Search

Diuron is a broad-spectrum herbicide used to control weeds and algae in the agriculture sector. Diuron as a water pollutant has been detected in various water bodies due to its slow biodegradation. The adsorption methods offer a promising solution because of their low costs and efficiencies. This article discusses the presence, fate, ecotoxicology, and removal of diuron from aqueous media by adsorption. It was observed that the most effective adsorbents are employed at dosages below 1.0 g L−1 in slightly acidic to neutral solutions (pH 6–7). Pseudo-second-order model describes the best fitting of the adsorption kinetics, while Langmuir isotherm is used for the determination of adsorption capacity. Activated carbon derived from argan nutshells exhibited exceptional adsorption capacity up to 780 mg g−1, followed by activated carbon obtained from cassava biomass with 122 mg g−1 adsorption capacity. It is also observed that increased dissolved oxygen in water enhances diuron removal with carbonaceous adsorbents (above 60% removal); even in the presence of other common pesticides. In fixed-bed systems, rice husk ash shows an adsorption capacity of 9.5 mg g−1. Finally, theoretical results suggest that diuron adsorption occurs through various physical interactions (π-π interactions, H-bonding, dipole-dipole, and van der Waals forces), depending on the adsorbent surface. Diuron removal is well established at the laboratory scale, but further research is needed to bridge the gap between successful lab-scale applications and continuous large-scale applications. [ABSTRACT FROM AUTHOR]

In this study, PROP adsorption was investigated using activated carbon derived from Bactris Guineensis residues and physical statistical modeling. The characterization results indicate high specific surface areas (624.72 and 1125.43 m2 g−1) and pore diameters (2.703 and 2.321 nm) for the peel and stone-activated carbon, respectively. Adsorption equilibrium was investigated at different temperatures (298 to 328 K), and it was found that the adsorption capacity increased with temperature, reaching maximum values of 168.7 and 112.94 mg g−1 for the peel and stone-activated carbon, respectively. The application of physical statistical modeling indicates that a monolayer model with one energy site is adequate for describing both systems, with an R2 above 0.986 and a low BIC of 20.021. According to the steric parameters, the density of molecules per site tends to increase by 116.9% for the stone and 61.6% for the peel. In addition, the model indicates that the number of molecules decreases with increasing temperature from 1.36 to 0.81 and from 1.03 to 0.82. These results indicate that temperature controls the number of receptor sites and the orientation in which propranolol is adsorbed at the surface. The adsorption energies were similar for both systems (approximately 10 kJ mol−1), which indicates that the adsorption occurred due to physical interactions. Finally, the application of thermodynamic potential functions indicates that the maximum entropy is reached at concentrations of half-saturation (Ce 3.85 and 4.6 mg L−1), which corresponds to 1.60 × 10–18 and 1.86 × 10–18 kJ mol−1 K−1 for the stone and peel, respectively. After this point, the number of available sites tends to decrease, which indicates the stabilization of the system. The Gibbs energy tended to decrease with increasing concentration at equilibrium, reaching minimum values of − 1.73 × 10–19 and − 1.99 × 10–19 kJ mol−1, respectively. Overall, the results obtained here further elucidate how the adsorption of propranolol occurs for different activated carbons from the same source. [ABSTRACT FROM AUTHOR]

The objective of this study is to develop a low-cost biosorbent using residual seeds of the Citrullus lanatus fruit for the removal of cationic dyes. Physicochemical parameters such as pH, adsorbent mass, contact time, and temperature were evaluated for their effects on dye removal. The biosorbent is composed of lignin and cellulose, exhibiting a highly heterogeneous surface with randomly distributed cavities and bulges. The adsorption of both dyes was most effective at natural pH with a dosage of 0.8 g L−1. Equilibrium was reached within 120 min, regardless of concentration, indicating rapid kinetics. The Elovich model and pseudo-second-order kinetics were observed for crystal violet and basic fuchsin dye, respectively. The Langmuir model fitted well with the equilibrium data of both dyes. However, the increased temperature had a negative impact on dye adsorption. The biosorbent also demonstrated satisfactory performance (R = 43%) against a synthetic mixture of dyes and inorganic salts, with a small mass transfer zone. The adsorption capacities for crystal violet and basic fuchsin dye were 48.13 mg g−1 and 44.26 mg g−1, respectively. Thermodynamic studies confirmed an exothermic nature of adsorption. Overall, this low-cost biosorbent showed potential for the removal of dyes from aqueous solutions. In this work, a novel biosorbent was developed using residual Citrullus lanatus fruit seeds that can efficiently remove cationic dyes from aqueous solutions. The biosorbent's composition includes lignin and cellulose, and its surface structure is highly heterogeneous, consisting of randomly distributed cavities and bulges. The biosorbent demonstrated a rapid and efficient adsorption capacity for both crystal violet and basic fuchsin, regardless of dye concentration. Moreover, the biosorbent was successfully employed in the treatment of a synthetic mixture containing several dyes and inorganic salts. Finally, the application of the biosorbent in continuous adsorption showed a low zone of mass transfer and high breakthrough time, indicating it to be an excellent material for fixed-bed operation. Overall, this study provides a low-cost and efficient alternative for the removal of dyes from aqueous solutions, with promising practical applications. Citrullus lanatus seed powder was produced and characterized. Crystal Violet (CV) and Basic Fuchsin (BF) contaminants were successfully removed by the powder. Low mass-transfer zone length and good adsorption capacities were obtained in a continuous system. A good performance was observed against a synthetic mixture. [ABSTRACT FROM AUTHOR]

