Presence Of Ammonium Sulfate Research Articles

Enhanced marmatite activation by copper with ammonium sulfate: An experimental and DFT investigation

The presence of iron atoms on the marmatite surface hinders effective interaction between the activator and the mineral, leading to unsatisfactory flotation performance through direct copper (Cu) activation. Hence, this study introduced ammonium sulfate to enhance the marmatite-activation capability by Cu ions. Additionally, the reinforcement mechanism was investigated through microflotation tests, atomic force microscopy (AFM), scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and density-functional theory (DFT) calculations. Microflotation results demonstrated that the addition of ammonium sulfate as a complexing reagent increased the flotation recovery of marmatite by 17.36%. AFM analysis revealed that marmatite subjected to enhanced activation (i.e., in the presence of ammonium sulfate) exhibited a considerably higher surface roughness than that subjected to direct Cu activation. Moreover, the average height of hill-shaped materials on the marmatite surface notably increased to 9.6 nm after enhanced Cu activation. SEM-EDS analysis revealed that the concentration of Cu atoms (2.2%) on the marmatite surface after enhanced Cu activation was nearly three times that (0.8%) after direct Cu activation. Additionally, XPS results indicated a considerably higher presence of the Cu–S component on the marmatite surface after enhanced Cu activation than after direct Cu activation. ToF-SIMS analysis indicated an increase in the fragment peaks of Cu+, CuOCS2+, OCS2−, and OC2H2S2− on the surface of enhanced-activated marmatite. Additionally, DFT calculations indicated that the presence of NH3 molecules enhanced electron transfer between Cu and S on the hydrated marmatite surface. The marmatite (1 1 0) surface exhibited more negative adsorption energy of Cu ions after the action of NH3 molecules, and NH3–Cu showed a more stable adsorption configuration than Cu. Therefore, the addition of ammonium sulfate enhanced the Cu activation for marmatite, thereby improving flotation performance.

Free radical mechanisms of ammonium sulfate as intensively used industrial materials on suppressing organic pollutants

Organic free radicals are critical intermediates for the generation and inhibition of organic pollutants during industrial processes. Clarifying the free radical mechanism of pollutant inhibition is significant for their efficient control. Ammonium sulfate is intensively used in industrial materials to suppress organic pollutants. In this study, organic free radical intermediate species in metal-catalyzed reactions inhibited by ammonium sulfate were identified using continuous-wave electron paramagnetic resonance (EPR) spectroscopy, providing direct evidence for the free radical mechanisms of organic pollutants inhibition. The transverse (T2) and longitudinal (T1) relaxation time variations catalyzed by different metal catalysts in the presence of ammonium sulfate were compared using pulsed-wave EPR. Consequently, after the addition of ammonium sulfate, the observed increase in T2 suggests that ammonium sulfate leads to radical concentration reduction. A decrease in the T1 relaxation time suggests the enhanced interaction between organic radicals and metals, which is an obstacle to subsequent radical reactions. Therefore, ammonium sulfate dominantly changed the free radical intermediates species, concentrations, and their reactivity, and then inhibited the organic pollutants formations. The inhibition mechanisms of ammonium sulfate on metal-catalyzed pollutants were then proposed combining EPR analysis, X-ray characterization, and high-resolution mass spectrometry screening. As a result, (1) occupying the active sites of metal catalysis and (2) inhibiting free radical intermediates are the two main intrinsic inhibition mechanisms of ammonium sulfate. The findings provide new perspectives on the efficient inhibition of organic pollutants in industrial processes involving various metal catalysts.

Study of bromelain and carboxymethyl cellulose surface interaction features in the process of their adsorption immobilisation

