Adsorption Equilibrium Model Research Articles

Mixed-Mode Adsorption of l-Tryptophan on D301 Resin through Hydrophobic Interaction/Ion Exchange/Ion Exclusion: Equilibrium and Kinetics Study.

The adsorption of l-tryptophan (l-Trp) was studied based on the hydrophobic interaction/ion exchange/ion exclusion mixed-mode adsorption resin D301. Firstly, the interaction mode between l-Trp and resin was analyzed by studying the influence of pH variation on the adsorption capability and the dissociation state of l-Trp. Secondly, the adsorption mechanism was illuminated by studying the adsorption equilibrium and kinetic behaviors. The adsorption equilibrium and a kinetics model were constructed. The augmentation of pH gradually elicited an enhancement in the adsorption capacity of l-Trp. l-Trp existing in varied dissociation states could be adsorbed by the resin, and the interaction mode relied upon the pH of the solution. An integrated adsorption equilibrium model with the coadsorption of different dissociation states of l-Trp was developed and could predict the adsorption isotherms at various pH levels satisfactorily. Both external mass transfer and intra-particle diffusion collectively imposed constraints on the mass transfer process of l-Trp onto the resin. An improved liquid film linear driving force model (ILM) was constructed, and the model provided a satisfactory fit for the adsorption kinetics curves of l-Trp at various pH levels. l-Trp molecules had a high mass transfer rate at a relatively low solution pH.

Mechanistic Understanding of Sieving Lithium Ions Using a Biobased Sorbent Technology for Sustainable Lithium Reclamation and Cleansing Brines.

Low-cost environmentally benign materials that can be produced in a large scale to extract lithium from brine resources could drive the lithium market toward a clean technology with high lithium recovery and production. Herein, we have investigated the utilization of a novel, environmentally benign, and low-cost biobased sorbent for the extraction of lithium from lithium-rich solutions. This biobased molecular sieving sorbent, iron(III)-tannate (Fe(III)-TA), belongs to a novel class of coordination polymer frameworks derived from a natural polyphenol-tannic acid (TA)-coordinated with iron(III) metal cations. Its lithium adsorption and kinetic isotherm studies conducted using lithium-rich aqueous solutions confirm the sorbent's dual function for lithium sieving via physisorption, chemisorption, and mass transfer diffusion processes. The adsorption equilibrium and kinetic isotherm models combined with the external and internal mass transfer diffusion models reveal a mechanistic pathway for lithium-ion adsorption. Aiding by forming a fluid film for external mass transfer diffusion of lithium ions, analytes adsorb onto the sorbent surface via physisorption and chemisorption followed by the internal mass transfer diffusion, occupying lithium ions in the sorbent's pores. The lithium adsorption efficiency studies conducted for brines with different concentrations of interference alkali and alkaline cations evidence that the sorbent's affinity for lithium ions strongly depends on the analyte concentration. The results evidence that the sorbent has the ability to lower the brine's salinity and significantly reduces the ratios of Mg/Li and Ca/Li by 4-fold and 10-fold, respectively, yielding lithium-rich solutions. Thus, implementing this innovative biobased sorbent technology as an add-in step into traditional lithium extraction and refining processes, one can design a cost-effective pathway to yield lithium-rich leachate by reducing the Mg/Li and Ca/Li ratio. Nonetheless, the present work demonstrates that Fe(III)-tannate is an effective multifunctional sorbent for sieving lithium from lithium-rich aqueous solutions as well as for desalinating brine resources to recover usable water. Thus, this biobased sorbent offers the possibility of effective application of lithium reclamation and remediation of brine, mitigating the environmental impact of brine discharge and large volume of freshwater usage for lithium extraction and refining.

Development of Biomass Derived Adsorbents using Wood Apple Pulp for the Removal of Contaminants

This study involves the development of biomass derived adsorbents from wood apple pulp for water and wastewater treatment. This biomass was modified by the addition of commercially available activated charcoal and copper nanoparticles. Adsorbent characterization was performed for understanding the surface morphology and surface area. These new adsorbents were further evaluated for their potentiality in removing dyes and API pollutants (Active Pharmaceutical Ingredient). All the adsorbents were highly effective in the removal of these contaminants, 96% of Malachite Green and 72% of Congo Red was removed with a high adsorption capacity of 45 mg/g. API pollutant (Ciprofloxacin) removal showed 52% removal, which is greater when compared to several modified adsorbents. Adsorption equilibrium models (Langmuir and Freundlich) and kinetic models (pseudo first order and pseudo second order) were evaluated for fit of the experimental data. In general, the isotherm studies indicated multilayer adsorption.

