Methyl Tert-butyl Ether Removal Research Articles

Eco-friendly removal of methyl tert-butyl ether from contaminated water using steam and CO2-activated carbons

AbstractPetrol frequently contains the additive methyl tertiary butyl ether (MTBE). Because of its significant health risks, MTBE pollution of surface and ground water is a severe concern for the environment. Highly porous physically activated carbons, particularly CO2-activated carbon (CO2-AC) and steam-activated carbon (Steam-AC), were obtained from date stones as potential eco-friendly adsorbents for MTBE from contaminated water. The chemical composition, microstructure, textural, and structural characteristics of adsorbents were characterised by elemental analysis, SEM, N2 sorption, XRD, and FTIR. The adsorption process evaluation based on the initial MTBE concentration, liquid-to-solid ratio, and equilibrium contact time. CO2-AC and steam-AC adsorbents have high surface areas of 819.5 m2/g, and 567.7 m2/g, respectively. At 40 °C, CO2-AC has an adsorption capability of 181.36 mg/g. The adsorption result was best fitted by the Freundlich model. The two-step intraparticle diffusion process prevailed the adsorption process, and the pseudo-second-order model presented an optimal fit for the adsorption kinetics models. Spontaneous physical adsorption was endothermic when CO2-AC adsorbs at 40 °C because ∆G was − 6.34 kJ/mol. Finally, the water quality improved and the salt content, the alkalinity, and the hardness decreased with the use of CO2-AC as an environmentally friendly adsorbent for removing MTBE from the polluted water.

A general review on the application of adsorption and oxidation combined processes on methyl tert-butyl ether removal

A general review on the application of adsorption and oxidation combined processes on methyl tert-butyl ether removal

Enhanced Methyl Tert-Butyl Ether Removal by Mixed Consortium: Performance and Adaptability

Methyl tert-butyl ether (MTBE) is widely used as a gasoline additive with toxicity and carcinogenicity, and has caused environmental pollution worldwide. Biodegradation is a promising method for the removal of MTBE from contaminated sites. In this paper, three strains with high adaptability and different degrading characteristics to MTBE were cultured. The kinetic models were established to systematically simulate the biodegradation of MTBE by various strains at different concentrations. Moreover, the removal of MTBE in a synergistic system containing a mixture of three pure strains was studied. The mixed consortium enhanced MTBE removal at high concentrations (30–50 mg/L), and the degradation efficiency was increased by about 20% compared to pure strains at a concentration of 30 mg/L. Further, the mixed consortium degraded MTBE nearly three times faster than any of the individual, indicating that the co-cultures of three pure cultures improved both efficiency and the rate of MTBE biodegradation. In addition, it was found that the mixed consortium effectively removed MTBE in the presence of other gasoline components, and exhibited stronger adaptability, especially at low or high temperatures. This study supports the cultivation of a mixed consortium to remediate MTBE-contaminated environments, either as a single substrate or in environments containing other gasoline components.

Effects of operational parameters on methyl tert-butyl ether removal by permeable reactive barrier from polluted waters

Background: Recalcitrant organics remediation from water resources continues to be a significant environmental problem and there is a continued effort to demonstrate practicable and economical treatment options for pollution removal. Methods: In this study, the efficiency of the permeable reactive barrier (PRB) in a column reactor using zero-valent iron (ZVI) particles and sand mixture in the removal of methyl tert-butyl ether (MTBE) from aquatic phases was investigated. The system performance was MTBE removal while initial pH, reaction time, pollutant content, catalyst load, hydraulic loading rate (HLR), and the reaction rate constant were independent variables. Results: The results showed that the process efficiency decreased by increasing pH, HLR, and pollutant concentration. In this case, the optimal conditions were obtained at pH=7, HLR=0.23 m3 /m2 ·d, and C0=1 mg/L, which achieved a remarkable removal efficiency up to 90.32%. The high nitrate concentrations and hardness as intervening factors reduced process efficiency to less than 44.61 and 51.4%, respectively. The lack of interfering factors had a considerable effect on the reaction rate of MTBE reduction, which is approximately 2.65 and 4.11 times higher than that in the presence of calcium hardness and nitrate, respectively. Conclusion: The PRB technology can be suggested as a reliable and robust system to remediate groundwater containing hydrocarbons based on filling media and hydraulic conditions.

