Reactive Extraction Research Articles

Reactive extraction of methanesulfonic acid from wastewater using trioctylamine

Wastewater containing methanesulfonic acid (MSA) mainly originates from the production process of metal detergent, which also contributes significantly to environmental pollution. This study investigates the extraction of MSA from wastewater using trioctylamine (TOA). A thorough investigation was carried out into the factors that affect extraction efficiency, such as the type of extractant, phase ratio (O/A), temperature, stirring speed, and extraction time. An extraction efficiency of 96.1% was achieved using TOA at 25 °C, 1400 r·min− 1, and an extraction time of 30 min. Various techniques including FT-IR, XPS, and high-resolution ESI-MS were employed to investigate the extraction mechanism. The results of different techniques revealed that the complexation between TOA and MSA occurred through ionic and hydrogen bonding interactions. Moreover, TOA was successfully regenerated through back-extraction with sodium hydroxide. The proposed extraction system is advantageous for eco-friendly engineering applications.

Analysis of Rhodamine B Content in Eyeshadow Cosmetic Preparations with UV-Vis Spectrophotometer and Butterfly Pea Flower (Clitoria ternatea L.) Extract

In the modern era, maintaining a good appearance is crucial. Many people are out there vying for the most outstanding looks. Many are also eager to spend money to improve their appearance, such as by undergoing various treatments and purchasing numerous cosmetic preparations. One type of cosmetics most often used by people is eyeshadow. As a decorative cosmetic, of course, eyeshadow has colouring content. However, Rhodamine B is still misused, a dangerous dye in eye shadow preparations, because most eye shadow palettes have a red base colour. As a result, the author recognizes the importance of researching to differentiate eyeshadow cosmetics containing Rhodamine B from those that do not, using natural ingredient indicators, given Indonesia's abundance of biodiversity. Rhodamine B may be detected using anthocyanins, natural pigments in various plants; one is butterfly pea flowers. The results of visual observations of the reaction of butterfly pea flower extract and cosmetic samples will then be confirmed using a UV-Vis Spectrophotometer. The qualitative analysis revealed that all eyeshadow samples tested positive for Rhodamine B, as shown by the colour change in the butterfly pea flower extract from blue to purple to pink. The quantitative examination revealed that Rhodamine B concentrations in five samples ranged from 0.419 mg/L to 15.891 mg/L. According to BPOM, cosmetic products should not include Rhodamine B (≤ 0 mg/L).

Reactive Extraction of Carboxylic Acids (Lactic, Propionic and Succinic Acids) using Tri-n-Butyl Amine Dissolved in Various Diluents

The current study intends to look into the extraction of lactic acid, propionic acid and succinic acids from aqueous solutions of these substances utilizing various solvent-extractant combinations to ascertain the most effective composition for the reactive extraction. The commercial value of succinic, propionic, and lactic acids in industrial processes led to their selection as the carboxylic acids. The process of recovering carboxylic acids from their aqueous solutions is accomplished by the Process Intensification method of reactive Tri-n-Butyl Amine was employed in the experiments because it has better stability, a lower water solubility, and is more eco-friendly than other extractants of the amine type. The extractants were dissolved in various diluents with various chemical structures, including 1-octanol, chloroform, and dimethylene chloride. Each experiment was conducted at 298.15 K. The distribution coefficient (KD), loading factor (Z), and extraction yield (%E) were used to compare the results in the range of 0.1 to 0.4 N acid concentration at various concentrations of Tri-n-Butyl Amine (10% to 40%). It was observed that at 0.1N and 40% amine concentration succinic acid attains a maximum distribution coefficient KD is 8.01 and equilibrium complexion KE1 is 7.5 for Tri-n-Butyl Amine, followed by propionic acid and lactic acid and a (1:1) type of acid amine complex was observed. The kinetic studies that were carried out using stirred cells to figure out the kinetic parameters such as order of the reaction with respect to acid and amine, mass transfer coefficient, and rate constant are also reported. The reaction with the highest Hatta number, MH=14, occurs in an instantaneous regime in 1-octanol when succinic acid and Tri-n-Butyl Amine interact.

