Addition Of Phosphate Research Articles

Three Birds with One Stone: N/P Recovery, Dewaterability Improvement, and Facilitating Liquid Digestate Treatment of Anaerobically Digested Sludge

This study developed a novel dewatering process coupled with nutrient recovery to raise the resource value of anaerobically digested sludge. The hydration of multicharged anions was proposed to compete with the hydration of hydrophilic organic components (i.e., salting-out effects). Accordingly, phosphate was used as the salting-out agent to improve sludge dewaterability, and simultaneously, it balanced the molar ratio of NH4+-N and PO43–-P in the aqueous phase, which could facilitate the recovery of N/P as struvite from the liquid digestate. The addition of phosphate (70% of its solubility) at the initial sludge pH of 5 could obtain the lowest centrifugally dewatering equilibrium height (h∞) of 0.036 cm and reduce the bound water fraction by 63.5%. For the first time, time-of-flight secondary ion mass spectrometry (ToF-SIMS) in situ identified the phosphorus speciation and microdistribution in anaerobically digested sludge. Additionally, the quartz crystal microbalance with dissipation (QCM-D) analysis confirmed that the organics-phosphate interactions led to a dense water-repelling system of sludge flocs with an increasing rigidity, which mainly contributed to the improved centrifugal dewatering performance. All the above contributions are expected to suggest a promising way for simultaneously recovering N/P, improving dewaterability, and facilitating liquid digestate treatment of anaerobically digested sludge.

Study of arsenic adsorption in calcareous soils: Competitive effect of phosphate, citrate, oxalate, humic acid and fulvic acid.

Arsenic (As) bio-availability in the soil is influenced by different organic and inorganic anions. In the present study, the effects of various competitive agents, including phosphate, citrate, oxalate, humic acid (HA), and fulvic acid (FA), on the adsorption of As in calcareous soils were investigated. The results revealed the presence of phosphate, citrate, and oxalate in soil has a significant impact on the arsenic retention (adsorption) in soil which increases the As bio-availability. The negative impact of the competing anions was increased at higher concentrations. The Double Site Langmuir (DSL) isotherm was best fitted to the adsorption data, which indicates that most of the As adsorbed on the low-energy surfaces (non-specific adsorption by oxides, clays, and clay-size calcite). Accordingly, in soil 1, the DSL predicted that, due to phosphate, citrate, and oxalate competition (at a concentration of 10mM), the adsorption capacity of the high- and low-energy surfaces decreased from 86.2 to 33.5, 82.1 and 61.3mg/kg and from 663 to 659, 335.8, and 303.5mg/kg, respectively, Moreover, after addition of phosphate, citrate, and oxalate to the soil-As system, the Langmuir constant of high-energy surfaces decreased from 0.686 to 0.074, 0.261, and 0.301L/mg, respectively. No regular trend was observed for the Langmuir constant of low-energy surfaces. Similarly, in soils 2, 3, and 4, the adsorption capacities of both high- and low-energy surfaces as well as the Langmuir constant of high-energy surfaces decreased by the addition of phosphate, citrate, and oxalate to the soil-As system. HA and FA did not have a significant effect on the As adsorption behavior. Phosphate, citrate, and oxalate, as interfering oxyanions, increased the As bio-availability in the calcareous soils by decreasing the As adsorption.

Influence of monoammonium phosphate on glyphosate adsorption-desorption in tropical soils: Effect of the order of sorbate additions.

Glyphosate and phosphate compete for the same adsorption sites in the soil because their adsorption mechanisms are similar as the herbicide contains a phosphate group. However, how this competition occurs in relation to the order of addition of the sorbate and the composition of the soils remains unclear. The effect of the soil clay composition and the order of glyphosate and monoammonium phosphate (MAP) additions on glyphosate sorption-desorption was investigated using three inceptisols collected from Colombian rice fields. Glyphosate adsorption isotherms were evaluated using the batch equilibrium method and were modeled applying the Freundlich equation. The values for glyphosate Kfa, when evaluated alone, ranged from 14.39 to 639.86mg1-na Lna kg-1. An agreement was found between adsorbed glyphosate, chlorites, and low initial phosphorous soil content. Preadsorbed MAP or simultaneous MAP-glyphosate additions to the soil revealed a drastic reduction in glyphosate Kfa values in soil containing the highest amount of 2×1 clays, but kaolinitic soils remained practically unaffected. Low desorption values could be associated with soils with the highest kaolinite content. Glyphosate remobilization was favored when the desorbing MAP solution was used in soils containing preadsorbed glyphosate. This study provides new knowledge on the effect of phosphorus fertilizers on glyphosate bioavailability in soils with different mineral compositions.

