Sulfate Concentrations Research Articles

Associations between the gut microbiota-derived metabolites with the parameters of 24-hour ambulatory blood pressure monitoring in patients on maintenance hemodialysis

Increasing number of studies’ results indicate that intestinal microbiota may be involved in the development and maintenance of hypertensive phenotype in patients with end-stage renal disease. Various metabolites of intestinal bacteria are considered as potential modulators of this association. Objective. To study the relationship between levels of uremic toxins of microbial origin in the blood serum, as well as the content of short-chain fatty acids in faeces and the 24-hour blood pressure profile indicators in patients on long-term hemodialysis. Materials and methods. Daily blood pressure (BP) monitoring results were analyzed in 80 patients on long-term hemodialysis, clinical laboratory parameters of whom, including the concentration of trimethylamine N-oxide (TMAO), p-cresyl sulfate and indoxyl sulfate in the blood serum, were assessed. A subgroup of 30 patients was examined by gas-liquid chromatography for total fecal content and spectrum of individual short-chain fatty acids (SCFAs). Associations between indicators were studied using the Pearson’s correlation coefficient and multivariate regression analysis. Results. The dynamics of BP level of the examined patients within 24 hours is characteristic for stable systolic and diastolic arterial hypertension. The daily mean value of pulse pressure (MPP) was also increased. Increased TMAO content (β=0.196; p=0.035) along with concentration of sodium (β=0.265; p=0.006) and C-reactive protein (β=0.225; p=0.03) were independent predictors of MPP increase in the adjusted multidimensional linear regression models. In addition, statistically significant inverse relationship of the mean daily and mean night levels of systolic BP, as well as MPP with total content of SCFAs in faeces, butyric acid level and total concentration of isoacids has been found. However, the found correlations lost their relevance after adjustment for other associated factors in multidimensional regression models. Conclusion. The obtained results provide additional evidence of the important role of intestinal bacteria metabolites in the development of arterial hypertension in patients receiving treatment with hemodialysis.

Combined inhibition of anaerobic digestion by sulfate, salinity, and ammonium: potential inhibitory factors in forward osmosis-concentrated municipal wastewater.

Combined inhibition of anaerobic digestion by sulfate, salinity, and ammonium: potential inhibitory factors in forward osmosis-concentrated municipal wastewater.

High-Diversity Plant-Based Diet and Gut Microbiome, Plasma Metabolome, and Symptoms in Adults with CKD.

Research suggests that eating a plant-dominant dietary pattern is beneficial to people with chronic kidney disease (CKD). The aim was to investigate how increasing the diversity of plant food intake would impact metabolomic, microbiome and clinical parameters in people with CKD. This study was a cross-over, randomized controlled trial involving 25 Australian adults diagnosed with stage 3-4 CKD. Participants were randomly allocated to follow two diets for 6 weeks each, separated by a minimum 4-week washout period: a high-diversity plant-based diet (HDPD, ≥30 unique plant foods weekly) and a low-diversity plant-based diet (LDPD, ≤15 unique plant foods weekly), alongside a usual kidney diet prescription. Data collection was completed at four timepoints (beginning and end of each intervention period). Primary outcome included a change in uremic toxins (indoxyl sulfate and p-Cresyl sulfate) concentrations. Secondary and exploratory outcomes included diet quality and nutritional status, fecal microbiome composition and diversity, plasma metabolome, symptom burden, quality of life scores, blood pressure, biochemical and anthropometric measures. Plasma and urinary uremic toxin levels did not consistently decrease across the cohort; however, significant reductions were observed in responders to the HDPD, particularly those with poorer kidney function and higher baseline uremic toxin levels. Neither diet caused electrolyte imbalances. The HDPD significantly improved diet quality, reduced potential renal acid load by an average of 47% from baseline, with an estimated marginal mean reduction of 9.96 (95% CI: -16.28 to -3.64), and compared to the LDPD, decreased total symptom burden, including constipation (95% CI: -4.11 to -0.54 and -0.91 to -0.22, respectively). It also shifted the gut microbiome toward increased production of beneficial metabolites like butyrate/isobutyrate. In contrast, the LDPD reduced microbial diversity and decreased the abundance of 27 species and 33 functional genes. This study demonstrated the safety and clinically relevant therapeutic benefits of aiming to incorporate 30 or more unique plant foods weekly in the diet of individuals with moderate CKD. It was observed that individuals with more advanced kidney disease and higher levels of uremic toxins may derive the greatest benefit from adopting a HDPD. ACTRN12619000442101.

