Chloride Sulfate Research Articles

Kinetic Study of Copper and Cobalt Dissolution from Sulfidic Ores in Sulfate–chloride Media

Kinetic Study of Copper and Cobalt Dissolution from Sulfidic Ores in Sulfate–chloride Media

Durability study on engineered cementitious composites with hybrid fibers under sulfate and chloride environments

Engineered cementitious composite (ECC) is an exclusive type of cement mixture composite which imparts high ductility and high tensile strength. Over the decades, enormous strides have been made in creating ECC with extreme tensile ductility, on the order of several hundred times than that of normal concrete or fiber reinforced concrete. The experimental behaviour of ECC which is combined with polyvinyl alcohol (PVA) and steel fibers has been investigated in this research. The main aim of the research is to study the durability of ECC through compressive strength for long-term exposure condition under chloride, sulfate and combined sulfate–chloride environmental conditions experimentally. In the present work, six different ECC mixtures with constant water-cement ratio were prepared with the total volume fiber fraction (Vf) of 2%. ECC mechanical properties such as compressive strength, flexure strength and uni-axial tensile strength have been experimentally determined. The test results emphasize that the flexural strength and uni-tensile strength of the ECC specimens with the combination of 1.5% PVA and 0.5% steel fibers were improved as supposed to conventional ECCs. The durability property has been carried out only for the optimized dosage of fibers after exposed to aggressive solutions. The performance of optimized dosage of ECC mixture with hybrid fibers was barely affected by the aggressive solutions of chloride and sulfate–chloride when compared the same with water.

High‐Voltage Aluminium‐Sulfur Batteries with Functional Polymer Membrane

AbstractA high‐voltage aluminium‐sulfur (Al‐S) battery is developed by employing the reversible electrochemical oxidation of S, favoring a high discharge voltage of around 1.8 V (vs Al3+/Al). The reversible multiple‐electron transformation between positive‐ and negative‐valence S compounds is further realized for activating a high‐capacity Al‐S battery. The formation of sulfur chlorides as charge products of S, including S2Cl2(l) as the dominant one, has been clearly identified. Benefiting from a functional polymer membrane infiltrated with AlCl3/acetamide electrolyte, which can suppress unwanted electrolyte reactions, restrict the shuttling of sulfur chlorides across the separator, and stabilize the Al anode against degradation, the Al‐S battery can deliver largely enhanced performance, with a capacity of 861 mAh g−1, capacity retentions of 92.1%/79.0% within 50/200 cycles, and durability of 490 cycles. The new electrochemistry scenarios shed light on the development of S‐based secondary batteries with higher energy densities for future.

Experimental Study on the Influence of Mogadishu Manufactured Sand on the Engineering Properties of Concrete

Due to the increasing demand for sand for construction activities across the world including Mogadishu Somalia, natural sand resources are growingly used up and its price is becoming increasingly high. This study aimed to research the influence of Mogadishu-manufactured sand on the engineering properties of concrete. Manufactured sand refers to fine aggregate which is less than 4.75mm. In this research, Mogadishu Manufactured sand was refined from the crushed limestone rock as a replacement for river sand. The overall objective of the study was to evaluate the influence of Mogadishu manufactured sand on the engineering properties of concrete; the specific objectives were to examine the properties of plastic and hardened concrete; to investigate the durability of concrete with Mogadishu manufactured sand. The study used manufactured sand in incomplete or complete replacement for natural sand. The basic aggregate tests considered were sieve analysis for fine and coarse aggregate, specific gravity, and water absorption was also done. Design mix of class 30 concrete having mix amount for both natural and manufactured sand was considered for the workability test (slump test and compaction factor test). The splitting tensile strength test and compressive strength test for 28 and 56 days was done. The study, in addition, considered durability testing by exposing the concrete to sodium chloride, magnesium sulphate, and sulphuric acid. Then final assessment was done to determine how these chemicals affected the concrete after 28 and 56 days of immersion. It was found that the slump and compaction factor values of the concrete mix with Mogadishu manufactured sand decreased compared to that of conventional concrete. Concrete with Mogadishu manufactured sand significantly improves the strength properties of the concrete up to 25% replacement and reduces as replacement increases. This was attributed to the presence of micro fines in the Mogadishu manufactured sand generated from limestone rock. When exposed to sulphuric acid, magnesium sulphate, and sodium chloride, the durability of concrete with manufactured sand were improved as compared to that of normal concrete with river sand. Hence from the experimental investigations, it is concluded that Mogadishu manufactured sand can be partially utilized as fine aggregate in concrete production of construction activities.

