Adsorption of BTX (benzene, toluene, o-xylene, and p-xylene) from aqueous solutions by modified periodic mesoporous organosilica

Evaluating low-cost permeable adsorptive barriers for the removal of benzene from groundwater: Laboratory experiments and numerical modelling

Permeable adsorptive barriers (PABs) consisting of individual (compost, zeolite, and brown coal) and composite (brown coal-compost and zeolite-compost) adsorbents were evaluated for their hydraulic performance and effectiveness in removing aqueous benzene using batch and column experiments. Different adsorption isotherms and kinetic models and different formulations of the equilibrium advection-dispersion equation (ADE) were evaluated for their capabilities to describe the benzene sorption in the media. The batch experiments showed that the adsorption of benzene by the adsorbents was favourable and could be adequately described by the Freundlich and Langmuir isotherms and the pseudo-second-order kinetic model. Particle attrition and structural reorganization occurred in the columns, possibly introducing preferential flow paths and resulting in slight changes in the final hydraulic conductivity values (4.3 × 10^-5 cm s^-1-1.7 × 10^-3 cm s^-1) relative to the initial values (4.2 × 10^-5 cm s^-1-2.14 × 10^-3 cm s^-1). Despite the fact that preferential flow appeared to have an impact on the performance of the investigated adsorbents, the brown coal-compost mixture proved to be the most effective adsorbent. It significantly delayed benzene breakthrough (R = 29), indicating that it can be applied as a low-cost effective adsorbent in PABs for sustainable remediation of benzene-contaminated groundwater. The formulated transport models could fairly describe the behaviour of benzene in the investigated media under dynamic flow conditions; however, model refinement and additional experimental studies are needed before pilot/full-scale applications to improve the fits and verify the benzene removal processes. Our results generally demonstrate how such studies can be useful in evaluating potential reactive barrier materials.

Removal of Benzene and Toluene from Synthetic Wastewater by Adsorption onto Magnetic Zeolitic Imidazole Framework Nanocomposites

Considering the risk associated with exposure to benzene and toluene in water resources, researchers have been motivated to conduct studies to remove them from aqueous solutions. Thus, by performing the present study, the potential of Fe3O4/zeolite imidazolate framework nanoparticles (Fe3O4@ZIF-8) was evaluated for the adsorption of benzene and toluene. Accordingly, the solution pH, Fe3O4@ZIF-8 dosage, mixing time, concentration of benzene and toluene, and temperature, were the parameters considered for conducting the batch experiments, for which their effect on adsorption efficiency was evaluated. Our conducted experiments introduced the neutral pH as the best pH range to obtain the maximum removal. Fitting the adsorption data into the various models revealed the aptness of the Langmuir isotherm equation in describing experimental information and highest adsorption capacity; for benzene it was 129.4, 134.2, 137.3, and 148.2 mg g-1, but for toluene it was 118.4, 125.2, 129.6, and 133.1 mg g-1, for temperature 20, 30, 40, and 50 °C, respectively. Using obtained optimal conditions, the adsorption efficiencies of benzene and toluene were obtained to be 98.4% and 93.1%, respectively. Kinetic studies showed acceptable coefficients for PSO kinetics and confirmed its suitability. Also, the recyclability results showed that for six consecutive periods of the adsorption-desorption process, the percentage of removal decreased by only 6% for benzene and toluene. Moreover, calculating thermodynamic parameter changes for benzene and toluene removal confirmed the favorability and spontaneity of the studied process and its endothermic nature. Considering the above findings, Fe3O4@ZIF-8 was found to be an operative adsorbent for removing pollutants.

Adsorption as a Process for Produced Water Treatment: A Review

Produced water (PW) is a by-product of oil and gas operations, and its production is foreseen to increase in the upcoming years. Such an increase is justified by various entities through their projection of the expected increase in the demand of oil and gas. The treatment of produced water is a significantly growing challenge for the oil and gas industry that requires serious attention. The first part of this review will present the underlying issue of produced water and relevant practices. With adsorption being defined as the least expensive treatment method, the second part will introduce general adsorption principals. The third part will describe the recent applications of adsorption for the treatment of PW with more focus of categorizing the adsorbents as natural and non-natural adsorbents. The main aim of this review is to shed light on the recent research related to PW treatment using adsorption. This is performed to highlight the shortcomings in PW adsorption research and recommend research pathways that can help in developing the field further.