Influence of phosphates in reduction of the aftertaste of steviol glycoside (derived from Stevia rebaudiana Bertoni) in black tea drinks

This study evaluated the effect of the addition of phosphates on the reduction of the aftertaste of steviol glycoside in black tea, through the methodology of hedonic thresholds. Initially, five phosphate salts were evaluated for their ability to reduce the aftertaste in three brands of commercial stevia. Stevia C and two phosphates (DSP and SPP) have been chosen from the results, because they showed the best results for the overall impression and the reduction of sweetness and bitterness, respectively. A blend of DSP and SPP was applied as a standard criterion. Finally, the compromised acceptance threshold (CAT) (2.81%) and hedonic rejection threshold (HRT) (0.054%) were determined. It was still possible to determine the HRT for the bitterness attribute in the value of 1.39%. The present study demonstrates that the use of phosphate allows the reduction of stevia aftertaste in black tea. Novelty Impact Statement Sensory tests showed a reduction of stevia aftertaste by phosphate salts; certain phosphate salts are able to further reduce bitterness and other sweetness; the combined use of phosphate salts aids in better performance.

Synthesis of a Magnetic Carnation-like Hydroxyapatite/Basic Calcium Carbonate Nanocomposite and Its Adsorption Behaviors for Lead Ions in Water.

Calcium-enriched compounds have great potential in the treatment of heavy-metal contaminated wastewater. Preparing stable basic calcium carbonate (BCC), which is a calcium-enriched compound, and applying it in practice is a great challenge. This work investigated the formation process of hierarchical hydroxyapatite (HAP)/BCC nanocomposites and their adsorption behaviors regarding lead ions (Pb2+). The morphology of the HAP/BCC nanocomposite was controlled by the addition of monododecyl phosphate (MDP). The carnation-like HAP/BCC nanocomposite was achieved with the addition of 30 g of MDP. The carnation-like HAP/BCC nanocomposite had a high Pb2+ adsorption capacity of 860 mg g−1. The pseudo-second-order and Freundlich model simulation results indicated that the adsorptions of Pb2+ on the nanocomposites belonged to the chemisorption and multilayer adsorption processes. The main effective adsorption components for the nanocomposites were calcium-enriched HAP and BCC. Through the Ca2+ ions exchanging with Pb2+, the HAP and BCC phases were converted to hydroxyl-pyromorphite (Pb-HAP) and hydrocerussite (Pb3(CO3)2(OH)2), respectively. The carnation-like HAP/BCC nanocomposite has great potential in the treatment of heavy metal ions. This facile method provides a new method for preparing a stable HAP/BCC nanocomposite and applying it in practice.

Human gelatin-based composite hydrogels for osteochondral tissue engineering and their adaptation into bioinks for extrusion, inkjet, and digital light processing bioprinting

The investigation of novel hydrogel systems allows for the study of relationships between biomaterials, cells, and other factors within osteochondral tissue engineering. Three-dimensional (3D) printing is a popular research method that can allow for further interrogation of these questions via the fabrication of 3D hydrogel environments that mimic tissue-specific, complex architectures. However, the adaptation of promising hydrogel biomaterial systems into 3D-printable bioinks remains a challenge. Here, we delineated an approach to that process. First, we characterized a novel methacryloylated gelatin composite hydrogel system and assessed how calcium phosphate and glycosaminoglycan additives upregulated bone- and cartilage-like matrix deposition and certain genetic markers of differentiation within human mesenchymal stem cells (hMSCs), such as RUNX2 and SOX9. Then, new assays were developed and utilized to study the effects of xanthan gum and nanofibrillated cellulose, which allowed for cohesive fiber deposition, reliable droplet formation, and non-fracturing digital light processing (DLP)-printed constructs within extrusion, inkjet, and DLP techniques, respectively. Finally, these bioinks were used to 3D print constructs containing viable encapsulated hMSCs over a 7 d period, where DLP printed constructs facilitated the highest observed increase in cell number over 7 d (∼2.4×). The results presented here describe the promotion of osteochondral phenotypes via these novel composite hydrogel formulations, establish their ability to bioprint viable, cell-encapsulating constructs using three different 3D printing methods on multiple bioprinters, and document how a library of modular bioink additives affected those physicochemical properties important to printability.

