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Silk fibroin (SF)–chondroitin sulfate (CS)-hybrid hydrogels (HHGs) containing kartogenin (KGN) were synthesized by the induction of di-tyrosine bonds, using enzymatic crosslinking in SF/CS blend solution. Then, physical crosslinking was performed to optimize the HHG properties. The results showed that the increasing of the β-sheet content as side effect of physical crosslinking from 10% to 40% affects KGN accumulative release percentage almost three times. Biological investigations using C28/I2 human chondrocyte cell line showed that the presence of KGN, CS, and optimized β-sheets content improved cell supporting behavior of HHG. Finally, KGN loaded HHG might be a promising candidate for cartilage repair. Schematic representation of fabrication of the dual crosslinked hybrid hydrogel containing silk fibroin and chondroitin sulfate by enzymatic crosslinking and physical crosslinking method for kartogenin release. Enzymatic crosslinking: shaping di-tyrosine formation bond between silk fibroin phenol groups and locking physically chondroitin sulfate between silk fibroin β-sheets. Physical crosslinking with water and/or ethanol treatments end up in increased β-sheets content. [ABSTRACT FROM AUTHOR]

Degradation efficiency of 4-bromo-2-chlorophenol (BCP) containing both chlorine and bromine substituents in Co/PMS process was investigated in the light of a wide range of substrate, oxidant, catalyst concentrations and pH value. The effects of chloride ion (Cl−) on degradation kinetics, total organic carbon (TOC) removal and intermediates formation during BCP depletion in Co/PMS system were studied. The kinetics results demonstrated that the dual effect of Cl− on BCP depletion in Co/PMS system due to different mechanisms involved. High concentrations of Cl− (>5 mM) can significantly promote the degradation of BCP, but did inhibit BCP mineralisation to a certain extent which was closely related to Cl− content. High degradation rates but lower mineralisation rates were found in the laboratory experiments, owing to the fact that BCP was mainly transformed to new halogenated intermediates instead of complete mineralisation. Gas chromatograph-mass spectrometer (GC-MS) data verified that a series of chlorinated by-products were formed during BCP decomposition process involving of the participation of Cl−. The proposed degradation pathways of BCP and its derivatives in presence of Cl− were discussed on the basis of intermediate products including the undesirable halogenated by-products recognised by GC-MS. These results might offer some new perspectives on the transformation fates of BCP by utilising Co/PMS regent. [ABSTRACT FROM AUTHOR]

This study examined the associations of long-term exposure to ambient fine particulate matter (PM2.5) compositions/ozone with methylation of peripheral brain-derived neurotrophic factor (BDNF) promoters. A total of 101 participants were recruited from a cohort in Shijiazhuang, Hebei province, China. They underwent baseline and follow-up surveys in 2011 and 2015. DNA methylation levels were detected by bisulfite-PCR amplification and pyrosequencing. Participants' three-year average levels of PM2.5 compositions and ozone were estimated. Bayesian kernel machine regression (BKMR) models were used to examine the joint effects of pollutants on methylation levels. Exposure to PM2.5 compositions and ozone mixtures at the 75th percentile was associated with increased methylation levels at CpG2 of BDNF promoter (203%, 95% CI: 89, 316) than the lowest level of exposure, and sulfate dominated the effect in the BKMR models.Our findings provide clues to the epigenetic mechanisms for the associations of PM2.5 compositions and ozone with BDNF. [ABSTRACT FROM AUTHOR]

To provide a theoretical basis for reducing thaumasite sulfate attack (TSA) and enhancing ground limestone utilization in cement-ground limestone cementitious materials, this study examines the mechanisms underlying thaumasite formation and its relationship with temperature, cations, and ground limestone, utilizing thermodynamic principles. The findings indicate that thaumasite formation is constrained above 60.35 °C. Between 48.15 and 60.35 °C, only direct route is feasible, while below 48.15 °C, both direct and woodfordite routes occur spontaneously. As temperature decreases, Gibbs free energy changes decrease for both routes, promoting thaumasite formation. Mg2+ facilitates thaumasite formation via woodfordite route, while Na+ promotes it via direct route. With both Mg2+ and Na+ present, thaumasite formation depends on Na+ to Mg2+ ratio: below 5 favors woodfordite route, exceeding 5 favors direct route. Ground limestone reduces sulfate required for thaumasite formation, favoring the woodfordite route and exacerbating TSA; however, excessive ground limestone has a dilution effect on cement, thereby reducing thaumasite formation. [ABSTRACT FROM AUTHOR]

The in-situ reduction of zero-valent iron (ZVI) is an effective method for removing chlorinated aliphatic hydrocarbons (CAHs) from groundwater. The heterogeneity of environmental conditions is also crucial in affecting dechlorination efficiency. Until now, the effect of Sulfate (SO42–) on ZVI activity has been debated, and the related mechanism research on SO42– behaviour during the abiotic reduction process of chlorinated alkanes is still lacking. In this study, the impacts of SO42– concentrations (0, 2, 4, 8, 80 mM) on the degradation of 1,1,2-trichloroethane (1,1,2-TCA) by micron-size ZVI (mZVI) and nano-size ZVI (nZVI) were systematically investigated. For mZVI, Kobs increased by 0.6 (2 mM), 0.5 (4 mM), 1.1 (8 mM), and 1.6 times (80 mM). For nZVI, Kobs decreased by 32% (2 mM), 39% (4 mM), 45% (8 mM), and 9% (80 mM). The results showed that SO42– increased the rate of 1,1,2-TCA degradation by mZVI but weakened the reduction performance of nZVI; however, this inhibition was reduced when the concentration reached 80 mM. SO42− controlled the degradation of 1,1,2-TCA mainly through the formation of different iron-sulfate complexes on the ZVI surface: water-soluble bidentate iron-sulfate complexes formed on the mZVI surface promoted the corrosion of the oxide layer and accelerated the reduction of 1,1,2-TCA, monodentate complexes mainly formed on the nZVI surface inhibited the reduction of 1,1,2-TCA by blocking surface sites. These results demonstrate the proof of concept to assist land managers in the field application of ZVI technology for the remediation of CAHs contaminated sites with different background concentrations of SO42−. [ABSTRACT FROM AUTHOR]

A fast, simple and cost-effective technique has been used to produce spray-drying porous particles of salbutamol sulfate (SS) for inhalation drug delivery. The particles were produced using water as solvent and ammonium bicarbonate as pore-forming agent. A full factorial experimental design (24) with a central point was used to evaluate the influence of process parameters (drying air inlet temperature, atomization air volume flowrate, feed volume flowrate and the pore-forming agent concentration) on process yield, moisture content, densities and particle size. In addition, particle morphology, in-vitro aerosolization properties, stability and cytotoxicity of selected samples were studied. Within the experimental design parameters window, it was shown that the highest inlet temperature and pore-forming agent concentration were the factors that more affected the process yield and tap density values. Particles with the lowest tap densities values exhibited porous morphology. In addition, the pore-forming agent concentration proved to be the most significant variable affecting particle size. The highest pore-forming agent concentration, the largest particle size. The porous particles exhibit remarkable aerosolization performance, surpassing the performance of previously reported SS porous particles and a commercial formulation. These powders showed a high process yield and the absence of ammonium bicarbonate in the final product, as confirmed by FT-IR. Furthermore, the powders presented good stability even over long periods of time and did not exhibit cytotoxicity on the murine alveolar macrophage cell line RAW 264.7. [ABSTRACT FROM AUTHOR]