Fresh and Hardened Properties of Self-Compacting Concrete Comprising a Copper Slag

Recycling trash and protecting natural resources are two of the many benefits of using copper slag as a fine aggregate in a concrete building. However, stakeholders need proven research output to build trust and initiate or enhance the use of such industrial waste in buildings. This study evaluated self-compacting concrete’s fresh and hardened characteristics (SCC) comprising a copper slag aggregate (CSA). For this purpose, six mixes were prepared by substituting river sand with CSA up to 50%, with a 10% increment. The properties of fresh SCC were evaluated using slump flow, V-funnel, and L-box tests. Several parameters of SCC were examined, including water absorption, sorptivity, chloride ion penetration, sulphate attack, and acid attack tests. Energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM) were used to investigate the concrete microstructure. The results indicated that the fresh characteristics of SCC were enhanced as the amount of CSA increased consistently. The durability properties showed a considerable enhancement in SCC mixes comprising up to 20% of CSA.

Effects of cation in sulfate chloride and nitrite on Ca(OH)2 activated ground granulated blast-furnace slag

This study explores the effects of the cations in sulfates, chlorides, and nitrites on calcium-hydroxide activated blast-furnace slag. Using several methods, it was demonstrated that the activators investigated could improve early strength development. Compared with chlorides and nitrites, the type of sulfate has a significant influence on slag hydration. Compared with K2SO4 and Na2SO4, the promotion of slag hydration in MgSO4, at an early age, is limited due to the precipitation of gypsum and brucite which retard the formation of hydrates and limits hydration kinetics during the initial stage. The high concentration of sulfate ions in the pore solution causes some ettringite to remain, promoting strength development. It was observed that the mechanism of pH increase in K2SO4 and Na2SO4 is due to the synergistic reactions between the sulfates and Ca(OH)2, while the low pH of MgSO4 due to the low solubility of brucite inhibits slag dissolution. The critical pH for promoting slag hydration was determined to be 13.1.

Analysis of the epidemiological variables associated with a high prevalence of bovine surra in the Chhattisgarh state of India.

Trypanosoma evansi, a unicellular haemoflagellate, causes surra in bovines and other economically important livestock species. We report here the epidemiological variables associated with the high prevalence of T. evansi infection in cattle in the plain agro-climatic zone of Chhattisgarh state, India. A total of 920 blood and sera samples were tested by a combination of parasitological, molecular and serodiagnostic tests. An overall prevalence of T. evansi was recorded as 4.57% (95% CI: 3.22-5.92%), 6.09% (95% CI: 4.54-7.63%), 63.91% (95% CI: 60.81-67.01%) and 55.33% (95% CI: 52.12-58.54%) by direct microscopy, PCR, ELISA and IFAT, respectively. The Chi-Square test established a significant correlation between the prevalence of T. evansi and the season, breed and place of the study, while the association with the gender and age of the animals was insignificant. The analysis of the prevalence ratio revealed a significant association of the breed, season and place of study with the prevalence of T. evansi. As per PR observed, the prevalence was 1.63 times higher in summer and 1.68 times higher in the rainy season than in the winter (reference season). The prevalence was higher in all the districts as compared to Rajnandgaon (reference district). The prevalence ratio in Sahiwal and HF cross-breed cattle was significantly higher than the Gir breed of cattle (reference). Durg district recorded the highest prevalence of surra, and the difference was significant. The medium IFAT titre, determined in a large number of sera collected from Durg, predicted a higher incidence of trypanosomosis in that district. Since T. evansi has a broad host range, the study predicted that a large population of livestock in Chhattisgarh state were at high risk of T. evansi infection. Treatment of the subclinically and clinically infected animals with selective curative drugs, such as diminazene aceturate, isometamidium chloride or the combination of quinapyramine sulphate and quinapyramine chloride, could help restore productivity and help in containing the infection.

