the Al and Fe of the ash or the native Al and Fe compounds present in soil before ash fertilization.

Biological Phosphorus Removal, Its Role in Phosphorus Recycling

At present the main types of phosphorus removal from wastewater effluents are chemical precipitation using alum or lime and biological removal. These methods of removal do not recycle phosphorus as a truly sustainable product because it is removed along with various other waste products. The development of phosphorus removal by crystallisation has provided a way of removing phosphorus in a form that has potential to be a raw material for the phosphate industry such as struvite and hydroxyapatite. Through combining biological phosphorus removal and crystallisation a number of benefits in terms of process economics can be made. By treating the effluent initially with a biological process a concentrated phosphorus effluent stream is produced. This concentration of phosphorus will significantly reduce the volume of effluent that needs to be treated which means that the crystallisation reactor size can be greatly reduced. This review describes the main types of commercial biological phosphorus removal technologies such as the Phostrip, the modified Bardenpho and Rotanox processes along with a comprehensive examination of current crystallisation processes. Together with an examination of the potential benefits of using biological removal and crystallisation in combination as a method of removing phosphorus so that it can be recycled.

Trees, soils, and food security

Trees have a different impact on soil properties than annual crops, because of their longer residence time, larger biomass accumulation, and longer–lasting, more extensive root systems. In natural forests nutrients are efficiently cycled with very small inputs and outputs from the system. In most agricultural systems the opposite happens. Agroforestry encompasses the continuum between these extremes, and emerging hard data is showing that successful agroforestry systems increase nutrient inputs, enhance internal flows, decrease nutrient losses and provide environmental benefits— when the competition for growth resources between the tree and the crop component is well managed. The three main determinants for overcoming rural poverty in Africa are (i) reversing soil fertility depletion, (ii) intensifying and diversifying land use with high–value products, and (iii) providing an enabling policy environment for the smallholder farming sector. Agroforestry practices can improve food production in a sustainable way through their contribution to soil fertility replenishment. The use of organic inputs as a source of biologically–fixed nitrogen, together with deep nitrate that is captured by trees, plays a major role in nitrogen replenishment. The combination of commercial phosphorus fertilizers with available organic resources may be the key to increasing and sustaining phosphorus capital. High–value trees— ‘Cinderella’ species, can fit in specific niches on farms, thereby making the system ecologically stable and more rewarding economically, in addition to diversifying and increasing rural incomes and improving food security. In the most heavily populated areas of East Africa, where farm size is extremely small, the number of trees on farms is increasing as farmers seek to reduce labour demands, compatible with the drift of some members of the family into the towns to earn off–farm income. Contrary to the concept that population pressure promotes deforestation, there is evidence that demonstrates that there are conditions under which increasing tree planting is occurring on farms in the tropics through successful agroforestry as human population density increases.

Arsenic, molybdenum, selenium, and tungsten contents of fertilizers and phosphate rocks

Abstract Contamination of soils with trace metals or semi‐metals has become a major public concern in recent years. Potential sources of these contaminants include commercial phosphorus (P) fertilizers and the phosphate rocks used in production of the P fertilizers. Solid commercial P fertilizers marketed in Iowa and phosphate rock samples (PRs) obtained from deposits around the world were analyzed for arsenic (As), molybdenum (Mo), selenium (Se), and tungsten (W). The fertilizer materials included 24 samples of triple superphosphate (TSP), 23 samples of monoammonium phosphate (MAP), and 25 samples of diammonium phosphate (DAP). Twelve PRs from different PR deposits in Africa, United States, and Peru were also analyzed. The concentrations of As and Mo were greater and more variable than those of Se and W in TSP, MAP, DAP, and PRs. The ranges and median values of As, expressed in mg/kg, were: TSP (2.4–18.5, 10.1), MAP (8.1–17.8, 12.4), DAP (6.8–15.6, 12.4), and PR (3.2–32.1, 9.6). The range and median valu...

Inhibition of phosphine liberation from amorphous red phosphorus

AbstractAn extensive study of the liberation of phosphine from commercial red phosphorus was undertaken. The influence of water, trace metals, magnesium, calcium and aluminium oxides and a selection of carbamates, phenols and quinones was investigated. Accelerated ageing tests at 50°C were used to assess the value of 1% (w/w) additions of p‐benzoquinone and 1,4‐naphthoquinone in particular, as inhibitors to the generation of phosphine from commercial phosphorus and a pyrotechnic composition including spindle oil and poly(vinylbutyral). The two quinones suppress the liberation of phosphine to &lt; 5% the rate of generation from commercial unoiled phosphorus. The mechanism of phosphine generation is obscure, but involves dissociation of water in the phosphorus surface region and the formation of phosphorus acids which may disproportionate yielding phosphine. Alternatively, or simultaneously, hydrogenation of phosphorus may take place liberating phosphine. The quinones presumably arrest these processes by preferentially combining with hydrogen or free‐radical intermediates. The use of silver‐nitrate‐impregnated charcoal cloth and granules to remove gaseous phosphine was also studied.

Determination of the miscibility of phosphorus additives in polymer matrices by high resolution solid state NMR

The measurement of high resolution solid state NMR proton T1p values (relaxation time in the rotating frame) provides a method for the study of the compatibility of phosphorus additives with polymer matrices. Results are compared for two commercial phosphorus stabilizers, bis (2,4 di-t-butylphenyl) pentaerythritol diphosphite (Phosphite 1) and tris (2,4 di-t-butylphenyl) phosphite (Phosphite 2), in 5% masterbatches in linear low density polyethylene (LLDPE). Phosphite 1 shows compatibility even when poorly mixed while the Phosphite 2 shows separation into two domains with different relaxation rates and different chemical shifts in the solid state.