Simultaneous removal of Pb and MTBE by mixed zeolites in fixed-bed column tests

The co-contamination of metals and organic pollutants, such as Pb and methyl tert-butyl ether (MTBE), in groundwater, has become a common and major phenomenon in many contaminated sites. This study evaluated the feasibility of their simultaneous removal with permeable reactive barrier (PRB) packed with mixed zeolites (clinoptilolite and ZSM-5) using fixed-bed column tests and breakthrough curve modeling. The effect of grain size on the permeability of PRB and removal efficacy was also assessed by granular and power clinoptilolite. The replacement of granular clinoptilolite by powder clinoptilolite largely reduced the breakthrough time but increased the saturation time nearly fourfold. The column adsorption capacity of clinoptilolite powders almost tripled that of clinoptilolite granules (130.6 mg/g versus 45.3 mg/g) due to higher specific surface areas. The minimum thickness and corresponding longevity of PRB were calculated as 7.12 cm and 321.5 min when 5% of granular clinoptilolite was mixed with 5% ZSM-5 and 90% sand as mixed PRB reactive media compared with 10.86 cm and 1230.2 min for the application of powder clinoptilolite. This study is expected to provide theoretical support and guidance for the practical application of mixed adsorbents in PRBs.

Mesoporous magnesia sorbent for removal of organic contaminant methyl tert -butyl ether (MTBE) from water

ABSTRACT Methyl tertiary butyl ether (MTBE) is used as a gasoline additive formed by the reaction of isobutylene and methanol. Due to its high water solubility and low soil adsorption coefficient, leakages from storage facilities cause immediate groundwater contamination. The aim is to use alternative adsorbent for the removal of MTBE that causes various environmental and health problems. Mesoporous magnesia (MgO) that was synthesized via template-free hydrothermal method and commercial adsorbent Sepabeads-207 (SP-207) were used in this study. MTBE adsorption experiments were carried out at room temperature with a fixed sorbent/liquid ratio (0.1 g sorbent/10 mL aqueous solution) and 100–500 mg/L MTBE initial concentrations. Batch adsorption experiments showed that MgO and SP-207 have high MTBE adsorption capacity with a maximum adsorption amount of 333 and 233 mg MTBE/g adsorbent. Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich models of adsorption isotherms were used to investigate the adsorption behavior and the Langmuir isotherm model showed a better fit. Adsorption kinetic studies were also performed, and the pseudo-second-order kinetics fitted well with experimental data. Gibbs free energy changes of adsorption were obtained as −48.4 and −60.3 kJ/mol for MgO and SP-207, respectively. Methanol was used to regenerate the used adsorbents, and the re-use of MgO demonstrated good performance.

Photocatalytic Removal of Methyl Tert-Butyl Ether by C-N-TiO2 Nanoparticles from Aqueous Solution

BackgroundThe elimination of methyl tert-butyl ether (MTBE) from water resources remains a main environmental concern. In the present study, photo-assissted process for removal of MTBE was examined in the solutions containing C-N-TiO2 nanoparticles under UV irradiation in the batch mode.MethodsThe effects of operational factors such as pH, initial catalyst concentration, and initial MTBE concentration on MTBE removal was investigated.ResultsThe optimum degradation condition for MTBE was obtained at pH 7, catalyst load of 100 mg/L, air flow rate = 0.1 L/min and C0 = 5 mg/L with 73 percent degradation of MTBE at 60 min. In addition, Analytical profiles on MTBE removal were based on the first-order kinetics model. However, the removal rate decreased by increasing initial concentration of MTBE.ConclusionThe findings showed that UV/C-N-TiO2 system is an efficient method for MTBE degradation from aqueous solution.

High Selective Composite Polyalkylmethylsiloxane Membranes for Pervaporative Removal of MTBE from Water: Effect of Polymer Side-chain.