Numerical simulation of foam displacement impacted by kinetic and equilibrium surfactant adsorption

This study explores the effectiveness of foam in reducing gas mobility in porous media impacted by surfactant adsorption in highly heterogeneous porous media. The research focuses on assessing the influence of kinetic and equilibrium adsorption during foam displacement on reservoir sweep efficiency, considering co-injection and SAG (Surfactant Alternating Gas) injection strategies. Including the surfactant on the liquid phase and considering the surfactant adsorption effects fitted by experimental data, the mathematical modeling combines Darcy’s law, fluid phase conservation, surfactant transport equations, and a non-Newtonian foam model in local equilibrium. The simulations utilize FOSSIL (FOam diSplacement SImuLator), an in-house software composed of a stable and conservative numerical algorithm with reduced numerical diffusion. These properties are achieved by combining a hybrid mixed finite element method to solve the Darcy system with a central-upwind finite volume scheme to approximate the transport equations and adopting an implicit adaptive method in time. The results reveal that while omitting adsorption phenomena enhances sweep efficiency due to reduced surfactant loss, differences between equilibrium and kinetic adsorption models are minor (up to 0.3% in production). Consequently, these results suggest using simple adsorption models, such as equilibrium isotherms, rather than more complex models, such as kinetics. Additionally, the SAG approach outperforms co-injection (up to 19% in production), despite the fact that the adsorption is detrimental to both of them, aligning with literature results and previous findings.

Bridging the Adsorption Data and Adsorption Process by Introducing a Polynomial Structure To Accurately Describe IUPAC Isotherms, Stepwise Isotherms, and Stepwise Breakthrough Curves.

Porous heterogeneous adsorbents, those composed of multiple pore structures and surface chemical adsorption sites, can result in various gas or vapor adsorption isotherms, including five types of IUPAC adsorption isotherms and stepwise adsorption isotherms that have been difficult to model using a single adsorption equilibrium model. The limitation of the above equilibrium model further restricts the calculations of complex stepwise breakthrough curves. To bridge the adsorption data and adsorption process, it is important to first develop a simple model or method to describe these isotherms of various complex adsorption systems. In this work, assuming that the effect of the diffusion rate can be neglected under the static condition and the adsorption process is discontinuous, the number of adsorption isotherm inflection points can be used to represent the changed number of adsorption interactions. With the introduction of the polynomial structure, a series of empirical or semi-empirical polynomial adsorption models were developed. The N-site polynomial Langmuir-Freundlich equation could accurately fit common type I, II, III, IV, and V adsorption isotherms and complex stepwise adsorption isotherms covering various adsorbates, such as volatile organic compounds (VOCs), toxic industrial chemicals (TICs), water vapor, and carbon dioxide, as well as different adsorbents, such as metal/covalent organic frameworks (MOFs/COFs), zeolites, and porous carbons. Similarly, the introduction of a polynomial structure, such as the N-site polynomial Yoon-Nelson equation, was also successful in the description of interesting stepwise breakthrough curves. This work provides a more accurate adsorption equilibrium model to characterize all types of isotherms. As a foundation model, it is expected to be used to simulate the gas-solid adsorption process inside the fixed and fluidized beds packed with porous adsorbents.

A novel statistical model for adsorption equilibrium using homotopy and generalized mean distributions

A novel statistical model for adsorption equilibrium using homotopy and generalized mean distributions

Modeling of multi-temperature Type I and II benzene/ammonia adsorption isotherms: Dual LF model and linearized DR model

Adsorption isotherm is basic data for evaluating the porous adsorbent adsorption capacity and explaining gas–solid adsorption behavior. Adsorption equilibrium modeling is a simple method to describe isotherm data in application. In this paper, taking C6H6 and NH3 as an example, multi-temperature Type I or Type II adsorption isotherms on AC, ASZMT, and 13X were investigated and fitted. Results show that C6H6 and NH3 adsorption behaviors on 13X both existed in chemisorption. At certain adsorbed capacity, the isosteric heats are higher than 50 kJ·mol−1. Type I and Type II C6H6 or NH3 adsorption isotherms could be successfully described using the extended Dual LF model·NH3 temperature-independent characteristic curves on AC and ASZMT were obtained using the Linearized DR model and successfully used to predict NH3 adsorption data at any pressure within the whole room temperature. Further, the Dual LF model was extended to describe other adsorption isotherms including IUPAC Type III, IV, and V. The R2 between the model and data were higher than 0.98, proving that it has universal applicability than other classical models such as Langmuir, Freundlich, Toth, and so on. It has the potential to be used as a general equilibrium model for adsorption process simulation in the future.