Enhancing heat and mass transfer in MHD tetra hybrid nanofluid on solar collector plate through fractal operator analysis

Improved solar heat transfer methods are needed for the widespread use of solar energy. Due of their exceptional thermal characteristics, nanofluids have received a great deal of interest in this field. This research examines the use of tetra hybrid nanofluids in solar applications, with an emphasis on heat and mass transport properties. Due to their advantageous thermal characteristics, these nanofluids are well-suited for solar power production and other thermal applications. Accurate results for velocity, concentration, and temperature profiles are produced thanks to the model's use of fractal fractional derivatives and the Crank-Nicholson method for obtaining numerical solutions. In order to learn how different variables affect heat transport, parametric experiments are performed. The results show that tetra hybrid nanofluids greatly improve heat transfer performance over standard nanofluids. This improvement helps flat-plate solar collectors absorb more sunlight and increase their overall efficiency. The rate of mass transfer between phases may be quantified in the design and research of chemical reactors using the Sherwood number, an important quantity in chemical engineering. Its value is shown in a number of processes, including extraction, distillation, and catalytic reactions.

Recovery of Copper from Secondary Sources Via Regeneration of Synergistic Reactive Extraction of D2EHPA-Cyanex 302 System

Recovery of Copper from Secondary Sources Via Regeneration of Synergistic Reactive Extraction of D2EHPA-Cyanex 302 System

Fractionation of phenolic aldehydes by liquid–liquid extraction and polymer resin adsorption

ABSTRACT The extraction and adsorption characteristics of three phenolic aldehydes with high physicochemical similarity in lignocellulosic biomass hydrolyzate, which are fermentation inhibitors, were investigated. The extraction process considered both physical extraction with two organic solvents and reactive extraction with five basic extractants. In physical extraction, n-hexane was found to be the most suitable organic solvent for selectively separating 4-hydroxybenzaldehyde from the three phenolic aldehydes, and in reactive extraction, trioctylphosphine oxide was identified as the most suitable basic extractant for the selective separation of syringaldehyde. In the adsorption process, various neutral polymer resins and anion-exchange polymer resins were employed. Among them, the neutral polymer resin XAD16 was found to be the most suitable for selectively separating 4-hydroxybenzaldehyde. To efficiently separate and concentrate the three phenolic aldehydes with equal mass percentages, a proposed five-step fractionation process included the aforementioned extraction and adsorption techniques. By implementing n-hexane-based physical extraction in step 4 and NaOH solution-based back-extraction in step 5 of the fractionation process, the purities of 4-hydroxybenzaldehyde, vanillin, and syringaldehyde in the final solution increased from their initial 33.3% each to 67.6%, 69.8%, and 76.4%, respectively, at a volume ratio of the aqueous phase to the organic phase of 1:15.

Exploration and multi performance evaluation of process intensification for separation of ethyl tert-butyl ether/ethanol from wastewater

Ethyl tert-butyl ether is a green gasoline additive that enhances fuel efficiency and can play an essential role in improving fuel performance. This study explored the separation of wastewater containing ethyl tert-butyl ether and ethanol by changing the pressure and adding reactions based on extractive distillation, using the synergistic effect of the entrainer, pressure, and chemical reaction. By utilizing coupling technology and process intensification concepts, developed a comprehensive series of intensified processes that have clarified the interaction mechanisms between the extractive distillation process (EDP), pressure swing extractive distillation process (PSEDP), and reactive extractive distillation process (REDP). Studying the separation and purification mechanisms of products and intermediates during the reaction process provides theoretical and practical support for optimizing chemical processes. Comparative analysis showed that the reactive extraction pressure swing distillation process (REPSDP) had preeminent economic and environmental benefits. The total annual cost of PSEDP, REDP, and REPSDP was reduced by 5.88 %, 1.68 %, and 10.08 %, respectively, compared with EDP. The gas emissions of PSEDP, REDP, REPSDP, and REPSDP with heat integration process (HI-REPSDP) are all lower than those of EDP. HI-REPSDP saves 47.59 % of gas emissions compared to EDP, highlighting its environmental benefits. HI-REPSDP has the best energy efficiency, reducing energy consumption by 47.58 % compared to EDP, significantly improving the energy utilization rate. It was found that the introduction of heat integration technology had a significant improvement effect. This research has crucial theoretical and practical value and provides guidance and reference for achieving a clean and efficient production process.