Adsorption immobilisation is a common approach to stabilise the catalytic activity of enzymes. It involves the attachment of their macromolecules to the surface of a carrier due to weak physical interactions and hydrogen bonds. According to modern concepts, this process is the ‘gentlest’ immobilisation technique in terms of the structure of the enzyme globule. Despite this fact, the activity of the immobilised preparation is often lower compared to the native enzyme. To understand the reasons, it is necessary to study the specific features of interactions within the enzyme-carrier system and to identify the types of interactions occurring between its components. When studying the structure of enzymes, it is critical to determine the nature and qualitative composition of amino acid residues on the surface of the enzyme macromolecule that interact with the carrier. If catalytically important residues are involved in the process, there may be a significant decrease in the enzyme activity. In this regard, the aim of the work was to study the features of interaction between bromelain, which is a cysteine protease, and carboxymethyl cellulose by desorption of the enzyme from the formed complex under different conditions (in the presence of ammonium sulphate or surfactant Triton X-100, including at different temperatures), as well as by flexible molecular docking. The studied substances are promising components for the production of biocatalysts for food or biomedical applications, so the study of their interaction features will expand the applications of bromelain. We determined that incubation of bromelain immobilised on carboxymethyl cellulose in solutions of ammonium sulphate with a concentration of 32 mM or higher and Triton X-100 with a concentration of 100 mM or higher resulted in the destruction of the complex and the desorption of the enzyme. It confirms that non-covalent interactions contribute to the formation of immobilised preparation. When we increased the incubation temperature of the complex above 60 °C, we also observed the release of the enzyme from the preparation, indicating the formation of hydrogen bonds between the enzyme and the carrier. In silico study confirmed the formation of these types of bonds and interactions. It was determined that the amino acid residues forming the active site of bromelain also formed bonds with the carrier.

N-Alkyl-1,2,4-triazole–Borane Complexes as High-Density Hypergolic Materials

AbstractHydrazine and its derivatives have served as a conventional bipropellant fuel for several decades. However, their extremely acute toxicity and carcinogenicity, high volatility, and environmental impact have attracted significant attention. In order to synthesize green bipropellant fuels with high density, high specific impulse, and good thermal stability, three novel N-alkyl-1,2,4-triazole–borane complexes were successfully synthesized by reacting alkylated 1,2,4-triazole coordinated with sodium borohydride in the presence of ammonium sulfate. During the droplet test with white fuming nitric acid, there was a relatively short ignition delay time of 98 ms. Additionally, these hypergolic fuels possessed a high density exceeding 1.10 g cm–3, and the specific impulse is ranging from 187 to 199 s, and the highest decomposition temperature reaches 153.4 °C. These results demonstrate their great potential as hypergolic fuels or hypergolic ionic liquid additives in the field of hypergolic materials.

A Comparative Study of Calcium Sulfate Alternatives in Compost Production for White Button Mushroom (Agaricus bisporus)

This study explores various potential substitutes for gypsum in the production of compost for white button mushrooms (Agaricus bisporus). During compost preparation, calcium sulfate (CaSO4) was replaced with calcium carbonate (CaCO3), ammonium sulfate ((NH4)2SO4), and monocalcium phosphate (Ca(H2PO4)2). Complete replacement of gypsum with calcium carbonate led to a significant pH increase during the second phase of composting, adversely affecting mushroom mycelium growth. Compost parameters were observed to be similar in scenarios where calcium sulfate was supplemented with calcium carbonate in 8:2 and 6:4 ratios, both with and without the presence of ammonium sulfate, and in 3:1 and 1:1 mixtures of calcium sulfate and monocalcium phosphate, when compared to traditional gypsum-based processes. All experimental compost mixtures yielded comparable mushroom crops in cultivation trials. Notably, the 8:2 mixture of calcium sulfate and calcium carbonate demonstrated superior performance in cultivation trials relative to the 6:4 mixture. However, supplementing these mixtures with ammonium sulfate resulted in similar crop yields. Monocalcium phosphate also emerged as a promising partial gypsum substitute, showing comparable crop production in both 3:1 and 1:1 ratios to the technological optimum. The exploration of alternative calcium sources like calcium carbonate and monocalcium phosphate reflects the adaptability of the industry in response to resource availability challenges. The potential use of byproducts like ammonium sulfate from the composting process itself offers a cost-effective and environmentally friendly approach to compost formulation, underscoring its worldwide relevance.

Isolation and Production of Cellulase from Bacteria Using Agro Waste

ABSTRACT: The development of appropriate procedures for the efficient treatment and utilization of wastes containing cellulose as an inexpensive carbon source has grown to be of substantial economic relevance. Cellulase enzyme, which is known to be produced by bacteria is responsible for degrading cellulose. Thus, isolation of Bacteria producing cellulase was performed using soil sample that were identified as Bacillus subtilis, Pseudomonas aeruginosa, Enterobacter cloacae using CMC medium. The medium for fermentation was optimized for maximum cellulase to be produced by the potential isolate. Various parameters like the time of Incubation, temperature, pH, nitrogen sources and carbon sources, were considered for optimization. The culture condition was optimized and found to be 40°C at pH 7 with maximum activity in the presence of ammonium sulphate and lactose as nitrogen and carbon sources respectively. Amongst these isolates the maximum cellulase activity was shown by Enterobacter cloacae followed by Pseudomonas aeruginosa and Bacillus subtilis by comparative study. The supplement for the medium was various agricultural waste added as an alternate source of carbon to produce cellulase. The medium with the presence of rice husk (1.76 IU/ml), followed by wheat husk(1.51 IU/ml) and castor seed waste (0.65 IU/ml), had the highest cellulase activity. Thus, this work aimed to compare the potential of all the above-mentioned isolates to use agro-waste for production of cellulase at optimized parameters.