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 production and consumption of cassava (Manihot esculenta) occur in several places worldwide, producing large volumes of waste, mostly in the form of bark. This study sought to bring a new purpose to this biomass through producing activated carbon to use as an adsorbent to remove the herbicide Diuron from water. It was observed that the carbon contains the functional groups of methyl, carbonyl, and hydroxyl in a strongly amorphous structure. The activated carbon had a surface area of 613.7 m2 g−1, a pore volume of 0.337 cm3 g−1, and a pore diameter of 1.18 nm. The Freundlich model was found to best describe the experimental data. It was observed that an increase in temperature favored adsorption, reaching a maximum experimental capacity of 222 mg g−1 at 328 K. The thermodynamic parameters showed that the adsorption was spontaneous, favorable, and endothermic. The enthalpy of adsorption magnitude was consistent with physical adsorption. Equilibrium was attained within 120 min. The linear driving force (LDF) model provided a strong statistical match to the kinetic curves. Diffusivity (Ds) and the model coefficient (KLDF) both increased with a rise in herbicide concentration. The adsorbent removed up to 68% of pollutants in a simulated effluent containing different herbicides. Activated carbon with zinc chloride (ZnCl2), produced from leftover cassava husks, was shown to be a viable alternative as an adsorbent for the treatment of effluents containing not only the herbicide Diuron but also a mixture of other herbicides. [ABSTRACT FROM AUTHOR]

[Display omitted] • Advances in glyphosate herbicide and its metabolite removal from water. • Presence of glyphosate herbicide and its metabolite in natural water. • Eco-toxicity of glyphosate herbicide and its metabolite. • Mechanism of adsorption removal. • Challenges and future perspectives. The glyphosate herbicide (GLY) is used globally to combat the weeds. This herbicide has been detected in different water resources and even in plant and food samples due to its hydrophilic properties. The GLY metabolite [aminomethylphosphonic acid (AMPA)] is highly deleterious to human health and aquatic biota. As a result, detection and remediation technologies have been the object of study in recent years. This review focuses on ecotoxicology, the presence of GLY in natural waters, detection methods in water, mitigation, and removal by adsorption. The adsorption method is discussed in detail with a main emphasis on optimization through pH, adsorbent dose, and contact time. The kinetics and thermodynamics of the removal were also described. The simulation studies are also included to understand the mechanism of removal at the supramolecular level. The regeneration of the adsorbent aspect has been discussed for making adsorption economic. Finally, Knowledge gaps and prospects are also highlighted to make this article the source for future advanced research in this area. [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]

• Powdered pecan pericarp (PPP) as biosorbent for MV2B dye from colored effluents. • The maximum biosorption capacity obtained from the Langmuir model was 642 mg g−1. • The column can operate until 52.5 h without regeneration. • PPP was able to achieve a color removal of 94.1% from a textile effluent. The application of dyes in industrial processes has become a growing preoccupation due to the high quantities of colored effluents generated, which need previous treatment before being discarded in water bodies. A powdered biosorbent was then prepared from pecan pericarp and HCl, in order to treat colored effluents containing the dye methyl violet 2B (MV2B) using batch and fixed-bed operation modes. The new biosorbent, so-called powdered pecan pericarp (PPP), was characterized by functional groups related to cellulose, lignin, and hemicellulose. In addition, the material was composed of particles with different sizes, amorphous structure, and rugous surface. The best pH for MV2B biosorption on the PPP was 8.5. The kinetic profile was better described by the general order model, being the equilibrium rapidly reached in the first 5 min for different initial concentrations MV2B. The equilibrium curves were better described by the Langmuir model, indicating homogenous biosorption. The maximum biosorption capacity of 642 mg g−1 was reached at 328 K. Biosorption was favorable and endothermic. PPP has removed 94.1% of color in the simulated effluent. The fixed-bed assays revealed that the column packed with PPP could operate during 52.5 h with a height of 25 cm. The Thomas, Bohart-Adams, and Yoon-Nelson models were suitable to describe the dynamic curves. Therefore, PPP can be used as an efficient and fast biosorbent to treat textile effluents containing MV2B dye. [ABSTRACT FROM AUTHOR]

A powdered biosorbent was developed by the processing of mandacaru (Cereus jamacaru) leaves, and tested as an alternative material to treat solutions containing Basic Fuchsin dye (BF) in discontinuous and continuous systems. A simple model (ILE model) based in the Langmuir isotherm was developed to predict the continuous biosorption. PML was a fast and efficient biosorbent, attaining biosorption capacity near to 400 mg g−1. PML was also efficient to treat a simulated effluent, providing color removal percentages around 90%. In relation to the continuous operation using PML, an excellent bed performance was found, with breakthrough time of 14 h, and length of mass transfer zone of 1.48 cm. The ILE model was able to predict the breakthrough curve. It can be concluded that PML is a low cost and efficient biosorbent to be used for decolorization of liquid streams in discontinuous and continuous systems. Unlabelled Image • A powdered biosorbent (PML) was prepared from mandacaru leaves. • PML was tested for batch and fixed bed biosorption of Basic Fuchsin (BF). • The maximum biosorption capacity was 398.90 mg g−1. • The breakthrough time was 14 h and the length of mass transfer zone was 1.48 cm. • PML is an efficient option to treat colored effluents in batch and fixed bed. [ABSTRACT FROM AUTHOR]

Emerging pollutants are a widespread environmental concern, andadsorption represents one of the choices available for the removal of suchcompounds from polluted waters. However, the set‐up of a new adsorption system requiresthe experimental determination of adsorption isotherms and their thoroughmodelling, for the sake of a convenient optimization. In this work, the Campomanesia guazumifolia biomass is adopted as precursor for the synthesis of anew adsorbent and then tested for the adsorption of KTP and 2,4‐D. Theadsorption performances of this biomass are significantly improved through atreatment with sulfuric acid, which allows obtaining higher removal efficiency ofthe target organic molecules. The experimental isotherms are measured at 298 – 328 K and pH 2. An ETAM model is employed for amodeling analysis of the experimental data, for the comprehension of theoccurring adsorption mechanism. Results demonstrated that adsorption of KTP isendothermic and occurs in multilayer with a multimolecular process, in whichthe molecular aggregation can be predicted. On the contrary, the adsorption of 2,4‐D on this functionalized biomass is exothermic. The adsorption energiesresulted to be < 40 kJ mol−1, indicating that physical adsorption forces are involved inthe removal of these organic molecules. [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]