Solid waste landfill (SWL) is known as a major pollution source contaminating air, water sources, and soil environment. The main hazard of SWL is leachate including high organic matter and nutrients. Recently, sulphate radical-based advanced oxidation processes (SR-AOPs) based on persulphate (PS) have been applied as a useful method for removal of chemical oxygen demand (COD) and ammonia from landfill leachate (LL). The removal efficiency of the SR-AOPs depends on effective parameters such as pH, oxidant dosage, catalyst dosage, temperature, reaction time, and so forth. Among SR-AOPs, thermal persulphate oxidation (TPO) seems to be promising for removal of both COD and ammonia; however, the high amount of energy cost is regarded as a major drawback. The drawbacks and future challenges for the use of SR-AOPs for LL have been discussed, and some strategies such as using coupled mechanisms of SR-AOPs have been proposed to tackle the common difficulties. Finally, the performance of SR-AOPs for treatment of LL has been compared with hydroxyl radical processes. [ABSTRACT FROM AUTHOR]

External sulphate attack (ESA) interferes with spatial changes in fracture toughness of cemented paste backfill (CPB) and affects its mechanical stability. Large-scale curing column models are developed to investigate the spatial evolution of mode-I and mode-II fracture toughness (i.e. KIC and KIIC) under seepage- and diffusion-induced ESA. It has been found that the seepage-induced ESA leads to spatial changes in KIC and KIIC of CPB at advanced ages and higher extent of degradation of fracture toughness is measured at a deeper position in CPB. Comparatively, KIc can be used as a reliable quantity to estimate KIIc under the diffusion-induced ESA. [ABSTRACT FROM AUTHOR]

Sodium tanshinone IIA sulphate (STS) is a product originated from Salvia miltiorrhiza Bunge [Lamiaceae], which exerts an antitumour effect. However, the role of STS on lung adenocarcinoma (LUAD) remains unexplored. Our study explores the effect and mechanism of STS against LUAD. LUAD cells were treated with 100 μM STS for 24 h and control group cells were cultured under normal medium conditions. Functionally, the viability, migration, invasion and angiogenesis of LUAD cells were examined by MTT, wound healing, transwell and tube formation assay, respectively. Moreover, cells were transvected with different transfection plasmids. Dual luciferase reporter and RNA immunoprecipitation (RIP) assays were used to verify the relationship between miR-874 and eEF-2K. STS significantly decreased the viability (40–50% reduction), migration (migration rate of A549 cells from 0.67 to 0.28, H1299 cells from 0.71 to 0.41), invasion (invasion numbers of A549 cells from 172 to 55, H1299 cells from 188 to 35) and angiogenesis (80-90% reduction) of LUAD cells. Downregulation of miR-874 partially abolished the antitumour effect of STS. EEF-2K was identified to be the target of miR-874, and its downregulation markedly abolished the effects of miR-874 downregulation on tumourigenesis of LUAD. Moreover, silencing of TG2 abrogated eEF-2K-induced progression of LUAD. STS attenuated the tumourigenesis of LUAD through the mediation of the miR-874/eEF-2K/TG2 axis. STS is a promising drug to fight against lung cancer, which might effectively reverse drug resistance when combined with classical anticancer drugs. [ABSTRACT FROM AUTHOR]

Subgrade is an essential factor for the service life of highways and railways, especially the sulfate attack of subgrade made of saline soil. Therefore, it is necessary to improve the transport property of subgrade. In this study, sulfate transport of cementitious materials-solidified saline soil was assessed. Firstly, factors affecting sulfate transport were characterized in natural soil. Furthermore, fly ash and lime were implemented to prepare a new kind of improved soil. By analyzing the microstructure development, influence of fly ash and lime on sulfate transport was investigated and the improved mix proportion was addressed. Finally, the last section focused on the mechanism for sulfate resistance of the soil. Raw materials, phase assemblage improvement, and pore structure refinement caused by filler effect and pozzolanic reaction effect of fly ash were the main reasons for the sulfate resistance increase. This study is helpful for the service life improvement of highways and railways. [ABSTRACT FROM AUTHOR]

Artemisinin-hydroxychloroquine sulfate tablets (AH) are regarded as a relatively inexpensive and novel combination therapy for the treatment of various forms of malaria, particularly aminoquinoline drugs-resistant strains of Plasmodium falciparum. Our aim was to conduct acute and subacute oral toxicity studies in non-rodents to obtain more nonclinical data on the safety of AH. Acute toxicity evaluation was performed in beagle dogs at single doses of 230, 530, 790, 1180, 2660, and 5000 mg/kg. Beagle dogs at doses of 0, 56, 84, and 126 mg/kg were used to assess subacute toxicity for 14 days. The approximate lethal dose range for acute oral administration of AH in dogs is found to be 790–1180 mg/kg, and toxic symptoms prior to death include gait instability, limb weakness, mental fatigue, tachypnea, and convulsion. Repeated doses of AH in dogs caused vomiting, soft feces, decreased activity, anorexia, and splenic red pulp vacuolation. Of note, AH could reduce body weight gain and prolong the QTc interval of individual dogs. Therefore, the no-observed-adverse-effect level (NOAEL) and lowest-observed-adverse-effect level (LOAEL) of oral administration of AH for 14 days in dogs are determined to be 84 mg/kg and 126 mg/kg, respectively. [ABSTRACT FROM AUTHOR]

In this paper, the effects of nano-zero valent iron (nZVI) on anaerobic digestion of sulphate wastewater with different SO 4 2 − /COD ratios, including the COD removal rate, methane yield, intermediate products and the change of microbial community structure, were investigated. The results showed that nZVI could effectively enhance the treatment efficiency and methane yield. Compared with the control group without nZVI, the methane yield increased from 348.6833 to 1007.05 mL CH4/gCODremoval with 4 g nZVI loading at SO 4 2 − /COD = 0.1. nZVI could make electron flow from sulphate reduction to methane production, which increased methane yield even at high sulphate concentration. The microbial community analysis showed that adding nZVI could increase the abundance of acetoclastic methanogens, which accelerated hydrolysis acidification. [ABSTRACT FROM AUTHOR]