Boron removal by glucamine-functionalized inverse vulcanized sulfur polymer

Boron removal by novel sulfur-based boron selective adsorbent is herein reported. The sulfur-based polymer prepared by the inverse vulcanization of sulfur and 4-vinylbenzyl chloride (VBC) under optimized reaction conditions was used as a substrate and further functionalized by N-methyl-D-glucamine (NMDG) under optimized reaction conditions. Batch adsorption boron removal tests showed that a pH of 9 results in the highest adsorption capacity while an increase in the adsorbent dosage also showed a non-linear increase in the removal capacity. Acid and alkali regeneration of the used adsorbent showed 86% of its initial capacity after five cycles. The equilibrium isotherms of the adsorption were best fitted with the Redlich-Peterson model indicating that the boron adsorption obeys the principles of both monolayer and multilayer adsorption with a Langmuir maximum adsorption capacity of 7.186 mg/g. On the other hand, pseudo-second-order best fitted the adsorption kinetics meaning that chemisorption is the main controlling mechanism. The thermodynamic studies showed an endothermic spontaneous adsorption process with an increased randomness degree at the solid/liquid interface after the adsorption. The developed adsorbent is the first sulfur-rich polymer and selective boron adsorbent that can effectively reduce boron in water while also offering a considerably lower price due to utilizing the cheap and already available elemental sulfur.

Isolation of local strain of Bacillus sp. SM-11, producing PHB using different waste raw as substrate

Polyhydroxyalkalonates (PHAs) have numerous industrial and medical applications, is being used in various medical applications such as scaffold, suture, heart valve and drug delivery etc. Poly 3-hydroxy butyrate (PHB) is the most common and important family member of PHAs. The bacterial strains which are able to produce higher quantities of PHA using low-cost substrates are always in demand. In the present study, a local strain of Bacillus sp. SM11 isolated from soil was screened for ability to produce biopolymer i.e., PHB (polyhydroxybutyrate). Various factors which have been found to have an impact on PHB production by the selected capable bacterial isolates were optimized viz., organic waste source (soya extract, whey, molasses, corn extract, and distillery waste liquor), nitrogen source (peptone, beef extract, yeast extract, ammonium chloride, and ammonium sulphate), pH, and trace elements. An optimized PHB yield of 3.53g/L was obtained using whey as a source of carbon, added with 1% of yeast extract as a nitrogen source at pH 6.0 in presence of calcium as a trace element. The outcome of the present study indicates that isolate is among one of the high PHB producing microorganism, using whey as a carbon source.

Predicting and analysing the quality of water resources for industrial purposes using integrated data-intelligent algorithms

The continuous increase in the rate of industrialization in developing countries, in recent times, calls for continuous industrial water quality assessment and prediction. This is to create more awareness and ensure cleaner and sustainable industrial production. Water quality for industrial uses is often described in terms of corrosion and scaling potentials (CSPs). In this paper, optimized artificial intelligence models (e.g. multiple regressions (MR), hierarchical clusters (HCs), and artificial neural networks (ANNs)) for assessing and predicting the CSPs of water resources were developed, for Ojoto suburb (SE Nigeria). Indices used in evaluating the CSPs are chloride–sulphate mass ratio (CSMR), Larson-Skold index (LSI), Langelier index (LI), aggressive index (AI), Ryznar stability index (RSI), Puckorius scaling index (PSI), and Revelle index (RI). This work is the first of its kind to utilize predictive models in simultaneously predicting the industrial water quality indices. Prior to the predictive modeling, R-mode HCs, correlation, principal component, and factor analyses were used to analyze the relationships between the physicochemical variables (pH–T–EC–TDS–TH–Ca–HCO3–Cl–SO4–Fe–Zn–Pb) and the CSP indices. Q-mode HCs effectively identified the spatiotemporal water corrosion/scaling risk classification and distribution in the area. Both MR and ANN models suitably predicted the CSP indices. However, both models better predicted AI, LI, RSI and PSI than LSI, RI and CSMR. The MR models’ performances were analyzed using R, R2, adjusted R2 and F-ratio values whereas the ANN models were verified using parity plots, R2, RMSE, and residual error plots. For the ANN modeling, scaled-conjugate-gradient optimizer outperformed gradient-descent optimizer. Also, ANN models outperformed the MR models. The practical implications of the present research findings were also discussed.