Pyrolysis mechanism of 1,1,1,2-tetrafluoroethane and 1,1,1,2-tetrafluoroethane/carbon dioxide as working fluids for transcritical power cycles: Insights from reactive force field molecular dynamics and density functional theory studies

Carbon dioxide-based mixtures in transcritical power cycle systems can enhance thermodynamic performance but may pose risks of thermal decomposition, potentially compromising system performance and safety. This study investigates the pyrolysis mechanism of 1,1,1,2-tetrafluoroethane (R134a)/carbon dioxide (CO₂), a typical CO₂-based mixture, using reactive force field molecular dynamics (ReaxFF-MD) simulations and density functional theory (DFT). ReaxFF-MD simulations are conducted at pressures ranging from 4 to 12 MPa and temperatures between 1800 K and 3200 K for various fluid compositions, including pure R134a and R134a/CO₂ mixtures at mole ratios of 0.7/0.3, 0.5/0.5, and 0.3/0.7. The effects of temperature, pressure, and composition on the thermal decomposition of both pure R134a and R134a/CO₂ mixtures are examined, with particular focus on behavior at 8 MPa. In the thermal decomposition of R134a/CO₂ mixtures, CO₂ inhibits the formation of F radicals and reduces their concentration through chemical reactions, thereby suppressing R134a decomposition. Pure R134a decomposes into primary products such as hydrogen fluoride (HF), fluorine (F), tetrafluoroethylene (C2HF4), trifluoromethyl radicals (CF3), and diatomic carbon (C2). The addition of CO2 results in the formation of additional products, including carbonyl fluoride (COF), oxygen (O), hydroxyl (HO), and formyl radicals (CHO). The decomposition pathways involve two reaction types: self-decomposition reactions dominate initially, while extraction reactions become more prominent later. Using the DFT approach, reaction energy barriers are analyzed to corroborate the ReaxFF-MD simulation findings. Moreover, the apparent activation energies for these reactions are quantified using first-order kinetics based on the Arrhenius equation, indicating that the thermal decomposition of R134a/CO2 mixtures is more challenging than that of pure R134a.

Utilizing environment-friendly eugenol as a diluent with trioctylamine for the reactive extraction of aqueous levulinic acid

This paper focuses on the reactive extraction of levulinic acid (LA) from aqueous solution by reactive extraction. This goal is achieved using eugenol, a green alternative in the industry, as a solvent in the liquid-liquid equilibrium (LLE) measurements for the ternary system of LA + Eugenol + H2O and quaternary systems of LA + Eugenol/ Methanol (MeOH) + H2O + Tri-n-octylamine (TOA) at T = 293.15 K. Additionally, the distribution coefficients (KD) were calculated for LA using the two diluents. Also, the ability of different diluents with TOA, in the extraction of LA were compared. The distribution coefficient of eugenol with TOA (KD = 9.44) is compared with other organic diluents which indicated that eugenol is a suitable option. MeOH, being the shortest chain alcohol, also turned out to be a diluent that could be utilized for extraction of LA with TOA. Furthermore, the Non-Random Two-Liquid (NRTL) excess Gibbs energy model was applied to correlate the measured phase equilibria. The obtained parameters were further validated using a decanter model.