This study investigates the performance of recycled aggregate concrete incorporating different sizes and concentrations of coarse aggregate under sodium sulphate and normal water curing. Ten mixes were produced, having two control mixes of 12 to 20 mm and 5 to 12 mm coarse aggregate size. The rest of the mixes have supplementary cementitious material with 0%, 15%, 30%, and 45% substitution of respective sizes normal aggregate by recycled aggregate. The fresh recycled aggregate concrete mixes were assessed through the slump, ball penetration, and compacting factor test, which exhibited a falling trend with the percentage increase of recycled aggregate. Moreover, compressive strength and ultrasonic pulse velocity drop with the percentage of RCA increases at 7, 28, and 91-days normal curing and 5% Na2SO4 solution curing at 91 days. The compressive strength and ultrasonic pulse velocity of 5-12 mm coarse aggregate concrete showed improvement over 12-20 mm coarse aggregate concrete of the same replacement for both curing. However, 5% Na2SO4 solution curing specimens exhibit around 5-11% decrease in compressive strength and higher penetration depth than normal curing . Furthermore, the outer face of the silica fume included samples have received fewer white patches after sodium sulphate immersion. [ABSTRACT FROM AUTHOR]

The oxidation of sulfur dioxide (SO2) to sulfate in the atmosphere is an important concern in regional air quality, global climate change, and human health. While gas-phase and liquid-phase oxidation of SO2 are widely regarded as important sources of sulfate, the contribution of the heterogeneous oxidation process on particle surfaces is controversial. Recently, this heterogeneous chemistry has been considered to be an important mechanism that is missing in current models to explain sulfate concentrations observed in haze episodes in East Asia. Therefore, the heterogeneous oxidation of SO2 on particles under the conditions of complex air pollution needs to be reassessed. This review summarizes the fundamental understanding of the heterogeneous reactions of SO2 on solid particles such as mineral dust, black carbon, sea salts, organic aerosol, and so on. The factors affecting the mechanism and kinetics of the heterogeneous reactions of SO2, including coexisting components (O3, NO2, H2O2, NH3, and VOCs), reactive sites, surface properties, relative humidity, and illumination, are reviewed. Reactive oxygen species involved in the heterogeneous oxidation of SO2 on particles are discussed. To our knowledge, while previous reviews have appeared on the oxidation of SO2 in the aqueous-phase, this is the first review on the atmospheric heterogeneous reactions of SO2 on the surface of solid particles, which can be of help in understanding the sulfur cycle in the atmosphere and its environmental impacts. A number of recommendations for future research are also presented. [ABSTRACT FROM AUTHOR]

Chemical reactions can lead to the expansion of the geomaterial because of the strong precipitation of minerals in the pores of the medium. The quantity and the variability of these reactions led to the development of several chemo-mechanical models. A generic chemo-poromechanical model is proposed to predict both the material degradation induced by various concrete pathologies and the environmental multi-factor impact on the macroscopic swelling. The model is based on the coupling between reactive transport (species diffusion and chemical reactions) and poromechanics. The mineralogy and the poromechanical properties are estimated by a hydration-micromechanics model which allows to consider the material effects. The main applications are dedicated to External Sulfate Attack and Delayed Ettringite Formation of cementitious material at mesoscale. The studies highlight the ability of the model to deal with complex and various phenomena such as coupling chemical reactions with calcium leaching, sulfate sorption and ettringite precipitation, and to consider their impact on the macroscopic expansion. Results also bring out the accuracy of the chemo-poromechanical model to simulate different swelling pathologies. The characteristic crack paths induced by differential strain, material impact, and swelling at the macroscopic scale, fit with experimental observations. [ABSTRACT FROM AUTHOR]

Sulphate-reducing bacteria (SRB) are known to cause severe corrosion of steel structures in various industries, resulting in significant economic and environmental consequences. This review paper critically examines the impact of SRB-induced corrosion on steel, including the formation of SRB biofilms, the effect on different types of steel, and the various models developed to investigate this phenomenon. The role of environmental factors in SRB-induced corrosion, molecular techniques for studying SRBs, and strategies for mitigating corrosion are discussed. Additionally, the sustainability implications of SRB-induced corrosion and the potential use of alternative materials were explored. By examining the current state of knowledge on this topic, this review aims to provide a comprehensive understanding of the impact of SRB-induced corrosion on steel and identify opportunities for further research and development. [ABSTRACT FROM AUTHOR]

Calcium–silicate–hydrate (C–S–H), the most important phase of hydrated portland cement, is responsible for the cementitious system's mechanical properties performance and durability. In a severe environment, C–S–H often suffers from sulphate attack, leading to severe concrete deterioration. The present work describes a detailed mechanism of sulphate attack on C–S–H from 28 to 270 days of sulphate curing (10% Na2SO4 solution) using XRD, TGA, FTIR, 29Si-NMR and FESEM/EDX techniques. The results show that gypsum is the only sulphate-bearing product formed by decalcification of calcium hydroxide first and then of C–S–H. Decalcification enhances polymerization in the C–S–H structure as an additional Q3 peak was observed in FTIR and 29Si-NMR analysis. The microstructure of C–S–H becomes more crystalline as the sulphate curing period increases, as observed in FESEM micrographs. In addition, sulphate adsorption on C–S–H was identified through FESEM/EDX, which could play an important role in the deterioration of cementitious materials. [ABSTRACT FROM AUTHOR]

Sulfate content in mining wastewater can reach concentrations over 2,000 mg·L−1, which is considered as a pollutant of concern. In this article, two cyanobacteria species were cultured using highly sulfated wastewater (3,000 mg·L−1) as the culture medium. This investigation aimed to analyze the sulfate bioremediation potential of microalgae while enhancing the uptaking of this pollutant through the design of a novel nutritional medium. The results obtained show the suitability of Arthrospira maxima as a bioremediation organism of sulfated wastewater. The appropriateness of this organism is based on its great growth performance when cultured in this residue, 2.16 times higher than the initial value. Moreover, the initially obtained sulfate reduction, 23.3%, was significantly enhanced to a final removal of 73% (2,247 mg·L−1). In addition, scanning electron microscopy and energy-dispersive X-ray spectroscopy were used to evaluate sulfur crystallization. To the best of our knowledge, there are no previous works focused on microalgal sulfate removal that have reached such an uptaking rate. Accordingly, this study presents the highest performance on sulfate microalgal bioremediation published to date. Our findings suggest that A. maxima can be cultured for sulfated wastewater bioremediation while showing a removal yield that is theoretically sufficient for industrial applications. To the best of our knowledge, this is the first study focused on the bioremediation potential of Arthrospira genre (Spirulin) for highly sulfated wastewaters depuration. Moreover, according to the available data, our study achieved the highest sulfate removal rate by using microalgae as a bioremediation organism. Thus, we strongly believe that our investigation provides up-to-date data in terms of mining wastewaters bioremediation, which can cause a strong impact on how these residues are managed. [ABSTRACT FROM AUTHOR]

The reactive MgO (r-MgO)-microbial curing technology can not only effectively improve the strength of electrolytic manganese residue (EMR) but also repair heavy metal ions. By conducting unconfined compressive strength (UCS) test, heavy metal leaching test, X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and mercury intrusion porosimetry (MIP), the effects of the type and concentration of sulfate on the strength and repair of heavy metals of the cured EMR under drying–wetting (DW) cycles were studied, and the strength and the evolution mechanism of heavy metal remediation is elucidated. The results indicate the following: With the increase in the number of DW cycles, the dry density of the samples in high concentration of MgSO4 first increased slightly and then decreased gradually and became stable. The dry density of the samples in Na2SO4, low concentration of MgSO4, and water generally showed a downward trend. The pH of the soaking solution slightly decreased, and the leaching concentration of heavy metal Mn2+ ions always remained at a low level. The UCS of the samples in MgSO4 first increased slightly and then decreased gradually, and then became stable. The amount of cured products first increased and then decreased, and the size of internal pores first decreased and then increased. The UCS of the samples in Na2SO4 and water gradually decreased and became stable. The amount of cured products gradually decreased, and the size of internal pores gradually increased. The research results provide a theoretical basis for the evaluation of resistance against the sulfate corrosion of cured EMR under DW cycles. [ABSTRACT FROM AUTHOR]