Synergistic inhibitive effect of a hybrid zinc oxide-benzalkonium chloride composite on the corrosion of carbon steel in a sulfuric acidic solution

Abstract Zinc oxide and quaternary ammonium-type surfactants have been separately recognized for their anti-corrosive efficiencies. Their composite, not investigated so far, could provide a synergetic anti-corrosion effect. In this respect, the aim of this study is to synthesize a composite material consisting of zinc oxide and benzalkonium chloride (ZnO-BAC) in varying mass ratios (3:1, 1:1, and 1:3). The inhibitory properties of the ZnO-BAC composite against carbon steel corrosion in a 0.5 M sulfuric acid solution were assessed under ambient conditions. First, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy were used to examine the chemical structure of the prepared composite. Then, the corrosion inhibitive performance of the devised inhibitors was screened using electrochemical, hydrogen collection, and weight loss measurements. Further, the surface morphology was examined using a scanning electron microscope, both before and after immersion in the corrosion medium. The electrochemical measurements indicate that the prepared inhibitor exhibits a predominant cathodic inhibition behavior and the maximum inhibition efficiency, approximately 91.9%, was achieved for one-to-one mass ratio. Similar results were obtained from weight loss and hydrogen evolution measurements, which showed that the ZnO-BAC composite reduced the corrosion rate of carbon steel by 69.9% and 64.9%, respectively. Finally, molecular dynamics and an adsorption equilibrium model were used to elucidate the mechanism of corrosion inhibition by the ZnO-BAC composite, which exhibits a high adsorption energy on the iron surface.

Adsorption equilibrium of activated carbon amid fluctuating benzene concentration in indoor environments

Adsorption is commonly employed to remove volatile organic compounds (VOCs) from indoor air. However, the reversibility of this process has been rarely explored in prior research. Meanwhile, some previous research indicated partial reversibility in adsorption and desorption processes, which has not been described in traditional adsorption equilibrium models. In this study, we measured benzene adsorption and desorption isotherms on 6 activated carbons within two concentration ranges: 0–3 ppm and 0–6 ppm. The results showed that the adsorption process was partially reversible and the desorption isotherm was hysteretic for all the samples. Different carbons exhibited distinct isotherm patterns, yet the desorption isotherms in the experimental concentration range can be calculated from the adsorption isotherms using the same empirical equation. In addition, we measured the breakthrough curves using the oscillating benzene concentration (6 ppm to background) on the test columns. Reversible adsorption was observed at low degrees of saturation of the test column. Especially for microporous activated carbon, desorption could be sustained for several hours with purging even at the breakthrough rate of about 10%. An adsorption equilibrium model incorporating partially reversible adsorption and hysteretic desorption isotherm was developed based on the experimental data, which allows a preliminary interpretation of the measured breakthrough curves at fluctuating inlet concentrations.

TEs enrichment characteristic in different size particulate from coal-fired flue gas: Part 2. Mechanism and correlation analysis

The correlation analysis between TEs enrichment and fly ash physiochemical properties was carried out to explore the TEs formation mechanism in different size fly ashes. The fly ash samples collected from circulating fluidized bed (CFB) and pulverized coal (PC) boilers were separated into PM100, PM50, PM10, and PM2.5 by aerodynamic cutting method, the TEs enrichment contents in different size particles were measured by ICP-MS, the porous structure and chemical components of different size particles were detected by BET and XRF characterization, the unburnt carbon contents in different size particles were analyzed by the improved two-atmosphere thermogravimetry. The porous structure correlation results show that the specific surface area of fly ash is positively related to TEs enrichment, and the high volatility As, Pb, and Cd have bigger specific surface area correlation coefficients. The fly ash pore size is found to have a negative relationship with TEs enrichment. An equilibrium adsorption model deriving from the Lennard-Jones 12–6 function was developed to reveal this negative correlation. It’s found that Cr, As, and Pb have higher pore size correlation coefficients because they have higher adsorption equilibrium constants. The unburnt carbon has a negative correlation with TEs because the unburnt carbon content decreases with particle size decrement meanwhile the TEs enrichment content increases with particle size abatement. The fly ash chemical components alumina, iron oxide, and calcium oxide have a positive correlation with TEs enrichment because they can absorb TEs by chemical effect. Based on the DFT calculation of gaseous lead and cadmium adsorption, it confirms that the highest TEs enrichment correlation of alumina is due to the strongest chemical adsorption effect.