Separation of BTX Fraction from Reservoir Brines by Sorption onto Hydrophobized Biomass in a Fixed-Bed-Column System

Oily brine from the gas and oil industries remains the most difficult wastewater to treat due to its complex chemical composition, which includes aromatic hydrocarbons. Even at low concentrations, the presence of BTX (benzene, toluene, xylenes) can be extremely harmful to aquatic ecosystems. Fixed-bed adsorption columns are recommended for oily water treatment due to their flexibility and easy operation. In this research, pine sawdust modified with polydimethysiloxane (PDMS) and hydrophobic nanosilica was applied as a sorbent in a filtration system. The surface modification of raw fiber allowed to change its morphology and increase the roughness of it. The Yoon–Nelson, Bohart–Adams, Clark, and Belter models were applied to simulate continuous biosorption. The Bohart–Adams model strongly correlated with the experimental data and described the whole dynamic behavior of the column. The effect of feed flow rate (10–50 mL/min) on breakthrough characteristics was determined. Both the breakthrough and saturation time decreased as the flow rate increased. This study indicated that hydrophobized pine sawdust is an effective low-cost potential biosorbent for the removal of BTX fraction from produced water in continuous column mode.

Application of multivariate analysis on naphthalene adsorption in aqueous solutions

Naphthalene (NAP) is found as a pollutant in water, soil, and air, and adsorption is the most prominent removal process of this compound, among the methods studied. A study concerning the types of adsorbents and the parameters with the greatest influence on the adsorption process is interesting to direct future works on new adsorbents. The use of multivariate data analysis tools becomes an appealing way to compile data obtained from bibliographic reviews and to establish a behavior in NAP adsorption. This work aims to evaluate the parameters with greater influence on NAP adsorption process regarding adsorption capacity (qe_exp) with the principal component analysis (PCA), and to group common NAP adsorbents by chemical characteristics through hierarchical cluster analysis (HCA). The variables qe_exp, S, [NAP]₀, T, CT, and [Ads] were used to perform PCA with correlation matrix. For the HCA, the variables S, [NAP]₀, T, CT, and [Ads] with average linkage method (UPGMA) and Euclidean distance were used. Through PCA, it is possible to infer that S and [NAP]₀ are the factors with greater influence in qe_exp of NAP, while T, CT, and [Ads] have little correlation. PCA also shows that activated charcoal is the adsorbent with higher qe_exp. HCA grouped the adsorbents into four groups by their chemical classes, except group A. Both PCA and HCA methods show themselves as potential tools to evaluate a data set of NAP adsorption processes.

Surface modification and characterization of carbonaceous adsorbents for the efficient removal of oil pollutants

In this study, the impact of different oxidizing agents on the structural integrity of activated carbon (AC) and multiwalled carbon nanotubes (MWCNTs) was studied for the removal of BTX from aqueous solution. Seven different combinations of green oxidizing agents (mild organic acids) in conjugation with NaOCl (basic oxidizing agent) were used. The modified adsorbents were analyzed by Brunauer, Emmett, and Teller (BET) surface area analyzer, Fourier transform infrared spectroscopy (FTIR), Boehm titration, Raman spectroscopy, thermal gravimetric analysis (TGA), x-ray diffraction (XRD), zeta potential, and variable pressure field emission scanning electron microscope (VPFESEM). The results suggested that the carbonaceous sorbents modified with combination of citric acid tartaric acid, malic acid and salicylic acid (CTMS-I) showed increased surface area (O-AC: 871.67 m²/g, O-MWCNTs: 336.37 m²/g) and total pore volume (O-AC: 0.59 cm³/g, O-MWCNTs: 0.04 cm³/g), with the significantly improved thermal stability. Preliminary batch adsorption experiments conducted using the present prepared O-AC and O-MWCNTs, showed an improved performance towards the adsorption of BTX, compared with other available reported adsorbents in the literature.

Mono and Poly-Cationic Adsorption of Heavy Metals Using Natural Glauconite

The issue of heavy metal pollution of industrial wastewaters is a major environmental concern nowadays. The aim of this study was to investigate the effectiveness of heavy metals removal from aqueous solutions by natural glauconite, in batch and dynamic systems. Glauconite was characterized by X-ray diffraction, nitrogen adsorption–desorption isotherm, scanning electron microscope, differential thermal analysis, and inductively coupled plasma spectroscopy. Cation exchange capacity, bulk density and point of zero charge were also determined. In the batch system, the impact of initial concentration, contact time, and pH of metal solutions on sorption efficiency was analysed, whereas for the dynamic system, the influence of flow rate was studied. The adsorption capacity in the batch system followed the order: Pb > Cd > Zn > Cu. The highest adsorption rate was achieved in the pH range 7–9. In the column experiments, the selectivity order in the case of mono-cationic system was the same as that of batch system, whereas in the case of poly-cationic system it was: Pb > Zn > Cd > Cu. With the increase of the flow rate, the total capacity at the exhaustion point increased.

