Kinetic Model Research Articles

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.

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.

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 384.62 mg/g for crystal violet dye, compared to 237.53 mg/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, 50 min, and 298 K. Additionally, the synthesized adsorbents demonstrated excellent regeneration and reusability over five adsorption-desorption cycles with minimal efficiency loss.

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.

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.

Alkali treatment of polymer microspheres to efficiently remove rhodamine 6G from aqueous media

Core-shell microspheres composed of poly(styrene)-poly(styrene-methacrylic acid) (PSt-P(St-MAA)) are prepared using a simple emulsion polymerization technique. After synthesis, the particles are subjected to an alkaline treatment to create a rough surface on microspheres. The microspheres demonstrate high efficiency as an adsorbent for removing the cationic dye rhodamine 6G (Rh6G) from water. Several methods, such as FT-IR, SEM, TGA and particle size analysis, are used to characterize both the synthesized PSt-P(St-MAA) microspheres and the microspheres after Rh6G adsorption (PSt-P(St-MAA)/Rh6G). The effects of factors such as initial pH, dye concentration, temperature of the dyeing solution and contact time on dye adsorption capacity are systematically investigated using the batch adsorption method. The adsorption capacity is increased steadily with higher pH levels, dye concentration, temperature and extended contact time. The findings reveal that the adsorption capacity could reach as high as 214.2 mg/g at 25 °C. Furthermore, the adsorption kinetics indicate that the process adhered to a pseudo-second-order kinetic model. The equilibrium adsorption data fit well with the Langmuir isotherm model. Thermodynamic analysis reveals that the adsorption process is endothermic, spontaneous and characterized as physisorption. The results confirm that PSt-P(St-MAA) microspheres are highly efficient in removing cationic dyes from wastewater.

Spatially Resolved Measurements in a Stagnation‐Flow Reactor: Kinetics of Catalytic NH3 Decomposition

AbstractA stagnation‐flow reactor was employed to investigate the decomposition of ammonia over a Ni/Al2O3 catalyst across a range of system pressures and ammonia mole fractions. The results indicate that the system pressure has a negligible impact on the light‐off behavior and the concentration profiles of NH₃. A comparison of 1D modelling with 3D computational fluid dynamics (CFD) computations justifies the use of the simpler flow model. Good agreement between experiments and the 1D simulation is achieved for two different kinetic models from literature in the mainly diffusion‐controlled regime. For lower temperatures, at which the process is kinetically controlled, the two mechanisms exhibit significant differences. The stagnation‐flow reactor concept is shown to be a promising tool for understanding, developing, and validating the reaction kinetics of heterogeneous catalytic processes.

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.

Recent Advances in the Growth and Compositional Modelling of III-V Nanowire Heterostructures.

Nanowire heterostructures offer almost unlimited possibilities for the bandgap engineering and monolithic integration of III-V photonics with Si electronics. The growth and compositional modelling of III-V nanowire heterostructures provides new insight into the formation mechanisms and assists in the suppression of interfacial broadening and optimization of optical properties. Different models have been proposed in the past decade to calculate the interfacial profiles in axial nanowire heterostructures mainly grown by molecular beam epitaxy and metal-organic vapour phase epitaxy. Based on various assumptions, existing models have different sets of parameters and can yield varying results and conclusions. By focusing on deterministic models based on classical nucleation theory and kinetic growth theory of III-V ternary monolayers in nanowires, we summarize recent advancements in the modelling of axial heterostructures in III-V nanowires, describe and classify the existing models, and determine their applicability to predictive modelling and to the fitting of the available experimental data. In particular, we consider the coordinate-dependent generalizations of the equilibrium, nucleation-limited, kinetic, and regular growth models to make interfacial profiles across axial heterostructures in different III-V nanowires. We examine the factors influencing the interfacial abruptness, discuss the governing parameters, limitations, and modelling of particular material systems, and highlight the areas that require further research.