Visualization and quantification of carbon "rusty sink" by rice root iron plaque: Mechanisms, functions, and global implications.

Paddies contain 78% higher organic carbon (C) stocks than adjacent upland soils, and iron (Fe) plaque formation on rice roots is one of the mechanisms that traps C. The process sequence, extent and global relevance of this C stabilization mechanism under oxic/anoxic conditions remains unclear. We quantified and localized the contribution of Fe plaque to organic matter stabilization in a microoxic area (rice rhizosphere) and evaluated roles of this C trap for global C sequestration in paddy soils. Visualization and localization of pH by imaging with planar optodes, enzyme activities by zymography, and root exudation by 14 C imaging, as well as upscale modeling enabled linkage of three groups of rhizosphere processes that are responsible for C stabilization from the micro- (root) to the macro- (ecosystem) levels. The 14 C activity in soil (reflecting stabilization of rhizodeposits) with Fe2+ addition was 1.4-1.5 times higher than that in the control and phosphate addition soils. Perfect co-localization of the hotspots of β-glucosidase activity (by zymography) with root exudation (14 C) showed that labile C and high enzyme activities were localized within Fe plaques. Fe2+ addition to soil and its microbial oxidation to Fe3+ by radial oxygen release from rice roots increased Fe plaque (Fe3+ ) formation by 1.7-2.5 times. The C amounts trapped by Fe plaque increased by 1.1 times after Fe2+ addition. Therefore, Fe plaque formed from amorphous and complex Fe (oxyhydr)oxides on the root surface act as a "rusty sink" for organic matter. Considering the area of coverage of paddy soils globally, upscaling by model revealed the radial oxygen loss from roots and bacterial Fe oxidation may trap up to 130 Mg C in Fe plaques per rice season. This represents an important annual surplus of new and stable C to the existing C pool under long-term rice cropping.

Consumer intention towards the phosphate-reduced processed meat products using the extended theory of planned behaviour

Phosphates are essential for maintaining various quality attributes of processed meat products such as water-binding properties, texture and sensory properties and their removal would drastically change the products' technical and sensory qualities. Currently, meat industries are faced with the challenge of removing phosphates to address the consumers' demand to remove the negatively perceived synthetic additives from processed meat products. This study measured these consumers' purchase intention of phosphate-reduced processed meat products with different quality, using the extended theory of planned behaviour (TPB). An online survey was conducted among the consumers (n = 548) of the Republic of Ireland (ROI) to predict their knowledge and attitude towards phosphate additives. Analysis of the survey responses showed that about two-third of the participants consumed processed meat products 5–6 times per week. The results of multiple linear regression showed that the theory constructs attitude, subjective norms, perceived health risks significantly (P < 0.05) influenced the consumer behavioural intention whereas the perceived behavioural control (PBC) produced insignificant impacts. The results also revealed that the extended TPB model predicted the consumers' intention with better explanatory power (adjusted R2 = 0.46) than the original TPB model. In conclusion, various recommendations and implications were developed based on the results to improve the consumers' purchase intention of these products.

Mobilization of arsenic from As-containing iron minerals under irrigation: Effects of exogenous substances, redox condition, and intermittent flow