For the first time, the effect of the side-chain in polyalkylmethylsiloxane towards pervaporative removal of methyl tert-butyl ether (MTBE) from water was studied. The noticeable enhancement of separation factor during the pervaporation of 1 wt.% MTBE solution in water through the dense film (40–50 µm) can be achieved by substitution of a methyl group (separation factor 111) for heptyl (161), octyl (169) or decyl (180) one in polyalkylmethylsiloxane. Composite membrane with the selective layer (~8 µm) made of polydecylmethylsiloxane (M10) on top of microfiltration support (MFFK membrane) demonstrated MTBE/water separation factor of 310, which was 72% greater than for the dense film (180). A high separation factor together with an overall flux of 0.82 kg·m−2·h−1 allowed this M10/MFFK composite membrane to outperform the commercial composite membranes. The analysis of the concentration polarization modulus and the boundary layer thickness revealed that the feed flow velocity should be gradually increased from 5 cm·s−1 for an initial solution (1 wt.% of MTBE in water) to 13 cm·s−1 for a depleted solution (0.2 wt.% of MTBE in water) to overcome the concentration polarization phenomena in case of composite membrane M10/MFFK (Texp = 50 °C).

The Fate of MTBE and BTEX in Constructed Wetlands

Hydrocarbon contamination of water resources is a global issue. These compounds are generated and discharged into the environment in industrial areas from chemical and petrochemical plants, oil refineries, power plants, and so forth. Fuel hydrocarbons, namely, BTEX (benzene, toluene, ethylbenzene, and xylenes) and MTBE (methyl tert-butyl ether), are commonly found in groundwater, posing environmental and health risks to humans and ecosystems. Nature-based technologies represent an alternative solution, providing high efficiency, an environmentally friendly character, simple operation, and cost efficiency, which are characteristics particularly desired by the international petroleum industry. This article discusses the use of the green technology of constructed wetlands to remediate water polluted with hydrocarbons. Although the number of related international experiences and studies is limited, the article presents the latest developments of wetland technology for the removal of MTBE and benzene-BTEX. The discussion includes the overall efficiency of the different wetland types that have been tested and used, the main transformation and removal processes that regulate the fate of BTEX and MTBE in constructed wetlands, and the potential for future investigations.

Bioremediation of gaseous methyl tert-butyl ether by combination of sulfuric acid modified bagasse activated carbon-bone biochar beads and Acinetobacter indicus screened from petroleum contaminated soil

Combination of sulfuric acid modified bagasse activated carbon-bone biochar beads and Acinetobacter indicus screened from petroleum contaminated soil was the best condition for gaseous methyl tert-butyl ether (MTBE) removal. It was found that H2SO4 modified bagasse AC in powder form had higher adsorption capacity (989.33 mg g−1) than that in bead form (1.94 mg g−1). In addition, bone biochar in powder form (3.51 mg g−1) also had higher adsorption capacity than that in bead form (1.63 mg g−1). This was the fact that material beads contained high moisture content that inhibited the penetration of gaseous MTBE into the material. And a mixed material of H2SO4 modified bagasse AC-bone biochar beads had the highest adsorption capacity (2.22 mg g−1) compared to individual H2SO4 modified bagasse AC beads (1.94 mg g−1) and bone biochar beads (1.63 mg g−1) due to a mixed material had more rough surface and high surface area on its material. So, gaseous MTBE can penetrate through this material more easily. Although the maximum adsorption capacity of H2SO4 modified bagasse AC in powder form was the highest but microorganism cannot sustain and survive in this form for a long time. Therefore, the material beads were more suitable for microorganism to grow and degrade gaseous MTBE. Microorganism can degrade MTBE and caused no secondary wastes. Moreover, A. indicus was a novel strain for MTBE removal that has not been previously reported. Therefore, a combination of A. indicus-mixed material beads was a good choice for MTBE removal in a biofilter system.

Effect of functional groups of biochars and their ash content on gaseous methyl tert-butyl ether removal

Air pollution is considered a major problem, especially the pollution from transportation. Methyl tert-butyl ether (MTBE) is commonly used as a gasoline additive. MTBE is obtained from incomplete combustion of gasoline and causes environmental problems. Biochars derived from agricultural waste, including rice husk, bone, corncob, bamboo, sawdust and bagasse, were used for methyl tert-butyl ether (MTBE) removal. It was found that bagasse biochar had the highest maximum adsorption capacity (Qmax) (8.26 mg g−1), while bone biochar had the lowest (3.51 mg g−1). It might be due to the fact that bone biochar had the highest ash content and functional groups of bone biochar surface was mainly phosphate and ether groups. These functional groups cannot react with MTBE. While bagasse biochar contained less ash content and had the highest functional groups of ester (CO) and carbonyl (CO) groups. These functional groups can bind with MTBE effectively. Therefore, functional groups on materials and their ash content can be used as a criteria for selecting the materials for MTBE removal.