Penentuan Kondisi Operasi Optimum Proses Ekstraksi Zat Warna Alami Dari Daun Senduduk (Melastoma malabathricum) Serta Penentuan Jenis Dan Konsentrasi Pengawet Ekstrak

Senduduk (Melastoma malabathricum) is a common wild plant found in shrubs. This plant has the potential to be a natural dye source, as its leaves contain tannins, flavonoids, saponins, anthocyanins, and carotenoids. The use of natural dyes in textiles needs to be massively enhanced to reduce the negative impact of synthetic dyes on the environment. This experiment aims to determine the optimum operating conditions for extraction and to determine the effective concentration of preservatives to inhibit biodegradation reactions in natural dye extracts from Senduduk leaves. Variables observed in the extraction process include time, temperature, and the ratio of the weight of the material to the solvent. The content of natural dyes in the extract was analyzed using gravimetric methods. The optimization of natural dye content with time, temperature, and the ratio of the weight of the material to the solvent volume was performed using Response Surface Methodology (RSM) with the Box-Behnken model. To determine the concentration of preservatives, chitosan and tannic acid were added to the natural dye extract, and storage was conducted for 20 days. Every 2 days, the extract was taken for analysis of natural dye concentration using gravimetric methods. The results of the study indicate that the optimum operating conditions for extraction were 45 minutes of time, 90°C temperature, and a ratio of the weight of the material to the solvent volume of 1:10 g/mL resulted in a natural dye content of 19.164%. The most effective preservative used to preserve natural dye extracts from Senduduk leaves is 0.50% tannic acid.

Prevalence of SARS-CoV-2 and Associated Factors Among Individuals During the Second Wave of Infection in Yaounde, Cameroon

Background: The first case of new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was reported in Cameroon on March 5, 2020, in Yaounde. Since then, viral propagation occurred nationwide with a higher burden in urban settings and limited evidence on transmission patterns. Our objective was to determine the prevalence of SARS-CoV-2 and associated factors among individuals in urban settings of Cameroon during the second wave of the pandemic. Methods: a population-based cross-sectional survey was conducted from January 18 to April 26, 2021, among 807 consenting individuals living in four major districts of the city of Yaoundé. Out of 711 nasopharyngeal swabs collected, 671 tests were performed by SARS-CoV-2 ribonucleic acid (RNA) extraction and real time-polymerase chain reaction (RT-PCR) at the National Public Health Laboratory (NPHL). Data were analysed using SPSS v21.0, with p < 0.05 considered statistically significant. Results: overall SARS-CoV-2 RNA positivity rate was 11.62% (78/671), without any significant difference between males and females with 10.9% versus 12.20% respectively (OR = 0.87, p = 0.5). However, clinical status was associated with SARS-CoV-2 RNA positivity rate in symptomatic (26.3%) vs. asymptomatic (9.7%) individuals (Odds Ratio [OR] = 3.30, p = 0.0001). Other factors associated with SARS-CoV-2 RNA positivity include exposure to more than 15min with confirmed cases, wearing a non-conventional facemask (p ˂ 0.05), the practice of occasional hand hygiene before and after contact with patients (OR = 3.60, p < 0.0001) or always as recommended (OR = 0.28, p = 0.0001), hand hygiene before and after occasional contact with objects (OR = 2.05, p = 0.0043) or always as recommended (OR = 0.48, p = 0.0027), surgical mask (OR = 0.17, p = 0.013) and standard mask (p = 0.026). Conclusion: From this urban setting of Cameroon, coronavirus disease 2019 (COVID-19) reached an alert burden (10-20%) during the second wave of the pandemic at the district level. Interestingly, SARS-CoV-2 infection was driven by the presence of symptoms, close contact with confirmed cases, limited adherence to recommended barrier measures, and the use of non-conventional facemasks.