Polyurea membrane for water cleaning: Kinetic and equilibrium modeling of dyes adsorption

Polyurea membrane for water cleaning: Kinetic and equilibrium modeling of dyes adsorption

Performance Evaluation of Phenol-Resin-Based Adsorbents for Heat Transformation Applications.

Phenol resins (PRs) are considered as relatively inexpensive adsorbents synthesized from agricultural biomass via employing a variety of synthesized procedures. The performance of PR for heat transformation application is not widely investigated. In this regard, the present study aims to evaluate the four PR derivative/refrigerant pairs, namely (i) KOH6-PR/CO2, (ii) SAC-2/HFC, (iii) KOH4-PR/ethanol, and (iv) KOH6-PR/ethanol, for adsorption cooling and adsorption heating applications. Ideal cycle analyses and/or thermodynamic modelling approaches were utilized comprising governing heat and mass balance equations and adsorption equilibrium models. The performance of the AHP system is explored by means of specific cooling energy (SCE), specific heating energy (SHE), and coefficient of performance (COP), both for cooling and heating applications, respectively. It has been realized that KOH6-PR/ethanol could produce a maximum SCE of 1080 kJ/kg/cycle and SHE of 2141 kJ/kg/cycle at a regeneration temperature (Treg) and condenser temperature (Tcond) of 80 °C, and 10 °C, respectively, followed by KOH4-PR/ethanol, SAC-2/HFC-32, and KOH6-PR/CO2. The maximum COP values were estimated to be 1.78 for heating and 0.80 for cooling applications, respectively, at Treg = 80 °C and Tcond = 10 °C. In addition, the study reveals that, corresponding to increase/decrease in condenser/evaporator pressure, both SCE and SHE decrease/increase, respectively; however, this varies in magnitude due to adsorption equilibrium of the studied PR derivative/refrigerant pairs.

Evaluating the emerging adsorbents for water production potential and thermodynamic limits of adsorption-based atmospheric water harvesting systems

In the context of global water scarcity, adsorption-based atmospheric water harvesting (AWH) is an emerging technology for providing potable water at anytime/anywhere. In this regard, the study evaluates silica-gel, zeolite, ionogel, polymer, membrane, and metal-organic framework based ten kinds of emerging adsorbents for the AWH systems. A thermodynamic modeling framework comprising of adsorption equilibrium models and governing steady-state equations is performed. Performance of AWH systems is always judged on water production potential (WPP), energy consumption (EC) whereas thermodynamic correctness can be measured by first (ηI) and second law (ηII) efficiencies. Thereby, the adsorbents are evaluated from perspectives of WPP, EC, ηI and ηII. As per results, ionogel based adsorbent enables maximum WPP ranging up to 1.55 kg/kg/cycle, EC of 4214.96 kJ/kgw/cycle, ηI of 0.54, and ηII of 0.21. Whereas MIL-101(Cr) observe WPP ranging up to 0.87 kg/kg/cycle, EC of 4499.84 kJ/kgw/cycle, ηI of 0.50, and ηII of 0.19. Parametric analyses results show that ηI of ionogel and MIL-101(Cr) can be increased up to 0.65 and 0.69 while ηII up to 0.23 and 0.25, respectively. Furthermore, ηI and ηII of dual-stage system can improve by 33% as compared to single-stage that can improve by 68-74% as compared to vapor compression system.

Modeling of multi-temperature IV and V-type water vapor adsorption isotherms on activated carbons for chemical protection

A static volumetric method measured the water vapor adsorption isotherms on porous activated carbons (AC and ASC-T) at 278.15 K ～ 308.15 K. Because of the difference in surface oxygen-containing functional groups, a Type-V isotherm represented water vapor adsorption on AC, whereas a Type-IV isotherm characterized ASC-T. The applicability of seven classical adsorption equilibrium models was analyzed and compared systemically. Results show that the Dual-sites Langmuir-Freundlich equation had the lowest residual errors (< 6 ml/g). Further, based on the linearization DA equation, a new partitioned segment-fitting strategy was first developed to describe multi-temperature adsorption isotherms. Two sets of the division points (P/P0) and parameters (n) were acquired. For AC and ASC-T, the best division point (P/P0) and parameter (n) were equal to 0.1 and 0.9, 0.2 and 2, respectively. The fitted results of multi-temperature adsorption isotherms show that the R2 values of AC and ASC-T both were bigger than 0.93, showing that the new fitting strategy has very good applicability. It offers the possibility to address the problem of the accurate description for multi-temperature water vapor adsorption data on porous activated carbons.