Treating MTBE-contaminated water using sewage sludge-derived activated carbon.

In this study, sewage sludge-derived activated carbon (SDAC) was synthesized, characterized, and tested for its potential as an adsorbent of methyl tert-butyl ether (MTBE). The SDAC was produced by activating the sludge with zinc chloride and subsequently subjected to various ranges of pyrolytic temperatures. It was then characterized using SEM/EDX, BET, and TGA. The SEM-EDX analyses showed that impurities like Fe, Al, Mg, Mn, Ca, and Na of the raw sludge were removed by the higher pyrolytic temperature and acid-washing procedures. TGA showed the thermal stability of the produced material. Results of the BET revealed a significant increase in surface area of the sludge from 1.5m2/g to 385m2/g after acid washing. The MTBE removal efficiency of 70% was achieved after 60min with 2g/L of SDAC at pH6, and initial MTBE concentration of 1ppm. The adsorption kinetics of SDAC fitted into pseudo-second-order reactions. This work demonstrated a beneficial use of a bio-waste material (sewage sludge) in water treatment technologies.

Kinetic and equilibrium modelling of MTBE (methyl tert-butyl ether) adsorption on ZSM-5 zeolite: Batch and column studies

The intensive use of methyl tert-butyl ether (MTBE) as a gasoline additive has resulted in serious environmental problems due to its high solubility, volatility and recalcitrance. The feasibility of permeable reactive barriers (PRBs) with ZSM-5 type zeolite as a reactive medium was explored for MTBE contaminated groundwater remediation. Batch adsorption studies showed that the MTBE adsorption onto ZSM-5 follows the Langmuir model and obeys the pseudo-second-order model with an adsorption capacity of 53.55 mg g−1. The adsorption process reached equilibrium within 24 h, and MTBE was barely desorbed with initial MTBE concentration of 300 mg L−1. The mass transfer process is found to be primarily controlled by pore diffusion for MTBE concentrations from 100 to 600 mg L−1. pH has little effect on the maximum adsorption capacity in the pH range of 2–10, while the presence of nickel reduces the capacity with Ni concentrations of 2.5–25 mg L−1. In fixed-bed column tests, the Dose-Response model fits the breakthrough curve well, showing a saturation time of ∼320 min and a removal capacity of ∼18.71 mg g−1 under the conditions of this study. Therefore, ZSM-5 is an extremely effective adsorbent for MTBE removal and has a huge potential to be used as a reactive medium in PRBs.

Removal of methyl tert-butyl ether (MTBE) from aqueous medium in the presence of nano-perfluorooctyl alumina (PFOAL): Experimental study of adsorption and catalytic ozonation processes

Abstract In this study, two types of nano- perfluorooctyl alumina (PFOALG and PFOALB) powders were synthesized using Wieserman and ultrasound assisted methods. XRD, SEM, BET, FT-IR and CHNOS analyses were used to characterize the nano-PFOALs. The performances of these samples were investigated for removal of MTBE from aqueous solutions using adsorption and catalytic ozonation processes. Four different adsorption isotherms, namely, Freundlich, Langmuir, BET multilayer adsorption and Temkin adsorption isotherms were used to modeling the adsorption equilibrium. The results showed that the equilibrium data of MTBE adsorption on nano-PFOALG adsorbent were well described by the BET isotherm model. The kinetics of MTBE adsorption on nano-PFOALG is best described by pseudo-second order model. Finally, the catalytic ability of nano-PFOALs was investigated for catalytic ozonation of MTBE. The removal percentage of MTBE by nano-PFOALs/O3 systems was about two times higher than ozonation alone after 90 min. Results showed that nano-PFOALs have high efficiency in catalytic ozonation of MTBE and suggested as suitable catalyst for contaminants removal in water using catalytic ozonation process.

Polypyrrole-Grafted Coconut Shell Biological Carbon as a Potential Adsorbent for Methyl Tert-Butyl Ether Removal: Characterization and Adsorption Capability.