Araucaria angustifolia bark (AA-bark), a waste generated in wood processing, was evaluated as a potential adsorbent to remove Gentian Violet (GV) dye from aqueous solutions. The AA-bark presented an amorphous structure with irregular surface and was composed mainly of lignin and holocellulose. These characteristics indicated that the adsorbent contains available sites to accommodate the dye molecules. The GV adsorption on AA-bark was favored at pH 8.0 with adsorbent dosage of 0.80 g L-1. Pseudo-nth order model was adequate to represent the adsorption kinetics of GV on AA-bark. A fast adsorption rate was verified, with the equilibrium being attained within 30 min. Equilibrium data were well represented by the Langmuir model. The maximum adsorption capacity was 305.3 mg g-1. Adsorption was spontaneous, favorable and endothermic. AA-bark was able to treat a simulated dye house effluent, reaching color removal values of 80%. An excellent performance was found in fixed bed experiments, where the length of the mass transfer zone was only 5.38 cm and the breakthrough time was 138.5 h. AA-bark can be regenerated two times using HNO3 0.5 mol L-1. AA-bark can be used as a low-cost material to treat colored effluents in batch and fixed bed adsorption systems. [ABSTRACT FROM AUTHOR]

Pará chestnut husk (Bertholletia excelsa) (PCH), an agro-industrial waste largely generated in Brazil, was employed as a low-cost and efficient biosorbent to remove the cationic dyes Crystal Violet (CV) and Methylene Blue (MB) from aqueous media. PCH presented an amorphous structure containing carboxylic acids, esters, ketones and aldehydes on the surface. Non-porous and irregular particles were also observed. For both dyes, the biosorption capacity was favored under acid conditions. Equilibrium was attained within 40 min at 25 °C with a PCH dosage of 0.5 g L-1 The biosorption kinetic curves were satisfactory explained by the pseudo-first-order model. The Freundlich model was best for representing the equilibrium curves. The maximum biosorption capacities were 83.6 and 83.8 mg g-1for CV and MB, respectively. PCH was efficient for treating a simulated textile effluent containing several dyes and chemicals, achieving a color removal of 90%. In this way, PCH can be considered as an option for treating colored effluents containing textile dyes. [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]

A porous activated carbon from Hovenia dulcis was prepared using zinc chloride (ZnCl 2) as an activating agent and applied to remove diuron in aqueous solutions. The carbon presented a smooth and regular surface, with an area of 898 m² g−1, narrow pores of average diameter equal to 1.242 nm, and volume of 0.296 cm3 g−1. Adsorption was favored by increasing the pH and temperature. Isothermal curves formed a characteristic plateau of the Langmuir monolayer isotherm. Thermodynamic results indicated that herbicide adsorption was spontaneous, favorable, and endothermic (ΔH0 = 35.9093 kJ mol−1). The decay of the diuron concentration displays that equilibrium is attained in 120 min. The best results were obtained at pH 6, temperature of 328 K and 200 rpm and C 0 of 200 mg·L−1. Langmuir model had the best adjustment, obtaining maximum adsorption capacity of 96.68 mg·g−1. Pore volume and surface diffusion model (PVSDM) was suitably represent the decline comportment of diuron. The adsorption mechanism was rate controlled by the external and internal mass transfer. In the treatment of a river water sample contaminated with diuron, activated carbon revealed high performance, reaching 95% removal of the emerging pollutant. [Display omitted] [ABSTRACT FROM AUTHOR]

In recent years the funeral industry has drawn attention from the scientific community concerning the potential pollution of the environment and the urban environment. In this review, the pollution caused by the cemeteries and crematoria around the world was addressed. The traditional burial leads to the production of ions, in the form of organic and heavy metals, bacteria, fungi, and viruses, that spread along with the soil and underwater. The crematoria produce small particles, trace gases (SO x , NO x , CO), and toxic organic volatiles. The effluent generated by both methods can lead to several environmental problems and further threaten human health. The current solution for the cemeteries in the development of a system in which effluent generated by the traditional burials are collected and treated before realizing in the environment. In addition to that, the green burial should be an alternative, since the corpse does not go through the embalming process, thus eliminating the presence of any undesired chemicals, that are further leached onto the environment. The crematoria should be employed as it is, however, the gas treatment station should be employed, to ensure the minimization of the impact on the environment. Last, future researches regarding the treatment of the cemeteries leached still need to be explored as well as the optimization and further development of the crematoria gas treatment process. [Display omitted] • The funerary industry is capable of concentrating and disperse hazardous elements, and pathogens. • The funerary industry is capable of causing environment and urban environment, causing risk to the population and the ecosystem. • Research demonstrating the treatment of necro slurry and crematory gases in large scale. • Law and regulation must bedeveloped and implement against the several pollution that the funerary industry causes. [ABSTRACT FROM AUTHOR]

The agroecology has proven to be a significant possibility of income for rural farmers and quality of consumption for urban populations wishing ecological food. Comparing the percentage of small farmers who remain in the field, it is the small portion that choo ses this type of production. Against this background the present work was to analyze the changes that agroecology generated in family farming scenario, giving greater emphasis will women's participation in this activity. With the help of EMATER, visits were made in properties located in the municipalities of Ronda Alta, Three Palms and Rondinha, getting reports on how agroecology is changing the lives of these women in the field. Initial results met the main goal of EMATER and other entities involved, which brought financial stability for the producer to keep up on the field. As a consequence of participation and autonomy that the process brought women, they were distinguished by their valuation, leaving aside the woman's view of home only. However the future prospects of this activity in the region is bleak, as the share of young people who want to continue the activities is small. [ABSTRACT FROM AUTHOR]