Flow condition mitigates the inhibition of high concentration Cu2+ on the sulfate reduction performance of microbial electrolysis cell

ABSTRACT Microbial electrolysis cells (MECs) are promising for treating acidic mine drainage (AMD) containing high concentrations of sulfates and heavy metals. However, the performance of MEC cathodic biofilms is influenced not only by high heavy metals concentrations but also by hydrodynamic mixing conditions. Yet, there is a lack of precise assessment on the impact of hydrodynamic mixing conditions on MEC treating sulfate-laden wastewater under high heavy metal stress, and the defense mechanisms of MECs remain unclear. This study investigated the effects of different hydrodynamic conditions (EG, flow condition; CG, stationary condition) on the performance of MECs treating sulfate wastewater under high heavy metal stress, delving into microbial activity, community composition, electrochemical performance, and microbial defense capabilities against heavy metals. The results indicated that under heavy metal stress, microbial cells underwent severe deformation and death, with the assimilatory sulfate reduction pathway severely impaired, leading to a decline in MEC performance, and the reduction rate of CG group was finally reduced to 14.47%. In contrast, under flow conditions, the EG group exhibited increased extracellular polymeric substances (EPS) composition, enhanced biofilm community diversity, and elevated levels of copper resistance genes, significantly mitigating the inhibitory effects of Cu2+ on microorganisms, ultimately maintaining a performance of 47.18%. Ultimately, Cu2+ in the system was removed through bioprecipitation and biosorption, forming CuS and Cu(OH)2. This work provides critical insights for scaling up MEC technology to address co-contamination challenges in acid mine drainage remediation, particularly for environments with hydrodynamic mixing conditions and elevated heavy metal concentrations.

Waste-Free Glucose to Erythritol Conversion—Innovations with Yarrowia lipolytica Wratislavia K1 UV15

This study investigates the waste-free bioconversion of glucose to erythritol using the UV-mutagenized strain Yarrowia lipolytica Wratislavia KI UV15. This research focuses on optimizing fermentation parameters to enhance erythritol yield, with a key emphasis on utilizing post-crystallization erythritol filtrate as a primary carbon source, promoting a cost-effective and sustainable approach to erythritol production. The experimental design included systematic variations in ammonium sulfate concentration, yeast extract supplementation, and initial glucose concentration. The results demonstrate that the UV15 strain achieves high erythritol production efficiency. An optimal nitrogen source concentration (3.1 g/L) and reduced yeast extract levels (0.25 g/L) provided the best results, achieving a maximum erythritol concentration of 174.8 g/L with a yield of 58.2%. Furthermore, lowering the initial glucose concentration further improved process efficiency, confirming the feasibility of using post-crystallization filtrate as an effective and sustainable carbon source. These findings highlight the biotechnological potential of Y. lipolytica UV15 in erythritol production, demonstrating its adaptability to waste-derived substrates and advancing the development of economically viable, environmentally sustainable production methods.

Spatial assessment of submarine groundwater discharge influence on aquifer water quality in the coastal region of Chettikulam to Kolachel, southern India: using SMI and HFE-D techniques.

Submarine Groundwater Discharge (SGD) has a global impact, affecting coastal aquifers, the freshwater environment, and contributing to coastal development. The present study investigates the impact of Submarine Groundwater Discharge (SGD) on groundwater geochemistry along the coast from Chettikulam to Kolachel in Southern India, with an emphasis on regional changes pre and post monsoons in the years 2023-2024. A total of 80 groundwater samples (40 from both monsoons) were analyzed using hydrochemical plots such as Piper, Wilcox, Gibbs, and Hydrochemical Facies Evolution Diagrams (HFE-D), along with AquaChem software and spatial mapping techniques. Hydrogeochemical analysis reveals significant seawater intrusion during the pre-monsoon period, with 48% of groundwater samples categorized under the Mixed Ca-Mg-Cl facies and 30% under the Ca-Cl facies, leading to elevated salinity, total dissolved solids (TDS), chloride, and sulfate concentrations. In contrast, post-monsoon conditions demonstrate improved water quality due to monsoonal recharge, with 55% of samples in the mixed Ca-Mg-Cl facies but exhibiting reduced salinity. Water Quality Index (WQI) analysis shows an increase in 'Excellent' water samples from 22.5% pre-monsoon to 37.5% post-monsoon. The Wilcox diagram highlights a reduction in salinity hazards, improving groundwater suitability for irrigation. The Seawater Mixing Index (SMI) indicates the seawater intrusion in coastal zones, although monsoonal dilution mitigates its effects. Seasonal variation in hydrochemical facies reveals a decrease in the freshening phase from 60% pre-monsoon to 45% post-monsoon, alongside an expansion of the intrusion phase from 40 to 55%. The study underscores the need for ongoing groundwater monitoring and effective water management strategies to sustainable coastal aquifers impacted by Submarine Groundwater Discharge (SGD).

