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This study explores the potential of the corozo fruit (Bactris guineensis) palm tree in the Colombian Caribbean as a source for porous carbon material. Its specific surface area, pore volume, and average pore size were obtained using N2 adsorption/desorption isotherms. The images of the precursor and adsorbent surface were obtained using scanning electron microscopy (SEM). Fourier transform infrared (FTIR) spectra were obtained to detect the main functional groups present and an X-ray diffraction analysis (XRD) was performed in order to analyze the structural organization of the materials. By carbonizing the fruit stone with zinc chloride, a porous carbon material was achieved with a substantial specific surface area (1125 m2 g⁻1) and pore volume (3.241 × 10−1 cm3 g⁻1). The material was tested for its adsorption capabilities of the drug propranolol. The optimal adsorption occurred under basic conditions and at a dosage of 0.7 g L⁻1. The Langmuir homogeneous surface model effectively described the equilibrium data and, as the temperature increased, the adsorption capacity improved, reaching a maximum of 134.7 mg g⁻1 at 328.15 K. The model constant was favorable to the temperature increase, increasing from 1.556 × 10−1 to 2.299 × 10−1 L mg−1. Thermodynamically, the adsorption of propranolol was found to be spontaneous and benefited from higher temperatures, indicating an endothermic nature (12.39 kJ mol⁻1). The negative ΔG0 values decreased from −26.28 to −29.99 kJ mol−1, with the more negative value occurring at 328 K. The adsorbent material exhibited rapid kinetics, with equilibrium times ranging from 30 to 120 min, depending on the initial concentration. The kinetics data were well-represented by the general order and linear driving force models. The rate constant of the general order model diminished from 1.124 × 10−3 to 9.458 × 10−14 with an increasing concentration. In summary, the leftover stone from the Bactris guineensis plant can be utilized to develop activated carbon, particularly when activated using zinc chloride. This material shows promise for efficiently adsorbing propranolol and potentially other emerging pollutants. [ABSTRACT FROM AUTHOR]

It is estimated that the growth of the population, the augmented expectancy of life, and the emergence of new pandemics will significantly increase the consumption of pharmaceutical drugs in the coming years. Due to its high efficiency, the group of fluoroquinolones, where the antibiotic ofloxacin hydrochloride (OFL) is found, is widely used to combat bacterial infections in humans and animals. The big problem is concentrated in the effluents generated by industries and hospitals. Additionally, most of the drug is not absorbed by the body and is released directly into domestic effluents. On the other hand, treatment stations have removal limitations for small concentrations. This review analyzed all adsorbents developed and used in OFL removal, listing the main parameters influencing the process. In the end, the other existing technologies in the literature and the gaps and future prospects were described. OFL adsorption in most studies occurs under basic conditions (pH between 6.5 and 8). The increase in concentration provides an increase in adsorption capacity. The adsorbents analyzed showed moderate kinetics, reaching equilibrium before 250 min for most studies. The pseudo-second-order model showed the best statistical fit. In most of the studies, the increase in temperature (313, 315, and 328 K) favored the adsorption of OFL. The Langmuir monolayer model represented most of the isothermal studies. The adsorption capacity varied from 3702 to 0.3986 mg g−1. In this aspect, factors such as OFL concentration and textural characteristics of the adsorbent exerted great influence. The thermodynamic parameters were compatible with the isothermal data, where the endothermic nature of the studies was confirmed. Physical interactions (π-π stacking, H bonding, hydrophobic and electrostatic interactions) governed the main adsorption mechanism. Although some studies stated that chemosorption occurred, thermodynamic parameters cannot validate the same. Coexisting ions in the solution can positively and negatively influence OFL adsorption. The listed studies are all applied to batch processes, where fixed bed studies should be better explored. From this review, it can be concluded that adsorption is a promising technique for OFL removal. However, it is extremely necessary to break the laboratory scale barrier and analyze possible conditions for applying these materials in treating real effluents together with combining technologies. • The adsorption of the antibiotic ofloxacin hydrochloride (OFL) was reviewed in this article. • The influence of the main parameters on OFL adsorption was discussed. • Langmuir isotherm and pseudo-second order kinetics were the best-fit models. • Most adsorbents showed moderate kinetics up to 250 min, with adsorption favored with increasing temperature. • The main adsorption mechanisms were π-π stacking interactions, H bonds, and hydrophobic and electrostatic interactions. [ABSTRACT FROM AUTHOR]

