Elemental Analyzer Research Articles

Extraction, Characterization and Antibacterial Activity of Chitosan from Mud Crab Scylla serrata

The shellfish waste accumulated on a huge scale at seashores and in the seafood industry and very low quantities were used to extract chitosan. In this study, chitosan was extracted from the mud crab Scylla serrata shell using conventional chemical methods. The extracted chitosan and commercial chitosan were verified through Field Emission Scanning Electron Microscopy (FE-SEM), Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD), and an elemental analyzer. ATR-FTIR spectrum confirmed the presence of characteristics compounds of chitosan and XRD patterns exhibited crystallinity of chitosan having centered peaks at 10º and 20º in 2θ. Moreover, 46.24% of the degree of deacetylation was obtained for the extracted chitosan altogether enhancing the quality of extracted chitosan. In addition to this, the extracted chitosan was tested for its antibacterial activity against two Gram-negative (E. coli and Pseudomonas) and two Gram-positive bacteria (Staphylococcus and Bacillus) in vitro. The antimicrobial activity of extracted chitosan was evident with the greater zone of inhibition against E. coli (26±0.32mm) and the least against Staphylococcus (18mm). Hence the present study gives insight into the biological properties of extracted chitosan from Scylla serrata thereby paving the way for its further use in biomedical science and microbiology.

Ecofriendly and biocompatible biochars derived from waste-branches for direct and efficient solid-phase extraction of benzodiazepines in crude urine sample prior to LC-MS/MS.

Biochars (BCs) derived from waste-branches of apple tree, grape tree, and oak were developed for direct solid-phase extraction (SPE) of five benzodiazepines (BZDs) in crude urine samples prior to liquid chromatography-tandem mass spectrometry (LC-MS/MS)determination. Scanning electron microscopy, elemental analyzer, X-ray diffractometry, N2 adsorption/desorption experiments, and Fourier transform infrared spectrometry characterizations revealed the existence of their mesoporous structure and numerous oxygen-containing functional groups. The obtained BCs not only possessed high affinity towards BZDs via π-π and hydrogen bond interactions, but also afforded the great biocompatibility of excluding interfering components from undiluted urine samples when using SPE adsorbents. Variables affecting SPE of target analytes were systematically optimized including pH, ionic strength, dilution ratio, washing solution, desorption solvent, and its volume. The method of BC-based SPE combined with LC-MS/MS exhibited awide linear range of 0.03-100ng/mL, alow detection limit of 0.01-0.08ng/mL, and satisfactory recovery of 77.6-106% for the studied BZDs. Notably, this method allowed the possibility of direct loading of undiluted urine samples and avoided tedious filtration and dilution steps, which significantly simplified the pretreatment process. Additionally, these BC sorbents derived from waste-branches were ecofriendly and cost-effective, providing a sustainable alternative for the traditional SPE sorbents. Thus, the proposed method has promising application for ecofriendly, simple, efficient, and reliable monitoring of BZDs in urine samples.

Development and Performance Evaluation of an Auxetic Yield Metal Damper for Enhanced Seismic Energy Dissipation

In this study, a new auxetic yield metal (AYM) damper is introduced for the first time based on the application of the auxetic structure. The performance of the proposed system is investigated via nonlinear finite element analysis by using ABAQUS commercial code. These types of steel dampers are fabricated from mild steel plate with elliptical holes and dissipate energy through the inelastic deformation of the constitutive material. To assess the capability of the proposed AYM damper, a set of nonlinear quasi-static finite element analyzes has been conducted on the damper with various geometric parameters. To ensure that the numerical models accurately predict the responses of AYM dampers, experimental validation techniques were employed. This validation confirms the models' sufficient accuracy in representing the dampers' behavior. According to the results, the proposed AYM damper exhibits a low yield displacement, stable hysteretic loops, a good range of ductility, and a high energy dissipating capacity. The specific energy absorption and ductility of the proposed auxetic damper are 32.5J/kg and 59, respectively. With its ductile behavior, this damper can dissipate a large amount of earthquake input energy. Furthermore, it is found that the use of proposed auxetic dampers in the steel frame, increases the hardness, strength and ductility of the frame and the energy absorption increased by 210%.

Seagrass population dynamics and biodiversity assemblages indicate negative effects of short-term nutrient enrichment in tropical island ecosystem.