Freshwater algal species consortia exhibit optimal biomass and biodiesel production under calcium chloride and magnesium sulphate stress

ABSTRACT Microalgae have been pioneering microbial cell factories for sustainable bioenergy production and other high-value product extraction. The present study affirms using mixed algal species (MAS) as a consortium for escalated biomass yield and lipid production under different calcium chloride and magnesium sulphate concentrations toward biofuel production. Of the different concentrations of Ca and Mg concentrations tested, 75 mg/L of calcium and 125 mg/L of magnesium displayed maximal biomass yield, cell density, and biomass productivity. The optimization revealed 18 days of day-light incubation for enhanced biomass and biochemical production. Further, a higher lipid content of 24.55% was noticed at 0 mg/L Ca, while a maximum lipid content of 22–23.2% was observed from the MAS grown in 100 and 125 mg/L Mg concentrations. Regarding the biodiesel yield from MAS, 0 mg/L Ca showed a higher biodiesel yield of 68.45%, while 65.62–68.33% was obtained from 75 mg/L and 125 mg/L Mg concentrations. In addition, the biodiesel produced from the high Ca concentration showed higher unsaturated fatty acids of 55.13%, whereas biodiesel obtained from a higher Mg – amended consortium presented high saturated fatty acids of 53.12%. The present work will enable environmental scientists to combinatorial benefits for utilizing microalgal consortium for circular bionomy aspects and attaining sustainable development goals. Moreover, the present attempt aims to assess the microalgal consortium-based – biodiesel production in accomplishing Sustainable Development Goal – 7 (clean and affordable energy) as enlisted by the UNSDG 2030 agenda.

Enhanced Hydrophobicity, Thermal Stability, and X-Ray Shielding Efficiency of BaSO4/P(VDF-HFP) Nanocomposites for Advanced Lead-Free Radiation Protection

In this research, polymer composite sheets were developed by blending poly (vinylidene fluoride-co-hexafluoropropylene) or P(VDF-HFP) with varying concentrations of barium sulfate (BaSO4) for X-ray shielding applications. The photon counting technique was used to evaluate the composite shielding characteristics through the linear attenuation coefficient. Surface properties, including surface morphology, hydrophobicity, and surface energy, were analyzed using an atomic force microscope (AFM) and a water contact angle machine. Scanning electron microscopy (SEM) was employed to investigate the microstructural distribution and dispersion of BaSO4 particles within the polymer matrix, providing insights into the composite’s uniformity and structural integrity. Additionally, the bulk properties of the composite polymer sheets, such as crystal structures, tensile strength, and thermal stability, were examined. The results demonstrate that increasing the concentration of BaSO4 in BaSO4/P(VDF-HFP) composite sheets significantly improves their X-ray attenuation capabilities. Moreover, higher BaSO4 concentrations enhance the material’s hydrophobicity, flexibility, and thermal stability, highlighting the potential of these composites for advanced radiation shielding applications.

Enhancing textile wastewater reuse: Integrating Fenton oxidation with membrane filtration.

Enhancing textile wastewater reuse: Integrating Fenton oxidation with membrane filtration.

Experimental study on dynamic mechanical properties of concrete under sulfate attack

Research on the dynamic mechanical properties of concrete under sulfate attack is the basis for the reasonable design and performance evaluation of anti-explosion and impact resistance in concrete structures under the erosion environment. In this study, the mechanical properties of concrete specimens subjected to sulfate attack under impact compression were measured using the split Hopkinson pressure bar (SHPB) test system. The basic mechanical properties (stress-strain curve, compressive strength, elastic modulus, peak strain) of concrete specimens subject to sulfate attack under high strain rate were obtained, and the variation laws of macroscopic failure characteristics and characteristics of energy dissipation of concrete specimens subject to sulfate attack with the loading strain rate were summarized. The results show that the compressive strength and elastic modulus of concrete specimens under different sulfate concentrations exhibit a significant strain rate effect. As the strain rate increases, the compressive strength and elastic modulus of concrete specimens gradually increase; compared with concrete free from sulfate attack, the compressive strength and elastic modulus of concrete subject to sulfate attack are more significantly influenced by strain rate. Overall, the peak strain of concrete increases with the increase of strain rate, but when the strain rate increases to a certain extent, the peak strain changes little. Under the same sulfate concentration, the macroscopic failure degree of concrete specimens increases obviously with the increase of strain rate. The dissipation energy of concrete subject to sulfate attack is more sensitive to the strain rate compared with concrete free from sulfate attack, and the increase of strain rate will obviously decrease the energy utilization rate of concrete subject to sulfate attack.