The powdered biomass of paddle cactus (Tacinga palmadora), a rustic plant of great occurrence in the driest regions of Brazil, was evaluated as a low-cost adsorbent to treat textile effluents containing crystal violet (CV) dye. The powdered paddle cactus (PPC) was mainly composed by lignin and holocellulose, as well as, a variety of functional groups. Best results for CV adsorption were found using an adsorbent dosage of 0.5 g L−1 at solution pH equivalent to 10.0. Fast adsorption kinetics was verified, being the equilibrium reached within 100 min, and the curves were well modeled by the pseudo-first-order model. The isotherms were well-represented by the Langmuir model. The maximum adsorption capacity was 228.74 mg g−1 at 328 K. The estimated thermodynamics parameters were ΔG0T = 328K of –9.08 kJ mol−1, ΔH0 of 12.44 kJ mol−1, and ΔS0 of 0.065 kJ mol−1 K−1. In addition, PPC was able to treat a simulated textile effluent containing organic and inorganic compounds, reaching 93% of color removal efficiency. These findings show that powdered paddle cactus can be applied as potential low-cost adsorbent to treat textile effluents containing CV. [ABSTRACT FROM AUTHOR]

Antibiotics are considered as the new generation water pollutants as these disturb endocrine systems if water contaminated with antibiotics is consumed. Among many antibiotics norfloxacin is present in various natural water bodies globally. This antibiotic is considered an emerging pollutant due to its low degradation in aquatic animals. Besides, it has many side effects on human vital organs. Therefore, the present article discusses the recent advances in the removal of norfloxacin by adsorption. This article describes the presence of norfloxacin in natural water, consumption, toxicity, various adsorbents for norfloxacin removal, optimization factors for norfloxacin removal, kinetics, thermodynamics, modeling, adsorption mechanism and regeneration of the adsorbents. Adsorption takes place in a monolayer following the Langmuir model. The Pseudo-second order model represents the kinetic data. The adsorption capacity ranged from 0.924 to 1282 mg g−1. In this sense, the parameters such as the NFX concentration added to the adsorbent textural properties exerted a great influence. Besides, the fixed bed-based removal at a large scale is also included. In addition to this, the simulation studies were also discussed to describe the adsorption mechanism. Finally, the research challenges and future perspectives have also been highlighted. This article will be highly useful for academicians, researchers, industry persons, and government authorities for designing future advanced experiments. [Display omitted] • Find literature errors of poor linearization fitting and thermodynamic parameters. • Reviewed and analyzed up-to-date peer-reviewed articles. • Correlated specific surface area and pore size with adsorption capacity. • Maximum adsorption capacities of up to 917.43 mg.g1. • Adsorption is higher at neutral pH due to the zwitterion characteristics of NFX. [ABSTRACT FROM AUTHOR]

