Kinetic Model Research Articles

Enhancement of Trihalomethane Adsorption Capacity Using Chitosan-Modified Coconut Shell Activated Carbon: Adsorption Characteristics and Mechanisms

There is a rising concern about the safety risk that trihalomethanes (THMs) in drinking water pose. In this work, to adsorb THMs such as chloroform (TCM), dibromochloromethane (DBCM), bromodichloromethane (BDCM), and bromoform (TBM), we coated chitosan (CS) on coconut shell activated carbon (CAC). The adsorbents were characterized using BET, XRD, FTIR, and SEM techniques. The impact of various variables was examined, including contact time, quantity of adsorbent, initial pH, and initial THM concentrations. Under the same conditions, TCM was adsorbed most efficiently, followed by BDCM, DBCM, and TBM. When the pH was between 4 and 8, the adsorption of THMs onto the coconut shell activated carbon supported chitosan (CS/CAC) varied relatively little; however, when the pH increased above 8, the adsorption of THMs decreased. For THMs, CS/CAC adsorption was a chemical reaction and monolayer adsorption that fit better with the pseudo-second-order kinetic model and the Langmuir isotherm model. According to the thermodynamic study, THMs were adsorbed endothermically and spontaneously on CS/CAC. For column experiments, the adsorption of THMs was influenced by bed height and flow rate. After up to four cycles of adsorption and desorption, it was found that the adsorbent was reusable. The maximum adsorption capacities for Langmuir were 187.27, 114.29, 93.28, and 89.61 µg/g for TCM, BDCM, DBCM, and TBM, respectively. CS/CAC has a high adsorption capacity, especially for TCM, which is responsible for a major portion of THMs in drinking water. This indicates that CS/CAC has a lot of potential uses when it comes to removing THMs from water.

Effects of Red Vinasse on Physicochemical Qualities of Blue Round Scad (Decapterus maruadsi) During Storage, and Shelf Life Prediction

A fish processed with red vinasse is a type of Fujian cuisine with regional characteristics. In order to monitor the effect of red vinasse on storage quality and shelf life of blue round scad (Decapterus maruadsi) during storage, the changes in fat content, thiobarbituric acid reactive substances (TBARS), composition of polyunsaturated fatty acids (PUFAs), pH value, texture, and sensory quality were studied at different storage temperatures (4 °C, 25 °C, and 37 °C). By analyzing the correlation between changes in sensory qualities and physical and chemical indexes, a first-order kinetic model and the Arrhenius equation were used to build a shelf-life prediction model for blue round scad during storage. The results showed that processing with red vinasse can significantly reduce the malondialdehyde (MDA) production and the decrease in PUFAs, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (p < 0.05) during storage. Based on partial least squares regression (PLSR), the storage temperature and time have a significant impact on the PUFA composition in blue round scad, which changed less when the samples were stored at 4 °C and 25 °C, and they had better nutritional composition of fatty acids at lower temperatures. Among the PUFAs, DHA (C22:6n-3) and EPA (C20:5n-3) had higher relative contents and significantly decreased during storage (p < 0.05). Additionally, the processing with red vinasse can slow down the increase in total volatile basic nitrogen (TVB-N) value and pH of blue round scad, maintain the appropriate hardness, elasticity, cohesion and chewability, and improve the overall sensory quality of the fish. In addition, according to the results of model prediction based on TBARS value, the storage shelf life of blue round scad with red vinasse added was 55 d, 2.7 d and 28 h at 4 °C, 25 °C and 37 °C, respectively. The accuracy of the forecast model was high, and the relative errors of the measured values and predicted values were less than 10%. Thus, it not only provided a theoretical basis for the processing and application of red vinasse to Chinese traditional food, but also provided innovative ideas for the safe storage and high-value utilization of blue round scad.

Preparation of NaA zeolite with graphite tailings and its adsorption of ammonia nitrogen.