The work aims to analyze both rural festivities that take place in the cities of Sao Sepe and Rascal / RS, giving a focus on media means used and the extent that these parties bring to the regions. Community festivals that take place in these contexts reveal, for example, a form of collective effort that remains alive, showing the organization of the community. Regarding the festive meal is the quality of food served beautifully and sick way, that express the consideration for the guests. The food is a factor which brings together, in so far as the party gives rise to eating and drinking, presenting thus socializing character of the food. These community parties involve periods prior preparation, in which members of the community boards meet - are also part of this process spouses and often (the) daughters (the). Participation in party preparation does not constitute a remunerated activity, all farmers work for free, by the community. Aiming to achieve the party's goals, either as disclosure of paper as is the case of the two events analyzed, or local income only. [ABSTRACT FROM AUTHOR]

[Display omitted] • Preparation and characterization of three activated carbon different sources for the removal of naproxen. • Adsorption isotherms for the naproxen were carried out for all adsorbent at different temperatures. • All the adsorption systems were well described by the monolayer adsorption with two different energy sites. • Thermodynamic parameters shown that the adsorption of naproxen presents an endothermic nature despite of the system. In this work, physical statistical models were employed to provide reasonable information regarding the adsorption of naproxen onto different activated carbons. The activated carbons were prepared from different biomasses (pitaya peels, jabuticaba peels, or grape residues from the winery process) using ZnCl 2 as an activator. All the adsorbents were characterized regarding their functional groups and morphological surfaces. The maximum capacity obtained for the activated carbons (at 328 K) was found to be: 167.0 mg g−1 for jabuticaba peels at pH 4; 158.81 mg g−1 for pitaya peels at pH 6.7; and last., grape residues the capacity was 176.0 mg g−1 at pH 7. The equilibrium data of the three adsorbents were well fitted to the monolayer with two energy sites adsorption model, assuming that NPX adsorption on the carbon surfaces occurs via two different functional groups. This statistical physics model calculated the number of NPX molecules bound on the surface and the saturated adsorption capacity for both functional groups at different temperatures. The obtained results indicate that the naproxen molecules can be adsorbed in a parallel and horizontal manner according to the material employed. The receptor density tends to increase with the temperature evolution, indicating that thermal energy and solubility play an important role in adsorption. Configurational entropy indicates similar thermodynamic behavior for all materials where higher disorder is found at the early stages of the adsorption, followed by and decrease a possible organization of the molecules on the surface. The Gibbs free energy shows that adsorption of naproxen is spontaneous in all cases and internal energy is proportional to the adsorption capacity indicating that the system releases energy as the adsorption occurs. Therefore, this article reports new findings to understand the adsorption mechanism of naproxen molecules on activated carbons prepared from lignocellulosic biomass. [ABSTRACT FROM AUTHOR]

[Display omitted] • High surface area activated carbon derived from Diospyros kaki fruit waste; • Remarkable adsorption capacity for aqueous-phase atrazine; • Linear driving force (LDF) model provides good fit to kinetic data; • Activated carbon efficient to remove atrazine in real river samples. In this work, Diospyros kaki fruit waste was employed as a precursor material to develop a high surface area activated carbon, which efficiently removed the toxic herbicide atrazine (ATZ) from synthetic water solutions and river waters. The alternative activated carbon presented excellent characteristics and structure, including high values of specific surface area (1067 m2 g−1) and pore volume (0.530 cm3 g−1) and some important functional groups on the surface. The temperature positively influenced the adsorption capacity, from 194.20 to 211.51 mg g−1. The Freundlich model was the proper one to represent the equilibrium data. Thermodynamic parameters confirmed the endothermic nature of the adsorption process. Kinetic studies confirmed that equilibrium was reached until 240 min, regardless of ATZ initial concentration. The LDF model adjusted well to the kinetic data, resulting in a diffusion coefficient ranging from 0.89x10-9 to 1.63x10-9 cm2 s−1 as the ATZ concentration increased. The activated carbon also decreased 85% of the ATZ concentration in a river water sample. Overall, the activated carbon developed from Diospyros kaki fruit waste presented an efficient ATZ removal from aqueous matrices. [ABSTRACT FROM AUTHOR]

Brazil's production and consumption of açai pulp (Euterpe oleracea) occur on a large scale. Most of the fruit is formed by the pit, which generates countless tons of residual biomass. A new purpose for this biomass, making its consumption highly sustainable, was presented in this study, where activated carbon (AC) was produced with zinc chloride for later use as an adsorbent. AC carbon formed by carbon and with a yield of 28 % was satisfactorily used as an adsorbent in removing the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). Removal efficiency was due to the highly porous surface (Vp = 0.467 cm3 g−1; Dp = 1.126 nm) and good surface área (SBET = 920.56 m2 g−1). The equilibrium data fit the Sips heterogeneous and homogeneous surface model better. It was observed that the increase in temperature favored adsorption, reaching a maximum experimental capacity of 218 mg g−1 at 328 K. The thermodynamic behavior indicated a spontaneous, favorable, and endothermic behavior. The magnitude of the enthalpy of adsorption was in agreement with the physical adsorption. Regardless of the herbicide concentration, the adsorbent displayed fast kinetics, reaching equilibrium within 120 min. The linear driving force (LDF) model provided a strong statistical match to the kinetic curves. AC with zinc chloride (ZnCl2), created from leftover açai biomass, is a potential alternative as an adsorbent for treating effluents containing 2,4-D. [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]

Paracetamol, a common pain reliever, has seen a significant rise in use, particularly during the Coronavirus Disease 2019 (COVID-19) pandemic. This widespread consumption has led to increased levels of paracetamol in the environment through wastewater discharge. This raises concerns about its potential impact on aquatic ecosystems. Here, we review the state-of-the-art methods for removing paracetamol from wastewater, focusing on adsorption techniques. We explore how different materials and operational conditions influence the effectiveness of this approach. We also discuss the potential of combining adsorption with oxidative methods for enhanced removal. We further assess the environmental impact by critically examining the ecotoxicological effects of paracetamol on aquatic organisms. This analysis compares established toxicity values with those observed in studies using real wastewater samples. Finally, we highlight the specific needs for further research and development of efficient and sustainable strategies to mitigate paracetamol pollution, ensuring the safety of both human and aquatic life. [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]

