Search Results (28)

Carbon disulfide (CS₂) is a highly toxic and flammable solvent extensively used in chemical processes and laboratory analyses. This review examines both air and biological monitoring methods for assessing the exposure of laboratory workers to CS₂. Emphasis is placed on the measurement of airborne CS₂ concentrations and the monitoring of 2-thiothiazolidine-4-carboxylic acid (TTCA) in urine, a key biomarker of exposure. By analysing case studies and practical applications, the paper outlines the effectiveness and limitations of current monitoring techniques. Additionally, the review addresses key challenges such as CS₂ volatility, dietary influence on biomarker levels, and the sufficiency of protective measures, including nitrile gloves. It also proposes best practices to mitigate exposure, such as improved ventilation, the use of polyvinyl alcohol gloves, and the substitution of CS₂ with less hazardous solvents. This comprehensive review underscores the need for continuous vigilance in managing chemical exposure and offers insights into how laboratories can better protect their workers by integrating air and biological monitoring strategies. Full article

Biofouling poses a significant challenge to the marine industry, and silicone anti-biofouling coatings have garnered extensive attention owing to their environmental friendliness and low surface energy. However, their widespread application is hindered by their low substrate adhesion and weak static antifouling capabilities. In this study, a novel silicone polymer polydimethylsiloxane (PDMS)-based poly(urea-thiourea-imine) (PDMS-PUTI) was synthesized via stepwise reactions of aminopropyl-terminated polydimethylsiloxane (APT-PDMS) with isophorone diisocyanate (IPDI), isophthalaldehyde (IPAL), and carbon disulfide (CS₂). Subsequently, a nanocomposite coating (AgNPs-x/PDMS-PUTI) was prepared by adding silver nanoparticles (AgNPs) to the polymer PDMS-PUTI. The dynamic multiple hydrogen bonds formed between urea and thiourea linkages, along with dynamic imine bonds in the polymer network, endowed the coating with outstanding self-healing properties, enabling complete scratch healing within 10 min at room temperature. Moreover, uniformly dispersed AgNPs not only reduced the surface energy of the coating but also significantly enhanced its antifouling performance. The antibacterial efficiency against common marine bacteria Pseudomonas aeruginosa (P.sp) and Staphylococcus aureus (S.sp) was reduced by 97.08% and 96.71%, respectively, whilst the diatom settlement density on the coating surface was as low as approximately 59 ± 3 diatom cells/mm². This study presents a novel approach to developing high-performance silicone antifouling coatings. Full article

The xanthation reaction is an exothermic reaction between alkali cellulose (AC) and carbon disulfide (CS₂) used to regenerate a viscose solution. The cooling system plays an important role during the reaction to yield more of the main product, cellulose xanthate (CX), instead of the by-product, sodium trithiocarbonate (TTC). Minimizing the yield of by-products during the reaction phase may lead to less by-product generation during the ripening process due to free caustic and excess CS₂ in the system. The reaction was performed in a batch reactor with an agitator (9.7 rpm) under vacuum conditions (350 mbar), and the temperature varied from 20 °C to 35 °C, as is applicable in industrial plants. Meanwhile, the CX and TTC were determined via UV spectroscopy. Since the temperature reaction will affect the period of the reaction, which impacts the productivity of industrial applications, the experiment was conducted with a temperature change during the reaction to obtain a good-quality product without impacting productivity. This work aimed to reach an optimum xanthation temperature under the same combination of hardwood and softwood dissolving pulp. The results indicated that the xanthation reaction has an advantage at lower temperatures compared to higher ones; however, having a lower temperature led to a longer reaction period. The TTC was shown to be 17.7% lower at lower temperatures than at higher temperatures, which means that the CX was at a higher percentage at lower temperatures. Interestingly, the combination of higher and lower temperatures gave good viscose quality, which may lead to less consumption of CS₂ and improve the environment due to less sulfur production during spinning. Full article