Synthesis of recyclable carbon/lignin biocomposite sorbent for in-situ uptake of BTX contaminants from wastewater

In this work, both palm-date pits and pulping black liquor industrial wastes were recycled as low-cost starting materials for the production of three series of granule activated carbon (gAC)/Kraft lignin (KL) (gAC/KL_x, x = 33, 50 and 67%) biocomposites using a one-pot solid-state method. The gAC/KL_x biocomposites with defined characteristics were examined towards batch adsorption of BTX (Benzene, Toluene, and Xylene) in multi-solute salty wastewaters. Optimization of adsorption performances under different experimental conditions were carried out using high performance liquid chromatography (HPLC). Adsorption modeling versus contact time (0-12 h) and BTX concentrations (150-2250 mg/L) were examined using non-linear forms of nine kinetic and five isotherm equations to best understand gAC/KL_0.5 suitability for BTX sorption/recovery processing. Accordingly, the gAC/KL_x at KL blended ratio of 50% was found to be the topmost to achieve the highest BTX capacity even at broad ranges of water salinity (0-100 g/L) and pH (3-9) values. The adsorption mechanism found to best described by physico-sorption (E ≈ 0.12-1.38 kJ/mol) via the hydrophobic interaction and diffusion mechanisms. In respect to gAC/KL_0.5 affinities, the sorption capacity followed the descending sequence of X ≥ T > B. Particularly, the maximum theoretical BTX capacity using the best fitted Langmuir-Freundlich model (L-FM) for gAC/KL_0.5 was found to be slightly higher than obtained by gAC (363.9 and 360.1 mg/g, respectively), along with higher initial sorption (h) rate (≈742.47 mg/g.h) than of gAC (≈559.85 mg/g.h) and KL (≈22.22 mg/g.h). Batch BTX sorption/recovery processes and estimated cost suggested the effective utilization of gAC/KL_0.5 as a promising in-expensive sorbent (0.31 ± 0.05 US$/kg) for commercial decontamination of petroleum hazardous (BTX) pollutants from wastewaters up to five reuse cycles.

The Possibilities of Using Broadleaf Cattail Seeds (Typha latifolia L.) as Super Absorbents for Removing Aromatic Hydrocarbons (BTEX) from an Aqueous Solution

Sorption of oil-related products (including mainly the propellants) is the very basic process that counteracts spreading these types of pollution into environment. Plenty of synthetic substances (including the monoaromatic hydrocarbons) are both from the surface and underground waters. The aim of this study was to present the research's results on the possibilities of using the broadleaf cattail (Typha latifolia L.) seeds as a sorbent of monoaromatic hydrocarbons from an aqueous solution. In order to increase sorptive capacity, the seeds biomass was submitted for the process of mercerizing in diversified time and temperature in water and the NaOH solution. The removal of benzene, toluene, ethylbenzene, o-xylene, m-xylene and cumene was carried out by means of the "batch method". All the conducted experiments have shown a high sorption level of the analysed pollutions from an aqueous solution. The best sorptive qualities appeared in the seeds drenched in 80 °C water for 4 h (W) 97 g/kg, what was 9.06% more absorbed hydrocarbons in comparison to the control sample (C) and 26.8% more than the smallest seeds drenched in NaOH for 240 min. in the temperature of 80 °C (N). The process of the seeds mercerizing that was conducted with the use of hot water appeared to be most effective, but seeds without mercerisation (C) is actually the material which absorbs the least amounts of energy for preparation and had quite good sorption capacity too.

Butylbenzene and tert-Butylbenzene-Sorption on Sand Particles and Biodegradation in the Presence of Plant Natural Surfactants

The effects of hydrocarbons sorption on sand and saponins presence in the system on butylbenzene and tert-butylbenzene biological degradation was investigated. Additionally, the impact of saponins-containing plant extracts on environmental microorganisms was studied. Results of cell surface property measurements in samples with saponins only revealed changes in cell surface hydrophobicity, electrokinetic potential and membrane permeability when compared to corresponding values for glucose-grown microbes. Subsequently, in sorption experiments, the hydrocarbon adsorption kinetics in bacteria-free samples were better explained with the pseudo-second order kinetic model as compared to the pseudo-first order and intraparticular diffusion models. Moreover, the equilibrium data fitted better to the Freundlich isotherm for both benzene derivatives. In the samples combining hydrocarbons sorption and biological degradation in the presence of saponins, alkane-substituted hydrocarbons removal was accelerated from 40% to 90% after 14 days and the best surfactant in this aspect was S. officinalis extract.