[Display omitted] • Recovery of biomass waste and its functionalization with H 2 SO 4 and HNO 3 in order to use it as an adsorbent to remove the reactive red dye 141 from an aqueous solution. • A theoretical physicochemical investigation of the adsorption of red reactive dye 141 on biomass treated with sulfuric acid and nitric acid was performed with statistical physics fundaments. • Physicochemical parameters were utilized to explain the dye adsorption at the molecular scale. The preparation and adsorption properties of avocado peels treated with H 2 SO 4 and HNO 3 for the removal of reactive red 141 dye are reported in this manuscript. Equilibrium adsorption of this organic dye on the two adsorbents was experimentally quantified at pH 6.5 and 298.15–328.15 K. An advanced physical model that assumed the formation of a finite number of layers of the adsorbed pollutant molecules on the adsorption sites was used to estimate the steric and energetic parameters of the dye adsorption mechanism. The modeling results showed dye molecular aggregation, in which each adsorption site of avocado peels treated with H 2 SO 4 and HNO 3 adsorbed several dye molecules simultaneously at different temperatures. The results also demonstrated that dye adsorption on avocado peels treated with these acids was exothermic. The estimated adsorption energies for the dye-treated biomass and dye-dye interactions indicated a physisorption associated with van der Waals forces and hydrogen bonding. The outcomes of this study contribute with insights into the adsorption mechanisms of dye molecules using treated avocado peels with the aim of developing sustainable water treatment methods according with a circular economy approach. [ABSTRACT FROM AUTHOR]

The potentiality of Phoma sp. inactive fungal biomass, waste from the bioherbicide production, was evaluated for the treatment of colored effluents containing Acid Red 18 (AR 18) dye. The batch experiments were performed to evaluate the following parameters: pH of the solution (2–10), dye concentration (50–200 mg L−1), adsorbent dose (0.5–2.5 g L−1), contact time (0–180 min) and temperature (298–328 K). The batch experiments using a synthetic dye solution revealed that Phoma sp. was efficient at pH of 2.0, 298 K and using a dosage of 1.25 g L−1. The process was fast, being the equilibrium reached within 180 min. The maximum value of biosorption capacity was 63.58 mg g−1, being the process favorable and exothermic. From the fixed bed assays, breakthrough curves were obtained, presenting a mass transfer zone of 7.08 cm and breakthrough time of 443 min. Phoma sp. was efficient to decolorize a simulated effluent, removing more than 90% of the color. From the obtained results, it can be concluded that Phoma sp. inactive biomass is a low–cost option to treat colored effluents in continuous and discontinuous biosorption modes. These indicate that Phoma sp. of inactive biomass is an option for the treatment of colored effluents. Image 1 • Phoma sp., a waste from the bioherbicide production, was evaluated as a new biosorbent options. • Phoma sp. waste was able to treat colored effluents in batch and fixed bed systems. • Phoma sp. was efficient to treat a simulated effluent, reaching 90% of color removal. [ABSTRACT FROM AUTHOR]

The production of cobalt oxide nanoparticles and their use in the adsorption of methylene blue (MB) from solution is described in the paper. The X-ray diffraction patterns show that the synthesized cobalt oxide nanoparticles have a crystalline cubic structure. The study of the adsorption of methylene blue onto the cobalt oxide nanoparticles involved determining the contact time and initial concentration of the adsorption of MB on the adsorbent. The kinetics of adsorption were analyzed using two kinetic models (pseudo-first order and pseudo-second order), and the pseudo-second-order model was found to be the most appropriate for describing the behavior of the adsorption. This study indicates that the MLTS (monolayer with the same number of molecules per site) model is the most suitable model for describing methylene blue/cobalt oxide systems, and the parameter values help to further understand the adsorption process with the steric parameters. Indicating that methylene blue is horizontally adsorbed onto the surface of the cobalt oxide, which is bonded to two different receptor sites. Regarding the temperature effect, it was found that the adsorption capacity increased, with the experimental value ranging from 313.7 to 405.3 mg g−1, while the MLTS predicted 313.32 and 408.16 mg g−1. From the thermodynamic functions, high entropy was found around 280 mg L−1 concentration. For all concentrations and temperatures examined, the Gibbs free energy and enthalpy of adsorption were found to be negative and positive, respectively, suggesting that the system is spontaneous and endothermic. According to this study's findings, methylene blue adsorption onto cobalt oxide nanoparticles happens via the creation of a monolayer, in which the same amount of molecules are adsorbed at two distinct locations. The findings shed light on the methylene blue adsorption process onto cobalt oxide nanoparticles, which have a variety of uses, including the remediation of wastewater. [ABSTRACT FROM AUTHOR]

Silicomanganese fumes (SMF) are industrial waste and a potential low-cost adsorbent for the removal of contaminants from water. In this study, the adsorption performance of SMF and NaOH-modified SMF (SMF-Na) for the removal of tetracycline (TC) from an aqueous solution was investigated. The characterization results showed the presence of functional groups (SiO 2 , -OH and C-O-C), a considerably higher surface area of the SMF-Na (142.59 m2 g−1) compared to the SMF (7.73 m2 g−1). The TC adsorption was favored under acidic conditions (pH 2–3) and increased with an increasing amount of adsorbent. The adsorption equilibrium was achieved in 360 min, and the presence of Na+ ions insignificantly influenced the TC adsorption. The Avrami model fitted better to the kinetic data with R2 = 0.995. The isothermal data was well represented by the Redlich-Peterson and Langmuir model. The maximum monolayer adsorption capacity of SMF and SMF-Na was 117 and 129 mg g−1, respectively. The thermodynamic results confirmed that the TC adsorption was endothermic and predominantly governed by physical forces. The removal of TC onto SMF and SMF-Na was maintained above 90 % even after five regeneration cycles The results suggested that SMF-Na is a promising alternative adsorbent for the removal of tetracycline antibiotics from wastewater streams. [Display omitted] • SMF is an industrial waste that treated with NaOH showed good removal of the antibiotic tetracycline. • Adsorption equilibrium is reached in 240 min, regardless of concentration. • The Avrami model showed a good fit to the kinetic data. • The isothermal data were well represented by the Langmuir monolayer model. • Adsorption is governed by physical interactions of an endothermic nature. [ABSTRACT FROM AUTHOR]