Irrigation activities can cause strong geochemical and hydrological fluctuations in the unsaturated zone, and affect arsenic (As) migration and transformation. The As geochemical cycle in the unsaturated zone is coupled with that of iron minerals through sorption-desorption, coprecipitation and redox processes. Dynamic batch experiments and wetting-drying cycling column experiments were conducted to evaluate As mobilization behaviors under the effects of exogenous substances, redox condition and intermittent flow. Our results show that As release under exogenous substances carried by irrigation (e.g., phosphate, carbonate, fulvic acid, humic acid, etc.) followed three trends with the types of exogenous inputs. Inorganic anions and organic matter resulted in opposite trends of arsenate release in different redox conditions. In anoxic environments, As(V) release was favored by the addition of phosphate and carbonate, while in oxic environments, the mobilization of As(V) was promoted by the addition of fulvic acid (FA). Further, intermittent irrigation promoted the reductive dissolution of Fe oxides and the mobilization of As. The addition of humic acid (HA) resulted in the mobilization of arsenate as As-Fe-HA ternary complexes. The mechanism of arsenic mobilization under irrigation has importance for prevention of arsenic exposure through soil to food chain transfer in typical high arsenic farmland.

Hybrid Alginate-Brushite Beads Easily Catalyze the Knoevenagel Condensation On-Water.

An innovative hybrid organic–inorganic material composed of alginate–brushite xerogel beads was successfully applied for the catalysis of the Knoevenagel condensation. The catalyst was derived from phosphated alginate xerogel microspheres formed from the ionotropic gelling effect of phosphated alginate. To this end, alginate was phosphated by the addition of diammonium hydrogen phosphate in a 1% w/w alginate gel. The phosphated alginate was subsequently precipitated by chelation of Ca2+ cations, generating a phosphated alginate hydrogel microsphere, which was washed and dried, forming hybrid organic–inorganic xerogel beads as a crystalline phosphate-rich mineral fraction covered by alginate. X-ray diffraction analysis revealed that the crystalline inorganic matrix of the material was composed predominantly of brushite. SEM analysis revealed plate-like, ribbon-like, or needle-like morphologies in the hybrid alginate–brushite beads. The hybrid material was tested as a catalyst for Knoevenagel condensation, which was performed ″on-water″ under mild conditions with aromatic aldehydes and activated methylene compounds, giving high yields (up to 97%). The reaction rate and product yield increased together with the reaction temperature for all reagents. The recyclable solid catalyst was effective for three runs, revealing the potential of the innovative hybrid catalyst as an eco-friendly heterogeneous catalyst.

Double-layer Remote Configuration with LaOF: Eu3+ and Sr3WO6:U Phosphors: A Selection for Enhancing The Optical Efficiency of WLEDs

Although the distant phosphor configuration is a good selection for high-luminescence WLEDs, it did not satisfy the high color adequacy standard. With the aim of achieving improved chromatic indices, including the index for color rendering (CRI) and the scale of color quality (CQS), for the distant phosphor structure, a dual-layer design with red or green phosphor addition is suggested in this research report. The color temperature of the WLEDs packets employed in this investigation is 8500 K. The phosphor configuration will be produced by layering green Sr3WO6:U or red LaOF:Eu3+ phosphor on top of the yellow phosphor YAG:Ce3+. The concentration of additional red phosphor LaOF:Eu3+ and green phosphor Sr3WO6:U will then be adjusted to observe the changes in color in luminescence performance of the WLED packages. The theory of Mie about scattering combined with Lambert Beer’s rule supports the investigation on optical results. The findings demonstrated a rise in CRI and CQS along with the existence of LaOF:Eu3+, indicating that the LaOF:Eu3+ presence has a major impact on these two elements. Because of the increased concentration of red light components within WLED packets, CRI and CQS increase with increasing concentration of LaOF:Eu3+. In the meantime, the green phosphor Sr3WO6:U improves the beams of light. However, if the concentrations of both the red LaOF:Eu3+ and the green Sr3WO6:U phosphors are above the corresponding level, the beams of light and color intensity will be reduced. The outcomes of this study are crucial references for producing WLEDs with greater light of white standard.

