Case Of Phosphorus Research Articles

Efficacy of point source legislation quantified for a 64-year river water quality trajectory of phosphorus loading

Changes in river water quality often follow typical trajectories characterized by sequential phases of degradation and recovery induced by management measures, typically achieved with combinations of legislative and technological interventions. However, the key question about the effectiveness of the different types of legal interventions – source control, use-related, and end-of-pipe – remains poorly understood. With the case of phosphorus (P), which is a valuable indicator of surface water quality and a widespread target of legislation at various governance levels in order to control eutrophication of water bodies, we quantified the relation between point source loading of P and resulting river water quality for a multidecadal trajectory of the river Ruhr (Germany). In particular, we analysed P-related legislation targeting point source pollution enforced at EU, national, state, and local level and linked their development with measured total phosphorus (TP) concentrations in the river Ruhr (Germany). To this end, we combined archival data with information in the literature and conducted interviews with contemporary witnesses to describe and quantify the efficacy of each legislative approach. Although not specifically targeted at P reduction, end-of-pipe measures (sewer systems and wastewater treatment plants (WWTP)) reduced TP inputs to surface waters already in the 1960s and 1970s, curbing TP inputs to the Ruhr by 38% in 1980. The first targeted source control legislation – the banning of phosphates in textile detergents in 1981 – effectively reduced TP concentrations in WWTP influents by 36% since 1990. In combination with stronger end-of-pipe legislation focusing on P elimination in WWTP since the 1990s, TP concentrations in WWTP effluents were reduced by 86% at the end of the 1990s and by 92% in 2021. Complete and successful source control for textile detergents made use-related legislation redundant. Our study demonstrates that source control measures should be prioritized, because they are the fastest way to curb emissions. These findings provide insights that can inform efficient decision-making regarding water quality in a trajectory perspective of hierarchical governance and technological needs, as well as effective policy-making and management for other pollutants requiring control from point sources.

Citric acid acidification of wheat straw derived biochar for overcoming nutrient deficiency in alkaline calcareous soil (Case of Phosphorus)

Phosphorous fixation in soils is a serious concern worldwide, and biochar is gaining attention daily due to its potential benefits for improving the agronomic benefits of applied phosphorus. The present study aims to enhance understanding of the phosphorus transformation process in a deprived sandy soil following biochar amendments (no-acidified wheat straw biochar and chemically modified (acidification with 0.01 M C6H8O7) along with or without phosphorus at 250 mg kg−1. A 54-day pot experiment was conducted with two biochar levels of 4%, 8% (w/w), and control, and two phosphorus levels (without or with phosphorus). The results indicate that the integration of acidified wheat straw biochar with phosphorus resulted in increased available phosphorus in the soil. We conclude that incorporating acidified wheat straw biochar is a promising practice to potentially improve phosphorus availability in deprived soils. Further research is needed to explore site-specific phosphorus management for sustainable crop production.

The Mechanical and Electrochemical Behaviour of Red Phosphorus in Lithium, Sodium and Potassium-Ion Batteries

Red phosphorus (RP) is a promising anode material for alkali-ion batteries due to its ability to alloy at low potentials with Li, Na and K to form the phases Li3P, Na3P and KP, delivering a high theoretical capacity of 2596, 2596 and 865 mAh g-1, respectively. However, its main disadvantage is its very large volumetric expansion during the alloying reaction (168% with Li, 331% with Na and 161% with K) that can cause, loss of electrical contact, low Coulombic efficiency, and ultimately poor cycle life. Other alloying materials such as silicon have shown to suffer from the fracturing of the particles during the reaction with lithium. In this work, we discuss if this is the case for phosphorus too [1]. Through comprehensive electrochemo-mechanical characterisation and modelling of the cycling stresses, we show that RP can be cycled at high current densities without fracture. A model that can simulate the volume expansion of RP during the reaction with the alkali metals Li, Na and K, as well as the generation and evolution of stresses on the particles is developed. Its use required the implementation of the elastic, plastic and fracture properties of RP that are measured by novel application of in-situ nanoindentation and powder compression. The validity of the model is also tested through in-situ TEM observation with extreme conditions (anisotropic ion diffusion and high current density) where no catastrophic failure was observed. The mechanical and the electrochemical characterisation, together with the model developed in this work allows for predictions to be made for the application of RP in alkali-ion batteries.REFERENCE[1] Capone et al., Matter 2020 3 (6), 2012-2028

O-aryl and Carbonyl Carbon Contents of Food Waste and Biosolid Predict P Availability in an Acidic Soil