Multifunctional cobalt oxide nanocomposites for efficient removal of heavy metals from aqueous solutions

In this study, co-precipitation synthesis of natural clay (NC) with Co3O4 nanoparticles (NPs) is carried out to elaborate the super NC@Co3O4 nanocomposites with admirable salinity confrontation, environmental stability and reusability, to eliminate heavy metal pollution such as toxic Pb(II) and Cd(II) ions. The advantages of using the NC@Co3O4 adsorbent are easy synthesis and biocompatibility. In addition, NC@Co3O4 can keep an excellent adsorption capacity by taking into account various environmental parameters such as the pH solution, NC@Co3O4 dose, adsorption process time and the initial heavy metals concentration. Furthermore, FTIR, XRD, TGA, SEM-EDS, TEM and AFM analyses were performed to confirm NC@Co3O4 nanocomposites synthesis and characterisation. The adsorption efficiencies of Pb(II) and Cd(II) ions by NC@Co3O4 nanocomposites were demonstrated to be up to 86.89% and 82.06% respectively. Regarding the adsorption from water onto the NC@Co3O4 nanocomposites, kinetics data were well fitted with PSO kinetic model, whereas a good agreement was found between the equilibrium adsorption and theoretical Langmuir isotherm model leading to maximum adsorption capacities of 55.24 and 52.91 mg/g, for Pb(II) and Cd(II) respectively. Monte Carlo (MC) simulations confirmed the spontaneous of this adsorption based on the negative values of Eads. The MC simulations were performed to highlight the interactions occurring between heavy metal ions and the surface of NC@Co3O4 nanocomposites, these were well correlated with the experimental results. Overall the study showed that NC@Co3O4 nanoadsorbents have strongly versatile applications and are well designed for pollutant removal from wastewater due to their unique adsorptive properties.

Construction and Application of Mineral Flotation Adsorption Equilibrium Model: Accurately Analyze Ions/Reagents Adsorption Behavior on Mineral Surface

Construction and Application of Mineral Flotation Adsorption Equilibrium Model: Accurately Analyze Ions/Reagents Adsorption Behavior on Mineral Surface

Ammonia Removal in Activated Carbons Prepared from Olive Oil Industry Waste

Activated carbons (ACs) from olive stone were prepared using CO2, steam, KOH, and H3PO4 as activating agents. The resultant activated carbons were characterized by proximate and ultimate analysis, N2 adsorption (Brunauer-Emmett-Teller (BET) method), iodine number, Boehm titration, temperature-programmed desorption (TPD), and Fourier transform infrared spectroscopy (FTIR). Ammonia (NH3) was used as a test molecule to be adsorbed. The BET surface areas of the ACs obtained ranged from 1000 to 1986 m2 g-1. Type I isotherms were obtained for all the samples, although steam and H3PO4 ACs showed a significant mesopore contribution. KOH activation resulted in carbon with a high microporosity (98%) and high iodine adsorption (1030 mg g-1). KOH AC prepared with a KOH/pyrolyzed char weight ratio of 2 and at 900 °C showed the highest NH3 adsorption (252 mg g-1), favored by the high microporosity and adequate acidity. Chemical activation (KOH and H3PO4) promotes higher NH3 adsorption than the physical ACs prepared (CO2 and steam). Langmuir and Freundlich adsorption equilibrium models were used to correlate the NH3 adsorption isotherms, obtaining the best fit for the Freundlich equation. The results indicated that olive stone-based activated carbon could be used for commercial AC to remove NH3 from gaseous streams.