Environmental pollution caused by the accumulation of graphite tailings (GT) is a significant global challenge. In this study, GT was utilized as a raw material to synthesize NaA zeolite (GTA), with synthesis conditions optimized. The synthesized GTA was characterized by SEM, EDS, BET, XRD, and FTIR, and its ammonia nitrogen (AN) adsorption performance was investigated under varying conditions, including dosage, pH, adsorption time, and temperature. The optimized synthesis conditions were an alkali melting temperature of 700°C, alkali-ore ratio of 1.2:1, aging time of 8h, hydrothermal temperature of 90°C, liquid-solid ratio of 6:1, and hydrothermal time of 8h, yielding a specific surface area of 36.62m2/g. In a 100mg/L AN solution at pH 7 and 30°C, GTA exhibited an adsorption capacity of 13.88mg/g within 1h. The adsorption process follows a pseudo-second-order kinetic model. The adsorption isotherm conforms to the Langmuir model, suggesting that the mechanism involves uniform monolayer adsorption on the surface. The adsorption of AN on zeolite is primarily controlled by chemical rather than physical adsorption. This study provides a foundation for the resource utilization of GT and AN treatment, with practical environmental implications.

Fabrication of tannic acid-incorporated polyvinylpyrrolidone/polyvinyl alcohol composite hydrogel and its application as an adsorbent for copper ion removal.

An effective tannic acid-incorporated polyvinylpyrrolidone/polyvinyl alcohol composite hydrogel with high-potential sorption capacity was developed for the removal of copper from aqueous solution. The composite hydrogel exhibited pH-dependent swelling, in which swelling and shrinking occurred reversibly with adjustment of the pH of the medium. At pH 4, the maximal adsorption capacity for copper at 30°C was 297.0mg g-1, and the adsorbent dose was 4g L-1. The adsorption kinetics were best fitted with a pseudo-second order kinetic model. The adsorption behavior was well predicted by the Freundlish isotherm. The thermodynamics parameters indicated a spontaneous and exothermic reaction with an increase in the entropy of the system. The chemical changes in the film structure before and after adsorption treatment were characterized by Scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS). The FTIR, XPS and XAS results confirmed that Cu bound to the oxygens in the -OH, C = O and N-(C = O)- functional groups on the T-HD. XAS analysis revealed the chemical composition and molecular geometry of the adsorbed copper ions. The single-solute adsorption and coadsorption mechanisms, which provide insight into cobalt-copper, nickel-copper, or nickel-cobalt-copper complex solutions, were investigated. The composite hydrogel exhibited excellent regeneration ability in EDTA solution. Notably, the adsorbent retained an adsorption efficiency exceeding 87% even after five regeneration cycles. On the basis of both adsorbent characteristics and adsorption performance, it was determined that the composite hydrogel has the potential to be used as a platform for developing materials to treat wastewater containing high levels of metal contaminants such as those from the electroplating industry.

Multifunctional Copper Sulfide Urchin‐Like Nanostructures for Adsorption and Photocatalysis of Water Contaminants

AbstractWe reported here a one‐step chemical route to prepare nanocomposites comprising CuS nanophases supported on GO sheets with magnetic properties. The synthesis reported here combines such materials in single‐nanostructures that show morphological features well‐suited for wastewater treatment. The photocatalytic performance of CuS/GO nanocomposites was first investigated towards the removal of a common organic dye (rhodamine B) and sulfamethoxazole (SMX), which is an antibiotic considered a water contaminant of emerging concern. The RhB and SMX adsorption efficiency of CuS/GO and Fe3O4/GO/CuS hybrids, as well as of CuS particles, was significantly higher than GO or Fe3O4/GO. Overall, the CuS‐based magnetic and CuS/GO hybrids have shown the capacity to uptake more than 80 % of RhB or SMX, after 120 minutes. Under blue‐led irradiation, almost complete degradation of RhB was achieved in the presence of CuS/Fe3O4/GO, after 180 minutes; and higher than 85 % degradation of SMX, after 240 minutes of irradiation. The photocatalytic behaviour of nanocomposites was best described by the first–order kinetic model, for which k values for degradation of RhB and SMX followed the order: CuS/Fe3O4/GO>CuS/GO>CuS. The tricomponent CuS/Fe3O4/GO can be easily recovered after use and be reused maintain their high photocatalytic performance, thus providing a sustainable and cost‐effective hybrid solution for water treatment.