Under the magnifying glass: A combined 3D model applied to cloudy warm Saturn-type exoplanets around M dwarfs

Warm Saturn-type exoplanets orbiting M dwarfs are particularly suitable for an in-depth cloud characterisation through transmission spectroscopy because the contrast of their stellar to planetary radius is favourable. The global temperatures of warm Saturns suggest efficient cloud formation in their atmospheres which in return affects the temperature, velocity, and chemical structure. However, a consistent modelling of the formation processes of cloud particles within the 3D atmosphere remains computationally challenging. We explore the combined atmospheric and micro-physical cloud structure and the kinetic gas-phase chemistry of warm Saturn-like exoplanets in the irradiation field of an M dwarf. The combined modelling approach supports the interpretation of observational data from current (e.g. JWST and CHEOPS) and future missions (PLATO, Ariel, and HWO). A combined 3D cloudy atmosphere model for HATS-6b was constructed by iteratively executing the 3D general circulation model (GCM) expeRT/MITgcm and a detailed kinetic cloud formation model, each in its full complexity. The resulting cloud particle number densities, particle sizes, and material compositions were used to derive the local cloud opacity which was then used in the next GCM iteration. The disequilibrium H/C/O/N gas-phase chemistry was calculated for each iteration to assess the resulting transmission spectrum in post-processing. We present the first model atmosphere that iteratively combines cloud formation and 3D GCM simulation and applied it to the warm Saturn HATS-6b. The cloud opacity feedback causes a temperature inversion at the sub-stellar point and at the evening terminator at gas pressures higher than 10$^ $ bar. Furthermore, clouds cool the atmosphere between $10^ $ bar and 10 bar, and they narrow the equatorial wind jet. The transmission spectrum shows muted gas-phase absorption and a cloud particle silicate feature at $ The combined atmosphere-cloud model retains the full physical complexity of each component and therefore enables a detailed physical interpretation with JWST NIRSpec and MIRI LRS observational accuracy. The model shows that warm Saturn-type exoplanets around M dwarfs are ideal candidates for a search for limb asymmetries in clouds and chemistry, for identifying the cloud particle composition by observing their spectral features, and for identifying in particular the cloud-induced strong thermal inversion that arises on these planets.

Design and utilisation of a novel poly imino-phosphorane composite for the effective removal of Pb2+ and Cr3+ ions from contaminated water sources

ABSTRACT This study introduces a novel chitosan-immobilised imino-phosphorane composite (Chi-iph) for the efficient removal of lead (Pb2+) and chromium (Cr3+) from wastewater. The successful synthesis of Chi-iph was confirmed using FT-IR, XPS, BET, EDX, TGA, 1H-NMR, 13C-NMR, EI/MS, and ICP-OES analyses. Various experimental parameters such as pH, equilibrium time, metal concentration, adsorbent dose, temperature, and eluents were optimised to enhance the adsorption performance. At 25°C, with pH values of 5.5 for Pb2+ and 4.5 for Cr3+, an initial concentration of 200 mg/L, and an agitation time of 20 min, the maximum adsorption capacities were 55 mg/g for Pb2+ and 45 mg/g for Cr3+. Kinetic modelling demonstrated that the pseudo-first-order model best predicted the adsorption process, yielding capacities of 56.65 mg/g for Pb2+ and 46.38 mg/g for Cr3+. Isotherm analysis showed that the Langmuir model was a better fit than the Freundlich model, with theoretical capacities of 56.81 mg/g for Pb2+ and 44.64 mg/g for Cr3+. The Dubinin–Radushkevich (D-R) isotherm revealed adsorption energy (E) values of 9.45 kJ/mol for Pb2+ and 8.64 kJ/mol for Cr3+, indicating a chemisorption process. Theoretical saturation capacities (qD) were 56.28 mg/g for Pb2+ and 45.58 mg/g for Cr3+. Temkin isotherm results, with bT values of 9.71 and 8.53 kJ/mol for Pb2+ and Cr3+ respectively, aligned closely with the D-R model, further confirming chemisorption. Thermodynamic studies indicated that the adsorption process is exothermic, spontaneous, and more favourable at lower temperatures. Complete desorption of the heavy metals was achieved using 1 M HNO₃, allowing for efficient metal recovery. In a practical application, the Chi-iph composite removed 11.5 mg/L of Pb2+ and 7.01 mg/L of Cr3+ from contaminated wastewater, demonstrating its potential for environmental remediation. The composite’s performance aligns with WHO and FAO guidelines, making it suitable for treating wastewater before disposal into marine environments.