• Activated biochar prepared from residues of palm tree Bactris guineensis. • High surface area and pore volume combined with excellent adsorption capacity of the drug propranolol hydrochloride. • The system tends to reach equilibrium in the 250 min and is well represented by the Avrami model. • With the maximum capacity obtained (161.3 mg g−1) at 328 K based on the Liu isotherm model. • Adsorption is favorable, spontaneous, and endothermic (ΔH0 = 7.403 kJ mol1). The production and consequently the consumption of the pulp of the fruit of the palm tree Bactris guineensis occurs extensively in Colombia. The majority of the fruit is formed by waste (peel and core), producing high residual biomass. Thus, it is necessary to find a practical utilization of these peels, making the production and consumption of the fruit of the palm tree Bactris guineensis highly sustainable. This study produced activated biochar chemically activated using ZnCl 2 and utilized it as an effective adsorbent. The high micropollutant uptake is because of the high porosity and good specific surface area (S BET = 625 m2 g−1). Under basic conditions, propranolol adsorption was favored for an adsorbent dosage of 0.7 g/L. The adsorbent showed fast kinetics, with the equilibrium influenced by the concentration. Avrami's model showed a satisfactory fit having a t 0.95 ranging from 47.8 to 179.3 min. Equilibrium data were best adjusted to the Liu isotherm model. The values of Q max increased with the temperature, reaching up to 161.3 mg g−1 (45 °C). The thermodynamic data showed ΔG° < 0 for 298–328 K (adsorption process favorable) ΔH°= + 7.403 kJ mol−1 (endothermic; magnitude compatible with physical adsorption), and ΔS°= +115.2 J K−1 mol−1 (releases of water molecules of the adsorbate before it being adsorbed in the carbon surface). The biochar chemically activated with ZnCl2, produced from the leftover peels of Colombian palm fruits, is therefore inferred to be a promising option as an adsorbent for the treatment of effluents containing the medication propranolol hydrochloride. [ABSTRACT FROM AUTHOR]

The PVSDM model was used for single and binary dye adsorption systems. This model is commonly used for adsorption in single systems, but this is the first time used in a binary mixture of dyes in the literature. To that end, a new adsorbent derived from Bauhinia forficata waste was created and described for eventual use in the treatment of a dye combination (methylene blue and crystal violet). The single and binary isotherms revealed that increasing the temperature decreases the methylene blue adsorption capacity while increasing the crystal violet adsorption capacity. The Langmuir and extended Langmuir models described the single and binary systems, respectively. Maximum adsorption capacities of 229.13 mg g−1 at 298 K for methylene blue and 324.12 mg g−1 at 328 K for crystal violet were obtained. The thermodynamic parameters showed that the adsorption process for both dyes is spontaneous, being exothermic for the methylene blue and endothermic for the crystal violet. Similar decay curves for the single and binary systems were observed. The PVSDM was able to describe both single and binary adsorption systems. The external mass transfer and the surface diffusion change according to the initial dye concentration and the system type (single or binary). [Display omitted] • The capacity of the single systems was 190.9 and 267.7 mg g−1, for the MB and CV. • The capacity for the mixture was 185.51 and 266.6 mg g−1 for the MB and CV. • The PVSDM model was able to describe the adsorption of single and binary systems. • The external mass transfer and surface diffusion changed according to the system. [ABSTRACT FROM AUTHOR]

[Display omitted] • Activated carbon (AC) from araçá fruit husks for atrazine adsorption. • It was a microporous material with a surface area of 431 m2 g−1. • The adsorption capacity was 35.67 mg g−1 at 328 K, and ΔH0 was 129.5 kJ mol−1. • Adsorption occurs due to electrostatic, H-bonds, π–π and n–π interactions. • The "araça" derived AC was promising in removing atrazine from aqueous solutions. The residual husks of the edible fruits of Psidium cattleianum were carbonized with FeCl 3 as an activating agent and used as an adsorbent to remove the toxic herbicide. After the carbonization step, changes in the material's structure were found. Activated carbon showed characteristics of microporous materials with a pore volume of 0.280 cm3 g−1 and surface area of 431 m2 g−1. Micrographs revealed the emergence of new cavities with a uniform and circular shape. The FTIR spectra showed the disappearance of some bands, remaining bands belonging to functional groups containing carbon, oxygen, and hydrogen. The XRD patterns confirmed the amorphous structure of the material even after the carbonization step, composed of amorphous graphitic carbon. EDS analysis showed that the carbon percentage increased and the oxygen decreased after the carbonization. The experiments were performed at neutral pH using 1 g L−1 of adsorbent. In equilibrium isotherms, the temperature played a considerable role in the adsorption capacity, increasing from 26.39 mg g−1 to 35.67 mg g−1 when the temperature varied from 298 to 328 K. The Liu isotherms were the ones that best fit the isotherm data. The changes in the adsorption enthalpy were endothermic (ΔH° 129.5 kJ mol−1). The general order kinetic model was the most adequate for kinetic data, presenting the lowest values of the Bayesian Information Criterion. Thus, activated carbon developed from the residues of the "araça" fruit showed promise in removing atrazine from aqueous solutions, with the great advantage of its high efficiency under neutral pH solutions and mild temperatures. [ABSTRACT FROM AUTHOR]