The targeted stimulation of micropores based on the transformation of coal’s molecular structure is proposed due to the chemical properties and difficult-to-transform properties of micropores. Carbon disulfide (CS₂) extraction is used as a targeted stimulation to reveal the internal evolution mechanism of micropore transformation. The variations of microcrystalline structures and micropores of bituminous coal and anthracite extracted by CS₂ were analyzed with X-ray diffraction (XRD), low-temperature carbon dioxide (CO₂) adsorption, and molecular simulation. The results show that CS₂ extraction, with the broken chain effect, swelling effect, and aromatic ring rearrangement effect, can promote micropore generation of bituminous coal by transforming the microcrystalline structure. Furthermore, CS₂ extraction on bituminous coal can decrease the average micropore size and increase the micropore volume and area. The aromatic layer fragmentation effect of CS₂ extraction on anthracite, compared to the micropore generation effect of the broken chain effect and swelling effect, can enlarge micropores more remarkably, as it induces an enhancement in the average micropore size and a decline in the micropore volume and area. The research is expected to provide a theoretical basis for establishing reservoir stimulation technology based on CS₂ extraction. Full article

The potential for using discarded viscose textiles to produce high-quality viscose fibres is limited by the low molecular weight of the cellulose and its continued reduction in the recycling process. Herein, we present a straightforward approach of reprocessing discarded viscose textiles while achieving high-quality recycled viscose fibres. Discarded viscose textile was defibrated and centrifuged, and the resulting fibres were reprocessed under industrially relevant conditions. The produced viscose dope was fluid and resulted in viscose fibres with properties comparable to fibres made from commercial wood cellulose pulp (titer ~2 dtex; dry elongation ~16%, dry tenacity ~15 cN/tex). To explore the potential for a more environmentally friendly production process, the steeping step was performed twice (double-steeping), thereby producing a more homogeneous viscose dope. Through double-steeping, the consumption of carbon disulfide (CS₂) could be reduced by 30.5%. The double-steeping method shows to be a suitable approach to reprocess discarded viscose textiles while reducing the environmental impact of the viscose process associated with the use of CS₂. Our work demonstrates that discarded viscose textile has the potential to be part of a circular textile value chain. Full article

In this paper, the physical adsorption of volatile organic compounds (VOCs) such as methyl chloride (CH₃Cl), carbon disulfide (CS₂), dimethyl sulfide (C₂H₆S), and benzene (C₆H₆) by three models of activated carbon (without a functional group, with a pyridine-containing functional group, and with a pyrrole-containing functional group) was simulated. The surface electrostatic potential (ESP), physical adsorption energy, and non-covalent interaction between activated carbon and VOC molecules were analyzed based on the density functional theory (DFT). The effect mechanism of nitrogen-containing functional groups on VOC adsorption by activated carbon was determined. Our simulations showed that nitrogen-containing functional groups can change the surface ESP and polarity of activated carbon. The pyrrole functional group is conducive to CH₃Cl and CS₂ adsorption on the activated carbon plane, while the pyridine functional group is relatively small or even unfavorable for CH₃Cl and CS₂ adsorption on the activated carbon plane. The promotional effect of the pyrrole functional group on the adsorption of C₂H₆S is more significant than that of the pyridine functional group. The adsorption of C₆H₆ on activated carbon occurs through parallel-displaced π–π stacking interactions, in which functional groups have little influence on it. The adsorption energy of VOCs on the activated carbon plane is higher than that at the edge, so VOCs are more likely to be adsorbed on the activated carbon plane. Full article

In this study, grand canonical Monte Carlo simulations (GCMC) and molecular dynamics simulations (MD) were used to construct models of activated carbon with hydroxyl-modified hexachlorobenzene basic unit contents of 0%, 12.5%, 25%, 35% and 50%. The mechanism of adsorption of carbon disulfide (CS₂) by hydroxyl-modified activated carbon was then studied. It is found that the introduction of hydroxyl functional groups will improve the adsorption capacity of activated carbon for carbon disulfide. As far as the simulation results are concerned, the activated carbon model containing 25% hydroxyl modified activated carbon basic units has the best adsorption performance for carbon disulfide molecules at 318 K and atmospheric pressure. At the same time, the changes in the porosity, accessible surface area of the solvent, ultimate diameter and maximum pore diameter of the activated carbon model also led to great differences in the diffusion coefficient of carbon disulfide molecules in different hydroxyl-modified activated carbons. However, the same adsorption heat and temperature had little effect on the adsorption of carbon disulfide molecules. Full article