Methyl tert-butyl ether (MTBE) has been used as a common gasoline additive worldwide since the late twentieth century, and it has become the most frequently detected groundwater pollutant in many countries. This study aimed to synthesize a novel microbial carrier to improve its adsorptive capacity for MTBE and biofilm formation, compared to the traditional granular activated carbon (GAC). A polypyrrole (PPy)-modified GAC composite (PPy/GAC) was synthesized, and characterized by Fourier transform infrared spectroscopy (FT-IR) and Brunauer-Emmett-Teller (BET) surface area analysis. The adsorption behaviors of MTBE were well described by the pseudo-second-order and Langmuir isotherm models. Furthermore, three biofilm reactors were established with PPy/GAC, PPy, and GAC as the carriers, respectively, and the degradation of MTBE under continuous flow was investigated. Compared to the biofilm reactors with PPy or GAC (which both broke after a period of operation), the PPy/GAC biofilm column produced stable effluents under variable treatment conditions with a long-term effluent MTBE concentration <20 μg/L. Pseudomonas aeruginosa and Acinetobacter pittii may be the predominant bacteria responsible for MTBE degradation in these biofilm reactors.

Organoclay-based nanoparticles from montmorillonite and natural clay deposits: Synthesis, characteristics, and application for MTBE removal

This study introduces organoclay-based submicron- and nanosized particles prepared from montmorillonite (SWy2) and naturally occurring clay deposits using sequential steps of wet ball milling, ultrasonication and sedimentation followed by an ion exchange process using two surfactants, long alkyl chain HDTMA+ (hexadecyltrimethylammonium bromide) and short alkyl chain TMA+ (tetramethylammonium bromide). The resultant organoclay-based nanoparticles were characterized using X-ray diffraction (XRD), thermogravimetric-differential thermal analysis (TG-DTA) and Fourier-transform infrared (FTIR) spectroscopy. The adsorption of MTBE (methyl tert-butyl ether) by organo-montmorillonite with different surfactant loadings (0.5–2.0 CEC) in aqueous solution was also investigated. The results of XRD analysis for organoclay-based nanoparticles showed that the value of d (001) increased with increasing alkyl chain length and surfactant loading. FTIR results showed that the functional groups of the organoclays changed due to the intercalation of the long alkyl chain surfactant HDTMA+ between clay layers. The removal of MTBE is highly dependent upon surfactant type and loading. The results indicated that the organo-montmorillonite-based nanoparticles prepared from HDTMA+ have a higher affinity for MTBE in aqueous solution than the organo-montmorillonite prepared from TMA+. Therefore, long alkyl chain HDTMA+ can be considered to be the most suitable organo-modifier for enhancing the adsorption characteristics of montmorillonite for MTBE removal.

Treatment of water contaminated by volatile organic compounds in hydroponic root mats

Hydroponic root mats (HRMs) are relatively new ecological water treatment technology with the aquatic vegetation forming buoyant root mats by their dense interwoven roots and rhizomes, either floating or sitting on the bottom of the water body. The aim of this study was to investigate the treatment of water contaminated by volatile organic compounds (VOCs) in HRMs under pilot-scale conditions. Floating hydroponic root mats (FHRM) and a hydroponic root mat filter (HRMF) mesocosms were established near a former industrial area in Leuna. The mesocosms received the contaminated groundwater with the main VOCs were benzene and methyl tert-butyl ether (MTBE). The results revealed that both systems exhibited a similar removal performance of MTBE during the two years operation. Seasonal variation was observed for benzene removal in both systems, with almost complete removal of benzene during summer period. The FHRM system exhibited higher benzene removal efficiency than the HRMF system, especially during the second year of operation. MTBE is more difficult to be removed than benzene in both systems, with overall MTBE mean removal efficiency of 32% as compare to 61% for benzene removal. Both benzene and MTBE removals are shown to be positively correlated with water loss in both systems, while air temperature only had significant influence on VOCs removal in the HRMF system. The emission rates of benzene and MTBE in the FHRM system are 8.4 and 6.9mgm−2 d−1, respectively. This removal accounted for 3.0% and 30.8% of the total benzene and MTBE removal. The emission rates of benzene and MTBE in the HRMF system were 6.0 and 1.4mgm−2 d−1, respectively, accounting for 2.3% and 8.3% of total removal of benzene and MTBE. In conclusion, HRMs can be an efficient approach to treat water contaminated by benzene in summer time, and the volatilization of benzene will decrease in the HRMs with the development of the root mat.