Synthesis of magnetic alginate beads based on magnesium ferrite (MgFe2O4) nanoparticles for removal of Sr (II) from aqueous solution: kinetic, equilibrium and thermodynamic studies

Novel magnetic alginate beads (MagAlgbeads) have been developed by incorporation of magnesium ferrite (MgFe₂O₄) in alginate beads with the aim of using them in the removal of strontium from aqueous solution. MagAlgbeads were characterized by transmission electron microscopy, scanning electron microscopy, X-ray fluorescence and Fourier transform infrared spectroscopy. The adsorption of strontium onto MagAlgbeads were found to depend on pH and strontium removal increases with increasing pH until pH is 6. Strontium adsorption kinetics run through pseudo-second-order model. Thermodynamically, strontium adsorption was endothermic and spontaneous. Langmuir isotherm gave good fitting for strontium removal with adsorption capacity of 505.5 mg/g. These results proved that the prepared MagAlgbeads are very efficient material for strontium adsorption.

Structural Variety and Adsorptive Properties of Mesoporous Silicas with Immobilized Oligosaccharide Groups

In this research, we report on the synthesis of mesoporous silicas with various quantities of immobilized oligosaccharide groups and different pore ordering degree. The hydrothermal co-condensation of tetraethyl orthosilicate and β-cyclodextrin-containing organosilane in the presence of cetyltrimethylammonium bromide template was employed. The purpose of this investigation was to show the opportunity of increasing β-cyclodextrin content in silica matrix by changing the molar ratio of initial reagents during organosilane synthesis and to determine whether the enhancing of immobilized groups on the surface influences on model aromatic compound adsorption from water. It was prepared several β-cyclodextrin-organosilanes by modification of (3-aminopropyl)triethoxysilane with oligosaccharide (the molar composition of reaction mixtures were 1:1, 3:1, and 5:1) with using N,N'-carbonyldiimidazole as linking agent. Three types of MCM-41 materials were obtained with 0.018, 0.072, and 0.095 mmol g^-1 β-cyclodextrin-group loading according to chemical analysis of silicas. The IR spectroscopy and potentiometric titration were also performed to confirm the presence of functional groups in the silica matrix. Nitrogen sorptometry experiments exhibited the decrease of high surface area (from 812 to 457 m² g^-1) and the average pore diameter (from 1.06 to 0.60 cm³ g^-1) of synthesized silicas with increasing of immobilized oligosaccharide groups. The influence of β-cyclodextrin-organosilane presence on the forming of hexagonally arranged porous structure of silicas was evaluated by X-ray diffraction and TEM analyses. As the loading of oligosaccharide groups increases in obtained silicas, the (100) reflex in diffraction patterns is even less intense and broader, denoting the decrease of long-range pore ordering. Adsorption experiments were carried out to study the effect of β-cyclodextrin groups' attendance in silica matrix on benzene uptakes from aqueous solutions. Experimental kinetic curves of benzene adsorption on synthesized silicas were compared with theoretical models of Lagergren and Ho-McKay for pseudo-first and pseudo-second-order processes. Langmuir and Freundlich isotherm models were used to evaluate adsorption processes and parameters. Obtained β-cyclodextrin-containing MCM-41 silicas demonstrate adsorption level performance of known samples and could be very promising for benzene uptakes from aqueous solutions in water treatment processes.