Investigation of Phosphorus Loaded V2O5/ZrO2 Catalysts for the Oxidative Dehydrogenation of Propane (ODH)

In this study, V2O5/ZrO2 samples loaded with different wt% of V2O5, ranging between 0% and 20% (wt% = 2.5, 3.6, 7.5, 10, and 20), were prepared and studied in the dehydrogenation of 2-butanol in order to investigate their acid-basic properties and to select the most interesting sample, that was identified in the 3.6 wt%V2O5/ZrO2. Such a catalyst was modified by adding phosphate at different atomic ratios (P/V = 0.5, 1, and 2) and further characterized by XRD, SEM-EDX, ESR, UV-Vis-PIR diffuse reflectance. Tests of catalytic dehydrogenation of 2-butanol were also performed. Then, the so-prepared samples were investigated in the oxidative dehydrogenation (ODH) of propane that represents the reaction of main interest in this study. It has been shown that the introduction of 3.6 wt%V2O5 and phosphate in the zirconia matrix enhances the stability of the tetragonal structure, improves acidity, and promotes ODH activity. Compared to the unpromoted 3.6 wt%V2O5/ZrO2 catalyst, the addition of phosphate increases the overall propane conversion from 12% to 20%, and also the propylene selectivity from 54% to near 64%, in the experimental conditions F °C3H8/F°O2/F°total (cm3/min): 3.6/1.8/60 at the temperature of 500 °C. The influence of the reaction mixture on the ODH, in particular the oxygen flow rate, was addressed. Highlights: Phosphorus loaded V2O5/ZrO2 catalysts were prepared and investigated in the oxidative dehydrogenation of propane. Addition of V2O5 and phosphorus to ZrO2 stabilized the tetragonal phase with respect to the monoclinic one. Among the prepared V2O5/ZrO2 samples, the most active catalyst corresponds to 3.6 wt% of V2O5/ ZrO2, The addition of phosphorus to 3.6 wt% V2O5/ZrO2 improves acidity and selectivity to propylene. Correlation between catalysts acidity and oxidative dehydrogenation of propane was observed.

Impacts of agar gum and fucoidan on gel properties of surimi products without phosphate.

Phosphate is widely used in surimi products to improve the gel properties. However, excess addition of phosphate occurs, which can harm the consumer's health. This study aimed to evaluate the effects of agar gum and fucoidan on maintaining the gel properties of surimi products instead of phosphate. Interestingly, our results showed that 0.125% of agar gum and fucoidan to replace phosphate could enhance water-holding capacity and maintain gel strength and textual properties of surimi products well. Especially at frozen storage for 1year, 0.125% of agar gum reduced the expressible moisture content of surimi products by around 10% (p < .05). Sensory evaluation showed that 0.125% of agar gum and fucoidan instead of phosphate can improve tissue and fondness of surimi products in refrigerated storage for 24 h but not in frozen storage for 1year. The addition of agar gum and fucoidan at a high concentration >0.50% increased the WHC, but significantly decreased gel strength and springiness of surimi products (p < .05). Particularly, 1.00% of agar gum and fucoidan reduced gel strength by around 20% (p < .05). It might be due to the destruction of the gel network structure of surimi protein following the excess addition of these polysaccharides. It can be concluded that 0.125% of agar gum and fucoidan can replace phosphate to develop high-quality surimi products, and excessive addition of them have negative effects.

Investigation of electrical conductivity and radical scavenging activity of boron phosphate filled polypyrrole nanocomposites

ABSTRACT In this study, the effects of the nanoscaled boron phosphate (BP) addition to polypyrrole (PPy) were investigated. Firstly, the composites containing different weight ratios of BP were prepared and characterized using Fourier-Transform Infrared-attenuated total reflection (FTIR-ATR), UV-vis, X-ray diffraction (XRD), and scanning electron microscopy analyzes. FTIR-ATR analyzes indicated the electrostatic interactions between PPy and BP molecules whereas UV-vis analyzes showed that charge carrier concentration increased with the addition of BP. The electrical conductivity measurements indicated that the electrical conductivity of the pristine PPy increased from 11.1 Scm−1 to 160.6 Scm−1 with the addition of 20% BP by weight. Furthermore, with the addition of 20% BP, the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH •) scavenging activity of PPy was significantly increased from 30.59 ± 0.5% to 49.18 ± 1.17% while 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS•+) scavenging activity improved from 21.97 ± 1.07% to 29.70 ± 0.04%. The observed data have shown that electrically conductive PPy/BP nanocomposites can be a promising component for antioxidant materials.