Wood emits volatile organic compounds (VOCs) that can affect people's health and air quality. Based on advanced oxidation processes (AOPs), sulfate radicals produced via thermally-activated persulfate (Na2S2O8, KHSO5) can minimize VOCs. This research aims to apply this technique to minimize the VOC content in Pinus radiata. The results showed that terpenes and alcohols were the main VOCs emitted from Pinus radiata, which were greatly minimized using four treatments; however, acetic acid and 3-furaldehyde emissions increased. Furthermore, the temperature and oxidizing agent contributed to VOC degradation. Characterization results, including FTIR, XRD, color tests, and compressive strength indicated that the AOP treatment caused only a slight decline in the wood properties, while effectively reducing VOC emissions by as much as 32.75–61.05%. [ABSTRACT FROM AUTHOR]

Sulfate-rich effluents have been successfully treated in anaerobic reactors using sulfate-reducing bacteria (SRB). Many authors have demonstrated that these systems require nitrogen and phosphorous supplementation to achieve high sulfate removal rates. However, the resource ratio theory assumes that some species can be dominant according to the nutritional relations used or even without external nutrient supplementation. Thus, this study evaluated the SRB communities in batch reactors without external nitrogen and phosphorus sources based on most probable number (MPN) quantification, denaturing gradient gel electrophoresis (DGGE) analyses and sequencing. The sulfate and chemical oxygen demand (COD) removal and kinetic parameters were also determined. After 100 days of operation, the sulfate and COD removal achieved 71.8 ± 10% and 86.5 ± 10%, respectively. The SRB population increased from 8.106 to 4x1012 MPN 100mL-1, and the richness of SRB bands was much higher at the end of the experiment compared to the inoculum. In addition, the sequenced bands from SRB-DGGE showed similarities to Desulfacinum infernum, Desulfobulbus sp, Syntrophobacter and Desulfomicrobium aestuarii-related sequences. Therefore, biological treatment of acid mine drainage wastewater was effective in the absence of nutrients, lowering costs and providing high sulfate removal efficiency. [ABSTRACT FROM AUTHOR]

It has been acknowledged for years that compounds containing sulfur (S) are an important source of endogenous acid production. In the metabolism, S is oxidized to sulfate, and therefore the mEq sulfate excreted in the urine is counted as acid retained in the body. In this study we show that pH in fluids with constant [Na] and [HEPES] declines as sulfate ions are added, and we show that titratable acidity increases exactly with the equivalents of sulfate. Therefore, sulfate excretion in urine is also acid excretion per se. This is in accordance with the down-regulation of proximal sulfate reabsorption under acidosis and the observation that children with distal renal tubular acidosis may be sulfate depleted. These results are well explained using charge-balance modeling, which is based only on the three fundamental principles of electroneutrality, conservation of mass, and rules of dissociation as devised from physical chemistry. In contrast, the findings are in contrast to expectations from conventional narratives. These are unable to understand the decreasing pH as sulfate is added since no conventional acid is present. The results may undermine the traditional notion of endogenous acid production since in the case of sulfur balance, S oxidation and its excretion as sulfate exactly balance each other. Possible clinical correlates with these findings are discussed. [ABSTRACT FROM AUTHOR]

In this paper, the influences of biochar on the anaerobic digestion of sulphate wastewater, including the COD removal rate, methane yield, intermediate products and the change of microbial community structure, were investigated. The results showed that sulphate could promote the anaerobic digestion with the SO42−/COD ratio increasing from 0 to 0.1, while the activity of MPB was inhibited, which led to the decrease of COD removal rate and methane yield with the SO42−/COD ratio increasing from 0.1 to 2. At 1 g biochar loading, 344.97 mL CH4/gCODremoval was obtained compared with the control group (220.70 CH4/gCODremoval) at 2 of SO42−/COD. Biochar could also reduce the secondary accumulation of NH4+–N and TVFA. Meanwhile, methanogenic microorganisms were selectively enriched especially for methanobacterium, methanosaeta and methanolinea, while the growth of SRB was inhibited with biochar addition. [ABSTRACT FROM AUTHOR]

Capacitive deionization (CDI) is an environmentally friendly desalination technique with low energy consumption. However, unmodified carbon electrode materials have poor sulfate selectivity and adsorption capacity. In this work, to improve sulfate selectivity, we prepared activated carbon materials loaded with different amino contents by grafting amino groups via acid treatment for different times. In the competitive ion adsorption experiments, the sulfate selectivity of AC was only 0.64 and the amino-modified AC increased by 1.98-2.52 times due to the formation of stronger hydrogen bonds between the amino group and sulfate. AC-NH2-4 had the best selectivity and the sulfate selective coefficient was 2.25. The desorption of sulfate was 92.46% within one hour. In addition, the surface of the amino-modified activated carbon showed significantly improved electrochemical properties and better capacitance. The specific capacitance of amino-modified AC in different electrolyte solutions was consistent with the competitive adsorption results. The specific capacitance of amino-modified AC in Na2SO4 electrolyte solution was the highest. The modified electrode material also had the advantages of a higher adsorption capacity and excellent regeneration performance after continuous electric adsorption–desorption cycles. Therefore, it may have development potential to selectively adsorb sulfate in practical applications. [ABSTRACT FROM AUTHOR]

This paper identifies the critical cement parameters that cause expansive delayed ettringite formation (DEF) and compares them with Australian cement standards and specifications. The comparison shows that general-purpose (GP) cements adhering to Standards Australia and specifications stipulating low sulphate, alkali contents may not be prone to expansive DEF. However, there is a lack of experimental evidence supporting the low risk of Australian cements for expansive DEF. Hence, in this study, the susceptibility of Australian GP cements to expansive DEF under different heat curing temperatures up to 90°C have been studied. Further, these cements have been chemically modified to simulate the characteristics of cements used where deleterious DEF is observed in field cases. The testing protocol included long-term mortar expansion studies supported by phase and microstructural analyses. The results indicate that mortars containing Australian GP cements do not exhibit DEF expansion. Furthermore, increasing the cement sulphate content to 4% or alkali content to 1% did not result in DEF expansion. However, for cements where both the sulphate and alkali contents were increased to 4% and 1%, respectively, mortars generated significant expansion associated with ettringite precipitation. Overall, the results obtained from this study indicate that GP cements complying with Standards Australia and specifications for sulphate and alkali limits are not susceptible to expansive DEF. [ABSTRACT FROM AUTHOR]