Subcellular mRNA kinetic modeling reveals nuclear retention as rate-limiting.

Eukaryotic mRNAs are transcribed, processed, translated, and degraded in different subcellular compartments. Here, we measured mRNA flow rates between subcellular compartments in mouse embryonic stem cells. By combining metabolic RNA labeling, biochemical fractionation, mRNA sequencing, and mathematical modeling, we determined the half-lives of nuclear pre-, nuclear mature, cytosolic, and membrane-associated mRNAs from over 9000 genes. In addition, we estimated transcript elongation rates. Many matured mRNAs have long nuclear half-lives, indicating nuclear retention as the rate-limiting step in the flow of mRNAs. In contrast, mRNA transcripts coding for transcription factors show fast kinetic rates, and in particular short nuclear half-lives. Differentially localized mRNAs have distinct rate constant combinations, implying modular regulation. Membrane stability is high for membrane-localized mRNA and cytosolic stability is high for cytosol-localized mRNA. mRNAs encoding target signals for membranes have low cytosolic and high membrane half-lives with minor differences between signals. Transcripts of nuclear-encoded mitochondrial proteins have long nuclear retention and cytoplasmic kinetics that do not reflect co-translational targeting. Our data and analyses provide a useful resource to study spatiotemporal gene expression regulation.

Mn3O4-MnOOH nanocomposites for the adsorption-based removal of nickel ions from wastewater.

The removal of nickel from wastewater is a significant environmental concern because of its potential hazards to environment. Adsorption is known as an efficient water treatment strategy and there is a growing interest in the development of new adsorbent materials providing rapid adsorption kinetics, cost-effectiveness, and high adsorption capacity. In this study, the feasibility of Mn3O4-MnOOH nanocomposites was evaluated as the adsorbent material for the removal of nickel ions from wastewater. The nanocomposites were prepared using a modified sonochemical method and characterized by XRD analysis and SEM images. Batch adsorption experiments were carried out under different experimental conditions obtained by varying solution pH, adsorbent amount, and contact period. Under the optimum adsorption conditions, the %RE value was recorded around 80% for 10mg/L Ni(II) ions. The adsorption characteristics were investigated with respect to adsorption isotherms and kinetics. Langmuir and Freundlich isotherm models were used to fit the adsorption data and the results indicated that adsorption of nickel ions onto nanocomposite could be complex and obey both monolayer adsorption and heterogeneous surface. Accordingly, maximum adsorption capacity of nanocomposites were calculated as 12.387mg/g. Research works comparing the kinetic models of pseudo-first-order, pseudo-second-order, and Elovich revealed that chemical sorption plays an important role as the rate-limiting step in the adsorption of nickel ions.

Kinetic Modeling in Temperature-Modulated Semiconductor Gas Sensor Utilizing Eley-Rideal Mechanism and Its Application in Discriminative Detection of VOCs.

This study presents a comprehensive kinetic investigation for describing the dynamic sensing process of semiconductor metal oxide (SMO)-based gas sensors, with a focus on the Eley-Rideal mechanism as a valid pathway. The modeling elucidates the direct interactions between volatile organic compounds (VOCs) and adsorbed oxygen on the material surface, providing insights into the temperature-dependent response characteristics of the sensor and addressing selectivity toward different VOCs fundamentally. By incorporating the effects of thermal modulation, the kinetic model was validated through theoretical fitting of experimental data obtained from a fabricated SnO2 nanoparticle gas sensor exposed to ethanol, n-propanol, toluene, and butanone at systematically varying operating temperatures. The results demonstrated that the model accurately captures response transient values, enabling a general framework for qualitatively discriminating specific gases based on their unique reaction kinetics. Furthermore, a machine learning procedure containing the above model and power laws of quantitative concentrations after identifying compounds was developed for the prediction of target VOCs. The qualitative accuracy was determined to be 99.4%, while quantifying with the mean absolute errors of 5.0, 7.5, 4.0, and 8.9 within the range of 25-200 ppm, respectively. The precise and straightforward strategy facilitates the response modeling of SMO-based gas sensors, offering a valuable platform for the designing model-driven algorithms applicable in gas analysis and monitoring.