Stenotrophomonas maltophilia isolated from gasoline-contaminated soil is capable of degrading methyl tert-butyl ether

Background: Methyl tert-butyl ether (MTBE) is a pollutant that causes deleterious effects on human and environmental health. Certain microbial cultures have shown the ability to degrade MTBE, suggesting that a novel bacterial species capable of degrading MTBE could be recovered. The goal of this study was to isolate, identify and characterize the members of a bacterial consortium capable of degrading MTBE. Results: The IPN-120526 bacterial consortium was obtained through batch enrichment using MTBE as the sole carbon and energy source. The cultivable fraction of the consortium was identified; of the isolates, only Stenotrophomonas maltophilia IPN-TD and Sphingopyxis sp. IPN-TE were capable of degrading MTBE. To the best of our knowledge, this report is the first demonstrating that S. maltophilia and Sphingopyxis sp. are capable of degrading MTBE. The degradation kinetics of MTBE demonstrated that S. maltophilia IPN-TD had a significantly higher overall MTBE degradation efficiency and rate (48.39 ± 3.18% and 1.56 ± 0.12 mg L -1 h -1 , respectively) than the IPN-120526 consortium (38.59 ± 2.17% and 1.25 ± 0.087 mg L -1 h -1 , respectively). The kinetics of MTBE removal by both cultures fit first-order and pseudo-first-order reaction models. Conclusions: These findings suggest that S. maltophilia IPN-TD in axenic culture has considerable potential for the detoxification of MTBE-contaminated water. Normal 0 21 false false false ES-TRAD JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:Tabla normal; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Cambria,serif; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin; mso-ansi-language:ES-TRAD;}

Enhanced simultaneous removal of MTBE and TCE mixture by Paracoccus sp. immobilized on waste silica gel

Contamination of groundwater with the gasoline additive methyl tert-butyl ether (MTBE) is often accompanied by the coexistence of chlorinated aliphatic contaminants such as trichloroethylene (TCE). This study reports for the first time an indigenous Paracoccus sp. using MTBE as a sole carbon source while cometabolizing TCE from the mixture. The culture was originally enriched and isolated from the sludge sample at a regional wastewater treatment plant in Macau Special Administrative Region (SAR), China. Waste silica gel was used as a matrix for the microbial immobilization. The effects of different concentrations of MTBE and TCE on the removal efficiencies were investigated, together with their interactions during the bioremoval process, as well as the effects of pH and temperature on MTBE and TCE removal rates. The adsorption kinetics of contaminants on silica gel was also evaluated and the adsorption capacities of MTBE (50 mg l−1) and TCE (50 mg l−1) were 0.42 mg g−1 and 0.65 mg g−1, respectively. In the immobilized system, TCE (20 mg l−1) was removed to non-detectable level while the highest removal efficiency for MTBE (40 mg l−1) was 70.2 ± 3.1%.

Performance of pilot-scale horizontal subsurface flow constructed wetlands treating groundwater contaminated with phenols and petroleum derivatives

Groundwater contaminated with various organic and inorganic pollutants is a major issue especially in historic industrial areas with chemical industries and refineries. In this study, Constructed Wetlands, as an ecological and environmentally sustainable alternative, were tested at pilot-scale for the removal of phenolic compounds and petroleum derivatives from contaminated groundwater in a pump-and-treat remediation research facility in Germany. Three horizontal subsurface-flow Constructed Wetlands (two planted, one unplanted) were fed with contaminated groundwater containing methyl tert-butyl ether (MTBE), benzene and ammonia. In two of the beds, a solution of phenol and m-cresol (15 and 2mg/L or 314.5 and 45.5mg/m2/d, respectively) was injected to the groundwater inflow. Results showed a complete removal of the two phenolic compounds in the beds without any alteration in the MTBE and benzene removal rates. This indicated that Constructed Wetlands are versatile and can be used to effectively treat different pollutants simultaneously. Higher contaminant removal efficiency of planted systems confirms the positive role of plants presence and their ability to promote biodegradation. Spatial distribution analyses showed that the major portion of the removal took place in the first part of wetland length, which indicated that the systems could potentially deal with higher loads and can be used to optimize the system design.