Effect of uni-divalent electrolyte in the interaction associated with solubility for the predominant form of L-isoleucine and L-serine in aqueous media

The study aimed to measure the solubilities of L-serine and L-isoleucine in an aqueous ammonium sulfate [(NH4)2SO4] solution at different temperatures (288.15 to 308.15 K) using a gravimetric technique. In pure aqueous media L-serine solubility is 4.1218 in mol•kg−1 of water while for L-isoleucine is 0.3094 mol•kg−1 at 298.15 K. The obtained solubility data was used to estimate the thermodynamic properties of the amino acids, such as the standard Gibbs free energy and standard entropy change during the solvation process. The analysis involved investigating the short range chemical interactions between the amino acids and the electrolyte solution, which significantly influenced the solvation thermodynamics. The study found that L-serine exhibited a salting in effect, meaning its solubility increased in the presence of ammonium sulfate, while L-isoleucine experienced a salting out effect, resulting in decreased solubility with the electrolyte. Additionally, solubility parameters were employed to assess the chemical strength of the amino acids and understand their solute–solvent interactions and relative solubilities in the solution. Overall, this experimental investigation provided valuable insights into the solvation behavior and chemical characteristics of L-serine and L-isoleucine in the presence of an electrolyte solution.

Biorecovery of ammonium from manure digestate by Acidithiobacillus thiooxidans

Livestock production has an undesirable impact on the environment as livestock waste generates considerable volumes of manure digestate rich in ammonia nitrogen. The purpose of this study was to develop a treatment technology for biorecovery of ammonium (NH4+) from manure digestate to facilitate its use as fertilizer in the form of ammonium sulfate (AS). Our method offers an energy saving, environmentally friendly, and easily controlled way to address the environmental consequences of livestock. Here, the feasibility of NH4+ biorecovery from the manure digestate by Acidithiobacillus thiooxidans (PTCC 1717) is shown. To conduct biorecovery, the bacterium was first adapted to high NH4+ concentration by progressive acclimatization to improve its tolerance. Sulfate (SO42−) accumulation of 57 mM at NH4+-rich manure digestate after 15 days of incubation exhibited good oxidizing ability of the acclimated A. thiooxidans. At last, the manure digestate rich in NH4+ and biogenic SO42− were dried at 60 °C and 6.02 g AS L−1 digestate was obtained. XRD and FTIR measurements confirmed the presence of AS in the biorecovered product.

Influence of the amount and fineness of grinding of ammonium sulfate on the properties of sulfate-containing urea

The objective of this work is to determine the optimal technological mode for obtaining sulfated urea with a balanced content of nitrogen and sulfur by adding ammonium sulfate to the urea melt before granulation. The article presents the results of a study of the dependence of the properties of sulfated urea on the degree of grinding and on the amount of ammonium sulfate, expressed by the mass ratio of CO (NH2)2: (NH4)2SO4 = 100 : (2.5-50). Methods for obtaining, granulating and studying the properties of sulfated urea samples are presented. In fertilizers obtained with the addition of ammonium sulfate to the urea melt at the studied ratios, the strength of the granules increases from the initial 2,53 to 4,80 MPa, the gyroscopic point decreases from 58,4% to 52,3. It was also revealed that when ammonium sulfate is added to the urea melt, the density and viscosity of the melt increase with an increase in the amount of ammonium sulfate introduced. At 135 ° C, an increase in the addition of ammonium sulfate from 2,5 to 50,0 mass parts per 100 mass parts of urea leads to an increase in density from 1,162 to 1,412 g/cm3, viscosity from 2,56 to 7,91 cΠɜ. It was found that the smaller the particle size of ammonium sulfate, the higher the strength of the urea granules. With a decrease in the dispersion of ammonium sulfate particles from 0,25 to 0,04 mm, the strength of sulfated urea granules increases, the presence of ammonium sulfate in the composition of urea reduces the dissolution rate, which makes it possible to prolong their action, in addition, it lowers the pH of the product, which prevents the release of ammonia during storage and transportation sulfated urea.

