Search

Sugarcane bagasse, a largely available waste worldwide, was submitted to solid-state fermentation (SSF) using the fungus Metarhizium anisopliae, aiming to produce enzymes. The solid waste generated from SSF was tested as an alternative biosorbent to treat colored effluents containing crystal violet (CV) dye. The biosorbent, here named BW (bagasse waste), was characterized, and experimental tests were performed to verify the influence of pH and dosage on the CV biosorption. Isotherms and biosorption kinetics were performed, and the biosorption thermodynamic parameters were determined. The potential of BW was also evaluated for the treatment of a simulated textile effluent. The maximum biosorption capacity was 131.2 mg g -1 at 328 K, and the Liu was the most appropriate model to represent equilibrium data. The biosorption was spontaneous and endothermic. The use of BW in the simulated effluent showed that it is an efficient material, reaching color removal values of 85%. Therefore, the sugarcane bagasse generated from SSF can be considered a potential biosorbent to remove CV from textile effluents. This finding is relevant from the total environment viewpoint, since, at the same time, SSF generates enzymes and a solid waste, which in turn can be used as biosorbent to treat colored effluents.

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 N 2 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 m 2 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.

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 HNO 3 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.

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]

In this work, coal bottom ash was modified by alkaline fusion route in order to improve its pore properties and make it a potential adsorbent to remove crystal violet dye from aqueous medium. The solids were characterized and posteriorly subjected to kinetic, isotherm, and thermodynamic studies, as well as regenerated and reused for five adsorption tests. The alkaline fusion step resulted in the amorphization of material and generation of high surface area (102 m 2 g −1) and pore volume (0.180 cm 3 g−1), resulting in superior performance compared to the raw material. Kinetic and equilibrium studies showed that the adsorption process was better adjusted by the pseudo-second order and Langmuir models, respectively. The maximum adsorption capacity at equilibrium was 177. 37 mg g−1, with the adsorptive step occurring spontaneously and endothermically. The adsorbent maintained notable levels of dye removal after five consecutive cycles of thermal regeneration and reuse. Besides, the adsorbent was able to remove 64% of the colour of simulated industrial wastewater. Therefore, the alkaline fusion step proved to be a route capable of transforming the coal bottom ash into an adsorbent with improved textural and adsorptive properties. [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]

In this work, for the first time, Cordia trichotoma sawdust, a residue derived from noble wood processing, was applied as an alternative biosorbent for the removal of crystal violet by discontinuous and continuous biosorption processes. The optimum conditions for biosorption of crystal violet were 7.5 pH and a biosorbent dosage of 0.8 g L−1. The biosorption kinetics showed that the equilibrium was reached at 120 min, achieving a maximum biosorption capacity of 107 mg g−1 for initial dye concentration of 200 mg L−1. The Elovich model was the proper model for representing the biosorption kinetics. The isotherm assays showed that the rise of temperature causes an increase in the biosorption capacity of the crystal violet, with a maximum biosorption capacity of 129.77 mg g−1 at 328 K. The Langmuir model was the most proper model for describing the behavior. The sign of ΔG0 indicates that the process was spontaneous and favorable, whereas the ΔH0 indicates an endothermic process. The treatment of the colored simulated effluent composed by dyes and salts resulted in 80% of color removal. The application of biosorbent in the fixed-bed system achieved a breakthrough time of 505 min, resulting in 83.35% of color removal. The Thomas and Yoon-Nelson models were able to describe the fixed-bed biosorption behavior. This collection of experimental evidence shows that the Cordia trichotoma sawdust can be applied for the removal of crystal violet and a mixture of other dyes that contain them. [ABSTRACT FROM AUTHOR]