Propylsulfonic acid-anchored isocyanurate-based periodic mesoporous organosilica (PMO-ICS-Pr-SO3H): A new and highly efficient recoverable nanoporous catalyst for the one-pot synthesis of bis(indolyl)methane derivatives

A new propylsulfonic acid-anchored isocyanurate bridging periodic mesoporous organosilica (PMO-ICS-Pr-SO₃H) was prepared and shown to be a highly efficient recyclable nanoporous catalyst for the one-pot synthesis of bis(indolyl)methane derivatives in good to excellent yields from indole and different aldehydes in EtOH under mild reaction conditions in short reaction times. Moreover, the nanoporous catalyst was recovered and reused at least four times without significant decrease in its catalytic activity. The PMO-ICS-Pr-SO₃H catalyst was characterizred by Fourier transform infrared (FTIR) spectroscopy, thermogravimetry analysis (TGA) and N₂ adsorption-desorption isotherms techniques as well as field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray (EDX) spectroscopy. Compared to the classical methodologies, this method illustrated significant advantages including low loading of the catalyst, high to excellent yields, short reaction times, avoiding the use of toxic transition metals or reactive reagents for modification of the catalytic activity, easy separation and purification of the products, and reusability of the catalyst.

Biosorption of metal ions using a low cost modified adsorbent (Mauritia flexuosa): experimental design and mathematical modeling

Buriti fibers were subjected to an alkaline pre-treatment and tested as an adsorbent to investigate the adsorption of copper, cadmium, lead and nickel in mono- and multi-element aqueous solutions, the results showed an increase in the adsorption capacity compared to the unmodified Buriti fiber. The effects of pH, adsorbent mass, agitation rate and initial metal ions concentration on the efficiency of the adsorption process were studied using a fractional 2(4-1) factorial design, and the results showed that all four parameters influenced metal adsorption differently. Fourier transform infrared spectrometry and X-ray fluorescence analysis were used to identify the groups that participated in the adsorption process and suggest its mechanisms and they indicated the probable mechanisms involved in the adsorption process are mainly ion exchange. Kinetic and thermodynamic equilibrium parameters were determined. The adsorption kinetics were adjusted to the homogeneous diffusion model. The adsorption equilibrium was reached in 30 min for Cu(2+) and Pb(2+), 20 min for Ni(2+) and instantaneously for Cd(2+). The results showed a significant difference was found in the competitiveness for the adsorption sites. A mathematical model was used to simulate the breakthrough curves in multi-element column adsorption considering the influences of external mass transfer and intraparticle diffusion resistance.

Magnetic iron oxide nanoparticles functionalized multi-walled carbon nanotubes for toluene, ethylbenzene and xylene removal from aqueous solution

An effectively and functionally magnetic multi-walled carbon nanotube (MWCNTs) nano-composite (APCNT-KOH) was synthesized by a one-pot and facile method. The residual Fe catalyst particles of the as-prepared MWCNTs were utilized as magnetic materials through KOH activation. The resulting APCNT-KOH exhibited very high adsorption capacities for toluene (T), ethylbenzene (E), and xylene (X) (TEX) pollutants than many other adsorbents, because of their large specific surface area and high degree of surface activity. The adsorption process was found to be pH, ionic strength, and temperature dependent, and the maximum adsorption capacity was observed at pH 6 for TEX pollutants. The adsorption isotherm data were analyzed by applying the Langmuir, Freundlich, and Dubinin-Radushkevich isothermal models. The Langmuir model showed the best fit to the experimental isotherm data with a maximum adsorption capacity(qm,toluene = 63.34 mg/g, qm, ethylbenzene = 249.44 mg/g, qm,m-xylene = 227.05 mg/g, qm,o-xylene = 138.04 mg/g, qm,p-xylene = 105.59 mg/g). Adsorption kinetics of TEX on APCNT-KOH was appropriately described by the pseudo-second-order rate model. The desorption experiments revealed the typical adsorption-desorption hysteresis, indicating that the adsorption and desorption processes of TEX undergo different pathways due to porous structure changes before and after adsorption and desorption. Collective results demonstrate that the functionalized magnetic APCNT-KOH composites are highly-effective adsorbents for TEX removal, which provides a promising and green route for MWCNTs in wastewater treatment.

Phase-induced porous composite microspheres sintered scaffold with protein–mineral interface for bone tissue engineering

Phase induced porous composite microspheres were solvent/non-solvent sintered to construct 3D multi-scale porous biomimetic scaffolds with and without protein for bone tissue engineering.

Evaluation of different bridged organosilicas as efficient adsorbents for the herbicide S-metolachlor

The adsorption ofS-metolachlor on (organo)silicas largely depends on their composition and textural properties. Periodic mesoporous benzenesilica was particularly efficient for repetitive adsorption cycles.

Removal of the hazardous, volatile, and organic compound benzene from aqueous solution using phosphoric acid activated carbon from rice husk

BACKGROUND

Benzene is one of the most hazardous organic pollutants in groundwater. The removal of benzene from water is very important from a health point of view and for environmental protection. In this study, benzene adsorption kinetics was investigated using phosphoric acid activated carbon, prepared from rice husk.