Influence of high hydrostatic pressure on protein clustering: Implications for processing and macroscopic crystallization.

High pressure (HP) is used in various industrial applications to sterilize a product stream or to confer desired properties. HP is also present during freezing processes, yet relatively little is known about its effects on protein phases. Protein clustering has been well-documented as a precursor to liquid-liquid phase separation (LLPS) and macroscopic crystallization. Several globular proteins have been previously shown to salt-out in the presence of ammonium sulfate, with clustering observed when approaching a first aggregation boundary, phase separation beyond a second aggregation boundary, and gel bead nucleation between them. Nanocrystalline structures have been observed within the salted-out macroscopic gels, suggesting clusters below the first aggregation boundary are precursors to macroscopic crystals. The present work examines the influence of pressures up to 400 MPa on salt-induced clustering in ovalbumin solutions on either side of the first aggregation boundary. Small-angle x-ray scattering (SAXS) on aged solutions approaching the boundary reveals the presence of protein clusters, and a computational deconvolution into fractional oligomer population contributions to scattering was used to assess salt-induced clustering with similar characteristics on either side of the first aggregation boundary. Surprisingly, HP-SAXS on fresh samples reveals a sharp shift in pressure effects on clustering across the boundary. The discrepancy in pressure response suggests a fundamental difference in the clustering mechanism across the first aggregation boundary, and that clusters in this region are early nucleated gels rather than crystal precursors. The current results are of interest to protein processing and LLPS, providing insights into competing mechanisms of protein aggregation and suggesting pressure-dictated clustering as a potential tool for controlling macroscopic phase behavior.

Activation of L-lactate oxidase by the formation of enzyme assemblies through liquid–liquid phase separation

The assembly state of enzymes is gaining interest as a mechanism for regulating the function of enzymes in living cells. One of the current topics in enzymology is the relationship between enzyme activity and the assembly state due to liquid–liquid phase separation. In this study, we demonstrated enzyme activation via the formation of enzyme assemblies using L-lactate oxidase (LOX). LOX formed hundreds of nanometer-scale assemblies with poly-L-lysine (PLL). In the presence of ammonium sulfate, the LOX-PLL clusters formed micrometer-scale liquid droplets. The enzyme activities of LOX in clusters and droplets were one order of magnitude higher than those in the dispersed state, owing to a decrease in KM and an increase in kcat. Moreover, the clusters exhibited a higher activation effect than the droplets. In addition, the conformation of LOX changed in the clusters, resulting in increased enzyme activation. Understanding enzyme activation and assembly states provides important information regarding enzyme function in living cells, in addition to biotechnology applications.

Processing of serpentenites of the Arvaten deposit of Uzbekistan with the use of ammonium sulphate

The article presents the results of a study of the processes of obtaining magnesium oxide by fusing serpentinites of the Arvaten deposit in the presence of ammonium sulfate, followed by grinding and treatment with water to separate silica from the suspension, neutralizing the filtrate with ammonia to pH 8.5 for precipitation and separation of impurity metal ions, precipitation and separation of ions magnesium from solution using ammonia and ammonium carbonate, thermal decomposition of magnesium corbanate to obtain magnesium oxide. It has been established that the use of ammonium sulfate for fusion of serpentite at a ratio of serpentenite: (NH4)2SO4 = 100: 201.77 and further processing of the resulting solutions allows you to obtain magnesium oxide with a composition (wt.%): MgO - 97.55; Fe2O3 - 0.86; A12O3 - 0.12; CaO - 0.18; SO3 - 0.48.

Increase in cysteine-mediated multimerization under attractive protein–protein interactions

The CASPON enzyme became an interesting enzyme for fusion protein processing because it generates an authentic N-terminus. However, the high cysteine content of the CASPON enzyme may induce aggregation via disulfide-bond formation, which can reduce enzymatic activity and be considered a critical quality attribute. Different multimerization states of the CASPON enzyme were isolated by preparative size exclusion chromatography and analyzed with respect to multimerization propensity and enzymatic activity. The impact of co-solutes on multimerization was studied in solution and in adsorbed state. Furthermore, protein–protein interactions in the presence of different co-solutes were measured by self-interaction chromatography and were then correlated to the multimerization propensity. The dimer was the most stable and active species with 50% higher enzymatic activity than the tetramer. Multimerization was mainly governed by a cysteine-mediated pathway, as indicated by DTT-induced reduction of most caspase multimers. In the presence of ammonium sulfate, attractive protein–protein interactions were consistent with those observed for higher multimerization when the cysteine-mediated pathway was followed. Multimerization was also observed under attractive conditions on a chromatographic stationary phase. These findings corroborate common rules to perform protein purification with low residence time to avoid disulfide bond formation and conformational change of the protein upon adsorption.