Organic waste streams, otherwise known as organic amendments (OA), contain potentially valuable nutrients which may additionally increase legacy nutrient availability in soil. This is particularly the case for phosphorus (P) where declining reserves of rock phosphate add an extra dimension to their utility. In acidic soils, OA have been reported to increase P availability through the action of O-aryl and carbonyl groups (represent organic acid compounds) by substituting previously fixed, legacy P and forming organometallic complexes to reduce P sorption. This study aimed to investigate if signature P (orthophosphate) and C (O-aryl and carbonyl) content of OA could be used to predict soil P availability, to replace traditional ways of testing OA and also for future prescriptive applications. Food waste and biosolid were the sources of OA in this study, with pyrolysis and composting processes used to create a range of functional groups. Nuclear magnetic resonance (NMR) spectroscopy was utilized to identify forms of C (solid-state 13C NMR) and P compounds (solution-state 31P NMR) in these OA. The O-aryl, carbonyl, and orthophosphate content were higher in pyrolysis and composted materials compared to their feedstock substrate. The effect of OA addition on soil P availability was monitored in a 110-day laboratory incubation study. Results showed an increase in soil P availability (Olsen P) and a decrease in soil P buffering capacity (PBC) after incubation. The increase in soil P availability was not predicted well by the NMR-derived orthophosphate content of OA, which may be due to the overestimation of plant-available orthophosphate content by the solution-state 31P NMR. Furthermore, an additional increase in soil ΔOlsen P (difference between observed and expected) was obtained above the Olsen P added from OA indicating substitution of previously fixed soil P. Both indices of P availability namely ΔOlsen P (r = 0.63–0.83) and ΔPBC (difference between treatment—control) (r = −0.50 to −0.80) showed strong (but opposite) correlations with the ratio of O-aryl to carbonyl C content of OA. It was concluded that the ratio of O-aryl and carbonyl C content of OA could be used to predict the P availability in acidic soil.

Sustainable Mineral Resource Management—Insights into the Case of Phosphorus

Although it is among the most abundant elements in Earth’s crust (11th [1]) and water (13th [2]), phosphorus (P) is commonly referred to as “life’s bottleneck”, as “life can multiply until all thephosphorus is gone, and then there is an inexorable halt which nothing can prevent . . . ” [3]. [...]

Valorisation of ferric sewage sludge ashes: Potential as a phosphorus source

Sewage sludge ashes (SSA), although a waste, contain elements with socio-economic and environmental potential that can be recovered. This is the case of phosphorus (P). SSA from two Danish incinerators were collected during two years and characterized. The sampling was done immediately after incineration (fresh SSA) or from an outdoor deposit (deposited SSA). Although morphology and mineral composition were similar, physico-chemical and metal concentration differences were found between incinerator plants and sampling periods. No differences were observed between deposited and fresh SSA, except for the parameters directly influenced by disposal conditions (e.g. moisture content). All the SSAs had high concentrations of P (up to 16wt%), but they all exceeded Danish EPA Cd and Ni thresholds for direct application at agricultural soil.Fresh and deposited SSA were acid washed aiming P extraction, achieving 50gP/kg (approx. 37% of total P), but metals were also co-extracted to the liquid phase. To avoid and/or minimize the metals pollution of the extracted P, selective P recovery from the SSA was tested, using the electrodialytic (ED) process. ED laboratory cells, with 3 compartments (3c) and 2 compartments (2c), and two acid concentrations (H2SO4, 0.08M and 0.19M) were used for 7days. The most concentrated acid solution increased P solubilization. The 2c-cell combined with the higher acid concentration resulted in higher P recoveries, 125g of P/kg of SSA in the anolyte. The obtained results showed that the ED process is a valuable tool for the SSA valorisation as it promotes simultaneous P recovery and metals extraction from the SSA.

The Right to Know the Geopotential of Minerals for Ensuring Food Supply Security: The Case of Phosphorus

Summary This supporting information provides some brief historical information on the right to know. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Two-dimensional mono-elemental semiconductor with electronically inactive defects: the case of phosphorus.