Effect of FNS Incorporation on the Properties of Ternary Blended Cement Containing Blast Furnace Slag and Fly Ash

This study aims to assess the properties of ternary blended concrete in terms of mechanical performance and resistance to chemical attack. Specimens consisted of concrete and paste having a water to binder ratio of 0.45 made with ordinary Portland cement, pozzolanic materials, and ferronickel slag. Results on compressive strength at l80 days of curing showed that ternary blended concrete with ferronickel slag was 8% to 18% higher than for OPC. For splitting tensile strength and flexural strength, however, there was no such trend. Durability was examined in terms of resistance to rapid chloride penetration, carbonation, and sulfate attack. Ternary mix showed always-higher resistance against chloride penetration and sulfate attack while being more susceptible to carbonation due to the lower pH of the cement matrix. In addition, all ternary mixes exhibited lower heat of hydration compared to OPC and binary mixes with pozzolanic materials showed the lowest heat evaporation. Furthermore, from the results of XRD analysis, identical hydration products were found irrespective to the binder, while a significant change was observed on the portlandite peak. Overall, results showed that the incorporation of ferronickel slag affected positively the properties of concrete.

Pulsed Electrodeposition and Properties of Nickel-Based Composite Coatings Modified with Graphene Oxide

Composite electrochemical coatings (CECs) on the basis of nickel modified with multilayer graphene oxide (GO) were deposited from a sulfate–chloride electrolyte in pulsed electrolysis mode. The microstructure of these CECs was studied by X-ray phase analysis and scanning electron microscopy. It was found that the microhardness of nickel–GO CECs increases by approximately 1.40 times compared to pure nickel. The corrosion–electrochemical behavior of nickel–GO composite coatings in 0.5 M H2SO4 was studied. Based on tests in 3.5% NaCl, it was found that the addition of graphene oxide particles into the matrix of nickel electrodeposits, increases their corrosion resistance by 1.40–1.50 times. This can be explained by the uniformity of the distribution of GO in the nickel matrix, which contributes to the reduction in grain size, as well as the impermeability and stability of graphene oxide.

Assessment of Geotechnical Properties of Laki Limestone for Coarse Aggregate, Nooriabad, Jamshoro Sindh, Pakistan

Present study is aimed at assessment of geotechnical properties of Laki limestone as coarse aggregate which is being quarried in Nooriabad area, Sindh, Pakistan. Coarse aggregate samples (n=20) of limestone were collected for the evaluation of physico-mechanical properties of the aggregate. Petrographic analysis revealed that the aggregate comprises of hard, compact, massive, crystalline and fossiliferous limestone. It is devoid of any reactive silica (chert, chalcedony) and other harmful constituents like clays or organic matter. Average values of specific gravity, absorption,bulk density, void content and combined index (EI + FI) of collected samples are 2.5, 2.1%, 1.54 g/cc, 38.55% and 13.04% respectively. The values of specific gravity (2.3-2.9), absorption (0-8%), bulk density (1.28 g/cc-1.92 g/cc) and void content (30%-45%) are varying within the range of normal weight aggregate as per American concrete institute (ACI)specifications. On the other hand, absorption values of aggregate samples are slightly higher (2.1%) than the reference range (2%) but meet other requirements. Mechanical properties including aggregate impact value (8.58%), aggregate crushing value (26.66%), Loss Angeles abrasion value (24.77%), sodium sulfate soundness (4.72%), water soluble sulfate (0.006%) and water soluble chloride (0.005%) are found to be within corresponding guidelines set by ASTM. On the other hand, average carbonate content is found to be 89.64% indicating that Laki limestone is of slightly low purity. Except absorption, all physical and mechanical properties lie within specified ranges. It is concluded that Laki limestone is suitable for use as road aggregate and concrete mix design.