Production, Partial Purification, and Characterization of Polygalacturonase from Aureobasidium pullulans P56 under Submerged Fermentation Using Agro-Industrial Wastes.

Polygalacturonase (PGase) production by Aureobasidium pullulans P56 under submerged fermentation was investigated using agro-industrial wastes and commercial carbon and nitrogen sources. The maximum PGase concentration was equivalent to 8.6U/mL that was obtained in presence of citrus pectin at 150rpm, 30°C, pH = 5.5, and 60h of fermentation conditions. However, a significant amount of enzyme production was also recorded upon the utilization of corncob (5.3U/mL) and wheat bran (4.4U/mL) as carbon sources. Amongst the different nitrogen sources, the highest enzyme production (8.2U/mL) was obtained in presence of ammonium sulphate and yeast extract simultaneously at a ratio of 1:1. The enzyme was partially purified by gel filtration using Sephadex G50 equilibrated and washed with 50mM-sodium acetate buffer. The obtained yield and specific activity were determined equivalent to 17% and 9.53U/mg, respectively. The molecular weight of the partially purified enzyme was estimated as 54kDa on SDS-PAGE. The conditions affecting the enzyme activity were determined and the highest enzyme activity was recorded at 40°C and 4.5pH. Amongst the tested metal ions, 2 and 5mM of CaCl2 concentrations increased the enzymatic activity by 30%. Overall, the use of corncob (2.5%) to produce PGase by A. pullulans represents an attractive agro-industrial substrate.

Salt and nitrogen amendment and optimization for cellulase and xylanase production using dilute acid hydrolysate of distillers' dried grains with solubles (DDGS) as the feedstock.

Distillers' dried grains with solubles (DDGS) is a by-product of dry-mill corn ethanol production comprising a high nutritional value due to residual fiber, protein, and lipid contents. The fiber content of DDGS is high enough to be considered a valuable source for the production of hydrolytic enzymes, such as cellulase and xylanases, which can be used for hydrolysis of lignocellulosic feedstock during ethanol production. The DDGS-based medium prepared after acid hydrolysis provides adequate sugars for enzyme production, while additional macronutrients, such as salts and nitrogen sources, can enhance the enzyme production. Therefore, this study was undertaken to evaluate the effect of salts (KH2PO4, CaCl2·2H2O, MgSO4·7H2O, FeSO4·7H2O, CoCl2·6H2O, and MnSO4·H2O), peptone, and yeast extract on enzyme secretion by four different Aspergillus niger strains and to optimize the nitrogen source for maximum enzyme production. Yeast extract improved the cellulase production (0.38IU/ml) for A. niger (NRRL 1956) as compared to peptone (0.29IU/ml). However, maximum cellulase productions of 0.42IU/ml and 0.45IU/ml were obtained by A. niger (NRRL 330) and A. niger (NRRL 567), respectively, in presence of ammonium sulfate. The optimized nitrogen amounts resulted in a significant increase in the cellulase production from 0.174 to 0.63IU/ml on day 9 of the fermentation with A. niger (NRRL 330). The composite model improved both cellulase and xylanase production. In conclusion, the optimization of all three nitrogen sources improved both cellulase and xylanase production in the DDGS-based media.

Deep insight into the reductive roasting treatment on iron removing from quartz

In the present work, Natural powder quartz (NPQ) ore was purified based on an integrated approach involving a reductive roasting pretreatment and acid leaching technology. The reductive thermal pretreatment was carried out through roasting in the presence of ammonium sulphate (AS). Compared with the conventional acid leaching technology, the content of iron remaining in concentrate could be reduced to below 0.3 μg·g−1 from 145.2 μg·g−1 after roasting in the presence of AS followed by acid leaching at room temperature. Thermogravimetric-mass spectrometry (TG-MS), colour responses of quartz and Density Functional Theory (DFT) were used to investigate the activation mechanism of iron by roasting with AS. It is inferred that SO2 was acted as a reducing agent which promoted the reduction of Fe (III) to Fe (II), which would facilitate the removal of trace iron impurity from NPQ. This study gives a new insight into the activation and removal mechanism of iron impurity from NPQ by reductive action.