Thermal stability of MDM and oxidative decomposition mechanism under the condition of air infiltration: A combined experimental, ReaxFF-MD and DFT study

When siloxanes are used as the working fluids of organic Rankine cycle systems, there is a possibility of air infiltration due to the large vacuum present in the condenser. To address this issue, experimental and simulation studies were conducted on the thermal stability and pyrolysis product characteristics of octamethyltrisiloxane (MDM) in the presence of air. The results indicated that air significantly promotes the decomposition of MDM at the temperatures above 250 °C. Air was helpful in increasing the formation of CH2O, CO, and CO2, and also enhanced polymerization of decomposition product of siloxane, leading to higher yields of MD2M, MD3M, MD4M, D3, D4, and D5. By combining reactive force field molecular dynamics (ReaxFF-MD) simulations with density functional theory (DFT) calculations, the microscopic mechanisms of MDM's oxidative decomposition by O2 in air and H2O under humid conditions were elucidated. O2 can easily combine with unsaturated Si atoms to form Si-O bonds, combine with CH3 radicals to form C-O bonds, and undergoes hydrogen extraction reactions to initiate decomposition. H2O mainly undergoes initial decomposition through CH3 radical hydrogenation and binding with unsaturated Si atoms. The generated O2H, O, and OH radicals tend to bind with Si atoms in molecules and radicals, facilitating polymerization reactions.

A Mode Evolution Metric to Extract Reaction Coordinates for Biomolecular Conformational Transitions.

The complex, multidimensional energy landscape of biomolecules makes the extraction of suitable, nonintuitive collective variables (CVs) that describe their conformational transitions challenging. At present, dimensionality reduction approaches and machine learning (ML) schemes are employed to obtain CVs from molecular dynamics (MD)/Monte Carlo (MC) trajectories or structural databanks for biomolecules. However, minimum sampling conditions to generate reliable CVs that accurately describe the underlying energy landscape remain unclear. Here, we address this issue by developing a Mode evolution Metric (MeM) to extract CVs that can pinpoint new states and describe local transitions in the vicinity of a reference minimum from nonequilibrated MD/MC trajectories. We present a general mathematical formulation of MeM for both statistical dimensionality reduction and machine learning approaches. Application of MeM to MC trajectories of model potential energy landscapes and MD trajectories of solvated alanine dipeptide reveals that the principal components which locate new states in the vicinity of a reference minimum emerge well before the trajectories locally equilibrate between the associated states. Finally, we demonstrate a possible application of MeM in designing efficient biased sampling schemes to construct accurate energy landscape slices that link transitions between states. MeM can help speed up the search for new minima around a biomolecular conformational state and enable the accurate estimation of thermodynamics for states lying on the energy landscape and the description of associated transitions.

Diversity of Mycotoxin-Producing Fungi in Leafy and Fruit Vegetables Sold in Port Harcourt Metropolis, Nigeria

Mycotoxins are secondary metabolites produced by fungi and are capable of causing diseases and even death in both humans and other animals. This study investigated the diversity of mycotoxin-producing fungi from leafy (Telfairia occidentalis and Bassica oleracea) and fruit (Solanum lycopersicum and Cucumis sativus) vegetables sold in Port Harcourt metropolis, Nigeria using molecular techniques. The fungi were isolated from vegetable samples showing signs of disease using standard methods. DNA extraction and Polymerase chain reaction were carried out at the molecular laboratory of Regional Centre of Biotechnology and Bioresources research, University of Port Harcourt. The isolates were screened for the presence of mycotoxigenic genes (nor1 (aflatoxin), tri6 (trichothecene), otanps (Ochratoxin A), fum13 (fumonisin) and ZEA (zearalenone)) using PCR technique. The isolates containing mycotoxins were identified using ITS gene sequences. Ten out of the eighteen isolates were positive for four (nor1, tri6, otanps and fum13) out of the five mycotoxigenic genes screened. The nine isolates included fungi belong to six genera: Meyerozyma, Pithomyces, Fusarium, Trametes, Penicillium and Aspergillus. The ten isolates were classified as Meyerozyma carbbica RCBBR_Sf13, Pithomyces chartarum RCBBR_Sf5, Fusarium falciforme RCBBR_Sf10, Trametes duplexa RCBBR_Sf17, Trametes versicolor RCBBR_Sf2a, Trametes duplexa RCBBR_Mf1, Fusarium longifundum RCBBR_Mf4, Penicillium soosanum RCBBR_Mf7, Aspergillus aflatoxiformans RCBBR_Sf9, Fusarium circinatum RCBBR_Sf3 based on their ITS gene sequences. Their ITS gene sequences have been deposited in GenBank under the accession numbers OR816039-OR816047, with the exception of Fusarium circinatum RCBBR_Sf3 which could not accession. This study has demonstrated that mycotoxin-producing fungi are diverse and widespread in leafy and fruit vegetables sold within Port Harcourt Metropolis. This raises both public health and food security concerns.