Direct visualization of the charge transfer state dynamics in dilute-donor organic photovoltaic blends.

The interconversion dynamics between charge transfer state charges (CTCs) and separated charges (SCs) is still an unresolved issue in the field of organic photovoltaics. Here, a transient absorption spectroscopy (TAS) study of a thermally evaporated small-molecule:fullerene system (α6T:C60) in different morphologies (dilute intermixed and phase separated) is presented. Spectral decomposition reveals two charge species with distinct absorption characteristics and different dynamics. Using time-dependent density functional theory, these species are identified as CTCs and SCs, where the spectral differences arise from broken symmetry in the charge transfer state that turns forbidden transitions into allowed ones. Based on this assignment, a kinetic model is formulated allowing the characterization of the charge generation, separation, and recombination mechanisms. We find that SCs are either formed directly from excitons within a few picoseconds or more slowly (~30-80 ps) from reversible splitting of CTCs. These findings constitute the first unambiguous observation of spectrally resolved CTCs and SCs.

Modification of nickel ferrite nanoparticles by sodium docusate surfactant for superior crystal violet dye removal from aqueous solutions.

In this study, nickel ferrite (NiFe2O4) nanoparticles were synthesized using the Pechini sol-gel method and modified with sodium docusate surfactant. The modified nanoparticles showed an enhanced adsorption capacity of 384.62mg/g for crystal violet dye, compared to 237.53mg/g for unmodified NiFe2O4. Characterization was performed using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM) techniques. The adsorption process was spontaneous, exothermic, and followed the Langmuir isotherm and pseudo-second-order kinetic model. Optimal conditions for maximum dye removal were achieved at pH 10, 50min, and 298K. Additionally, the synthesized adsorbents demonstrated excellent regeneration and reusability over five adsorption-desorption cycles with minimal efficiency loss.

Electrochemical nucleation and growth kinetics: insights from single particle scanning electrochemical cell microscopy studies.

The kinetics of particle nucleation and growth are critical to a wide variety of electrochemical systems. While studies carried out at the single particle level are promising for improving our understanding of nucleation and growth processes, conventional analytical frameworks commonly employed in bulk studies may not be appropriate for single particle experiments. Here, we present scanning electrochemical cell microscopy (SECCM) studies of Ag nucleation and growth on carbon and indium tin oxide (ITO) electrodes. Statistical analyses of the data from these experiments reveal significant discrepancies with traditional, quasi-equilibrium kinetic models commonly employed in the analysis of particle nucleation in electrochemical systems. Time-dependent kinetic models are presented capable of appropriately analysing the data generated via SECCM to extract meaningful chemical quantities such as surface energies and kinetic rate constants. These results demonstrate a powerful new approach to the analysis of single particle nucleation and growth data which could be leveraged in differentiating behavior within spatially heterogeneous systems.

Towards the discovery of unrevealed flufenamic acid cocrystals via structural resemblance for enhanced topical drug delivery.