Bioderived Magnetic Iron Oxide Nanoparticles from Leaf Extract of Argyreia Nervosa for Electrochemical Biosensing of Pesticide

In this work, we have utilized leaves extract of Argyreia Nervosa (AN) to synthesize magnetic iron oxide nanoparticles by using the mixed precursor salt (ferric chloride and ferrous sulphate). After nanoparticles synthesis, it was initially characterized using Fourier Transform Infrared spectroscopy (FT-IR), UV–visible spectrophotometry (UV-Visible), Transmission Electron Microscope (TEM), and Scanning Electron Microscope (SEM). Further, characterization in this work is needed, namely AFM, XRD, and electrochemical studies (Differential Pulse Voltammetry (DPV) and Cyclic Voltammetry (CV)). The desired work is novel for synthesizing magnetic iron nanoparticles and their utilization for fabricating electrochemical biosensor devices for pesticide detection. Hence, in this study, we have focused on synthesizing magnetic iron oxide nanoparticles via the biogenic route of synthesis for fabricating an enzyme-biosensor for the determination of pesticides, which will open a new avenue for developing nanobiosensing devices through a greener and sustainable approach that is green/bioinspired/bioderived synthesis of nanomaterials that utilizes phytochemicals.

Study on the Erosion Mechanism of the Solidified Silt Under Sulphate–Chloride Erosion

Study on the Erosion Mechanism of the Solidified Silt Under Sulphate–Chloride Erosion

Renewable Reagent for Nucleophilic Fluorination.

Herein, we report a study on the reactivity of three 1,3-diarylimidazolium-based fluoride reagents, with a general formula of [IPrH][F(HF)n] (n = 0, 1, or 2), that tackle the challenges of limited solubility, hygroscopicity, instability, and laborious preparation procedures of nucleophilic fluoride reagents. Fluorination of 4-tert-butylbenzyl bromide reveals that trifluoride [IPrH][F(HF)2] is the most selective reagent. Microwave-assisted activation coupled with the addition of sterically hindered amine DIPEA or alkali metal fluorides increases the rate of fluorination with [IPrH][F(HF)2], making it an excellent reagent for the fluorination of various organic substrates. The scope of substrates includes benzyl bromides, iodides, chlorides, aliphatic halides, tosylates, mesylates, α-haloketones, a silyl chloride, acyl and sulfuryl chlorides, and a nitroarene. The exceptional stability of the air-stable and nonhygroscopic [IPrH][F(HF)2] reagent is illustrated by its convenient synthesis and detailed experimental regeneration protocol using hydrofluoric acid without organic solvents.

Polyhumous Dystrophic Pit Lakes: Hydrographic and Hydrochemical Characteristics on the Example of Reservoirs in the Włoszczowska Basin, Central Poland

The article presents the hydrographic and hydrochemical characteristics of post-exploitation reservoirs formed in peat excavations. Two natural bog lakes were selected as the control objects for the study. The research indicated that both the waters of post-exploitation peat reservoirs and natural bog lakes show low electrolytic conductivity (<100 µS/cm) and acidic water reaction (pH < 5.5). The concentration of major cations and anions is also very low. The concentration of calcium and magnesium does not exceed a few mg/L. Hydrochemically, all post-exploitation peat reservoirs are bi-ionic sulphate–calcium (SO42−-Ca2+). This distinguishes post-exploitation peat reservoirs from natural bog lakes in which multi-ion waters were found, for example, sulphate–chloride–calcium (SO42−-Cl−-Ca2+) and sulphate–calcium–sodium (SO42−-Ca2+-Na+). The calculated water humic state index (HSI) allowed the classifying of the examined reservoirs as polyhumous. The value of this index, in all reservoirs, was >50. Based on the calculated hydrochemical dystrophy index (HDI), it was found that all post-exploitation peat reservoirs are dystrophic. So far, no such hydrochemical type has been found in other post-exploitation peat reservoirs. Therefore, the examined objects should be classified as unique post-exploitation peat reservoirs.