The wastes from the macro-fungus Agaricus bisporus were used as an eco-friendly and low-cost adsorbent for the treatment of colored effluents containing the recalcitrant dyes, acid red 97 (AR97) and crystal violet (CV). The macro-fungal waste presented an amorphous structure, composed of particles with different sizes and shapes. Also, it presents typical functional chemical groups of proteins and carbohydrates with a point of zero charge of 4.6. The optimum conditions for the dosage were found to be as follows: 0.5 g L−1 with an initial pH at 2.0 for the AR97 and 8.0 for the CV. From the kinetic test, it was found that it took 210 min and an adsorption capacity of 165 mg g−1 for the AR97. Concerning the CV kinetics, it took 120 min to reach the equilibrium and it achieved an adsorption capacity of 165.9 mg g−1. The Elovich model was the most proper model for describing the experimental data, achieving an R2 ≥ 0.997 and MSE ≤ 36.98 (mg g−1)2. The isotherm curves were best represented by the Langmuir model, predicting maximum adsorption capacity of 372.69 and 228.74 mg g−1 for the AR97 and CV, respectively. The process was spontaneous and favorable for both dyes. The ∆H0 values were 9.53 and 10.69 kJ mol−1 for AR97 and CV, respectively, indicating physical and endothermic adsorption. Overall, the wastes from Agaricus bisporus have the potential to adsorb cationic and anionic dyes, thus solving environmental problems related to water quality and residue disposal. [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]

The Ocotea puberula bark powder (OPBP) was evaluated as an effective adsorbent for the removal of crystal violet (CV) from colored effluents. OPBP was characterized and presented a surface with large cavities, organized as a honeycomb. The main functional groups of OPBP were O-H, N-H, C=O, and C-O-C. The adsorption of CV on OPBP was favorable at pH 9 with a dosage of 0.75 g L−1. The Avrami model was the most suitable to represent the adsorption kinetic profile, being the estimated equilibrium concentration value of 3.37 mg L−1 for an initial concentration of 50 mg L−1 (CV removal of 93.3%). The equilibrium was reached within 90 min. The data were better described by the Langmuir isotherm, reaching a maximum adsorption capacity of 444.34 mg g−1 at 328 K. The Gibbs free energy ranged from − 26.3554 to − 27.8055 kJ mol−1, and the enthalpy variation was − 11.1519 kJ mol−1. The external mass transfer was the rate-limiting step, with Biot numbers ranging from 0.0011 to 0.25. Lastly, OPBP application for the treatment of two different simulated effluents was effective, achieving a removal percentage of 90%. [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]

Dyes are widely used in many industrial sectors, many contain harmful substances to human health, and their release into the environment entails several environmental problems, generating a major worldwide concern as water resources are increasingly limited. The development of cheap and efficient biosorbents that remove these pollutants is of utmost importance. In this study, powdered seeds of the araticum fruit (Annona crassiflora) were used in the biosorption of crystal violet (CV) dye from aqueous solutions and simulated textile effluents. Through the characterization techniques, it can be observed that the material presented an amorphous structure, containing an irregular surface composed mainly by groups containing carbon, hydrogen, and oxygen. CV biosorption was favored at the natural pH of the solution (7.5) for a dosage of 0.7 g L−1 of araticum seed powder. The pseudo-second-order model was the most suitable to represent the biosorption kinetics in the removal of the CV. Biosorption capacity reached equilibrium in the first minutes at the lowest concentrations, and, at the highest, after 120 min. The equilibrium data were well represented by the Langmuir model, with a maximum biosorption capacity of 300.96 mg g−1 at 328 K. Biosorption had a spontaneous and endothermic nature. In the treatment of a simulated effluent, the biosorbent removed 87.8% of the color, proving to be efficient. Therefore, the araticum seeds powder (ASP) can be used as a low-cost material for the treatment of colored effluents containing the crystal violet (CV) dye. [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]

• 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]

• 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]