Cocrystallization has emerged as a promising formulation strategy for modulating transdermal drug absorption by enhancing solubility and permeability. However, challenges related to cocrystal dissociation in the semi-solid state need to be addressed to mitigate regulatory concerns before the widespread implementation of topical cocrystal products in clinical practice. This study aimed to develop oil-based topical formulations incorporating cocrystals with distinct thermodynamic stabilities, followed by investigating the roles of different structurally similar coformers and oily vehicles on their physicochemical properties. Three pharmaceutical cocrystals of poorly water-soluble flufenamic acid (FFA) were synthesized with isomeric pyridine carboxamides in a 1:1 stoichiometry via rapid solvent removal. These included the reported flufenamic acid-nicotinamide cocrystal (FFA-NIC), the long-elusive flufenamic acid-isonicotinamide cocrystal (FFA-IST) and flufenamic acid-picolinamide cocrystal (FFA-PIC). The resulting cocrystals, which exhibited different hydrogen bonding patterns, were characterized using powder X-ray diffraction, differential scanning calorimetry, Fourier transform infrared spectroscopy, and structural analysis through single crystal X-ray diffraction. The cocrystals were further formulated in a series of oleaginous and absorption bases, including liquid paraffin, Vaseline, lanolin, and theobroma oil, for topical delivery. The cocrystal dissociation, content uniformity, and in vitro membrane diffusion were assessed. Notably, although all FFA cocrystals exhibited thermodynamic instability in aqueous solution, a significantly reduced propensity for cocrystal dissociation was observed in the ointment bases. Integrated computational analyses of packing efficiency and interaction energy revealed that the thermodynamic stability of cocrystals followed a descending order of FFA-NIC > FFA-PIC > FFA-IST. Compared with raw FFA, FFA-IST and FFA-PIC, which had larger positive ΔVnon-H and ΔEcocryst, achieved superior cumulative diffusion of FFA from Vaseline, with a 4.3-fold (p = 0.0003) and 3.3-fold (p = 0.0029) increase at 6 h in a Franz diffusion cell model, respectively. The diffusion of all FFA cocrystals mainly followed the Higuchi kinetic model and was positively correlated with the intrinsic dissolution rate.

Transcriptional regulators ensuring specific gene expression and decision-making at high TGFβ doses.

TGFβ-signaling regulates cancer progression by controlling cell division, migration, and death. These outcomes are mediated by gene expression changes, but the mechanisms of decision-making toward specific fates remain unclear. Here, we combine SMAD transcription factor imaging, genome-wide RNA sequencing, and morphological assays to quantitatively link signaling, gene expression, and fate decisions in mammary epithelial cells. Fitting genome-wide kinetic models to our time-resolved data, we find that most of the TGFβ target genes can be explained as direct targets of SMAD transcription factors, whereas the remainder show signs of complex regulation, involving delayed regulation and strong amplification at high TGFβ doses. Knockdown experiments followed by global RNA sequencing revealed transcription factors interacting with SMADs in feedforward loops to control delayed and dose-discriminating target genes, thereby reinforcing the specific epithelial-to-mesenchymal transition at high TGFβ doses. We identified early repressors, preventing premature activation, and a late activator, boosting gene expression responses for a sufficiently strong TGFβ stimulus. Taken together, we present a global view of TGFβ-dependent gene regulation and describe specificity mechanisms reinforcing cellular decision-making.

Dose compensation for decreased biological effective dose due to intrafractional interruption during radiotherapy: integration with a commercial treatment planning system.

While the biological effective dose (BED) has been used to estimate the damage to tumor cells in radiotherapy, BED does not consider intrafractional interruption (IFI) occurring during irradiation. We aim to develop a framework to evaluate the decrease in BED [ΔBED] and to create a plan compensating for the decrease by IFI.
Approach. ΔBED was calculated using a model based on the microdosimetric kinetic model (MKM) for four brain tumor cases treated using a volumetric-modulated arc therapy. Four biologically compensated plans (BCPs) were created in the treatment planning system by a single-time optimization using a base plan considering ΔBED created in in-house software and optimization objectives for the original clinically delivered plan to achieve a homogeneous BED distribution within the planning target volume (PTV). The BED-volume histogram was evaluated for non-compensated plan and BCP with different timepoint of interruption, a percentage of gantry rotation angle (GRA) before interruption in planned GRA,ηand duration of interruptionτ. Characteristics of the dose accumulation were analyzed for different collimator angle sets, Plan A (10°, 85°) and Plan B (45° and 315°), for the first case.
Main Results. Hot spots in the ΔBED distribution forη= 25%, 50%, and 75% were observed at superior-and-interior ends, central region, and peripheral region in PTV, respectively. These behaviors could be understood by characteristics of the MKM-based model producing maximum ΔBED at 50% of the dose accumulation. ΔBED50%ranged 4.5-6.6%, 5.0-7.3%, and 5.3-7.7% forτ= 60, 90, and 120 mins, respectively. Plan A showed fast dose accumulation at superior and inferior edges while slow on peripheries in the lateral dose profile. Plan B showed more homogeneous PD distributions than Plan A during irradiation.
Significance. The developed framework successfully evaluated and compensated for the decreased BED distribution.&#xD.