Spectroscopic Investigation on the Effects of Biochar and Soluble Phosphorus on Grass Clipping Vermicomposting

Seeking to evaluate the hypothesis that biochar optimises the composting and vermicomposting processes as well as their product quality, we carried out field and greenhouse experiments. Four grass clipping composting treatments (only grass, grass + single superphosphate (SSP), grass + biochar and grass + SSP + biochar) were evaluated. At the end of the maturation period (150 days), the composts were submitted to vermicomposting (Eisenia fetida earthworm) for an additional 90 days. Ordinary fine charcoal was selected due to its low cost (a by-product of charcoal production) and great availability; this is important since the obtained product presents low commercial value. A greater maturity of the organic matter (humification) was observed in the vermicompost treatments compared with the compost-only treatments. The addition of phosphate significantly reduced the pH (from 6.7 to 4.8), doubled the electrical conductivity and inhibited biological activity, resulting in less than 2% of the number of earthworms found in the treatment without phosphate. The addition of soluble phosphate inhibited the humification process, resulting in a less-stable compound with the preservation of labile structures, primarily cellulose. The P species found corroborate these findings because the pyrophosphate conversion from SSP in the absence of biochar may explain the strong acidification and increased electric conductivity. Biochar appears to prevent this conversion, thus mitigating the deleterious effects of SSP and favouring the formation of organic P species from SSP (78.5% of P in organic form with biochar compared to only 12.8% in the treatments without biochar). In short, biochar decreases pyrophosphate formation from SSP, avoiding acidification and salinity; therefore, biochar improves the whole composting and vermicomposting process and product quality. Vermicompost with SSP and biochar should be tested as a soil conditioner on account of its greater proportion of stabilized C and organic P.

Do Soluble Phosphates Direct the Formose Reaction towards Pentose Sugars?

The formose reaction has been a leading hypothesis for the prebiotic synthesis of sugars such as ribose for many decades but tends to produce complex mixtures of sugars and often tars. Channeling the formose reaction towards the synthesis of biologically useful sugars such as ribose has been a holy grail of origins-of-life research. Here, we tested the hypothesis that a simple, prebiotically plausible phosphorylating agent, acetyl phosphate, could direct the formose reaction towards ribose through phosphorylation of intermediates in a manner resembling gluconeogenesis and the pentose phosphate pathway. We did indeed find that addition of acetyl phosphate to a developing formose reaction stabilized pentoses, including ribose, such that after 5 h of reaction about 10-fold more ribose remained compared with control runs. But mechanistic analyses using liquid chromatography-mass spectrometry showed that, far from being directed towards ribose by phosphorylation, the formose reaction was halted by the precipitation of Ca2+ ions as phosphate minerals such as apatite and hydroxyapatite. Adding orthophosphate had the same effect. Phosphorylated sugars were only detected below the limit of quantification when adding acetyl phosphate. Nonetheless, our findings are not strictly negative. The sensitivity of the formose reaction to geochemically reasonable conditions, combined with the apparent stability of ribose under these conditions, serves as a valuable constraint on possible pathways of sugar synthesis at the origin of life.

Insight into the effect of phosphate on ferrihydrite colloid-mediated transport of tetracycline in saturated porous media.

Colloid-mediated contaminant mobility is absolutely critical for the environmental behavior of contaminants such as antibiotics in water resources. In this study, the influences of phosphate (a commonly inorganic ligand in the environment) on the ferrihydrite colloid-mediated transport of tetracycline (TC, a typical antibiotic) in porous media were investigated. In the absence of colloids, phosphate promoted TC mobility due to the competitive deposition of phosphate and TC on the sand surface as well as the electrostatic repulsion. Interestingly, ferrihydrite colloids could inhibit TC transport; however, the inhibitory effect of the colloids was weakened by the addition of phosphate. This phenomenon stemmed from colloid-associated TC mobility, the increased electrostatic repulsion induced by adsorbed phosphate, and deposition site competition effect. Another interesting finding was that the impacts of phosphate on the colloid-mediated mobility of TC were pH-dependent. That is, phosphate exhibited a weaker effect on the inhibitory role of ferrihydrite colloids in TC mobility at pH 5.0 than that at pH 7.0; specially, ferrihydrite colloids acted as possible carriers of TC and facilitated antibiotic transport at pH 9.0. The observations were ascribed to different influences of phosphate on the binding affinity of ferrihydrite toward TC and the mobility of free TC under different pH conditions. Therefore, the findings of this study provide useful information about the fate and co-transport of antibiotics and natural mineral colloids in the presence of inorganic ligands in the aquatic environment.