This study assessed the influence of anthropogenic short-term nutrient enrichment (hereafter enriched) effects on seagrass population dynamics (recruitment, growth rate and mortality), morphometric traits, productivity, and leaf biodiversity assemblages in the islands of Andaman and Nicobar (ANI) of India and contrasted these findings with away from these enriched areas (hereafter pristine). Seagrass (Thalassia hemprichii and Cymodocea rotundata), and sediment samples were collected in the dry season (October-May) of ANI. Reconstruction techniques, an indirect measurement of plant growth was used to derive leaf plastochrone interval (PI), i.e., number of days required to produce one leaf by the seagrass. Sediment, organic matter (OM) and carbon (C) were quantified using, loss on ignition method and CHNS elemental analyser. The total N in leaves of T. hemprichii and C. rotundata increased 3.3-fold and 2.4-fold than pristine conditions. Increased N accumulation resulted in higher shoot densities, below ground biomass, and productivity for both seagrasses. T. hemprichii and C. rotundata took 26.07 and 19.76 days respectively to produce new seagrass leaf under enriched conditions. Low apex densities resulted in lower meadow migration and increased meadow fragmentation under enriched conditions. The above ground-biomass and leaf length of T. hemprichii and C. rotundata decreased under enriched conditions leading to lower leaf meiofauna abundance. The long-term average recruitment for both T. hemprichii and C. rotundata increased under enriched conditions resulting in 3.5-fold and 11-fold higher current population growth rates resulting in increased younger plants. Contrastingly, these younger plants did not survive longer under enriched conditions, reducing the long-term seagrass population longevity to 4 years, compared to 6-7 years longevity under pristine conditions. This study highlights that nutrient enrichment in tropical islands benefits seagrass in short-term but reduces seagrass meadow migration, population longevity and biodiversity assemblages, thus reducing seagrass ecosystem service provisions, which calls for urgent monitoring and conservation of seagrass ecosystems of ANI, India.

Physicochemical Properties of Biochar Prepared from Guinea Corn Straw as a Function of Different Pyrolysis Temperatures

The present study examined the effect of pyrolysis temperature on the physicochemical properties of biochar produced from guinea corn straws at different temperatures (300-600℃). However, the produced biochars were designated as BCG-300, BCG-400, BCG-500 and BCG-600, respectively. The produced biochar’s were characterized by different analytical techniques. These include; the proximate and elemental analyses, morphological, crystallographic, functional groups and specific surface area analyses were investigated using elemental analyzer, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy and Brunauer–Emmett–Teller (BET), respectively. The results indicated that. increasing pyrolysis temperature increased the content of fixed carbon (C), the C content, the total content of K, Ca, and Fe, as well as the cation exchange capacity (CEC), pH, and EC. While the yield, the content of volatile matter O and H, and the ratios of O/C and H/C decreased. Additionally, at higher pyrolysis temperature, the BET surface area and pore volume increased with increased in temperature, typically due to the increase of the micropore surface area and micropore volume. Furthermore, the data of Fourier transformation infrared showed that at higher pyrolysis temperature, the biochar aromaticity increased and decreased in polarity. Similarly, the crystalline mineral components increased with pyrolysis temperatures due to the cellulose loss, as indicated by X-ray diffraction analysis and scanning electron microscope images. Hence, pyrolysis temperature has a strong effect on biochar properties, and therefore biochars can be produced by changing pyrolysis temperature in order to meet their applications, such as carbon sequestration, greenhouse gas mitigation and as an adsorbent for organic and inorganic contaminants when applied to the environment etc.

Intercomparison of Indexable Cutting Inserts' Wear Progress and Chip Formation During Machining Hardened Steel AISI 4337 and Austenitic Stainless Steel AISI 316 L.