Study of the Pyrolysis of Ayous and Kambala Co-Products: Kinetic Modeling of the Two Species

A kinetic model based on the two-stage semi-global multi-reaction model of Grioui was developed using the TG and DTG curves for the by-products of Kambala and Ayous. These two tropical species are widely used in the Republic of Congo. The TG and DTG curves were obtained through thermogravimetry at five different heating rates (3, 7, 10, and 20 K/min) up to a final temperature of 800 °C under a nitrogen atmosphere. The thermal decomposition of both species started at similar temperatures, but the profiles exhibited notable differences. Kambala showed a distinct profile with two peaks at approximately 500 °C and 700 °C, which upon further investigation were found to correspond to ash decomposition. Additionally, the shoulder present in Ayous between 250 °C and 300 °C, attributed to hemicelluloses degradation, was absent in the DTG curves for Kambala. The kinetic model for Ayous was formulated in three steps, while the model for Kambala consisted of four steps. Both models accurately predicted the thermal degradation of the wood species, and the resulting kinetic parameters aligned with those reported in the literature.

Physicochemical Characterization and Kinetics Study of Polymer Carriers with Vitamin C for Controlled Release Applications.

This study focuses on the selection and evaluation of a kinetic model for the release of vitamin C from different delivery systems, including microcapsules, hydrogels, and a hybrid system combining both. The microcapsules were synthesized from a 2% sodium alginate solution and with vitamin C incorporated in selected formulations. Hydrogels were obtained through photopolymerization using poly(ethylene glycol) diacrylate and polyvinyl alcohol, with and without the addition of vitamin C. The hybrid system incorporated the vitamin C-containing microcapsules within the hydrogel matrix. Physicochemical properties, such as density, porosity, and water vapor transmission rate (WVTR), were evaluated. Kinetic studies of vitamin C release were conducted under dynamic and static conditions, and the experimental data were fitted to six different kinetic models: zero-order, first-order, second-order, Higuchi, Korsmeyer-Peppas, and Hixson-Crowell. The Higuchi and Korsmeyer-Peppas models provided the best fit for most systems, indicating that the release is predominantly controlled by diffusion and, in dynamic conditions, swelling of the matrix. The hybrid system, while exhibiting slower release than the microcapsules and hydrogel alone, demonstrated more controlled and sustained release, which is advantageous for applications requiring prolonged action.

Fabrication of CaCO3 Microcubes and Mechanistic Study for Efficient Removal of Pb from Aqueous Solution.

Pb(II) contamination in aquatic environments has adverse effects on humans even at a low concentration, so the efficient removal of Pb at a low cost is vital for achieving an environmentally friendly, sustainable, and healthy society. A variety of CaCO3-based functional adsorbents have been synthesized to remove Pb, but the adsorption capacity is still unsatisfactory. Herein, calcite CaCO3 microcubes/parallelepipeds are synthesized via simple precipitation and a hydrothermal approach and found to outperform previously reported nano-adsorbents considerably. The CaCO3 achieves a high removal efficiency for Pb(II) (>99%) at a very low dosage (0.04-0.1 g/L) and an initial Pb(II) concentration of 100 mg/L. The CaCO3 presents an excellent adsorption capacity of 4018 mg/g for Pb(II) removal and depicts good stability over a wide range of pH 6-11. The maximum adsorption kinetics are fitted well by the pseudo-second-order kinetic model, whereas the Freundlich isotherm delineates the adsorption data at equilibrium well, indicating a multilayer adsorption process. The ex situ study confirms that the Pb(II) adsorption mechanism by CaCO3 can be attributed to the rapid metal-ion-exchange reaction between Pb(II) and Ca2+. Furthermore, a red shift in the Fourier Transform Infrared (FTIR) spectroscopy peak from 1386 cm-1 to 1374 cm-1 of CaCO3 after Pb removal indicates the adsorption of Pb onto the surface. This adsorbent provides an opportunity to treat wastewater and can be extended to remove other toxic heavy metals.