Experimental Investigation of boron phosphate Incorporated speek/pvdf blend membrane for proton exchange membrane fuel cells

The recent studies focused on the blend membranes to a great extent due to their capability of gathering some important polymer characteristic features. In this survey, boron phosphate (BP) doped sulfonated poly (ether ether ketone)/Poly (vinylidene fluoride) (SPEEK/PVDF) blend membrane having high ionic conduction capability was synthesized. The boron phosphate doping to the membrane matrix enhanced the membrane properties in terms of proton exchange membrane conditions. The sol-gel and casting method was used to synthesise the SPEEK/PVDF blend membrane. The characterization tests to observe the structure of the membrane, such as X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), FT-IR and mechanical/thermal stability tests were conducted. The membrane ionic transportation and water retention were improved directly by the addition of boron phosphate. The highest power density (242 mW cm−2) and current density (400 mA cm−2) at 0.6 V were obtained by SPEEK/PVDF/10BP, respectively. Additionally, the proton conductivity value of 39 mS cm−1 was obtained for SPEEK/PVDF/10BP sample at 80 °C. The authors concluded that both boron phosphate additive and SPEEK/PVDF blend membrane have promising results for fuel cell future operations.

Improved hydrodeoxygenation of lignin-derived oxygenates and biomass pyrolysis oil into hydrocarbon fuels using titania-supported nickel phosphide catalysts

Biomass pyrolysis oil is a potentially essential renewable energy source that can serve as an alternative to petroleum-based fuels and chemicals. In this study, biomass pyrolysis oil was converted into petroleum-like deoxygenated hydrocarbons via catalytic hydrodeoxygenation using a titania-supported nickel phosphide catalyst. The phosphor precursor was added to several transition metals, including nickel, cobalt, copper, and iron, supported on titania. The formation of isolated nickel phosphide particles, which were active for complete hydrodeoxygenation, was confirmed by the characterization of prepared catalysts. As a model reactant of biomass pyrolysis oil, a mixture of alkyl-methoxyphenol compounds was hydrodeoxygenated to produce completely deoxygenated compounds, generating an 87% yield of cycloalkanes at 300 °C and 4 MPa H2 for a reaction time of 2 h. The hydrodeoxygenation of biomass pyrolysis oil also generated a 37.4% yield of hydrocarbon fuels. The high hydrodeoxygenation activity can be attributed to the synergy between the hydrogenating metals and the acid sites, which can be improved by electron transfer from a slightly cationic nickel to a slightly anionic phosphor. Furthermore, the addition of phosphor improved the formation of highly dispersed nickel particles, increasing the quantity of hydrogen-adsorbing surface metals. The observations in this study indicate that the efficient conversion of lignocellulose-derivatives into chemicals and fuels can be achieved using modified non-precious transition metal catalysts.

The Tol–Pal system of Escherichia coli plays an unexpected role in the import of the oxyanions chromate and phosphate

Chromate is a toxic metal that enters bacteria by using oxyanion importers. Here, we show that each mutant of the Tol–Pal system of Escherichia coli exhibited increased chromate resistance. This system, which spans the cell envelope, plays a major role in envelope integrity and septation. The ΔtolQR mutant accumulated three-fold less chromate than the wild-type. Addition of phosphate but not sulfate to rich medium drastically reduced chromate toxicity and import in the wild-type strain. Furthermore, the intracellular concentration of free inorganic phosphate was significantly reduced for the ΔtolR mutant in comparison to the wild-type strain. Moreover, extracellular labeled phosphate was significantly less incorporated into the ΔtolR mutant. Finally, two distinct TolQR mutant complexes, specifically affected in Tol–Pal energization without affecting the TolQRA complex structure, did not complement the ΔtolQR mutant for inorganic phosphate accumulation. We thus propose that, while the Pst system is well known to import inorganic phosphate, the Tol–Pal system participates to phosphate uptake in particular at medium to high extracellular phosphate concentrations. Since mutations disabling the Tol–Pal system lead to pleiotropic effects, chromate resistance and reduced inorganic phosphate import could occur from an indirect effect of mutations in components of the Tol–Pal system.