Development of a derivatization RP-HPLC method for determination of sulfuryl chloride in chlorosulfonic acid for gefapixant citrate manufacture

Control of process impurities during manufacturing of drug substance is critical to ensure quality and process robustness. During commercial process development for the gefapixant citrate drug substance, several process impurities were found to derive from sulfuryl chloride, an impurity in the raw material, chlorosulfonic acid (CSA). This made controlling the CSA quality essential for commercial production of this drug substance. Various direct analysis methods were evaluated and found unsuitable because of the highly reactive nature and structural similarity of sulfuryl chloride and CSA. Therefore, a robust derivatization reversed-phase high performance liquid chromatography (RP-HPLC) method was developed and validated to accurately quantify sulfuryl chloride in CSA. The derivatization method was utilized to evaluate many CSA batches from different commercial suppliers and to establish a correlation between sulfuryl chloride levels in CSA and the levels of process impurities in downstream materials. The methodology described herein informed the development of setting the specification on sulfuryl chloride for CSA to ensure a robust process for manufacturing high-quality gefapixant citrate drug substance. The derivatization method was successfully validated and transferred to the commercial commodity supplier for release testing of CSA as a raw material for gefapixant citrate commercial campaigns.

Self-Sustaining Water Softening–Desalination Processes: Chloride–Sulfate Systems

Self-Sustaining Water Softening–Desalination Processes: Chloride–Sulfate Systems

Synthesis, antibacterial, antibiofilm evaluation and molecular docking studies of 3-methyl- 2-propyl-2H-[1,2,4]triazolo[4,3b] [1,2,4,6]thiatriazine-1,1-dioxide

ABSTRACT. In the current study, a simple method for the synthesis of 3-methyl-2-propyl-2H-[1,2,4]triazolo[4,3b][1,2,4,6]thiatriazine-1,1-dioxide (2) was carried out. In the presence of pyridine, a reaction between amidine (1) and sulfuryl chloride occurs. FTIR spectroscopy, 1H and 13C NMR, mass spectra, and elemental analysis were utilized in order to verify the structure of a novel synthetic molecule. The antibacterial activities of compound (2) were tested against eight pathogenic bacteria and the minimum inhibitory concentration as well as minimum bactericidal concentration were determined. Moreover, the possible antibiofilm effect of compound (2) was evaluated. Molecular docking was investigated to determine the interaction between compound (2) and eight crystal structures of bacterial and yeast proteins associated with virulence activity and antimicrobial resistance. Our results showed that the new 3-methyl-2-propyl-2H-[1,2,4]triazolo[4,3b][1,2,4,6]thiatriazine-1,1-dioxide (2) compound has a moderate antibacterial activity toward the selected pathogenic bacteria. The obtained MICs varied from 32 to 512 µg/mL being the lowest values attributed to Staphylococcus epidermidis ATCC 14990 and Streptococcus mutans ATCC 25175 (MIC = 32 µg/mL).We noted also that heterocyclic compound (2) may inhibit bacterial biofilm formation at concentration depend manner with a lowest value obtained against S.mutans ATCC 25175 (BIC50 = 490 µg/mL). Molecular docking showed a promising inhibitory activity of compound (2) on TetM-mediated tetracycline resistance (3J25) and Staphylococcus aureus gyrase (3G7B) with lower binding energy compared to the other target proteins.
 
 KEY WORDS: Synthesis, Thiatriazine-1,1-dioxide, Antibacterial, Antibiofilm, Molecular docking
 Bull. Chem. Soc. Ethiop. 2022, 36(1), 109-117. 
 DOI: https://dx.doi.org/10.4314/bcse.v36i1.10