This paper explores the effects of concentration of acid activation on the properties of rare earth tailings catalyst. The results show that the denitration activity of rare earth tailings catalyst is enhanced by acid activation. The best denitration activity of catalyst, activated by sulfuric acid of 8 mol/L, is 86%. [ABSTRACT FROM AUTHOR]

This paper explores the effects of concentration of acid activation on the properties of rare earth tailings catalyst. The results show that the denitration activity of rare earth tailings catalyst is enhanced by acid activation. The best denitration activity of catalyst, activated by sulfuric acid of 8 mol/L, is 86%. [ABSTRACT FROM AUTHOR]

Surfactants have been used to modulate mechanical properties and hydration of calcium sulfate hemihydrates or other cement-like material, especially to improve the properties of cheap materials. In gypsum industry, β-Hemihydrate (β-H) costs less than the a-hemihydrate but presents lower mechanical strength after hydration. In this study, a group of polysulfonates was designed and synthesized to investigate their structure-performance relationship in hydration of β-H and properties of the gypsum plaster. It was found that the hydration of β-H can be modulated by changing the hydrophilic side chain of the polysulfonates, which endowed the gypsum with differential mechanical strength and water absorption. The sodium alkenyl methyl polyoxyethylene ether amide vinyl/ally sulfonate offered the β-H gypsum highest water absorption, retarded hydration and enhanced mechanical strengths by forming compacter rod crystals. The mechanical strength and water absorption of the gypsum were not in direct proportion to hydrophilicity of the polysulfonates and the molar fraction of sulfonic groups, but related to their McGowan's HLB values. When the HLB values were below 15, the water absorption of β-H gypsum induced by the polymers increases with the increasing HLB values of the polymers. [ABSTRACT FROM AUTHOR]

Single crystals of L-alanine and Lithium sulfate doped L-alanine crystals were successfully grown by the slow evaporation method. The powder XRD studies were used to analyze the crystalline nature of the crystals. ICP analysis confirms the presence of lithium in the grown L-alanine crystal. The optical bandgap of grown crystals was measured by UV–Vis spectroscopy, and different functional groups present in the grown crystals have been identified by the FTIR spectral analysis. The dielectric studies of the grown crystals were performed at different temperatures as a function of the frequency. The photoconductivity study contributed its positive photoconducting nature. The second harmonic generation for the grown crystal was confirmed by the Kurtz–Perry technique. [ABSTRACT FROM AUTHOR]

The lightweight aggregate ceramsite (LAC) was prepared from by-product sulfate salt slag (BPSS) of high-salt organic wastewater with fly ash. The BPSS fixation rate, leaching toxicity, morphological structures and potential environmental risks of heavy metals in LAC were investigated. BPSS can be fixed in LAC when the mass ratio of Fly ash: Kaolin: clay was 7:1:2, the addition of BPSS was 28%, the heating rate was 8°C min−1, and the calcination temperature was 1100°C. The characteristics of the LAC met the requirements for Chinese lightweight aggregate standards (GB/T17431.2-2010). The Total Organic Carbon (TOC) content of the aqueous leaching liquor in LAC was less than 0.5 mg·L−1. And the fixation rate of heavy metal was more than 99%, which meets the requirements of GB 5085.3-2007. The BPSS immobilization mechanisms were mainly related to the formation of new crystal phases, including Leucite (KAlSi2O6), Albite (Na2O·Al2O3·6SiO2), Potash Feldspar (K2O·Al2O3·6SiO2), Jadeite (NaAlSi2O6), Hauyne ([Na,Ca]8[Si,Al]12O24[SO4]2), Nosean (Na8Al6Si6O24SO4), and Sodalite (Na8Al6Si6O24[MnO4]2) by incorporation of heavy metals in high-temperature curing reaction. This work provides an effective method for the harmless treatment and recycling of by-product salt residues from high-salt organic wastewater. [ABSTRACT FROM AUTHOR]

Cement–bentonite (CB) slurry cutoff walls are extensively utilized to restrict the horizontal flow of fluids. In this study, cement was replaced by four various contents of 0%, 10%, 20%, and 30% by natural zeolite to evaluate its effects on the unconfined compressive strength, flexural strength, tensile strength, and the coefficient of permeability of cement–bentonite–zeolite (CBZ) specimens. Since underground cutoff walls are always in danger of sulfate attack, the CBZ specimens were immersed in three different containers with three different pH values of 2, 5, and 8 to study the sulfate resistance of this material. Results have indicated that the strength of specimens decreases with an increase in zeolite content at early ages; however, increasing the amount of zeolite up to 20% improves the mechanical properties and permeability of cutoff wall materials at late ages. The bentonite/cement (B/C) ratio equal to 0.2 shows a relatively better response than B/C ratios equal to 0.14 and 0.3. Curing specimens in the sulfate environment increased the mechanical strength of specimens and decreased the coefficient of permeability at first ages. At the late ages, curing in sulfate solutions manifested disadvantageous effects on specimens; however, specimens containing zeolite indicated higher sulfate resistance than specimens without zeolite. [ABSTRACT FROM AUTHOR]

The purpose of this work is to investigate sulfate removal from aqueous solutions by electrocoagulation (EC). The influence of electrolysis time, initial pH, and current density was carried out. The interaction of the several effects on removal efficiency was also studied. The Box-Behnken experimental design (BBD) in Response Surface Methodology (RSM) was applied in the development of statistical analysis, modeling, and interpretation of the resultant treatment data of sulfate removal by EC. The optimum conditions for highest removal ratio of sulfate from aqueous solution were: current density of 10 mA/cm2, initial pH equal 5 and electrolysis time of 60 min. Sulfate removal efficiency reach a maximum value of 98.76% and the predicted value is 100%. According to ANOVA results, the correlation coefficient (R2) value of 98% proved that experimental data and model predictions agreed well. The R2adj and R2pred were also in a reasonable agreement (98% and 95% respectively). The mathematical model that describes the EC process was determined and proved that all variable had linear and quadratic significant effect on sulfate removal efficiency. The optimum conditions founded using BBD conducted to 60 and 90% of sulfate removal respectively from seawater and brackish water. [ABSTRACT FROM AUTHOR]

This study aimed to identify human cytosolic sulfotransferases (SULTs) that are capable of mediating hyperoside sulfation and examine the impact of genetic polymorphisms on their sulfating activity. Of the thirteen known human SULTs analyzed, five (1A1, 1A2, 1A3, 1C2, and 1C4) displayed sulfating activity toward hyperoside. Kinetic parameters of SULT1C4 that showed the strongest sulfating activity were determined. Ten SULT1C4 allozymes previously prepared were shown to display differential sulfating activities toward hyperoside, revealing clearly the functional impact of SULT1C4 genetic polymorphisms. These findings provided a robust biochemical foundation for further studies on the metabolism of hyperoside by sulfation. [ABSTRACT FROM AUTHOR]