Fly ash (FA) was modified through alkaline fusion with NaOH (MFAAF) and applied as an adsorbent to remove methyl violet 10B (MV10B) in an aqueous medium. It was found that the alkaline fusion provided a significant reduction of the crystalline phase of FA. FA and MFAAF are mainly composed of aluminum, silicon, and iron oxides. The pore volume and surface area values of MFAAF were 0.1541 and 65.4 m2 g−1, being 154 and 130 times higher than the precursor material. Alkaline fusion led to an alteration in the morphology, from spheres to an undefined shape. MFAAF presented an MV10B removal percentage eight times higher than the FA, employing an adsorbent amount of 1 g L−1 at pH 7.5. The pseudo-second-order model well-described adsorption kinetics. For the equilibrium data, the Freundlich model was the proper one. At 298 K, the maximum adsorption capacity was 77.61 mg g−1. The adsorptive process was exothermic and spontaneous. MFAAF adsorbent was effective in removing 62.3% of coloration from the simulated effluent. Last, the regeneration test shows that the adsorbent can maintain the adsorption capacity during 5 cycles. These results indicate that the MAAF revealed the potential to be used as an adsorbent in industrial adsorption processes. [ABSTRACT FROM AUTHOR]

• Novel Hyper Cross-Linked Resin: ICYN-PPA, a new and cost-effective adsorbent synthesized in a single step from commercially available materials. • High Adsorption Capacity: ICYN-PPA exhibits a remarkable adsorption capacity of 112.8 mg g−1 for efficient removal of Bisphenol A from aqueous solutions. • Fast Kinetics: The system reaches equilibrium in just 350 min, showcasing the rapid adsorption kinetics of ICYN-PPA. • Thermal Stability: ICYN-PPA's exceptional thermal stability makes it a promising candidate for decontamination processes in BPA-containing effluents. • Environmentally Friendly Solution: ICYN-PPA offers a sustainable approach to mitigate Bisphenol A's harmful effects on human health and aquatic life, contributing to environmental preservation. The widespread utility of Bisphenol A (BPA) in the production of diverse plastic substances including mineral water bottles, food packets, toys, tickets, etc. leads to its release to the environment through industrial effluents that contaminate both the surface and underground water. Given its higher toxicity and harmful effects on both human health and aquatic life, the adsorption of BPA has been the subject of recent studies at present. Herein, we disclose the synthesis of a new hyper cross-linked resin (ICYN-PPA), derived from commercially available 3,3′-(piperazine-1,4-diyl)bis(propan-1-amine) and tris(2,3-epoxypropyl) isocyanurate in a single step reaction, and its adsorptive performance for the removal of BPA from aqueous solution. The thermally stable ICYN-PPA, which is porous and exhibits different sizes of particles on its surface, displayed optimum removal of BPA. The isothermal studies were well represented by the Koble-Corrigan model, where the capacity increased from 216.6 to 228.6 mg g−1 with an increasing temperature of 318 K. The linear driving force model (LDF) was efficient in representing the kinetic data. Whereas the system tends to reach equilibrium after 350 min. The surface diffusion coefficients were 1.301 × 10−16 and 1.859 × 10−16 cm2 s−1 for BPA adsorption on isocyanurate based hyper crosslinked resins. The thermodynamic parameters confirmed the endothermic nature of the process (ΔH0 = 35.83 kJ mol−1) based on physical interactions. [ABSTRACT FROM AUTHOR]