RESULTS

An initial rapid uptake of benzene was observed and became almost constant after 40 minutes of contact. Kinetic data was analyzed using pseudo first order, pseudo second order, and Elovich equations. Kinetic data was well fitted to pseudo-second order models (R(2) = 0.98), indicating chemisorption. Results from intraparticle diffusion and Boyed models indicate that particle diffusion is the most probable operating mechanism and does not control the kinetics of benzene sorption. A comparative study on the benzene adsorption revealed that the rice husk carbon (RHC) had better benzene adsorption capacity (365 mg/g) as compared to other adsorbents.

CONCLUSIONS

In conclusion, we have demonstrated that rice husk carbons are efficient benzene adsorbents and that they possess a good potential for benzene removal in wastewater treatment. Graphical AbstractPhosphoric acid activated carbon from rice husk and benzene adsorption mechanism.

Periodic Mesoporous Organosilicas: from simple to complex bridges; a comprehensive overview of functions, morphologies and applications

Periodic Mesoporous Organosilicas (PMOs) were developed in 1999 and are basically ordered templated mesoporous organosilicas, prepared by the combination of a surfactant as template and a silsesquioxane as the organosilica precursor. They were one of the first examples of the so-called "hybrid" organic/inorganic materials. In the years that followed, an amazing variety of functional groups, morphologies and applications has been developed. Some of these high-end applications, like low-k buffer layers in microelectronics, chiral catalysts, chromatographic supports, selective adsorbents and light-harvesting devices, have clearly shown their potential. In this review, we will give a comprehensive overview of all these different functionalities and applications that have been created for Periodic Mesoporous Organosilicas.

Kinetic and thermodynamic studies of toluene, ethylbenzene, and m-xylene adsorption from aqueous solutions onto KOH-activated multiwalled carbon nanotubes

Multiwalled carbon nanotubes activated by KOH (CNTs-KOH) were synthesized and employed as adsorbents to study adsorption characteristics of toluene, ethylbenzene, and m-xylene (TEX) from aqueous solutions. Kinetics data were fitted by pseudo-second-order model, and intraparticle diffusion was not the only rate-controlling step. Adsorption isotherm data could fit well with Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) models. The maximum adsorption capacities on CNTs-KOH are 87.12, 322.05, and 247.83 mg/g for toluene, ethylbenzene, and m-xylene, respectively. The adsorption capacities of TEX onto CNTs-KOH increased with contact time and decreased with temperature and are not significantly affected by humic acid. However, Cr(6+) could decrease adsorption of TEX by 17.66, 4.51, and 12.69% as (K(d)(1) - K(d)(2))/K(d)(1), respectively. The thermodynamics parameters indicated that adsorption was a feasible, exothermic, and spontaneous process in nature and a physisorption process. The present CNTs-KOH show a better EX adsorption performance than other adsorbents, suggesting that CNTs-KOH are promising EX adsorbents in wastewater treatment.

BTEX removal from aqueous solutions by HDTMA-modified Y zeolite

Various technologies have been used for the treatment and remediation of areas contaminated by BTEX (benzene, toluene, ethylbenzene and xylenes), which are organic compounds that are of particular concern due to their toxicity. Potential applications of synthetic zeolites for environmental fieldwork have also been reported worldwide. In this work, a hexadecyltrimethyl ammonium (HDTMA) surfactant-modified synthetic zeolite was investigated for its efficiency in removing BTEX from aqueous solutions. Three surfactant-modified zeolites were synthesized, with amounts of surfactant corresponding to 50%, 100%, and 200% of the total cation-exchange capacity (CEC) of the synthetic zeolite Y. The results of the BTEX adsorption experiments onto both synthetic zeolite and surfactant-modified zeolites (SMZ) showed that the SMZ-100 (zeolite modified with surfactant levels at 100% of CEC) was the most efficient modified zeolite for BTEX removal. Kinetics studies indicated that the multicomponent adsorption equilibrium was reached within 6 h and followed pseudo-second-order kinetics. The Langmuir, Freundlich, Redlich-Peterson and Temkin models were used to evaluate the BTEX adsorption capacity by SMZ-100. The Temkin model was found to be suitable for all BTEX compounds in a multicomponent system. Regeneration cycles of the modified zeolite were also performed, and the results showed that the adsorbent could be used efficiently in as many as four adsorption cycles, except for benzene.