Microfluidic supercritical CO2 applications: Solvent extraction, nanoparticle synthesis, and chemical reaction

Supercritical CO2, known for its non-toxic, non-flammable and abundant properties, is well-perceived as a green alternative to hazardous organic solvents. It has attracted considerable interest in food, pharmaceuticals, chromatography, and catalysis fields. When supercritical CO2 is integrated into microfluidic systems, it offers several advantages compared to conventional macro-scale supercritical reactors. These include optical transparency, small volume, rapid reaction, and precise manipulation of fluids, making microfluidics a versatile tool for process optimization and fundamental studies of extraction and reaction kinetics in supercritical CO2 applications. Moreover, the small length scale of microfluidics allows for the production of uniform nanoparticles with reduced particle size, beneficial for nanomaterial synthesis. In this perspective, we review microfluidic investigations involving supercritical CO2, with a particular focus on three primary applications, namely, solvent extraction, nanoparticle synthesis, and chemical reactions. We provide a summary of the experimental innovations, key mechanisms, and principle findings from these microfluidic studies, aiming to spark further interest. Finally, we conclude this review with some discussion on the future perspectives in this field.

Prevalence of trypanosomiasis caused by Trypanosoma evansi (Kinetoplastea, Trypanosomatidae) in domestic ruminants from Southern Punjab, Pakistan.

Trypanosomiasis, a parasitic infection caused by various Trypanosoma species, poses a significant threat to global livestock, affecting both human health and economic sectors. This study aimed to estimate the prevalence of Trypanosoma evansi in Southern Punjab, Pakistan, focusing on key ruminant species, including camels, cattle, buffaloes, goats, and sheep. A total of 240 blood samples, comprising 48 samples from each animal species (camel, cattle, buffaloes, goat, and sheep) were collected from three districts in Southern Punjab. The collected samples were subjected to thin smear microscopy, DNA extraction, and polymerase chain reaction (PCR) amplification. The molecular characterization was conducted using the TBR primer set, which targeted repeated satellite DNA regions and the cytochrome oxidase II gene of T. evansi. About 22.08% (53/240) of overall samples were positive for trypanosomiasis, with prevalence rates being 23.75% (19/80), 21.25% (17/80), and 21.75% (17/80) for districts Muzaffargarh, Lodhran, and Bahawalpur, respectively. 5.83% (14/240) of samples tested for T. evansi using PCR were positive in the districts of Muzaffargarh 7.50% (6/80), Lodhran 5.00% (4/80), and Bahawalpur 5.00% (4/80). Among the animals tested, camels had the highest positivity rate. The microscopic examination confirmed infection rates of 45.83% (22/48) for camels, 18.75% (9/48) for cattle, 8.33% (4/48) for buffaloes, 18.75% (9/48) for goats, and 18.75% (9/48) for sheep (p < 0.001). PCR results did not reveal substantial differences (p < 0.05) in prevalence: camels 12.50% (6/48), cattle 6.25% (3/48), buffaloes 0% (0/48), goats 8.33% (4/48), sheep 2.08% (1/48); while distinct disparities were detected district-wise: Muzaffargarh 23.75% (19/80), Lodhran 21.25% (17/80), and Bahawalpur 21.25% (17/80). The PCR results for these districts were insignificantly different: 7.50% (6/80), 5% (4/80), and 5% (4/80). The microscopic infection rate in camels from Bahawalpur was 56.30% (9/16). The microscopic analysis in Buffaloes reported a 6.30% (1/16) infection rate, but PCR results indicated no infections (0%) in any district. A significant difference (p < 0.001) in identifying Trypanosoma species was found between positively and negatively tested animals in both microscopic and PCR methods. This study emphasizes the necessity of regularly using PCR-based screening for its superior sensitivity and specificity over traditional microscopy. The varying occurrence of trypanosomiasis among districts reflects the intricate nature of this diseases epidemiology in the region. Reducing economic losses from trypanosomiasis in Southern Punjab, Pakistan, requires targeted interventions, such as vector control measures and farmer education.