This article deals with a mutual comparison of indexable cutting inserts of the CNMG 120408 type from two different manufacturers during the machining of hardened steel AISI 4337 and austenitic stainless steel AISI 316 L. The main goal is to analyse the different wear processes depending on the difference in the manufacturer's design and also depending on the properties of the different machined materials. The progress of the wear of the main spine of the tool, the types of wear and the service life of the cutting edge were monitored, with the achievement of the critical value VBmax = 300 µm being the standard. In addition to the wear of the inserts, the production of chips was monitored in terms of their shape, average size and number of chips per 100 g of chips produced. In order to understand the relationships arising from the obtained data, an SEM equipped with an elemental analyser was used to analyse the coating layers and the substrate of the unworn inserts and the types of wear and the intensity of the surface damage of the worn inserts. A several-fold difference in the lifetime of the cutting edge was found, both in terms of design and in terms of the selected machined material, while in both cases the cutting edge with Al2O3 and TiCN layers of half thickness achieved a better result in liveness. From the point of view of chip formation, very similar results in shape and average length were observed despite the different designs of chip breakers. Cutting inserts with half the thickness of the coating layers achieved longer cutting edge life in the non-primary material application compared to the target workpiece material. At the same time, it was observed that a thinner coating layer has a positive effect on chip formation in terms of its length and shape.

Diverse Farming Systems and their Impact on Macro and Microelement Content of Vegetables & Crops.

The present study investigates the effect of conventional and organic farming systems on the nutritional profile of crops. Different crops, namely -millet, sorghum, sesame, mustard, fenugreek, berseem, pea, potato, and onion were cultivated through conventional agriculture in which chemical fertilizers like urea, DAP (Diammonium Phosphate) and pesticides were used and organic farming in which organic fertilizers like seaweed and vermicompost were used. The experimental study was done on a field in north India from 2019 to 2021 in six different seasons, and the nutrient profile of the crops with respect to macroelements (S, K, Na, P, Ca, Mg) and microelements (B, Cu, Fe, Mn, Zn, Al) was compared. Macro and microelements were analyzed by Element analyzer and ICP-OES in both types of farming systems. The content of macro, as well as microelements, was found to be significantly higher in all the organically produced crops as compared to the conventionally grown crops. Significant differences were observed in the macroelement content of organic onion (P- 900 mg/kg, K-2000mg/kg) and organic pea (K 2250 mg/kg) as compared to the content of conventionally grown onion (P-756 mg/kg, K- 1550 mg/kg) and pea (K-2000 mg/kg). Similarly, microelement content in the organic sesame (Fe - 3.12 mg/kg), organic millet (Fe- 2.19 mg/kg), and organic potato (Zn-200 mg/kg) was higher as compared to conventionally grown sesame (Fe 2.05 mg/kg), millet (Fe- 1.56 mg/kg) and potato (Zn 167 mg/kg). This investigation concludes that crops with optimum nutritional content can be produced through organic farming with minimum input and maximum production.

Preparation and Application of Weak Cation Exchange Resin Based on Thiol Click Reaction.

Using poly(styrene-divinylbenzene) microspheres as stationary phase matrix and mercaptosuccinic acid as a modifier, a new weak cation exchange resin was synthesized by thiol click reaction. The conditions for thiol-chlorine click reaction and thiol-alkene click reaction were optimized. The surface morphology and chemical composition of the modified microspheres were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, and an elemental analyzer. The stationary phase can achieve the separation of six common cations within 25min. A homemade weak cation chromatographic column was used to determine the impurities of Na+ and K+ and the content of tetramethylammonium ions in tetramethylammonium hydroxide samples. The method showed a good linear correlation in the range of 0.1-500.0mg/L with correlation coefficients of 0.9998-0.9999, and the limits of detection (signal-to-noise ratio ≥ 3) were 0.01-0.20mg/L. The intra-day relative standard deviations (RSDs) were in the range of 1.1%-4.4%, and the inter-day RSDs were in the range of 0.8%-14.8%. The spiked recoveries were in the range of 91.92%-119.86%. The results showed that the prepared stationary phase exhibited effective separation ability and good reproducibility, which was suitable for the analysis of the impurities of Na+, K+, and the content of tetramethylammonium in the tetramethylammonium reagents.

Growth pattern and turnover of carbon and nitrogen measured by stable isotope ratios in the hair of sika deer (Cervus nippon).