The deep gap states created by defects in semiconductors typically deteriorate the performance of (opto)electronic devices. This has limited the applications of two-dimensional (2D) metal dichalcogenides (MX2) and underscored the need for a new 2D semiconductor without defect-induced deep gap states. In this work, we demonstrate that a 2D mono-elemental semiconductor is a promising candidate. This is exemplified by first-principles study of 2D phosphorus (P), a recently fabricated high-mobility semiconductor. Most of the defects, including intrinsic point defects and grain boundaries, are electronically inactive, thanks to the homoelemental bonding, which is not preferred in heteroelemental system such as MX2. Unlike MX2, the edges of which create deep gap states and cannot be eliminated by passivation, the edge states of 2D P can be removed from the band gap by hydrogen termination. We further find that both the type and the concentration of charge carriers in 2D P can be tuned by doping with foreign atoms. Our work sheds light on the role of defects in the electronic structure of materials.

Preferential Positioning of Dopants and Co-Dopants in Embedded and Freestanding Si Nanocrystals

In this work we aim at understanding the effect of n- and p-type substitutional doping in the case of matrix-embedded and freestanding Si nanocrystals. By means of ab initio calculations we identify the preferential positioning of the dopants and its effect on the structural properties with respect to the undoped case. Subsequently, we consider the case of phosphorus and boron co-doped nanocrystals showing that, against the single-doping situation, the energetics strongly favors the binding of the impurities at the nanocrystal surface. Indeed we demonstrate that the polar B-P bond forms a stable permanent electric dipole that radially points inward in the nanocrystal. Such a noteworthy characteristic and its physical consequences are discussed alongside new potential applications.

Risking public health by approving some health claims? – The case of phosphorus

There is a well-established consensus on the many biological functions of essential nutrients, and related general function health claims will be soon authorised in the European Union. Such claims about the role of nutrients in the body’s growth, development and functioning could provide a powerful marketing tool and significant increase in the consumption of specific food products. Even though these claims are scientifically substantiated, there are both health and ethical concerns about whether such claims should be allowed where the intake of these nutrients easily exceeds the recommendations and a bigger intake might have adverse affects. The case of phosphorus and its role in the maintenance of normal bone is discussed.

Influence of isoelectronic impurities on the electronic structure of BN nanotubes

Via the example of a (5, 5) boron-nitrogen armchair nanotube, the influence of isoelectronic substitutional impurities on the electronic structure of BN nanotubes has been investigated with the use of linear augmented cylindrical waves. The treatment is based on the local density approximation and the muffin-tin approximation for the electron potential. In this method, the electronic spectrum of a system is governed by the free motion of electrons in the interatomic space between cylindrical barriers and the electron scattering on atomic centers. It has been found that the substitution of one atom of N by P leads to the splitting of all twofold degenerate bands by 0.2 eV on average, a decrease in the energy gap from 3.5 to 2.8 eV, the separation of the s(P) band from the high-energy region of the s(B, N) band, as well as to the formation of the impurity π(P) and π*(P) bands, which form the valence-band top and conduction-band bottom in the doped system. The influence of an As atom on the electronic structure of (5, 5) BN nanotubes is qualitatively similar to the case of phosphorus, but the energy gap is smaller by 0.5 eV. The optical gap in the nanotubes is closed due to the effect of the Sb atom impurity. A substitution of one B atom by an Al atom results in the strong perturbation of the band structure and the energy gap in this case is only 1.6 eV in contrast to the weak indium-induced perturbation of the band structure of the BN nanotube. In the latter case, the energy gap is 2.9 eV. The above effects can be detected by the optical and photoelectron spectroscopy methods, as well as by measuring the electrical properties of the nanotubes. They can be used to create electronic devices based on boron-nitrogen nanotubes.

Strategies for Protecting and Restoring Rhode Island's Watersheds on Multiple Scales

The Clean Water Act has traditionally preserved the quality and quantity of a region's water by focusing resources on areas with known or anticipated problems. USEPA Region 1 is taking the supplemental, longer-range approach of protecting areas of New England where natural resources are still healthy. As part of Region 1 's “New England Resource Protection” approach, stakeholders participate in an open process that identifies healthy ecosystems and characterizes how well they support aquatic life and human health. Since the concerns of stakeholders are usually local, the process also displays areas of nonattainment within individual watersheds and determines their likely causes. One of the most powerful ways to display these types of information on multiple scales is to use a geographic information system (GIS). The case of phosphorus in southern Rhode Island's Tucker Pond illustrates how a GIS can help integrate concerns from the public, data from Clean Water Act monitoring, and information from the New England Resource Protection Project to identify types of environmental assessment questions on scales ranging from states to subwatersheds. By involving the public at all stages of the process and better informing them about their watersheds, this new approach makes them better stewards of their environment.

A case of phosphorus poisoning reported as a possible case of yellow fever

A case of phosphorus poisoning reported as a possible case of yellow fever