Types and sources of salts causing exfoliation and efflorescence in stone relics at Yongling Mausoleum

The Yongling Mausoleum in Chengdu contains stone statues that provide valuable insights into the art and culture of the Five Dynasties and Ten Kingdoms period. The sandstone, primarily composed of quartz, calcite, and potassium feldspar, has suffered severe forms of deterioration, including exfoliation and efflorescence, mainly due to salt weathering. This study analyzed salts in exfoliation and efflorescence powder using IC, OM, μ-RS, FTIR, and SEM-EDS, identifying gypsum as the predominant salt. ESEM-EDS and XRD further confirmed that the surface crystals were gypsum and thenardite. Combined with the structural degradation, waterborne ions, and atmospheric pollutants, Na⁺ and SO₄²⁻ primarily originated from historical water accumulation, seepage, and sulfur dioxide exposure. Notably, the sulfate concentration in the efflorescent stone powder reached 0.922%, indicating an extremely severe level of salt damage. These findings clarify the deterioration mechanisms and provide a scientific basis for future conservation efforts.

Effect of sulphate type on the strength and swelling properties of lime-GGBS-stabilised sulphate-bearing soil

ABSTRACT Lime-activated ground granulated blast furnace slag (GGBS) is usually used to treat gypseous soils. However, sulphate-bearing soils often contain other sulphates, e.g., sodium sulphate (Na2SO4), potassium sulphate (K2SO4) and magnesium sulphate (MgSO4). Therefore, in this study, lime-GGBS was used as a curing agent for stabilising four sulphate-bearing soils, which were named as Na-soil, K-soil, Mg-soil, and Ca-soil. Unconfined compressive strength (UCS), swelling, X-ray diffraction, scanning electron microscopy and inductively coupled plasma spectroscopy tests, were conducted to explore the macro- and micro-properties of the lime-GGBS-stabilised soils. The results showed that at 5000 ppm sulphate, stabilised Mg-soil had the lowest swelling and highest UCS. At 20,000 ppm sulphate, stabilised Ca-soil had the lowest swelling, while stabilised Na-soil had the highest UCS. Generally, increasing sulphate concentration decreased swelling for Ca-soil but increased for other three soils, and decreased UCS for Mg-soil but increased for other three soils. This was because less ettringite was generated in the stabilised Ca-soil and the formation of magnesium silicate hydrate (MSH) in the stabilised Mg-soil. Therefore, the sulphate type had a significant impact on the swelling and strength properties of lime-GGBS-stabilised sulphate-bearing soil. It is essential to identify the sulphate type before stabilising the soil on-site.

Effect of SDS Surfactant on Two-Phase Flows in Horizontal Pipelines

Surfactants significantly influence the flow patterns of gas-liquid two-phase flows. Understanding the behavior of multiphase flows in the presence of surfactants is crucial for optimizing hydrate transport in pipelines. This study presents experimental investigations into the effects of surfactant-induced surface tension variations on gas-liquid two-phase spiral flows in horizontal pipelines. Four distinct flow patterns were identified: spiral linear flow, spiral wave-stratified flow, spiral axial flow, and spiral dispersed flow. Notably, spiral bubbly flow and spiral slug flow were absent in gas-liquid two-phase spiral flows with a low concentration of the anionic surfactant sodium dodecyl sulfate (SDS). A flow pattern map was developed to describe gas-liquid two-phase spiral flows in horizontal pipelines with low SDS concentrations. The results indicate that increasing the liquid-phase velocity reduces the spiral diameter and attenuates the flow patterns while increasing the pitch of the spiral flows. Furthermore, at a constant gas-phase void fraction, the pressure drop is highest in spiral wave-stratified flow and lowest in spiral dispersed flow.

Self-organizing maps provide new insights into the MixSIAR model for calculating source contributions of sulfate contamination in groundwater.

Self-organizing maps provide new insights into the MixSIAR model for calculating source contributions of sulfate contamination in groundwater.