Thermodynamic studies of Congo red dye adsorption: avoiding erroneous conclusions from the use of isotherm models

The importance of adsorption in water purification and the need to guard against erroneous conclusions often associated with the use of equilibrium adsorption model studies in adsorption systems informed this work. Water purification by adsorption of Congo red (CR) from synthetic aqueous solution to acid treated corncob charcoal (ATCC) was carried out at three different pH values (8.0, 10.5, and 12.0) and at temperatures 10–40 °C. The maximum adsorption capacity of ATCC for CR was 85.8 mg/g at pH 12. The resulting data from the batch adsorption studies were plotted at different temperatures and were fitted to linear form of three isotherm models; Freundlich, Langmuir, and Temkin. Though all three models fitted the experimental data linearly, only Langmuir model was able to account for the observed thermodynamic behavior of the adsorbent–adsorbate systems under the pH conditions. The standard enthalpy values for the adsorption of CR on ATCC at pH 8.0, 10.5, and 12.0 were −5.010 ± 0.312, −7.024 ± 0.440, and −71.426 ± 3.130 kJ mol−1, respectively. The corresponding entropies at pH 8.0, 10.5, and 12.0 were 98.7 ± 1.0, 87.8 ± 1.5, and 129.0 ± 10.5 J mol−1 K−1, respectively. The effect of pH on the thermodynamic quantities were rationalized on the basis of the type of interaction between the CR and the adsorbent. To determine the most suitable model, it was important to juxtapose the observed dependence of adsorption affinity on temperature with the thermodynamic information of the adsorption studies.

Silk Fibroin/Soursop Seed Bio-Adsorbent for Crystal Violet and Copper Metal Ion Removal

Groundwater highly contaminated with organic substances and heavy metal ions in the Kariangau Industrial Area, Balikpapan, East Kalimantan is indicated by the comparatively high COD. Therefore, the technology for treating wastewater to remove various toxins before releasing it into the environment needs to be advanced. Here, we present a green synthetic method of a composite adsorbent (SF/SS) using soursop seeds and silkworm cocoons. SEM, FTIR, and BET were used to analyze the physicochemical characteristics of the adsorbent. Mechanistic investigation of the SF/SS adsorbent performance for the removal of Cu2+ metal ions and crystal violet (CV) was conducted, while taking into account variables affecting adsorption properties. The Freundlich and Langmuir isotherm adsorption models were used to fit the adsorption equilibrium, while pseudo-first and second-order models were used to assess the adsorption kinetics. The mesoporous SF/SS adsorbent exhibited the highest adsorption capacities of 78.6 and 69.2 mg‧g-1, respectively. The pseudo-first model showed the best fit for CV removal with a kinetic rate of 0.0634 min-1, while the Freundlich model exhibited the best fitting for both of CV and Cu2+ removal. The results showed that SF/SS can be applied as an efficient adsorbent for both of heavy metal and organic dye removal.

Equilibrium and Kinetic Modeling of Crystal Violet Dye Adsorption by a Marine Diatom, Skeletonema costatum.

Significant efforts have been made to improve adsorbents capable of eliminating pollutants from aqueous solutions, making it simple and quick to separate from the treated solution. In the current study, the removal of Crystal Violet Dye (CVD) from an aqueous synthetic solution onto a marine diatom alga, Skeletonema costatum, was investigated. Different experiments were conducted as a function of different pH, contact time, adsorbent dosage, temperature, and initial CVD concentration. The highest adsorption efficiency (98%) was obtained at 0.4 g of S. costatum, pH 3, and a contact time of 120 min, at 25 °C. Furthermore, Fourier-transform infrared spectroscopy (FTIR) results display that binding of CVD on S. costatum may occur by electrostatic and complexation reactions. Moreover, the Brunauer–Emmett–Teller surface area analysis (BET) obtained was 87.17 m2 g−1, which, in addition to a scanning electron microscope (SEM), reveals large pores that could enhance the uptake of large molecules. However, the equilibrium adsorption models were conducted by Halsey, Langmuir, Freundlich, Henderson, and Tempkin isotherm. In addition, multilayer adsorption isotherm best described the uptake of CVD onto S. costatum. The maximum monolayer adsorption capacity (qmax) was 6.410 mg g−1. Moreover, thermodynamic parameters of the adsorption studies suggested that the uptake of CVD onto S. costatum was endothermic and spontaneous. The pseudo-first-order, pseudo-second-order, and intra-particle diffusion kinetic equations were applied to model the adsorption kinetic data. It was seen that the kinetics of the adsorption may be described using pseudo-second-order kinetic equations. Finally, the present work concluded that the marine diatom alga S. costatum is suitable as a natural material for the adsorption of CVD.