[Display omitted] • Microporous activated carbon (Hd-AC) from Hovenia dulcis for atrazine adsorption. • The maximum adsorption capacity was 58 mg g−1 at 328 K. • Satisfactory isothermal fit to the Freundlich model. • The LDF model represented the adsorption kinetics. • Hd-AC showed 70% removal efficiency from river water contaminated with atrazine. The species Hovenia dulcis has become a major issue for the Brazilian biome due to its high adaptation and accelerated propagation, putting the local biodiversity at risk. In this sense, this study sought to generate a new purpose for the fruits of this peculiar species. They were carbonized with ZnCl 2 to produce porous activated carbon, which was used to remove the herbicide atrazine from aqueous solutions. The Hovenia dulcis activated carbon (Hd -AC) presented a surface area of 898.4 m2/g, with narrow pores with an average diameter of 1.24 nm and a pore volume of 0.296 cm3 g−1. Hd -AC for atrazine adsorption was efficient at a pH of 6.0 for an adsorbent dosage of 0.5 g/L, where the adsorption capacity was 58 mg g−1 at 328 K. The isothermal curves showed a good adjustment to the Freundlich isotherm. The thermodynamic results indicated that herbicide adsorption was spontaneous, favorable, and endothermic (ΔH° = 8.21 kJ mol−1). Besides, the linear driving force model (LDF) was used satisfactorily to describe the kinetic behavior of atrazine. Also, in treating a sample of river water contaminated with atrazine, Hd -AC showed high performance, reaching the removal of 70 % of the emerging pollutant. Therefore, using the residual fruits of the Hovenia dulcis as biomass to prepare a highly porous adsorbent reveals a promising alternative. [ABSTRACT FROM AUTHOR]

This review focuses on the application of β-cyclodextrin (β-CD) polymer nanocomposites (NCs) in the heavy metals (HMs) removal from contaminated water sources. This manuscript's originality consists of an in-depth analysis of recent advances in using β-cyclodextrin nanocomposites (β-CD-NCs) to remove HMs from wastewater, highlighting literature gaps, innovations, and challenges in this field, suggesting perspectives on existing theories, and outlining implications for future research directions. Combining nanoparticles with the β-CD polymer yields stable, reusable β-CD-NCs that are effective and efficient in HM adsorption. The article reviews the various techniques for synthesizing β-CD-NCs and their structural characterization. It also includes processing and functionalization strategies to optimize binding capacity and selectivity for specific HMs. The paper reviews mechanisms underpinning HM adsorption through complexation, ion exchange, and electrostatic interactions. It also reviews how adsorption efficiency is affected by different environmental conditions, such as variations in pH, temperature, and competing ions. This will enable case studies on the applications of β-CD-NCs, particularly for addressing global water pollution. Finally, the current limitations and future perspectives are considered, focusing on the further research needed to optimize these materials for sustainable and cost-effective HM removal on a large scale. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Walnut shells were used as a novel adsorbent. • Isotherm, kinetic, thermodynamic, and mechanistic studies were performed. • The adsorption was spontaneous and endothermic, as shown by the G, H, E, and S values. • A mechanism of monolayer adsorption was concluded by statistical physics modeling. The present study investigates the adsorption of the anionic dye methyl orange (MO) using raw walnut shells (RWS). Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy techniques were used to evaluate RWS collected in the Moroccan High Atlas (Tounfite) highlands. The batch mode adsorption experiments showed a remarkable removal during the first ten minutes, suggesting that the adsorption capacity is controlled by several parameters related to both the medium and the adsorbent. Based on the experimental results, 98 % of the MO dye was adsorbed on the walnut shell at pH >5 and room temperature (25±2 °C). The general order best explained the adsorption of MO on the walnut shells, suggesting that the number of active sites required changes with temperature. The two-layer model was the most appropriate physical-statistical model to explain the L-2 isotherms regarding the adsorption equilibrium. According to the models, methyl orange tends to be adsorbed on the surface of the monolayer, with individual molecules then adsorbing on top of each other. At all temperatures studied, the adsorption is endothermic and tends to be spontaneous, according to simulations of thermodynamic functions of RWS. [ABSTRACT FROM AUTHOR]

[Display omitted] • Activated and supported olive hull charcoal has been valued as an adsorbent of phenol and p-nitrophenol. • Structural and textural properties have been assessed using several techniques. • Ni-AC shows a higher adsorbed quantity than other activated carbons. • The phenol and p-nitrophenol adsorption phenomena have been described by statistical physical modeling. The adsorption of phenols and p-nitrophenols on prepared activated carbons is one of the most important wastewater treatment processes. The four catalysts (RC, AC, Ni-AC) were prepared from the olive shell and characterized by Fourier transfer infrared spectroscopy, scanning electron microscopy, N 2 adsorption/desorption, zero charge point, and X-ray diffraction, which confirmed the success of the process. The results showed that the impregnation improved the adsorption capacity of the carbon material. For p-nitrophenol, an increase from 90 mg/g to 156 mg/g was observed for Ni-AC and 143 mg/g for Cu-AC. Analysis of the model parameters showed that the adsorbate particles have a non-parallel exposure with respect to the surface of the nickel-bridged activated biochar and that each functional group of the adsorbent binds to several particles simultaneously. Finally, the adsorption forces suggest that physical forces, including hydrogen bonding and van der Waals forces, are likely to be involved in the adsorption, as indicated by values below 22 kJ/mole. The results of adsorption tests of phenol and p-nitrophenol by the prepared materials showed that these materials could replace other more expensive adsorbents. [ABSTRACT FROM AUTHOR]