Characterizations the PbS Nanoparticles Prepared by Plasma Induced Chemical Reaction

The research target explores how the bursting current and sodium sulfate (Na2S) concentration affect the structural and morphological properties of lead sulfide (PbS) nanoparticles. Three currents of 50, 60, and 70 A were run via a 0.5 mm-diameter lead wire. By dissolving 1, 0.75, 0.5 g of the sodium sulfate in 100 ml of water, 3 concentrations of sodium sulfate salt 10, 7.5, and 5 mg/cm3 were obtained. The sulfur ions react with lead ions when the wire explodes, producing PbS nanoparticles. X-ray diffraction analysis (XRD) of the particle structure revealed a face centered cube arrangement (fcc). The nanoparticles' size and form were detected utilizing a scanning electron microscope (SEM). SEM images showed that the PbS nanoparticle is spherical and that there is a correlation between the current and the size of the nanoparticles. The average particle size was measured at 30, 24, and 36 nm at currents of 50, 60, and 70 A, respectively. The variation in lead sulfate concentration slightly impacted the morphology and dimensions of the particles. This enables us to deduce the viability of creating lead sulfate nanoparticles in an easy, cost-effective, high-purity, and environmentally friendly technique.

Sulfate concentration and redox state control the pyrite formation and sulfur cycle in a T-OAE lake, Sichuan Basin, China

Sulfate concentration and redox state control the pyrite formation and sulfur cycle in a T-OAE lake, Sichuan Basin, China

Study of the Scattering Capacity of Sulfate Electrolyte for Electrolytic-Plasma Polishing

A method for calculating the scattering capacity using a sectional anode for the electrolytic-plasma polishing variant, both with and without taking into account the edge effects, has been developed and tested. An increase in the scattering capacity of the electrolyte is shown to depend on both an increase in the hydrodynamic parameters of the sulfate electrolyte and a decrease in the processing voltage, in the electrolyte temperature, and in the concentration of ammonium sulfate in the electrolyte. The maximum scattering capacity (taking into account the edge effects) was found to be 95% at a processing voltage of 250 volts, an electrolyte temperature of 60 ºС, and an ammonium sulfate concentration of 3%.

Mine Water Discharge Chemistry and Potential Risk in a Former Mining Area

The Maramures region, located in North-Western Romania, was a renowned center of mining and smelting in the last century. Nowadays, all the mines have been decommissioned or are under conservation and greening works, but the acidic waters from some closed or abandoned mine galleries negatively affect the nearby streams and, in some cases, the entire river system. In this study, 46 elements and 6 anion concentrations were used to assess the pollution in 12 mine water discharge samples collected in two mining areas in Maramures. The results showed high concentrations of sulfate (average 1264 mg/L) and toxic elements, namely Mn (average 25.1 mg/L), Fe (average 23.0 mg/L), and Zn (average 12.5 mg/L). The sum of the REEs concentration ranged from 1.24 µg/L to 2917 µg/L, with an average of 363 µg/L, with La, Ce, and Nd being the most abundant. High correlations were found between REEs and Li, Be, Al, Sc, V, Mn, Fe, Co, Ni, Y, SO42−, and NO2−. According to the pollution index, the discharge of mine water poses different degrees of ecological risk. The health hazard index calculated for 37 elements revealed an extremely high non-cancer risk and, in addition, an increased carcinogenic risk for Cd, As, and Cr.

The removal of high Se(IV) and Cd(II) concentrations in sulfur autotrophic reactor based on the "hibernation-like microbial survival strategy".

The removal of high Se(IV) and Cd(II) concentrations in sulfur autotrophic reactor based on the "hibernation-like microbial survival strategy".

Innovative pre-treatments for reverse osmosis to reclaim water from biotech and municipal wastewater for the industrial symbiosis in Kalundborg

ABSTRACT The challenge of water reclamation using membranes in this study was the quite unique wastewater composition resulting from a high share of biotech wastewater. The high content of organic matter and high concentrations of calcium, bicarbonate, and sulphate were considered as challenging for membrane processes. Consequently, an innovative ultra-tight ultrafiltration (u-t UF) membrane was developed and tested on-site at pilot scale. In comparison, a conventional UF and an open nanofiltration (NF) were piloted. The aim was to find the best pre-treatment option for reverse osmosis (RO) to reduce fouling and scaling and produce fit-for-purpose water; for example, cooling. Overall, the quality of the currently used water source was surpassed by the pilot plant. Only a standard post-treatment of the RO permeate was necessary for stabilisation. Results indicated that denser membranes only minimally reduced fouling of RO. An assessment comparing the treatment trains in a life cycle assessment using the data collected from the pilot operation (UF/NF operating settings, RO plant performance, and the design of multi-stage industrial scale RO) revealed lower greenhouse gas emissions compared to seawater desalination. However, if RO brine needs to be treated, greenhouse gas emissions for water supply via wastewater reuse exceed other freshwater source.