Kinetic modeling of the removal of phenolic compounds from olive mill wastewater by hierarchical zeolite/carbon nanotubes: Isotherm, kinetics, and thermodynamic

ABSTRACT In this study, plain zeolite (ZSM5) and hierarchical zeolite (H-ZSM5) were synthesized as efficient adsorbents for the removal of polyphenolic/antioxidant compounds from olive mill wastewater (OMW). The XRD and FTIR results confirmed the successful synthesis of ZSM5 zeolites. SEM images and BET demonstrated that H-ZSM5 possessed a markedly greater surface area of 337.99 m2/g in contrast to ZSM5 (162.84 m2/g). For H-ZSM5, the values determined for pore volume, total volume, and pore diameters are 77.655 cm3 g−1, 0.1844 cm3 g−1, and 2.1826 nm. The absolute zeta potential values varied between 5.36 ± 1.21 and − 46.41 ± 1.32 mV, with the peak absolute value of − 46.41 ± 1.32 mV occurring at pH 4. The optimal conditions for the removal of phenolic compounds, achieving an efficiency exceeding 90%, were identified as a pH of 4, an adsorbent dosage of 50 mg, and a contact duration of 90 minutes. The adsorption isotherm was found to align with the Langmuir model rather than the Freundlich model, indicating a monolayer adsorption capacity of 48.7 mg/g. Kinetic studies were consistent with a pseudo-first-order model (R2 >0.99). Ultimately, the thermodynamic analysis suggested that the adsorption of OMW onto ZSM5 is both spontaneous and governed by a physisorption mechanism.

A Journey through Process Development Enhanced by Kinetic Modeling: An Efficient Manufacturing Route to Balcinrenone

A Journey through Process Development Enhanced by Kinetic Modeling: An Efficient Manufacturing Route to Balcinrenone

Multiscale Responsive Kinetic Modeling: Quantifying Biomolecular Reaction Flux under Varying Electrochemical Conditions.

Attaining a complete thermodynamic and kinetic characterization for processes involving multiple interconnected rare-event transitions remains a central challenge in molecular biophysics. This challenge is amplified when the process must be understood under a range of reaction conditions. Herein, we present a novel condition-responsive kinetic modeling framework that can combine the strengths of bottom-up rate quantification from multiscale simulations with top-down solution refinement using both equilibrium and nonequilibrium experimental data. Although this framework can be applied to any process, we demonstrate its use for electrochemically driven transport through channels and transporters via the development of electrochemically responsive rates. Using the Cl-/H+ antiporter ClC-ec1 as a model system, we show how optimal and predictive kinetic solutions can be obtained when the solution space is grounded by thermodynamic constraints, seeded through multiscale rate quantification, and further refined with experimental data, such as electrophysiology assays. Turning to the Shaker K+ channel, we demonstrate that optimal solutions and biophysical insights can also be obtained with sufficient experimental data. This multi-pathway method also proves capable of identifying single-pathway dominant channel mechanisms but reveals that competing and off-pathway flux is still essential to replicate experimental findings and to describe concentration-dependent channel rectification.