Isolation and Identification of Halophilic Bacteria Isolated from Mangrove Soil in Blue Lagoon, Port Dickson, Negeri Sembilan

Halophiles bacteria are capable of tolerating and surviving in extreme salinity due to the special biological structure that it possesses. Classification of halophilic bacteria includes slight, moderate, and extreme halophiles which range from low to high concentrations of salt. Biotechnological products yielded from bacteria residing in saline environment are proven to be valuable in a few industries. The isolated halophilic bacteria may yield powerful biomolecules such as enzymes which can enhance plant development, hence boosting agricultural industries. However, the insufficient data related to halophiles available in Malaysia may reduce the potential use of these bacteria in related industries. The goal of this study is to isolate and identify the potential halophilic bacteria and to determine the tolerance of halophiles in different concentrations of salt. Collection of soil samples was done at the mangrove soil in Blue Lagoon, Port Dickson, Negeri Sembilan. Isolation and purification of halophiles was done on nutrient agar media supplemented with 3% salt. Next, Gram-staining was performed on 4 colonies of bacteria with different types of single colony appearances. Then, the selected bacteria with different colony and morphological characteristics were tested in nutrient broth supplemented with 0%, 3%, 10% and 20% of salt. Molecular identification was conducted which involved DNA extraction and Polymerase Chain Reaction. All 4 isolates selected were tested to be Gram-stain positive and possessed rod-shaped. The bacteria have various salinity tolerance levels which may be due to the presence of different enzymes produced in their cells. Gene sequences and phylogenetic tree were analyzed based on 16s rRNA sequences to identify the species of the isolates. At the end of the experiment, isolate 2A1 and 2A4 were identified as Bacillus sp., while isolate 2A2 and 2A3 were identified as Cytobacillus oceanisediminis.

Efficient separation of vanadium and chromium by the complexation with sulfate ions in solvent extraction using EHEHPA

The significant chemical similarity between vanadium and chromium complicates the process of efficient extracting V(Ⅳ) from the solution containing Cr(Ⅲ) to prepare high-purity vanadyl sulfate electrolyte. In this study, the separation of vanadium and chromium with 2-ethylhexyl phosphoric acid-2-ethylhexyl ester (EHEHPA) was enhanced by increasing the concentration of SO42−. Under the extraction equilibrium pH of 2.5, the extraction of Cr(III) was suppressed by increasing the concentration of SO42− anions, which hardly affected the extraction efficiency of V(IV), achieving a separation factor as high as 5780.6 at SO42− concentration of 1.75 mol·L−1. Furthermore, after pretreatment of the water-leaching solution of sodium-roasted vanadium slag, extraction was carried out under the conditions of equilibrium pH of 1.8 and SO42− concentration of about 2.00 mol·L−1, and after stripping, the vanadyl sulfate electrolyte containing 2.12 mol·L−1 of vanadium and only 0.11 mg·L−1 of chromium was obtained. It was proved that Cr(Ⅲ) mainly extracted in the form of CrSO4+ into organic phase by one EHEHPA dimer as [CrSO4(H2O)]+ under higher SO42− concentrations (e.g., ≥1.50 mol·L−1), while Cr(Ⅲ) was extracted by two EHEHPA dimers as Cr3+ without SO42− in the solution. Based on the density functional theory, the complex structures of Cr(III) were optimized and the energy changes of Cr(III) extraction reactions were calculated, indicating the complexation between SO42− and Cr(III) under higher SO42− concentrations resulting in the inhibition of Cr(III) extraction, and thus enhancing the separation of vanadium and chromium.