The use of enzyme-based biosensors for the detection and quantification of analytes of interest such as contaminants of emerging concern, including over-the-counter medication, provides an attractive alternative compared to more established techniques. However, their direct application to real environmental matrices is still under investigation due to the various drawbacks in their implementation. Here, we report the development of bioelectrodes using laccase enzymes immobilized onto carbon paper electrodes modified with nanostructured molybdenum disulfide (MoS₂). The laccase enzymes were two isoforms (LacI and LacII) produced and purified from the fungus Pycnoporus sanguineus CS43 that is native to Mexico. A commercial purified enzyme from the fungus Trametes versicolor (TvL) was also evaluated to compare their performance. The developed bioelectrodes were used in the biosensing of acetaminophen, a drug widely used to relieve fever and pain, and of which there is recent concern about its effect on the environment after its final disposal. The use of MoS₂ as a transducer modifier was evaluated, and it was found that the best detection was achieved using a concentration of 1 mg/mL. Moreover, it was found that the laccase with the best biosensing efficiency was LacII, which achieved an LOD of 0.2 µM and a sensitivity of 0.108 µA/µM cm² in the buffer matrix. Moreover, the performance of the bioelectrodes in a composite groundwater sample from Northeast Mexico was analyzed, achieving an LOD of 0.5 µM and a sensitivity of 0.015 µA/µM cm². The LOD values found are among the lowest reported for biosensors based on the use of oxidoreductase enzymes, while the sensitivity is the highest currently reported. Full article

Screening of absorbents is essential for improving the removal rate of carbon disulfide (CS₂) waste air by absorption. In this work, the UNIFAC model in Aspen Plus was utilized to calculate the excess Gibbs function and absorption potential of the binary system of CS₂ with various alcohols, ethers, esters, amines, and aromatic hydrocarbons. The results were used to quantitatively compare the efficiency of each solvent for CS₂ absorption. The theoretical predictions were then verified by absorption experiments in a packed tower. The results showed that the performance of various solvents to CS₂ roughly followed the order of esters < alcohols < amines < heavy aromatics < glycol ethers. Meanwhile, N-methyl-2-pyrrolidone (NMP) is the optimal absorbent for CS₂ waste air treatment. Additionally, the process parameters of absorption and desorption of NMP were optimized. The results illustrated that the average mass removal efficiency of CS₂ by NMP is 95.2% under following conditions: liquid–gas ratio of 3.75 L·m⁻³, a temperature of 20 °C, and inlet concentration lower than 10,000 mg·m⁻³. Under the conditions of 115 °C, 10 kPa, and a desorption time of 45 min, the average desorption rate of CS₂ is 99.6%, and the average water content after desorption is 0.39%. Furthermore, the recycled lean liquid can maintain an excellent CS₂ purification effect during the recycling process. Full article

Herein, dithiocarbamate-modified biochar (BC-HDTC) was successfully synthesized with nitric acid (HNO₃), thionyl chloride (SOCl₂), branched PEI and carbon disulfide (CS₂). The effective anchoring of amine and dithiocarbamate groups onto the surface of the biochar was proven by SEM, FTIR, XPS, N2 adsorption–desorption experiment. The batch experiments demonstrated BC-HDTC can selectively remove 98% Pb(II) within multi-metals solution when pH = 5, T = 30 °C. The impact of variations on the BC-HDTC were researched (pH, contact duration, Pb(II) original concentration).The sorption kinetics (pseudo-first-order, pseudo-second-order, intra-particle diffusion model) and isotherm modeling (Langmuir, Freundlich, and tempkin models) of Pb(II) on BC-HDTC were investigated. The adsorption process was depicted to attain equilibrium in less than 20 min and to fit the Langmuir isotherms and pseudo-2nd-order kinetics satisfactorily. The complexation of functional groups of HDTC (amine/imine and dithiocarbamate) with Pb(II) as well as the ion exchange between Na(I) and Pb(II) are the main adsorption mechanisms. Pb(II) onto BC-HDTC was endothermic and spontaneous, according to thermodynamic parameters. After 4 consecutive adsorption-desorption cycles, Pb removal efficiency of BC- HDTC remained over 90%. This work revealed the significant potential for Pb(II) contamination of BC-HDTC, a valuable and reusable adsorbent. Full article

A CdS/SnS nanocomposite was prepared using a simple hydrothermal method and used as a sensitive material for the detection of carbon disulfide (CS₂) based on cataluminescence (CTL). The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS) and X-ray photoelectron spectroscopy (XPS). The results show that the CdS/SnS nanocomposite sensor has a high sensitivity to CS₂ at a relatively low operating temperature (162 °C); the response time is about 3 s, and the recovery time is about 16 s. The modification of CdS effectively enhances the sensitivity of SnS sensors. The CTL intensity shows a good linear relationship at gas concentrations ranging from 6.75 to 168.75 ppm (R² = 09974), and the limit of detection (LOD) of CS₂ reached 0.96 ppm. In addition, the CdS/SnS sensor has excellent selectivity and good stability towards CS₂. The mechanism of the sensor is discussed in detail. This research shows that CdS/SnS has great potential for the detection of CS₂. Full article