It is alarming that synthetic food dyes (FD) are widely used in various industries and that these facilities discharge their wastewater into the environment without treating it. FDs mixed into industrial wastewater pose a threat to the environment and human health. Therefore, removing FDs from wastewater is very important. This review explores the burgeoning field of FD removal from wastewater through adsorption using biological materials (BMs). By synthesizing a wealth of research findings, this comprehensive review elucidates the diverse array of BMs employed, ranging from algae and fungi to agricultural residues and microbial biomass. Furthermore, this review investigates challenges in practical applications, such as process optimization and scalability, offering insights into bridging the gap between laboratory successes and real-world implementations. Harnessing the remarkable adsorptive potential of BMs, this review presents a roadmap toward transformative solutions for FD removal, promising cleaner and safer production practices in the food and beverage industry. • Emphasize the various biological materials and food dyes. • Highlighted factors that influence the adsorption efficiency of food dyes. • Discuss the adsorption mechanism of food dyes onto biological materials. • Comparative analysis of the various biological materials used for food dye removal. [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]

For the first time, the applicability of amethyst mining rejects as a novel photo-Fenton catalyst was evaluated. Catalyst characterization was analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), specific surface area (BET), and X-ray fluorescence (FRX). The effects of operating parameters, such as pH (2.0–4.0), catalyst dosage (0.25–1.0 g L−1), and H 2 O 2 concentration (2.5–8.5 mmol L−1) on the degradation efficiency of Ponceau 4R dye were evaluated. The amethyst mining rejects presented a mesoporous structure, an average pore size of 9.73 nm, a specific surface area of 13.43 m2 g−1, and 23%wt of Fe 2 O 3 on its chemical composition. The material showed an excellent catalytic efficiency, reaching 97.02% decolorization at 60 min and 75.40% TOC removal at 300 min, in the following reaction conditions: catalyst dosage: 0.75 g L−1, H 2 O 2 concentration: 4.5 mmol L−1, and pH: 3. The waste also showed high stability and effectiveness after three successive reuse cycles. In addition, the catalyst was highly effective for treating synthetic wastewater composed of various hazardous dyes and salts. [Display omitted] • For the first time, amethyst mining rejects were employed as a novel photo-Fenton catalyst. • Amethyst mining rejects exhibited remarkable degradation efficiency of Ponceau 4R dye. • The material was able to treat a synthetic mixture of hazardous dyes and salts. [ABSTRACT FROM AUTHOR]

The residual bark of the tree species Campomanesia guazumifolia was successfully modified with H2SO4 and applied to remove the toxic herbicide 2.4-dichlorophenoxyacetic (2.4-D) from aqueous solutions. The characterization techniques made it possible to observe that the material maintained its amorphous structure; however, a new FTIR band emerged, indicating the interaction of the lignocellulosic matrix with sulfuric acid. Micrographs showed that the material maintained its irregular shape; however, new spaces and cavities appeared after the acidic modification. Regardless of the herbicide concentration, the system tended to equilibrium after 120 min. Using the best statistical coefficients, the Elovich model was the one that best fitted the kinetic data. The temperature increase in the system negatively influenced the adsorption of 2.4-D, reaching a maximum capacity of 312.81 mg g−1 at 298 K. The equilibrium curves showed a better fit to the Tóth model. Thermodynamic parameters confirmed the exothermic nature of the system (ΔH0 = −59.86 kJ mol−1). As a residue obtained from urban pruning, the bark of Campomanesia guazumifolia treated with sulfuric acid is a promising and highly efficient alternative for removing the widely used and toxic 2.4-D herbicide from aqueous solutions. [ABSTRACT FROM AUTHOR]

Fluoride contamination in water sources poses a significant challenge to human health and the environment. In recent years, adsorption technology has emerged as a promising approach for water defluoridation due to its efficiency and cost-effectiveness. This review article comprehensively explores the advances in water defluoridation through adsorption processes. Various adsorbents, including natural and synthetic materials, have been investigated for their efficacy in removing fluoride ions from water. The mechanisms underlying adsorption interactions are elucidated, shedding light on the factors influencing defluoridation efficiency. Moreover, the review outlines the current state of technology, highlighting successful case studies and field applications. Future perspectives in the field of water defluoridation by adsorption are discussed, emphasizing the need for sustainable and scalable solutions. The integration of novel materials, process optimization, and the development of hybrid technologies are proposed as pathways to address existing challenges and enhance the overall efficacy of water defluoridation. This comprehensive assessment of the advances and future directions in adsorption-based water defluoridation provides valuable insights for researchers, policymakers, and practitioners working towards ensuring safe and accessible drinking water for all. [ABSTRACT FROM AUTHOR]

• Fixed bed adsorption of crystal violet dye (CV) on treated pecan pericarp. • Mass transfer approach based on the intraparticle diffusion and axial dispersion. • The external mass transfer coefficient (k f) was 4.39 × 10–3 cm s−1. • The fixed bed adsorption was technically viable. • The axial dispersion coefficient (D L) ranged from 0.79 × 10–6 to 7.81 × 10–6 cm2 s−1. This research was focused on the representation of the fixed bed adsorption of crystal violet dye (CV) on treated pecan pericarp (Carya illinoensis) using a mass transfer approach based on the intraparticle diffusion and axial dispersion. The operation was firstly evaluated in batch mode to determine the external mass transfer coefficients, the equilibrium relation, and the thermodynamic aspects. It was then studied the continuous operation. In this case, the breakthrough curves were modeled by a phenomenological approach, based on the combination of the fluid phase mass balance with intraparticle diffusion (FBID). The results were compared with the Thomas model, which not considers the axial dispersion. The external mass transfer was 4.39 × 10-3 cm s−1. The equilibrium relation was better represented by the Langmuir model. The adsorption process was endothermic, with a maximum adsorption capacity of 639.7 mg g−1. Concerning fixed-bed adsorption evaluation, Thomas and FBID models were able to describe the breakthrough tendencies. Nevertheless, the FBID was used to estimate the axial dispersion coefficient, which ranged from 0.79 × 10-6 to 7.81 × 10-6 cm2 s−1. [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]