Synthesis of cefixime loaded PCL/HPMC blend nanoparticles: a controlled release study and in vitro anti-bacterial evaluation

Aim To enhance cefixime’s effectiveness and address drug delivery challenges like concentration at the site, dose, and time, present study investigated the impact of polymer blends on cefixime’s in vitro release profile. Methods Cefixime-loaded nanoparticles were prepared via a modified solvent evaporation method, forming a W/O/W double emulsion. Characterisation included FT-IR, zeta potential, TGA, TEM, and XRD, with in vitro studies and kinetic models used to analyse the release mechanism. Results The PH-4 nanoparticle formulation (80:20 PCL/HPMC, 0.5% PVA) achieved an 81% loading rate, no adverse effects, and a controlled release of 84.66%±2.53 over 30 days. It showed stable physicochemical properties, with in vitro antibacterial tests revealing inhibition zones of 27.4 ± 2.12 mm for E. coli and 17.2 ± 2.23 mm for S. aureus at 12 hours. Conclusion Based on the findings, developed nanoparticulate system containing PCL/HPMC demonstrates its efficacy and safety as a controlled drug delivery method for antibiotics like cefixime.

Efficient removal of a pharmaceutical compound on organoclay: batch experiment, DFT calculation, statistical physics, and modeling

This study was performed to evaluate the adsorptive properties of bentonite. Natural bentonite was found to adsorb considerable amounts of Salicylic acid (SA) after modification by hexadecyltrimethylammonium bromide (HDTMA). Batch studies investigated the adsorptive properties of the modified natural bentonite (organobentonite). The characterization results show the increase in the d001 spacing from 1.13 to 1.53 nm for raw bentonite and organobentonite, respectively. The FTIR analysis indicates the asymmetric vs. (CH2) and symmetric vs. (CH2) stretching modes for clay loaded with surfactant molecules are 2919 and 2845 cm−1, respectively. We investigate parameters such as contact time, pH, temperature, and initial concentration. Desorption and regeneration were also studied. The kinetic analysis shows that the adsorption equilibrium of salicylic acid onto organoclay was reached after 120 min and fits well to a pseudo-second-order kinetic model with the contribution of intraparticular diffusion. In addition, the adjustment of the isothermal models indicated that the Langmuir-Freundlich model best fit the isotherms data for unmodified bentonite and the Langmuir model for modified bentonite. The maximum adsorption capacity of organobentonite is 128 mg g−1 at 25 °C. According to the statistical physics model, the SA could be adsorbed on the surface of organoclay in a non-parallel orientation. The desorption-regeneration investigation revealed that the material could be successfully reused for three cycles of SA adsorption. Mechanistic studies of SA sorption on organobentonite have highlighted several mechanisms: hydrogen bonding, electrostatic attraction, and hydrophobic interaction.

In Situ Potentiometric Monitoring of Nitrate Removal from Aqueous Solution by Activated Carbon and Ion Exchange Resin.

A nitrate selective electrode was used for real-time in situ potentiometric monitoring of a batch nitrate removal process using activated carbon and ion exchange resin. A plasticized polymeric membrane consisting of polyvinyl chloride, 2-nitrophenyl octyl ether and tridodecyl methyl ammonium chloride was incorporated into an ion-selective electrode body. First, the dynamic potential response of the electrode to nitrate was investigated. Two commercial activated carbons with different physical properties were then tested. Nitrate removal with these carbons was monitored potentiometrically using several nitrate concentrations. The extreme turbidity of the solutions was not a drawback during potentiometric monitoring of the process, which is a clear advantage over other methods such as optical monitoring. The potential versus time recordings were converted into nitrate concentration versus time plots, which were evaluated with different adsorption kinetic models. A pseudo-second order kinetic model for nitrate adsorption on both activated carbons was found to fit the experimental data very well. The values of the kinetic parameters were very different between the two activated carbons. The proposed methodology was also satisfactorily applied to the study of nitrate removal by an ion exchange resin. In this case, the experimental results clearly follow a pseudo-first order kinetic model. Potential applications of the proposed methodology for monitoring nitrate removal in real water samples are discussed.