Hair is known to preserve diet history and other physiological information during its growth period and is often used in chemical analyses. However, the growth patterns and turnover of hair vary according to the animal species or habitat, so understanding these patterns in the target animal is necessary for interpreting the results of hair analyses. In this study, we aimed to elucidate the growth pattern and dietary information of winter coat hair in captive sika deer (Cervus nippon). Experiments involving hair-staining and shaving were conducted to elucidate the growth pattern of sika deer hair. A diet-switching experiment was conducted to ascertain what dietary information is reflected in the carbon and nitrogen stable isotope values of the deer winter coat. Hair samples collected from each body site (head, shoulder, back, and hip) were analyzed using an elemental analyser interfaced with an isotope-ratio mass spectrometer. The winter coat grows from early September to early November, and then stops after that. During the growth period of the winter coat, the hair of the shoulder and back grew at a constant rate. The carbon and nitrogen stable isotope values of hair reflected the deer's feeding history during hair growth, but there seemed to be a time lag in the hip hair. The results suggest that the guard hair of the shoulder is suitable for hair analysis in sika deer. The obtained information on growth patterns and isotopic change of hair from captive sika deer according to diet be useful for interpreting the results of future analyses using hair samples of wild deer.

Non-linear kinetic model of coke deactivation in methanol-to-gasoline conversion: Effects of nano and micro ZSM-5 crystals

Methanol-to-gasoline conversion over ZSM-5 catalysts, a non-petroleum carbon fuel process, is significantly impacted by coke deposition, which deactivates the catalyst by blocking zeolite pores during the reaction and diffusion process. This study investigated the differences in coke species development and deactivation using a non-linear kinetic model, comparing microcrystalline ZSM-5 with longer pore lengths to nanocrystalline ZSM-5 with shorter pores, both tested at 350°C. Catalyst and coke were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), temperature-programmed oxidation (TPO), thermogravimetric analysis (TGA), and an elemental analyzer. Micro ZSM-5 initially achieved 99 % conversion but rapidly dropped to 61 % due to coke buildup, while nano ZSM-5 maintained over 98 % conversion for 24 hours before declining, highlighting the superior catalytic durability of shorter pores. Micro ZSM-5 showed faster coking, accumulating 7.19 % coke with higher temperature-resistant graphitic coke, whereas nano ZSM-5 exhibited a lower coke buildup of 4.56 %, forming primarily amorphous coke. A two-step non-linear kinetic model for soft and hard coke oxidation was applied, with the second-order model providing the highest correlation coefficient. The activation energy for coke decomposition was influenced by pore length, revealing distinct kinetic behaviors for hydrogen-deficient graphitic coke and amorphous coke. This study underscores the importance of zeolite pore structure on coke formation, deposition patterns, and catalytic durability, offering deeper insights into the methanol-to-gasoline conversion process.

β-Cyclodextrin Catalyzed, One-Pot Multicomponent Synthesis and Antimicrobial Potential of N-Aminopolyhydroquinoline Derivatives.

In the present report, we have described the synthesis of N-aminopolyhydroquinoline (N-PHQ) derivatives using highly efficient β-cyclodextrin (β-CD) as a catalyst by the Hantzsch condensation of substituted aromatic aldehydes, dimedone, and hydrazine hydrate in one pot. The reactions were completed in a shorter time without the generation of any other byproduct. The synthesized N-PHQs were washed thoroughly with distilled water and recrystallized with ethanol to get highly purified products (as crystals). The structure of the synthesized N-PHQs was established by using advanced spectroscopic techniques like FT-IR, NMR (1H, 13C, DEPT, COSY, and HSQC), ESI-MS, and Elemental Analyzer. The N-PHQs derivatives demonstrated moderate to excellent resistance against the tested strains (both fungal as well as bacterial). The presence of polar groups, which are able to form H-bonds, attached to the phenyl ring like -NO2 (4b and 4c), and -OMe (4i, 4j, and 4k) exhibits excellent activity, which is comparable to standard drugs, amoxicillin and fluconazole.

14C AMS measurement of CO2 samples with the high throughput HVE gas interface system

Abstract The newly designed HVE gas interface enables the AMS measurement of carbon samples in CO2 form. The CO2, e.g. resulting from the sample combustion in an elemental analyzer, is adsorbed in a zeolite trap and subsequently transferred to a motor-driven syringe. Once diluted with He, the gas mixture is transferred into the ion source of the AMS system. A carbon ion beam is formed in the ion source and mass-analyzed by the AMS system, resulting in 13C/12C and 14C/12C isotopic ratios. The HVE gas interface features two traps and two syringes to maximize the sample throughput, which results in more than 10 samples per hour. The first performance results of CO2 gas sample AMS measurements that were performed with the HVE gas interface in combination with the HVE 210 kV AMS system are presented in this paper. The measurements show that the gas interface contribution to the 14C/12C background is in the 10–15 level and to the precision is at or below 1%.