An inactive biomass of a new fungus recently discovered, Diaporthe schini, was evaluated for the biosorption of crystal violet (CV) in simulated textile effluents. The characterization assays were performed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and N2 adsorption/desorption isotherms. The influences of pH and biosorbent dosage on the biosorption capacity were evaluated. Kinetics, equilibrium and thermodynamic studies were also carried out. Characterization techniques showed an amorphous biosorbent, with a rough surface containing irregular particles and surface area of 6.5 m² g-1. The most adequate values of pH and biosorbent dosage were 7.5 and 0.4 g L-1, respectively. The Elovich kinetic model and the Sips equilibrium model were suitable to fit the experimental data. The biosorption capacity increased with temperature, reaching a maximum biosorption capacity of 642.3 mg g-1 at 328 K. The biosorption was a spontaneous and endothermic process. Diaporthe schini inactive biomass was an interesting biosorbent to treat colored effluents, presenting efficiency of 87% in the decolorization of a simulated dye house effluent. [ABSTRACT FROM AUTHOR]

• Facile modification of montmorillonite with sodium metasilicate. • Interface adsorption of Cr 2 O 7 2-, MoO 4 2- and NO 3 – for economic water treatment. • Kinetics and thermodynamics of adsorption. • Developed method may be used at natural water pHs of 6.5. • Developed method may be used to remove Cr 2 O 7 2-, MoO 4 2- and NO 3 in any water body. Natural montmorillonite (cationic adsorbent) was modified with sodium metasilicate to invert its adsorption capacity for the ability to adsorb anions from wastewater. The textural characteristics decreased several times due to interlayer space blocking with a surface area of 2.7 m2/g. The ζ-potential changed from negative to positive (10.4 mV). The adsorption of inorganic anions Cr 2 O 7 2-, MoO 4 2- and NO 3 – was 0.11; 0.049; 0.052 mmol/g. Equilibrium was achieved within 25–30 min with 80–85 % adsorption in the first 10–15 min. The adsorption kinetics of all anions correlated well with the pseudo-second-order model with R2 0.993–0.999 and was largely determined by the external diffusion of the adsorbent to the surface. Adsorption increased with an increase in mass and charge of the adsorbent anions. The adsorption isotherms were best approximated by the Redlich-Peterson model, with a value of i = 0.6–0.65 at 293 K and i = 0.8–0.95 at 313 K. The activation energy of the process was: E a (Cr 2 O 7 2-) = 0.63 kJ/mol; E a (MoO 4 2-) = 11.59 kJ/mol; Ea(NO 3 –) = 22.49 kJ/mol). The values of the energy and enthalpy of adsorption indicated that nitrate anions were adsorbed on the surface due to the physical adsorption (orientation component). Besides, the chromate and molybdenum anions were adsorbed due to the formation of weak hydrogen bonds with protonated aluminol and silanol groups of montmorillonite. Finally, the removal of these anions was up to 90 % at a natural water pH of 6.5. It means that the reported method may be prospective to remove Cr 2 O 7 2-, MoO 4 2-, and NO 3 – from water. [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]

• Application of sta-phy modelling coupled to DFT calculations is essential for understanding the adsorption mechanisms. • The mono-layer model with one energy site (M 1:1) successfully represented the phenomena occurring on a microscopic level. • Changes in orientation with increased temperature decrease atrazine interaction with the AC by increasing self-repulsion. • The neutrality of the diuron can evenly balance the charges on the surface, increasing the adsorption efficiency. • Electrostatic mapping supplies a perspective to the interpretation and evolution of the modelled steric parameters. Atrazine and diuron are two pesticide compounds with very low surface interaction capacity, whose adsorption efficiency remains a challenge in environmental remediation applications. In this work, statistical physics (sta-phy) modelling and density functional theory (DFT) calculations have explored several still unveiled mechanisms involved. A model activated carbon (AC) sample was produced with Hovenia dulcis fruit residues, a local invasive tree species. The adsorption process was spontaneous and endothermic, and the adsorption capacities (Q m) increased as the temperature increased. The number of adsorbate molecules per site (n) decreased as the density of the receptor site (N m) increased, revealing that the temperature influences the geometry of the molecules during the surface interaction. According to the electrostatic mapping provided by the DFT calculations, it was possible to infer that the obtained Q m values for atrazine, between 42.54 and 73.20 mg g−1, can be a response caused by its own self-repulsion. For diuron, due to its increased neutrality, the potential balance of the electrostatic charges between adsorbate-adsorbent tends to be more effective, resulting in higher Q m values, ranging from 97.91 to 119.7 mg g−1. Therefore, the combination of sta-phy modelling with quantum mechanics calculations is a powerful tool for mechanism interpretation, capable of providing complementary insights into the adsorption process from both adsorbent and adsorbate perspectives. [ABSTRACT FROM AUTHOR]

• The functionalization of Physalis peruviana biomass with H 2 SO 4 is reported. • The surface chemistry of this modified biomass was characterized. • Adsorption of ketoprofen and 2,2-dichlorophenoxyactic acid is studied. • Application of physical model on adsorption isotherms. In this research, a functionalization of Physalis peruviana biomass with H 2 SO 4 and its application in the adsorption of ketoprofen and 2,2-dichlorophenoxyactic acid is reported. In particular, the adsorption properties of this biomass were improved through a sulfuric acid treatment to enhance its removal performance of organic molecules. Surface chemistry of this modified biomass was also characterized. Experimental adsorption isotherms of these organic pollutants were determined at 298 – 328 K and pH 2. A multilayer statistical physics model was used in the data modeling to analyze the corresponding adsorption mechanism. Results showed that the endothermic multilayer adsorption of ketoprofen was a multi-molecular process where molecular aggregation could be expected. On the other hand, the adsorption of 2,2-dichlorophenoxyactic acid on this functionalized biomass was multi-anchoring. Adsorption energies (ΔE 1) varied from 4.13 to 5.53 kJ/mol for KTP and from 7.54 to 7.96 kJ/mol for 2,4-D herbicide. These results showed that physical adsorption forces were involved in the removal of these organic molecules with this functionalized biomass because the adsorption energies < 40 kJ/mol. [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]