Bioleaching of lithium from jadarite, spodumene, and lepidolite using Acidiothiobacillus ferrooxidans

Lithium (Li) is becoming increasingly important due to its use in clean technologies that are required for the transition to net zero. Although acidophilic bioleaching has been used to recover metals from a wide range of deposits, its potential to recover Li has not yet been fully explored. In this study, we used a model Fe(II)- and S-oxidising bacterium, Acidiothiobacillus ferrooxidans (At. Ferrooxidans), to extract Li from three different minerals and kinetic modelling to predict the dominant reaction pathways for Li release. Bioleaching of Li from the aluminosilicate minerals lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2) and spodumene (LiAl(Si2O6)) was slow, with only up to 14% (approximately 12 mg/L) of Li released over 30 days. By contrast, At. ferrooxidans accelerated Li leaching from a Li-bearing borosilicate clay (jadarite, LiNaB3SiO7OH) by over 50% (over 120 mg/L) in 21 days of leaching, and consistently enhanced Li release throughout the experiment compared to the uninoculated control. Biofilm formation and flocculation of sediment occurred exclusively in the experiments with At. ferrooxidans and jadarite. Fe(II) present in the jadarite-bearing clay acted as an electron donor. Chemical leaching of Li from jadarite using H2SO4 was most effective, releasing approximately 75% (180 mg/L) of Li, but required more acid than bioleaching for pH control. Kinetic modelling was unable to replicate the data for jadarite bioleaching after primary abiotic leaching stages, suggesting additional processes beyond chemical leaching were responsible for the release of Li. A new crystalline phase, tentatively identified as boric acid, was observed to form after acid leaching of jadarite. Overall, the results demonstrate the potential for acidophilic bioleaching to recover Li from jadarite, with relevance for other Li-bearing deposits.

Proton-exchange induced reactivity in layered oxides for lithium-ion batteries.

LiNixCoyMn1-x-yO2 (0 < x, y < 1, NCM) is the dominant positive material for the state-of-the-art lithium-ion batteries. However, the sensitivity of NCM materials to moisture makes their manufacturing, storage, transportation, electrode processing and recycling complicated. Although it is recognized that protons play a critical role in their structure stability and performance, proton exchange with Li+ in NCM materials has not been well understood. Here, we employ advanced characterizations and computational studies to elucidate how protons intercalate into the layered structure of NCM, leading to the leaching of Li+ and the formation of protonated NCM. It is found that protonation facilitates cation rearrangement and formation of impurity phases in NCM, significantly deteriorating structural stability. The adverse effects induced by protons become increasingly pronounced with a higher Ni content in NCM. Through a comprehensive investigation into the thermodynamics and kinetics of protonation, we discover that Li deficiencies in NCM materials can be resolved via solution process in the presence of Li+ ions and controlled proton concentration. The underlying mechanism of relithiation is further explored through materials characterizations and kinetics modeling. This work provides crucial insights into controlling structural and compositional defects of Li-ion battery positive material in complicated processing environment.

Biosorption of cypermethrin from aqueous solutions by Pediococcus acidilactici: kinetics, isotherms, and mechanisms.

Pediococcus acidilactici is an effective adsorbent for removing of pyrethroid insecticides. This study investigated the biosorption characteristics and mechanisms of P. acidilactici D15 using adsorption measurement, scanning electron microscopy, and Fourier-transform infrared spectroscopy. Isotherm and kinetic models were used to analyze the biosorption process. The Langmuir isotherm model best described the cypermethrin biosorption process, with the maximum adsorption capacity of P. acidilactici D15 being 21.404 mg/g. The biosorption appeared to involve monolayer coverage with uniform forces. The pseudo-second-order model also fits well. The rate-controlling steps involved intraparticle diffusion, film diffusion and chemosorption. The main cellular components involved in cypermethrin biosorption were exopolysaccharides, spheroplast, and cell wall, especially peptidoglycan. The functional groups (-OH, -NH, -CH3, -CH2, -CH, -CONH-, -CO, and -C-O-C-) from proteins, polysaccharides, and peptidoglycan on the cell surface likely played a role in binding cypermethrin. Additionally, P. acidilactici D15 effectively reduced cypermethrin in pickle wastewater. These findings suggest that P. acidilactici D15 could be a potential agent for reducing pesticide residues, laying the groundwork for treating pickle wastewater containing such pesticide residues. © 2024 Society of Chemical Industry.