[Display omitted] • In-house chitin was used for the removal of Cd(II) at different temperatures. • The developed chitin presented classical groups reported in the literature, in special nonporous surface. • It was found that the system quickly reached equilibrium at 15 min for all the temperatures investigated. • Physical-statistical modeling indicates that the Cd(II) are adsorbed forming a monolayer. • Potential thermodynamic parameters were evaluated individually. This work analyzes the adsorption of cadmium, a potentially toxic pollutant, on biopolymers synthesized from shrimp shells, as a promising new adsorbent. Spectroscopic analysis, such as FTIR, ATD/ATG, XRD, and SEM/EDX techniques, were used to characterize chitin before it was exposed to cadmium ions. Experimental data indicate that Cd(II) adsorption proceeds with pseudo-second-order model kinetics and is influenced by increasing temperature. In the equilibrium, the maximum adsorption capacity obtained was 58.82 mg g−1 at a temperature of 308 K. Experiments to obtain adsorption data were performed at T = 298–318 K. The saturated adsorption capacities of Cd(II) range from 57.40 to 59.90 mg g−1. The application of the physics-statistics model indicates that the Cd(II) atoms are adsorbed on the surface of the chitosan forming a monolayer. In addition to that, the results also show that the adsorption affinity increases with the system temperature, resulting in higher affinity and an increase of 30% in the adsorption capacity. The adsorption energy was found to be around 2.5 kJ mol−1, indicating that the adsorption is physical and endothermic. The entropy was found to quickly increases (reaching a maximum value of 6 × 10−22 kJ mol−1 K−1) at low concentrations followed by the equilibrium after the 40 mg L−1, indicating that the equilibrium is quickly reached. The Gibbs free energy indicates that the process is spontaneous (ranging from −1.364 to −1.451 kJ mol−1) and that the energy tends to remain constant after 15 mg L−1. Last, the results indicate that the Cd(II) is adsorbed due to dipole–dipole interactions and possible coordination bounds. The results of tests on the adsorption of cadmium by chitin showed that this biopolymer could replace other more expensive adsorbents. [ABSTRACT FROM AUTHOR]

• Adsorption of potential toxic dyes (methylene blue and crystal violet) was studied. • A promising adsorbent was produced and tested during adsorption tests. • A physical model was applied on the entire adsorption data set. • Steric explanations supported a better understanding of the adsorption mechanism. • Two energies described the interactive effects of the adsorption systems. This paper analyzes the adsorption of two potential toxic dyes, i.e. methylene blue (MB) and crystal violet (CV) onto Bauhinia forficata residual fruit powder (BFRFP) as a new promising adsorbent. The experiments aimed at retrievement of adsorption data are carried out at T = 298–328 K and are coupled with an adsorbent characterization to better highlight the MB and CV dyes adsorption mechanism. MB adsorption capacity at saturation (ACS) varies from 181.48 to 201 mg.g−1, while for CV dye, it ranges from 263.06 to 282.61 mg.g−1. This difference is not very significant but reflects that the BFRFP has a higher affinity to remove CV dye. Comparing with some alternative adsorbents, the BFRFP adsorbent shows to be a competitive material for the removal of MB and CV dyes from polluted water. A model assuming that MB and CV dyes are removed via a formation of two layers on BFRFP is chosen as the one that, from a physical point of view, better interpret their adsorption mechanisms. The prediction of the number of dyes adsorbed on BFRFP is approximately equal to 1 for both the dyes, testifying that they are removed without an aggregation process and with slanted position. The physical model generates two energies to describe the interactive effects between both dyes and BFRFP adsorbent (dye- BFRFP) and between dyes (dye-dye). Results show that physical interactions occur during the adsorption process. [ABSTRACT FROM AUTHOR]