In this study, regeneration of DCF-spent activated carbon by microwave (MW) activated persulphate (PS), (MW+PS) and PS alone was investigated. The regeneration processes were optimised to achieve high adsorptive capacity with low operating cost, simultaneously. Optimisation was carried out with Taguchi L9 experimental design. Optimum conditions determined for (MW+PS) process were found as PS dose of 0.3 g, MW power of 406 W, the regeneration time of 8 min and pH of 7, while the optimum conditions determined for PS processes were found as PS dose of 1.5 g PS, the regeneration time of 15 min and pH of 9. At optimum conditions, an adsorptive capacity of 9.8 mg DCF/g GAC with an operating cost of 0.020 €/g GAC and an adsorptive capacity of 5.0 mg DCF/g GAC with an operating cost of 0.077 €/g GAC were found for (MW+PS) and PS processes, respectively. ANOVA analysis found that the most effective parameter to the responses for both regeneration processes was the PS dose, and its effect was 43.5% and 72.5% for (MW+PS) and PS processes, respectively. The regenerated GAC after at least 6 regeneration cycles was found to have a capacity above the adsorptive capacity of the raw GAC. [ABSTRACT FROM AUTHOR]

The impact of p-cresyl sulfate (PCS) and indoxyl sulfate (IS) on the prognosis of patients with uremia remains controversial. We performed a prospective study on peritoneal dialysis (PD) to investigate the relationship between PCS or IS levels with clinical outcomes. This prospective cohort study investigated the association of serum PCS and IS with clinical outcomes in patients undertaking PD. We performed a correlations analysis to explore the influencing factors of PCS an IS. Meta-analysis was conducted to objectively evaluate the prognostic effects of PCS and IS on different stages of CKD patients. A total of 127 patients were enrolled consecutively and followed with an average period of 51.3 months. Multivariate Cox regression showed that serum total PCS not only contributed to the occurrence of PD failure event (HR: 1.05, 95% CI = 1.02 to 1.07, p < 0.001), but also increased the risk of cardiovascular event (HR: 1.08, 95% CI = 1.04 to 1.13, p < 0.001) and PD-associated peritonitis (HR: 1.04, 95% CI = 1.02 to 1.08, p = 0.001). Dividing the total PCS level by 18.99 mg/L, which was calculated from the best cutoff value of the ROC curve, patients with total PCS higher than 18.99 mg/L had worse prognosis. Meta-analysis confirmed its value in cardiovascular event in PD. The serum total PCS concentration was a detrimental factor for higher PD failure event, cardiovascular event, and PD-associated peritonitis. It could be used as an innovative marker in predicting poor clinical outcome in PD. [ABSTRACT FROM AUTHOR]

Many compounds containing sulfur and phosphorous are present in wastewater of various industries like food processing, paper making, etc. The higher level of phosphate and sulfate ions causes many problems in everyday life. Based on this, nickel monometallic and nickel-cobalt bimetallic nanoparticles were synthesized using leaves extract of Coix lacryma-jobi L. and applied for sulfate and phosphate ions removal. UV-Vis. spectroscopy, fourier transformed infrared spectroscopy; scanning electron microscopy; X-ray diffraction, and energy-dispersive X-ray spectroscopy were used as characterizing techniques for synthesized nanoparticles. UV spectra for Ni nanoparticles showed the absorption band in the 380–400 nm range, while for Ni-Co bimetallic nanoparticles was noticed at 396 nm and 513 nm. Different functional groups were observed in FTIR spectra of leaves extract which acted as reducing and capping agents to form stable NPs. Different factors like adsorbent dosage, pH, temperature, adsorbate concentration, and time were optimized for maximum removal of sulfate and phosphate anions. The antioxidant potential of prepared nanoparticles was assessed by three different methods. The kinetics, thermodynamics, and adsorption isotherms were also studied for these ions removal. In the current study, the green approach was easy, time-saving and proved to be beneficial to remove sulfate and phosphate anions from wastewater. The leaves extract of Coix lacryma-jobi L. were employed for the synthesis of nickel monometallic and nickel-cobalt bimetallic nanoparticles and employed for the removal of sulfate and phosphate ions from aqueous solution. Antioxidant potential of biosynthesized nanoparticles was also assessed. Hence, the biosynthesized nanomaterial found to be novel adsorbent for removal of sulfate and phosphate from waste water. This research work has not been previously reported in literature. [ABSTRACT FROM AUTHOR]

In this work, uranium(VI) sorption from aqueous sulphate medium using tri-n-octylamine impregnated Siplite LX-16 resin has been investigated using batch experiments. The sorption parameters including aqueous pH, initial U(VI) concentration, aqueous solution volume to impregnated resin weight (v/w) ratio, contact time and the sorption temperature have been studied. The experimental data have been examined by both equilibrium isotherms and kinetic sorption models. It was found that, the sorption process of U(VI) onto the working resin follows both Langmuir and Freundlich isotherms and quite agrees with the pseudo-second order and intraparticle diffusion models. [ABSTRACT FROM AUTHOR]

Diabetes mellitus is one of the most concerning conditions, and its chronic consequences are almost always accompanied by infection, oxidative stress, and inflammation. Reducing excessive reactive oxygen species and the wound's inflammatory response is a necessary treatment during the acute inflammatory phase of diabetic wound healing. Malva sylvestris extract (MS) containing nanofibers containing neomycin sulfate (NS) were synthesized for this investigation, and their impact on the healing process of diabetic wounds was assessed. Using Design Expert, the electrospinning process for the fabrication of NS nanofibers (NS-NF) was adjusted for applied voltage (X1), the distance between the needle's tip and the collector (X2), and the feed rate (X3) for attaining desired entrapment efficacy [EE] and average nanofiber diameter (ND). The optimal formulation can be prepared with 19.11 kV of voltage, 20 cm of distance, and a flow rate of 0.502 mL/h utilizing the desirability approach. All the selected parameters and responses have their impact on drug delivery from nanofibers. In addition, M. sylvestris extracts have been added into the optimal formulation [MS-NS-NF] and assessed for their surface morphology, tensile strength, water absorption potential, and in vitro drug release studies. The NS and MS delivery from MS-NS-NF has been extended for more than 60 h. M. sylvestris-loaded nanofibers demonstrated superior antibacterial activity compared to plain NS nanofibers. The scaffolds featured a broad aspect and a highly linked porous fibrous network structure. Histomorphometry study and the in vitro scratch assay demonstrate the formulation's efficacy in treating diabetic wound healing. The cells treated with MS-NS-NF in vivo demonstrated that wound dressings successfully reduced both acute and chronic inflammations. To improve the healing of diabetic wounds, MS-NS-NF may be regarded as an appropriate candidate for wound dressing. [ABSTRACT FROM AUTHOR]