Diversity of bartonellae in mites (Acari: Mesostigmata: Macronyssidae and Spinturnicidae) of boreal forest bats: Association of host specificity of mites and habitat selection of hosts with vector potential.

Research into various bacterial pathogens that can be transmitted between different animals and may have zoonotic potential has led to the discovery of different strains of Bartonella sp. in bats and their associated ectoparasites. Despite their enormous species diversity, only a few studies have focussed on the detection of bacterial pathogens in insectivorous bats of boreal forests and their associated Macronyssidae and Spinturnicidae mites. We collected and molecularly analysed mite samples from forest-dwelling bat species distributed all along the boreal belt of the Palearctic, from Central Europe to Far East. Ectoparasitic mites were pooled for DNA extraction and DNA amplification polymerase chain reaction (PCRs) were conducted to detect the presence of various bacterial (Anaplasmataceae, Bartonella sp., Rickettsia sp., Mycoplasma sp.) and protozoal (Hepatozoon sp.) pathogens. Bartonella sp. DNA was detected in four different mite species (Macronyssidae: Steatonyssus periblepharus and Spinturnicidae: Spinturnix acuminata, Sp. myoti and Sp. mystacinus), with different prevalences of the targeted gene (gltA, 16-23S ribosomal RNA intergenic spacer and ftsZ). Larger pools (>5 samples pooled) were more likely to harbour Bartonella sp. DNA, than smaller ones. In addition, cave-dwelling bat hosts and host generalist mite species are more associated with Bartonella spp. presence. Spinturnicidae mites may transmit several distinct Bartonella strains, which cluster phylogenetically close to Bartonella species known to cause diseases in humans and livestock. Mites with ubiquitous presence may facilitate the long-term maintenance (and even local recurrence) of Bartonella-infestations inside local bat populations, thus acting as continuous reservoirs for Bartonella spp in bats.

Prevalence of hepatitis A and E viruses in wastewater in Asian countries

Hepatitis A and E viruses (HAV and HEV, respectively) remain a significant global health concern despite advancements in healthcare and vaccination programs. Regular monitoring and vaccine efficacy of HAV are still lacking in different countries. This study aimed to investigate HAV and HEV prevalence in developed, developing, and least-developed Asian countries using wastewater as a surveillance tool. A total of 232 untreated wastewater samples were collected from six wastewater treatment plants, a sewage treatment plant, or an open drainage in six countries [Nepal (n = 51), Indonesia (n = 37), Thailand (n = 30), Vietnam (n = 27), the Philippines (n = 17), and Japan (n = 70)] between April and October 2022. Viruses in wastewater were concentrated by simple centrifugation or polyethylene glycol precipitation method, followed by viral RNA extraction and reverse transcription-quantitative polymerase chain reaction. HAV and HEV RNA were detected in the samples from Nepal (51 % for HAV and 2 % for HEV), Thailand (3 % for both viruses), and Japan (1 % for HAV and 24 % for HEV). Only HAV RNA was found in 11 % of the samples in Indonesia, whereas only HEV RNA was detected in Vietnam and the Philippines, with a positive ratio of 15 % and 12 %, respectively. These results highlighted the geographic variability in HAV and HEV prevalence, underscoring the need for localized public health strategies to address specific viral hepatitis challenges in each country.