[Display omitted] • Adsorption of ketoprofen and paracetamol from water; • Novel activated carbon from endocarp of the species Butia capitata ; • High surface area and pore volume coupled to excellent adsorption capacity; • Elucidation of molecular interactions in a mixture of compounds. • Competitive activated carbon with estimated cost of 2.54 USD kg-1. In this work, endocarp of the species Butia capitata was employed as precursor material to prepare a novel activated carbon with intrinsic properties to remove ketoprofen and paracetamol from water efficiently. The activated carbon presented a predominantly microporous structure, with an average pore diameter of 1.23 nm, a total pore volume of 0.449 cm3 g−1, and a high specific surface area, 820 m2 g−1. The adsorption kinetics showed a rapid initial decay for both pharmaceuticals, with the system entering equilibrium after 120 min for ketoprofen and 180 min for paracetamol. The pseudo-second-order model presented the best fit for ketoprofen and the Elovich model for paracetamol. The adsorption equilibrium data show that temperature can increase or decrease the adsorption capacity, being found a maximum adsorption capacity of 108.79 and 100.60 mg g−1 for the ketoprofen and paracetamol, respectively. The Freundlich and Langmuir models presented the best statistical adjustments for the adsorption of ketoprofen and paracetamol, respectively. The thermodynamic analysis confirmed an endothermic process for ketoprofen (ΔH0 = 11.98 kJ mol−1) and exothermic for paracetamol (ΔH0 = -13.37 kJ mol−1). The recycle tests revealed that the adsorbent has an average decrease for removal percentage of only 1.88 % for ketoprofen and 1.57 % for paracetamol. Estimations costs indicate that the price of 1 kg of activated carbon costs is 2.39 USD at minimum. Last, the material presented a highly efficient adsorptive activity to treat a synthetic mixture containing several pharmaceutical compounds and salts, reaching 84.82% removal. [ABSTRACT FROM AUTHOR]

• Adsorption of crystal violet and rhodamine B on nanotubes was theoretically and experimentally analyzed. • Surface chemistry of the functionalized multiwalled carbon nanotubes was performed. • Physicochemical interpretation of the single and binary dye adsorption mechanisms. • Dye adsorption mechanisms was characterized via statistical physics parameters. The crystal violet (CV) and rhodamine B (RhB) dyes were selected in this paper to study their adsorption on functionalized multiwalled carbon nanotubes (MCN). Adsorbent morphology and its corresponding physicochemical properties were characterized by applying various experimental techniques namely SEM, XRD and FTIR. Results of phenomenological modeling and the experimental adsorption data showed that the adsorption capacities of both dyes in single solutions were similar. However, synergistic and antagonistic adsorption effects were observed in binary solutions. Results indicated that the CV dye molecule was practically adsorbed in a double amount in comparison to the RhB dye molecule at most of the adsorption temperatures. Saturation adsorption capacities ranged from 0.57 to 0.86 mmol/g and from 0.75 to 0.88 mmol/g for CV and RB dyes at 298–328 K, respectively. It has been concluded that the size of dye molecule played a negligible role during the adsorption. CV and RhB dye molecules can interact with the same functional groups of the adsorbent. A competitive statistical physics model was reliable to predict the multicomponent adsorption behavior of these dyes. The adsorption orientation of both dyes was discussed using the results of the physical modeling and a possible theoretical mechanism was proposed based on the estimated adsorption energies. Finally, the effect of temperature on the adsorbent performance for both single and binary dye solutions was analyzed providing a clear understanding of the observed trends in the experimental dye adsorption capacities. [ABSTRACT FROM AUTHOR]

• Lignocellulosic biomasses were used to study the adsorption of a textile dye. • Pecan nutshell, para chestnut husk, araucaria bark and palm cactus were used as adsorbents. • Monolayer and double layer models allowed the interpretation of dye adsorption mechanism. Biomasses from pecan nutshell (PN), para chestnut husk (PCH), araucaria bark (AB) and palm cactus (PC) were employed to study the adsorption mechanism of a relevant textile pollutant namely crystal violet (CV). Experimental isotherm data performed at the best condition of pH showed that the temperature had no effect on the adsorption of CV on PN and PCH, while the CV dye removal with AB and PC was significant affected by this operating parameter. Monolayer and double layer adsorption models were applied to analyze and explain, based on statistical physics, the removal mechanism of CV using these adsorbents. The application of these statistical physics models allowed to deduce theoretically that the active sites of PN and PCH practically attracted the same number (i.e., 1.12 < n ms < 1.20) of CV dye molecules at all adsorption temperatures; while a variable number of CV dye molecules (0. 81 < n ms < 2.10) could be bonded by the adsorption sites of adsorbents AB and PC. It was also confirmed that the temperature has a negligible effect on the adsorbed quantity of the systems CV-PN and CV-PCH, but it significantly impacted the systems CV-AB and CV-PC generating different magnitudes of the adsorption energies. The adsorption energy was calculated and the adsorption mechanism was analyzed thus suggesting that hydrogen bindings and van der Waals interactions could be possible for the adsorption of this dye on tested biomasses at optimum pH. [ABSTRACT FROM AUTHOR]