This study investigated the impact of different cuing history on the sulfate resistance of Portland-Limestone cement (PLC). Mortars of Portland cement (PC) and PLC with different dosages of limestone, 10%, 20%, 30% by mass, were cured in water at 20 °C and 60 °C for 28 days before immersed in Na2SO4 solution 50 g/L at 20 °C for sulfate resistance test. In addition to monitoring the length and mass changes of mortars, MIP and XRD were used to investigate microstructure and evolution of phase assemblages. Results show that PLC mortars cured at 20 °C give a poorer sulfate resistance than PC, the higher the limestone dosages in PLC, the worse sulfate resistance of the mortar. However, it is contrary for mortars cured at 60 °C. PLC shows a much better sulfate resistance than PC, and the higher the limestone dosages, the better sulfate resistance of the PLC mortars. The incorporation of limestone in PLC at dosages of 10–30% leads to the increase of carboaluminates content and the deterioration of pore structure, which is the main factor responsible for worsening the sulfate resistance of PLC mortars cured at 20 °C. When cured at 60 °C, the reduction of available aluminate caused by the dilution effect of limestone improves the sulfate resistance of PLC mortars. The formation of gypsum is not the main cause of the expansion. [ABSTRACT FROM AUTHOR]

Perchlorate ( ClO 4 − ) industrial wastewater requires efficient removal to prevent adverse environmental impacts, however, high concentration and low biodegradability give rise to poor ClO 4 − bioreduction performance. S 2 − -autotrophic granular sludge ( S 2 − -AuGS) was firstly cultivated for high concentration perchlorate ( ClO 4 − ) removal in the upflow anaerobic sludge blanket (UASB) reactor ( ClO 4 − : 150 mg L−1). Simultaneously, the S 2 − was utilized to control the SO 4 2 − generation as electron donor, the effluent SO 4 2 − concentration (190 mg L−1) was satisfied with drinking water standard (250 mg L−1). Under the optimized condition of hydraulic retention time (HRT) (6 h) and S 2 − / ClO 4 − molar ratio (2.2), more EPS was secreted, which promoted the S 2 − -AuGS formation and stability. Though acclimation of 146 d, the S 2 − -AuGS was formed with a large average granular sludge size (612 μm) and an excellent settleability (sludge volume index: SVI5/SVI30 = 1). With the mature S 2 − -AuGS formation, the highest ClO 4 − and S 2 − loading was increased to 1.06 and 0.75 kg m−3 d−1. Interestingly, Georgfuchsia, Methyloversatilis, Sulfurisoma, and Exiguobacterium were the main microbial community in the S 2 − -AuGS. This study proposed to form a novel S 2 − -AuGS for developing the high ClO 4 − concentration removal performance and to utilize the S 2 − as an electron donor for controlling the excessive SO 4 2 − generation. [ABSTRACT FROM AUTHOR]

Phosphogypsum (PG) is a solid waste generated from phosphate fertilisers industries. It represents a serious threat to the aquatic and terrestrial environment because of its acidity and its high content in heavy metals and radionuclides. The aim of this work is to describe the formation of PG during the synthesis of the phosphoric acid, the entrapment of Zinc (Zn) in PG and its lixiviation in presence of a natural organic matter extracted as powder from the cladodes of Opuntia ficus-indica (OFI) using physical and chemical characterisation techniques such as FTIR, XRD, SEM-EDX, laser diffraction, and AAS. The formation of PG mainly occurs in the pH range between 4.6 and 3 and it accompanies the transformation of H2(PO4)− into phosphoric acid H3PO4. The maximal Zn incorporation within the PG was reached at pH 6 and decreased progressively with pH. Zinc was found to have a great tendency to migrate from PG particles to OFI's suspensions since a maximum Zn removal percentage of 93% was achieved. [ABSTRACT FROM AUTHOR]

The metal based phosphate and sulfate mixture, Cu3(PO4)2⋅ 1.65 NaH2PO4 ⋅ 1.35 NaHSO4 has been synthesized and characterized with different measurement techniques. Six different composites such as A1, A2, A3, A4, A5 and A6 have been synthesized by charging different proportions of a mixture with a fixed quantity of wall care putty (Birla make). Similarly, four different composites such as B1, B2, B3 and B4 have been synthesized by charging different proportion of a mixture with a fixed quantity of CaCO3 and polyvinyl acetate (PVAc) glue. The C1 mixture has also been synthesized using CaCO3 and polyvinyl acetate (PVAc) glue without the addition of the mixture. The thermal behavior was evaluated in the temperature range 303 K to 573 K and vice versa in two thermal cycles as well as from 173 K from 298 K for one thermal cycle. The thermal behavior of the mixture was studied at a rate of 10 K min−1 while composites were studied at 5 K min−1. The net specific heat capacities (Cp) of composites are found to be, A2 (-0.11 Jg−1K−1), A3 (-0.13 Jg−1K−1), A6 (-0.12 Jg−1K−1), B1 (-0.13 Jg−1K−1), B2 (-0.10 Jg−1K−1), B3 (-0.11 Jg−1K−1) and B4 (-0.17 Jg−1K−1). These composites can be utilized as heat retardant materials. [ABSTRACT FROM AUTHOR]

The sorption characteristics of uranium onto a strongly basic anion exchanger, Purolite A400, were investigated. The characteristics of Purolite A400, before and after sorption of uranium, were determined using scanning electron microscopy (SEM) and energetic-dispersive X-ray (EDX). The influence of the different parameters, which may affect the process of uranium sorption process, had been tracked. Specifically, impacts of initial uranium concentration, pH, contact time and temperature, on uranium removal, were studied. In addition, the sorption kinetics and equilibrium parameters were assessed. At the optimum conditions, the adsorption capacity of uranium was found to be nearly 117.6 mg/g. The kinetics and isotherm studies could show that the uranium sorption onto Purolite A400 is following the models of pseudo-second-order and Langmuir isotherm respectively. The thermodynamic parameters had indicated that the adsorption of uranium is an exothermic and spontaneous process. The detected results of uranium sorption could reveal that Purolite A400 is a suitable material for pre-concentration of uranium (VI) species from sulfate leach liquor. [ABSTRACT FROM AUTHOR]

Tomato (Solanum lycopersicum L.), grown in iron deficient and calcareous soils, exhibits poor growth and yield loss, which may be moderated using biostimulants. A field experiment was conducted to determine the efficacy of the application of iron glutamate (Fe-Glu), iron sulfate (FeSO4), and L-glutamate (Glu) on growth and yield performance. Foliar application included: no treatment (NS), 0.50% FeSO4, 1% FeSO4, 0.50% Fe-Glu, 1% Fe-Glu, 0.50% L-Glu, or 1% L-Glu. Foliar application of 1% Fe-Glu increased plant height by 31%, shoot fresh weight by 25%, root fresh weight by 38%, and canopy diameter by 23%. Exogenous application with 1% Fe-Glu improved the fruit count and overall yield by 57% and 44%, respectively. There was an increase in fruit length by 20% and an increase in fruit diameter by 25%, respectively, due to foliar application of 1% Fe-Glu. Use of 1% Fe-Glu foliar might act as a better biostimulant than conventional sulfate salts in increasing tomato crop performance. [ABSTRACT FROM AUTHOR]