Improving soil carbon estimates of Philippine mangroves using localized organic matter to organic carbon equations

BackgroundSoutheast Asian (SEA) mangroves are globally recognized as blue carbon hotspots. Methodologies that measure mangrove soil carbon stock (SCS) are either accurate but costly (i.e., elemental analyzers), or economical but less accurate (i.e., loss-on-ignition [LOI]). Most SEA countries estimate SCS by measuring soil organic matter (OM) through the LOI method then converting it into organic carbon (OC) using a conventional conversion equation (%Corg = 0.415 * % LOI + 2.89, R2 = 0.59, n = 78) developed from Palau mangroves. The local site conditions in Palau does not reflect the wide range of environmental settings and disturbances in the Philippines. Consequently, the conventional conversion equation possibly compounds the inaccuracies of converting OM to OC causing over- or under-estimated SCS. Here, we generated a localized OM-OC conversion equation and tested its accuracy in computing SCS against the conventional equation. The localized equation was generated by plotting % OC (from elemental analyzer) against the % OM (from LOI). The study was conducted in different mangrove stands (natural, restored, and mangrove-recolonized fishponds) in Oriental Mindoro and Sorsogon, Philippines from the West and North Philippine Sea biogeographic regions, respectively. The OM:OC ratios were also statistically tested based on (a) stand types, (b) among natural stands, and (c) across different ages of the restored and recolonized stands. Increasing the accuracy of OM-OC conversion equations will improve SCS estimates that will yield reasonable C emission reduction targets for the country’s commitments on Nationally Determined Contributions (NDC) under the Paris Agreement.ResultsThe localized conversion equation is %OC = 0.36 * % LOI + 2.40 (R2 = 0.67; n = 458). The SOM:OC ratios showed significant differences based on stand types (x2 = 19.24; P = 6.63 × 10–05), among natural stands (F = 23.22; p = 1.17 × 10–08), and among ages of restored (F = 5.14; P = 0.03) and recolonized stands (F = 3.4; P = 0.02). SCS estimates using the localized (5%) and stand-specific equations (7%) were similar with the values derived from an elemental analyzer. In contrast, the conventional equation overestimates SCS by 20%.ConclusionsThe calculated SCS improves as the conversion equation becomes more reflective of localized site conditions. Both localized and stand-specific conversion equations yielded more accurate SCS compared to the conventional equation. While our study explored only two out of the six marine biogeographic regions in the Philippines, we proved that having a localized conversion equation leads to improved SCS measurements. Using our proposed equations will make more realistic SCS targets (and therefore GHG reductions) in designing mangrove restoration programs to achieve the country’s NDC commitments.

WDXRF Analysis of White Colour Pigments Used by Ancient Artists in Central Tanzania Rock Paintings

In central Tanzania, there are large numbers of ancient rock paintings which have been drawn mostly on shelter rocks. Different colours were used in the paintings including white paint. The pigments and the material used by ancient artists in making these colours were not known. This study aimed to determine the composition of the white colour and suggests the pigments and materials used in making the white colour. A technique namely WDXRF was used to determine the composition of white paint in order to suggest the pigment used while a CHN elemental analyser was used to determine the presence and amount of organic carbon in the samples. The results from the analysis of the rock sample were compared to the results of the analysis of the paint sample. White colour was found to be from chalk (CaCO3) and gypsum (CaSO4X2H2O). Both pigments were found to contain some amount of organic carbon in different concentration. Organic carbon in the pigment is related to the use of organic binders during the preparation of the colour.