• A new adsorbent was prepared from the residue of Butiacapitate. • The adsorption of pharmaceutical molecules was studied. • Adsorption of ketoprofen was endothermic, while paracetamol was exothermic. • A double-layer model with two energies deriving from statistical physics was applied. • This study highlights the important aspects of the adsorption mechanism. This paper describes the removal process via adsorption of paracetamol (PRC) and ketoprofen (KTP) on activated charcoal prepared from the residue of the fruit of Butiacapitate. Some adsorbent characterizations are carried out for a plausible analysis of the adsorption results and for the description of adsorption mechanism. Modelling investigations show that the double layer derived from statistical physiscs can be adopted to interpret the adsorption data. Interestingly, the adsorption mechanism can be elucidated via the model parameters determined at different temperatures. The performance of the adsorbent in terms of maximum adsorption capacity increased from 101.16 to 134.52 mg/g for KTP molecules and decreased from 98.19 to 73 mg/g for PRC molecules, by increasing the temperature, which are in line with the experimental values retrieved. These tendencies of adsorption capacities may be related to the behavior of the number of PRC and KTP pharmaceuticals captured per functional group of the adsorbent. Overall, the modeling results show also that the values of adsorption energies associated to the two layers of KTP and PRC molecules on the adsorbent surface are lower than 40 kJ/mol, implying that only physical type interactions occur in the removal process of these pharmaceutical molecules. [ABSTRACT FROM AUTHOR]

In this paper, the adsorption of the herbicide 2,4-D and the drug ketoprofen on wheat husks Fagopyrum esculentum treated with H 2 SO 4 is experimentally and analytically analyzed. The adsorbent is fully characterized through some techniques such as FT-IR, SEM, and XRD. Adsorption tests are carried out to optimize the performances in terms of adsorbent dosage and solution pH. Subsequently, the impact of temperature is determined through the realization of adsorption isotherms. A multilayer model is employed to microscopically interpret the adsorption mechanism of both the investigated compounds. The modelling analysis shows that the number of molecules bound per adsorption site varied from 0.68 to 2.77 and from 2.23 to 3.59 for ketoprofen and herbicide 2,4-D, respectively. These estimated values testify that an aggregation process occurs during adsorption. The global number of formed layers of each adsorbate is also determined, showing a significant reduction from 5.73 to 2.61 for ketoprofen and from 1.79 to 1.5 for herbicide 2,4-D with the temperature. For a complete understanding of the adsorption mechanism, the saturation adsorption capacity and adsorption energy were calculated and interpreted. Overall, it may be inferred that physical interactions govern how these contaminants adsorb on the tested adsorbent. [Display omitted] • The adsorption of the herbicide 2,4-D and the drug ketoprofen was investigated. • The wheat husks Fagopyrum esculentum was employed as an adsorbent. • Application of physical adsorption model to ascribe new interpretations of the adsorption mechanism. • Description of the adsorption orientation of both pollutants. • Estimation and interpretation of adsorption energies. [ABSTRACT FROM AUTHOR]