In this work, an RP-HPLC method was established for the simultaneous quantification of antazoline sulfate and naphazoline nitrate in commercial ophthalmic formulations. The proposed method was validated for sensitivity, selectivity, linearity, accuracy, precision, and stability, and was found to be suitable for routine analysis of these two active ingredients in the presence of degradation products. The optimized conditions using a C18 column, a mobile phase (phosphate buffer: methanol, 80:20), a flow rate of 1.5 mL/min, and detection at 285 nm at room temperature. The quantification method for antazoline sulfate and naphazoline nitrate in the pharmaceutical formulation was validated in accordance with International Conference on Harmonization (ICH) Q2 (R1) guidelines for the quantitative measurement of these pharmaceuticals. Under optimal conditions, a linear relationship with high correlation coefficients (0.9999 for Antazoline Sulfate and 0.9997 for Naphazoline Nitrate) was established between the concentration ranges of 0.11 to 0.35 mg/mL for Antazoline sulfate and 0.006–0.02 mg/mL for Naphazoline nitrate. The detection limits of Antazoline sulfate and Naphazoline nitrate were determined to be 0.3 and 0.06 μg/mL, respectively. The developed method can be useful for quality control and stability testing of ophthalmic formulations containing antazoline nitrate and naphazoline sulfate. [ABSTRACT FROM AUTHOR]

In this work, we described a simple method to manufacture a novel nitrile butadiene rubber (NBR) filled with cupric sulfate (CuSO4) and tetramethylthiuram disulfide (TMTD) via simple mixing and heat pressing. Cure characteristics analysis, the motion capability of polymer segments, physical properties, micromorphology, swelling properties and dynamic characteristics were explored comprehensively. The results demonstrated that the three-dimensional network was cross-linked by the metal coordination interactions between the nitrile group and copper ion. The cure curve, tensile strength and crosslinking density exhibited a considerable increasing with the addition of TMTD in NBR/CuSO4 compounds, which was due to the synergistic effect between Cu2+ and Me2NCSn• (n = 1–2) radicals generated by the pyrolysis of TMTD, resulting in the formation of the hyperactive compounds [Cu(SnCNMe2)]•2+ and promoting the coordination crosslinking between -CN and Cu2+ significantly. The NBR/CuSO4/TMTD vulcanizates induced by the synergistic effect would play a crucial role in practical application for the excellent physical properties. [ABSTRACT FROM AUTHOR]

The present study investigated the partition and extraction conduct of Cu (II) in Aqueous Two-Phase Systems (ATPS) of Poly (Ethylene Glycol) (PEG)–zinc sulfate in the presence of ammonium thiocyanate as an extractor. The polymer weight percent in the feed (20, 25, and 30%), salt weight percent in the feed (15, 23, and 31%), polymer molecular weight (2000, 4000, and 6000 g.mol-1), and the pH (2.5, 3.6, and 4.7) are the determiners of the partition coefficient of Cu (II) in the target system. The Central Composite Design (CCD) was taken into account to investigate the impacts of various parameters on the partition coefficient of Cu (II) by a quadratic model. High F-value (50.58), very low P-value (<0.0001), non-significant lack of fit, the determination coefficient (R2 = 0.9793) demonstrate an excellent correlation between experimental and predicted values of the response. The model results indicated that the pH and weight percent of the salt in the feed had major and minor effects on the copper ion partition coefficient, respectively. The pH of ATPS can alter the Cu (II) partition coefficient through the variation of the copper ion net charge. The weight percent of polymer in the feed decreased the partition coefficients. Moreover, by increasing the polymer molecular weight, the partition coefficient of Cu (II) was increased. The highest value for the productivity of Cu ions extraction was found to be 93.3% with regard to the excellent separation factors (pH = 4.7, PEG molecular weight = 6000, PEG concentration = 20 and salt concentration = 15) [ABSTRACT FROM AUTHOR]

Fe-600 grade steels are recommended for high rises and other structures in India that require high-load carrying capacity (particularly in seismic zones) due to its excellent mechanical properties. But structures in food processing, agricultural waste handling, etc., industries and high rises are subjected to attack of sulphates as well as acid rain. The present work investigates the efficacy of electroless nickel coatings in corrosion prevention of Fe-600 grade rebars exposed to aggressive sulphate environment. Ni-P, Ni-P-W and Ni-P-Cu coatings were deposited on the rebars. Electrochemical tests such as potentiodynamic polarization and electrochemical impedance spectroscopy were employed to investigate the corrosion behaviour in 0.5 M sulphuric acid. It was seen that corrosion potential of rebars was nobler when they were coated with electroless nickel ternary variant coatings. Electrochemical impedance spectra also validated the same. Scanning electron microscope images of the surface of the bare rebars post electrochemical tests revealed a completely cracked morphology due to severe attack of sulphates. Whereas the surface of Ni-P-W coated rebar revealed the least damage and highest corrosion resistance. [ABSTRACT FROM AUTHOR]

Large amounts of waste white cement bypass dust (WCBPD) are generated in huge heaps near white cement factories in Jordan, posing growing environmental concerns related to potential hazardous impact and additional disposal cost. This research evaluates possible and suitable recycling of WCBPD as a partial replacement of Portland cement in the production of the rapidly expanding roller compacted concrete (RCC). This experimental work aims to test the influence of using different proportions (10, 20, 30, and 40%) of WCBPD on the mechanical performance and durability of RCC subjected to sulphate attack. The investigation included compressive strength, a non-destructive test (ultrasonic pulse velocity), water absorption coefficient, and the sulphate linear expansion test. The experimental results were promising for recycling WCBPD as fractions of Portland cement in RCC mixtures at small amounts. Compared to reference cylinders, the reduction in compression strength was about 10, 28, 32 and 39% for 10, 20, 30 and 40% WCBPD replacement ratios, respectively. All RCC mixtures showed satisfactory sulphate resistance since no significant loss in compressive strength nor a significant increase in expansion ratio occurred due to sulphate exposure. The reductions in compressive strength at 180 days of sulphate exposure were 12.8, 15.6, 15.9, 16.1 and 16.6% for RCC cylinders prepared with WCBPD partial replacements of 0, 10, 20, 30 and 40%, respectively. [ABSTRACT FROM AUTHOR]

Understanding how individual pollution sources contribute to ambient sulfate pollution is critical for assessing past and future air quality regulations. Since attribution to specific sources is typically not encoded in spatial air pollution data, we develop a mechanistic model which we use to estimate, with uncertainty, the contribution of ambient sulfate concentrations attributable specifically to sulfur dioxide (SO2) emissions from individual coal-fired power plants in the central United States. We propose a multivariate Ornstein–Uhlenbeck (OU) process approximation to the dynamics of the underlying space-time chemical transport process, and its distributional properties are leveraged to specify novel probability models for spatial data that are viewed as either a snapshot or time-averaged observation of the OU process. Using US EPA SO2 emissions data from 193 power plants and state-of-the-art estimates of ground-level annual mean sulfate concentrations, we estimate that in 2011—a time of active power plant regulatory action—existing flue-gas desulfurization (FGD) technologies at 66 power plants reduced population-weighted exposure to ambient sulfate by 1.97 μg/m3 (95% CI: 1.80–2.15). Furthermore, we anticipate future regulatory benefits by estimating that installing FGD technologies at the five largest SO2-emitting facilities would reduce human exposure to ambient sulfate by an additional 0.45 μg/m3 (95% CI: 0.33–0.54). for this article are available online. [ABSTRACT FROM AUTHOR]