Investigation of the effect of condensed phase on the energy conditions for the initiation of the plasma-chemical process of flue gas cleaning by a pulsed electron beam

This work investigates the processes of dissipation of the charge and energy of a pulsed electron beam in gas compositions (nitrogen, carbon dioxide and oxygen) in the presence of ammonium sulphate and nitrate. A pulsed electron beam generated by the TEA-500 accelerator (Tomsk, Russia) with an electron energy of up to 410 keV, a beam current of up to 5 kA (I0 ), and a half-amplitude voltage pulse duration of 60 ns was injected into a 46 cm long drift chamber filled with a gas mixture. The pulsed electron beam current (IFC ) passing through the drift chamber was registered using a sectioned calorimeter with beam charge monitor function, and the efficiency of the current passage of the beam was determined as the ratio qFC/q0 , where q0 is the beam charge measured at the place of its injection into the chamber drift. The pressure in the drift chamber varied (375, 560 and 760 Torr, humidity value 15% ± 5% and 50% ± 5%). The geometric dimensions of the plasma-chemical reactor for initiating plasma-chemical reactions of flue gas cleaning were determined.

Formation of ammonium uranate on uranium dioxide during aging under controlled storage conditions

• UO 2 aging was characterized via microscopic and spectroscopic methods. • Saturated (NH 4 ) 2 SO 4 solutions were used to maintain constant relative humidity. • Storage conditions led to alteration regardless of temperature. • SEM and FTIR provide evidence of ammonium uranate formation on the surface of UO 2 . The analysis and characterization of uranium dioxide (UO 2 ) under controlled storage conditions can provide insight into potential alteration products and overall stability, which has relevance for nuclear fuel cycle processes, environmental management, and the stability of used nuclear fuel in a repository. In this work, UO 2 was monitored as a function of time (6–24 months) and temperature at constant relative humidity (81% RH) in the presence of ammonium sulfate. The morphology of the aged material was described using scanning electron microscopy and a previously published lexicon, while phase changes were confirmed using X-ray diffraction. Additional characterization was carried out using energy dispersive X-ray spectroscopy, transmission electron microscopy, Raman spectroscopy, and Fourier transform infrared spectroscopy to further identify aging effects. Over time, UO 2 transitioned to a mixed phase assemblage. Among the alteration was ammonium uranate, a common fuel cycle compound, which was identified from its morphological and spectral characteristics. This work highlights the affinity and persistence of ammonium uranate compounds and emphasizes the need to continue investigating these alteration systems.

Isolation and characterization of phosphate solubilizing bacteria in saline soil from Costal Region of Odisha

The present study was conducted to isolate phosphate solubilizing bacteria (PSB) from rhizospheric saline soils of coastal Odisha, India and evaluated their phosphate solubilizing ability. Total four PSB were isolated based on the halo zone formation (solubilizing index 2.63-3.14) on PVK agar medium and were characterized based on biochemical and molecular characteristics as Bacillus subtilis (B1), B. megaterium (B2), Sphingomonas paucimobilis (P2) and Kocuria kristinae (P6). The inorganic phosphate released by PSB ranged from 18.532 to 38.250µg/ml with decreasing the pH PVK broth up to 3.9. Acid phosphatase activity for PSB were recorded 84.237-98.658µmol/min. Glucose was found to be the best carbon source for B. subtilis, Sphingomonas paucimobilis and Kocuria kristinae whereas mannitol for B. megaterium. Optimum acid phosphatase activity was observed for all the four PSB isolates in presence of ammonium sulphate as nitrogen source in PVK broth at 30oC and pH 7.0.

Highly conductive colloidal carbon based suspension for flow-assisted electrochemical systems

SummaryCarbon suspension electrodes are promising for flow-assisted electrochemical energy storage systems. They serve as flowable electrodes in electrolyte solutions of flow batteries, or flow capacitors. They can also be used for other applications such as capacitive deionization of water. However, developments of such suspensions remain challenging. The suspensions should combine low viscosity and high electronic conductivity for optimized performances. In this work, we report a flowable aqueous carbon dispersion which exhibits a viscosity of only 2 Pa.s at a shear rate of 5 s−1 for a concentration of particles of 7 wt%. This suspension displays an electronic conductivity of 65 mS/cm, nearly two orders of magnitude greater than previously investigated related materials. The investigated suspensions are stabilized by sodium alginate and arabic gum in the presence of ammonium sulfate. Their use in flowable systems for the storage and discharge of electrical charges is demonstrated.