Utilization of papermaking black liquor as liquid phase for hydrothermal carbonization of corn stalks: The unique role of alkali for production of hydrochar

Papermaking black liquor (BL) contains a large amount of organic matter, alkali, and salt, which has high value in industrial and agricultural production. In the present paper, hydrothermal carbonization (HTC) technology has been employed to deal with BL and corn stalk (CS) under various conditions. A variety of analytical technologies, including Fourier Transform Infrared Spectrometer, X-Ray Diffraction, element analyzer, comprehensive thermal analyzer, scanning electron microscope, chromatography/mass spectrometry, TOC analyzer, and density functional theory (DFT), were used to characterize the physicochemical properties of hydrochar and aqueous phase product. The effects of experimental parameters (temperature, solid-liquid ratio, and time) on the HTC of BL and CS were systematically investigated. The higher energy yield and densification of hydrochar prepared by our HTC technology were obtained at 260 ℃ in 30 min with a solid-liquid ratio of 1:3. Mechanism study indicates that NaOH, which comes from the original BL, could effectively facilitate the cleavage of β–O–4 bond in lignin and β–1–4 glycosidic bond in cellulose and hemicellulose molecules. Hemicellulose and cellulose are more susceptible to degradation relevant to the lignin in the presence of NaOH. Elementary analysis shows that the dosage of BL is important for improving energy densification of hydrochar. The combustion characteristics show that hydrochar presents a thermochemical behavior, which is close to bituminous coal. Owing to hydroxyl ion in NaOH ion pair was consumed in the series of dehydrogenation reactions, pH of HTC aqueous phase product significantly decreases from 11 to 13 in original BL to 4.8–5. Such results indicate that a completely change for the components of BL could be obtained by our HTC technology, which provide a novel idea for the treatment of Papermaking BL without concentration.

Spectroscopic investigation on shuttlecock-shaped liquid crystalline trimers: Mesomorphic behaviour and its application in optical storage devices

In this paper, we discuss the synthesis and characterization of 2,3,4-tris[n-((4-(-cyanophenyl)diazenyl)phenoxy)alkyloxy]benzonitrile obtained by coupling 2,3,4-trihydroxy benzonitrile and (E)-4-((4-((n-bromoalkyl)oxy)phenyl)diazenyl)benzonitrile, pertain to shuttlecock shaped liquid crystals. The molecular structure was confirmed by NMR spectroscopic and elemental analyzer. The thermal behavior of the trimers was assessed using a polarizing optical microscope (POM) and differential scanning calorimetry (DSC). The three diazo groups in the trimers enabled us to study the photo-isomerization effect and evaluate their potential applications in optical storage devices. Importantly, we found these trimers easy to synthesize and process, paving the way for cost-effective alternatives to traditional LC materials. We fabricated an optical storage device to study the light effects on shuttlecock-shaped LC trimers, demonstrating that the geometry of the trimers plays a crucial role in determining structure-property relationships.

Comparative study of the sequential extraction methodologies for fractionation analysis of mercury in coal of Thar coalfield.

The primary objective of this study was to evaluate the bound fractions of mercury (Hg), physicochemical parameters, and mineral composition of coal. Coal samples were collected from various depths within Block-VII of the Thar coalfield in Pakistan. The Hg associated with different chemical fractions of coal was extracted using a sequential extraction scheme as per the community bureau of reference (BCR) protocol. This study utilized both the BCR-sequential extraction method (BCR-SEM) and a single-step sequential extraction based on an ultrasonic-assisted method (SSE-UAM) for the fractionation analysis of Hg in coal. The extraction methodologies, BCR-SEM and SSE-UAM, were specifically designed for analyzing Hg fractionation in coal samples. The SSE-UAM offers an operational advantage, requiring only 2h compared to the 51h needed for BCR-SEM. The analyses were validated using standard reference material (SRM-1635a) and the spiking addition method, achieving a recovery percentage of 97.1% for total Hg concentrations using the pseudo-extraction method in SRM-1635A. Total Hg content in the coal samples ranged from 0.60 to 2.34µgg-1 across four different coal seams from Block-VII of the Thar coalfield. Additionally, Hg concentration was observed to decrease with increasing depth, attributed to changes in mineralogical composition. The highest concentration of Hg was detected at a depth of 200-203m, while the lowest concentration was at a depth of 152-154m. The concentration of Hg in various fractions was 32-60% in the acid-soluble fraction, 1.72-4.92% in the reducible fraction, and 9.58-50.8% in the oxidizable fractions. The coal sample characteristics were analyzed using an elemental analyzer and scanning electron microscopy with energy-dispersive spectroscopy. Cold vapor atomic absorption spectrometry (CV-AAS) was used to measure the extracted fractional concentration of Hg in coal.