Soluble sulfur (S₈) and insoluble sulfur (IS) have different application fields, and molecular dynamics simulation can reveal their differences in solubility in solvents. It is found that in the simulated carbon disulfide (CS₂) solvent, soluble sulfur in the form of clusters mainly promotes the dissolution of clusters through van der Waals interaction between solvent molecules (CS₂) and S₈, and the solubility gradually increases with the increase in temperature. However, the strong interaction between polymer chains of insoluble sulfur in the form of polymer hinders the diffusion of IS into CS₂ solvent, which is not conducive to high-temperature dissolution. The simulated solubility parameter shows that the solubility parameter of soluble sulfur is closer to that of the solvent, which is consistent with the above explanation that soluble sulfur is easy to dissolve. Full article

Odor released from the sewage sludge composting process often has a negative impact on the sewage sludge treatment facility and becomes a hindrance to promoting compost technology. This study investigated the effect of adding KNO₃ on the emissions of volatile sulfur compounds, such as hydrogen sulfide (H₂S), dimethyl sulfide (DMS), and carbon disulfide (CS₂), during sewage sludge composting and on the physicochemical properties of compost products, such as arylsulfatase activity, available sulfur, total sulfur, moisture content, and germination index. The results showed that the addition of KNO₃ could inhibit the emissions of volatile sulfur compounds during composting. KNO₃ can also increase the heating rate and peak temperature of the compost pile and reduce the available sulfur loss. The addition of 4% and 8% KNO₃ had the best effect on H₂S emissions, and it reduced the emissions of H₂S during composting by 19.5% and 20.0%, respectively. The addition of 4% KNO₃ had the best effect on DMS and CS₂ emissions, and it reduced the emissions of DMS and CS₂ by 75.8% and 63.0%, respectively. Furthermore, adding 4% KNO₃ had the best effect from the perspective of improving the germination index of the compost. Full article

This review provides an overview of the assessment of the endocrine disrupting (ED) properties of carbon disulfide (CS₂), following the methodology used at the European level to identify endocrine disruptors. Relevant in vitro, in vivo studies and human data are analyzed. The assessment presented here focuses on one endocrine activity, i.e., thyroid disruption, and two main adverse effects, neurotoxicity and cardiotoxicity. The data available on the different ED or non-ED modes of action (MoA), known to trigger these adverse effects, are described and the strength of evidence of the different MoA is weighted. We conclude that the adverse effects could be due to systemic toxicity rather than endocrine-mediated toxicity. This assessment illustrates the scientific and regulatory challenges in differentiating a specific endocrine disruption from an indirect endocrine effect resulting from a non-ED mediated systemic toxicity. This issue of evaluating the ED properties of highly toxic and reactive substances has been insufficiently developed by European guidance so far and needs to be further addressed. Finally, this example also raises questions about the capacity of the technics available in toxicology to address such a complex issue with certainty. Full article

Quercetin (QR), abundant in plants, is used to treat colitis and gastric ulcer and is also a promising anticancer agent. To quantificationally detect QR, a sensitive electrochemical sensor was fabricated by palladium nanoparticles loaded on carbon sphere @ molybdenum disulfide nanosheet core-shell composites (Cs@MoS₂-Pd NPs). The Cs@MoS₂-Pd NPs worked to remedy the shortcomings of MoS₂ and exhibited good catalytic activity to QR. The oxidation reaction of QR on Cs@MoS₂-Pd NPs/GCE involved two electrons and two protons. Furthermore, the molecular surface for electrostatic potential, Laplacian bond order, and Gibbs free energy were computationally simulated to speculate the order and site of the oxidation of QR. The results showed that the 4′ O–H and 3′ O–H broke successively during the oxidation reaction. When the concentration of QR was within 0.5 to 12 μM, the fabricated sensor could achieve linear detection, and the detection limit was 0.02 μM (S/N = 3). In addition, the sensor possessed good selectivity, repeatability, and stability, which has a broad prospect in practical application. Full article