The porous structure of ZSM-5 zeolite strongly affects the adsorption, especially when resistant compounds are present in the water, such as naphthenic acid in oil-produced water. In this sense, ME-ZSM-5 zeolite was synthesized by adding sodium alginate for later use as an adsorbent to remove naphthenic acid from synthetic water and real oil-produced water. Firstly, the results showed that the structural characteristics of the modified zeolite were improved by using sodium alginate (surface area of 235.58 m2 g−1 and total pore volume of 0.125 cm3 g−1). Besides, the adsorption of naphthenic acid from synthetic water was optimal using an adsorbent dosage of 3 g L−1 and pH 4, being the adsorption capacity of 195 mg g−1. Still, in synthetic solutions, the enthalpy of adsorption confirmed an exothermic process, and kinetic studies showed that the system reached equilibrium within the first 50 min. Finally, ME-ZSM-5 was applied to remove naphthenic acid from a real sample of oil-produced water and removed 92%. Therefore, ME-ZSM-5 zeolite was successfully synthesized and could be used as adsorbent material to uptake naphthenic acid from oil-produced water. [Display omitted] • ME-ZSM-5 zeolite was synthesized to treat oil-produced water from offshore. • ME-ZSM-5 could be used to uptake naphthenic acid from oil-produced water. • The maximum adsorption capacity was 195 mg g−1 at 298 K. • The adsorption equilibrium occurred within 50 min. • The efficiency in treating real oil-produced water was 92%. [ABSTRACT FROM AUTHOR]

• Quaternary adsorption of Cu2+, Co2+, Ni2+ and Ag+ ions was investigated. • Development of a new quaternary adsorption model. • Adsorption of Cu2+, Co2+ and Ni2+ ions was endothermic, while the Ag+ adsorption was exothermic. • Ag+ adsorption was reduced from single-compound to quaternary system. Quaternary adsorption of Cu2+, Co2+, Ni2+ and Ag+ ions on an adsorbent obtained from the alkaline fusion of wastewater treatment sludge was investigated. Adsorption tests in both single-compound and quaternary systems were carried out and the analysis of adsorption mechanism was done by the application of a new quaternary model. This model was developed from a general methodology based on the application of grand canonical ensemble in statistical physics. This adsorbent was characterized by different analytical techniques. Experimental data showed that the adsorption of Cu2+, Co2+and Ni2+ ions was endothermic, while the Ag+ adsorption was exothermic. Ag+ adsorption was significantly reduced from single-compound to quaternary system due to the competitive effect caused by the other divalent ions, while the adsorption capacities of Cu2+, Co2+ and Ni2+ were not significantly affected in the multicomponent solution. A significant competitive effect of Cu2+, Co2+ and Ni2+ ions on the adsorption of Ag+ ions occurred. Modelling analysis showed that the adsorption of Cu2+, Co2+ and Ni2+ ions was a multi-ionic process at all tested temperatures, while the adsorption of Ag+ was a multi-ionic process only at low temperatures (298 and 308 K). Finally, the statistical physics model confirmed that the adsorption energies corresponded to physical interactions forces and the water molecule adsorption played a relevant role during the removal of these trace metals. [ABSTRACT FROM AUTHOR]

• Methylene blue adsorption on a biomass was analyzed via theoretical physics-based calculations. • Role of biomass functionalities for dye adsorption was explained. • DFT simulation characterized the interactions between the methylene blue andbiomass surface. • Experimental and theoretical findings of dye adsorption on lignocellulosic biomass ere reported. The adsorption of the methylene blue on the biomass obtained from brazilian berries seeds was studied. Experimental adsorption data and results of the physicochemical characterization of the adsorbent besides theoretical physics-based calculations were utilized to understand the dye adsorption mechanism. A monolayer adsorption model was proposed to simulate the dye adsorption assuming an interaction adsorbent + adsorbate via two different functional groups on biomass surface. This statistical physics model calculated the number of bonded MB dye molecules and the saturated adsorption capacity for both functional groups at different temperatures. For instance, the values of n 1 and n 2 were 0.34 and 0.51 at 298 K thus indicating that MB molecules interacted via a horizontal adsorption orientation with two and three functional groups of biomass surface. Calculations based on statistical physics and density functional theory characterized the role and relevance of proposed functional groups on dye adsorption including its thermodynamic parameters. Results demonstrated that the hydrogen and oxygen functionalities of biomass surface were the main responsible functional groups for dye adsorption. Therefore, this paper reports new findings to understand the adsorption mechanism of dye molecules on lignocellulosic biomasses. [ABSTRACT FROM AUTHOR]