Remediation of Arsenic and Heavy Metals and Soil Stabilization by Waste Chitosan based Biochar

Objectives : This study aims to evaluate the feasibility of converting waste chitosan adsorbents, laden with microalgae, into biochar for application as a stabilizing agent to remediate heavy metal-contaminated soil and improve soil quality.Methods : Waste chitosan adsorbents were converted into biochar through two processes: dry thermal carbonization at 400°C to produce pyrochar and hydrothermal carbonization at 200°C to produce hydrochar. The elemental compositions, surface functional groups, morphologies of the biochars were evaluated by elemental analyzer, FT-IR spectrometer, and SEM analysis. The arsenic and heavy metal adsorption characteristics of the produced biochars were assessed. Additionally, the produced biochars were applied as stabilizing agents to arsenic and heavy metal-contaminated soil with varying mixing ratios of 2, 5 and 10 wt%. After a one-week soil stabilization experiment, soil properties and TCLP(Toxicity Characteristic Leaching Procedure) leaching tests were conducted.Results and Discussion : The pyrochar produced from waste chitosan exhibited a porous structure with high pH (pH 10) and minimal surface functional groups. The hydrochar consisted of spherical particles with functional groups such as hydroxyl and amine groups on the surface, exhibiting a slightly acidic pH of 5.8. Pyrochar has a higher adsorption capacity for cationic heavy metals compared to hydrochar due to its porous structure and high pH. On the other hand, when applied to soil, hydrochar demonstrated superior stabilization efficiency for arsenic and heavy metals. This is attributed to the diverse surface functional groups containing oxygen on the hydrochar. The stabilization efficiency was influenced by the biochar mixing ratio, with a 5% hydrochar application resulting in 10-64% stabilization efficiency for all elements.Conclusion : This study confirmed that biochar produced from waste chitosan effectively stabilizes arsenic and heavy metals in soils. Additionally, the quantity of biochar used can impact its effectiveness in stabilization.

Metal ion complexes of 2-thioxoimidazolidine-4-one derivatives mixed ligand synthesis, characterization, in-vitro biological activities and in-silico studies

A series of complexes of [Mn (III), Co(II), Cu(II), and Cd(II)] were synthesized with two new 2-thioxoimidazolidin-4-one derivates ligands. These ligands were characterized using an elemental analyzer (CHNS), 1H NMR spectroscopy, FT-IR spectroscopy, and UV–Vis spectroscopy. The synthesized complexes were characterized by magnetic susceptibility measurements, electrical conductance analysis, and atomic absorption spectroscopy. The biological activity of the ligands and complexes were determined against E. coli, B. subtilis, A. niger, and P. chrysogenum. To determine the influence of different metal-ion concentrations on microbial growth, we used molecular docking to evaluate antibacterial activity targeting antimicrobial sites. Our findings indicate that the metal ion complexes exhibited varying degrees of antimicrobial activity, affecting the growth of the tested organisms.

Imminent prognosis for piperazinium-based ionic liquids applications for coal desulfurization

Sulfur is one of the most important quality parameters for coal rank and utility in power generation. Combustion of coal having high sulfur content leads to SOx emissions which have detrimental impacts on the environment and human health. For sulfur remediation, N-methyl piperazinium-based room temperature ionic liquids (RTILs) were synthesized with two acidic anions precursors’ dimethyl sulfate and Perchloric acid. These novel RTILs were characterized using standardized analytical techniques of FTIR, 1H NMR, 13C NMR, HPLC, and TGA/DSC. Thermal stability of dimethyl piperazinium methyl sulfate [DMPI+][MeSO4−] and methyl piperazinium perchlorate [MPI+][ClO4−] was 284 °C and 256 °C. The proximate and ultimate analysis of coal samples collected from block II of the Thar coal field shows high moisture content (29–47 %) and gross calorific value between 5006–6660 Btu/lb suggesting it is Lignite-B type fuel. Total sulfur content in coal samples was 1–4.1 % reflecting variable degree of sulfurization. Coal cleansing through oxidative extractive desulfurization theme using nifty combinations of these acidic RTILs was verified by HPLC, FTIR, CHNS Elemental Analyzer, and X-ray Florescence (XRF) techniques. Sulfur leaching from the coal matrix was higher for methyl piperazinium perchlorate and an 85 % decrease in the sulfur part of coal along with increased heat content through this study suggests cleaner and sustainable use of coal.