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In this study, the improvement of a clay soil contaminated with MTBE (methyl tert-butyl ether) using magnesium oxide and hydrated lime was studied. Soil contaminated with MTBE was prepared in the laboratory, then mixed with different percentages of magnesium oxide and hydrated lime. Natural soil was also mixed with the same percentages used with the desired additives. Atterberg limits, compaction, Unconfined compressive strength, and SEM tests were performed on all samples. To determine the strength, the samples were prepared by static method and tested after 7, 14, and 28 days of curing time. The results showed that magnesium oxide and lime both increase the strength and E50 and thus improve natural and contaminated soil, which is a function of the percentage of used additives and curing time. The Comparison of improvement results showed that the final strength in natural soil is higher than in contaminated soil. In addition, the comparison of the results showed that lime has less effect on soil improvement compared to magnesium oxide. The SEM results also showed that the increase in strength is due to the cement materials produced during the carbonation process, which makes the particles paste to each other and make a rigid body.

In this study, the improvement a clay soil contaminated with MTBE (methyl tert-butyl ether) using magnesium oxide and hydrated lime was studied. Soil contaminated with MTBE was prepared in the laboratory, then mixed with different percentages of magnesium oxide and hydrated lime. Natural soil was also mixed with the same percentages used with the desired additives. Atterberg limits, compaction, Unconfined compressive strength, and SEM tests were performed on all samples. To determine the strength, the samples were prepared by static method and tested after 7, 14, and 28 days of curing time. The results showed that magnesium oxide and lime both increase the strength and E50 and thus improve the properties natural and contaminated soil, which are function of the percentage of used additives and curing time. The Comparison of improvement results showed that the final strength in natural soil is higher than in contaminated soil. In addition, the comparison of the results showed that lime has less effect on soil improvement compared to magnesium oxide. The SEM results also showed that the increase in strength is due to the cement materials produced during the carbonation process, which makes the particles paste to each other and causes a rigid body. [ABSTRACT FROM AUTHOR]

Nowadays, Producing and using chemical compounds in different industrials has caused environmental pollution. One of these compounds that can bring a widespread pollution in natural resources is Methyl Tert-Butyl Ether (MTBE). This organic compound that is produced in petrochemical industries is used as a substitute to produce lead free gasoline in all over the world. Human exposure to MTBE may cause dizziness, coughing, fever, headaches, vomiting, muscular aches, sleepiness and skin and eye irritation. Concerning the destructive consequences of MTBE on the environment, and human health, clearing polluted resources are vital. The main objective of this study is dedicated to treat MTBE-contaminated waters through adsorption process in the presence of granular activated carbon (GAC). In this study, the effect of pH as well as exposure time on the removal of MTBE from aqueous solution have been examined and finally the efficacies of the process is assessed in terms of organic compounds removal and GAC reusability. According to the results, the adsorption capacity of used activated carbon depends considerably on the PH and reaction time. In this study, after 45 minutes of reaction time at PH of 8 the maximum COD removal efficiency of 62% was achieved. In this research both the Langmuir and Freundlich isotherm model best represented the MTBE adsorption behavior of GAC, having R2 of 92.2% and 84.6%, respectively. Moreover, maximum capacity of adsorption, in optimized condition, was estimated to be 67 mg of COD per each gr of GAC.

Background & aim: Methyl-tertiary butyl ether (MTBE) is one of the fuel oxygenated additive that is used to reduce the environmental pollution resulting from engine combustion. The present study was conducted to evaluate the acute (1 day) and sub chronic (30 days) effects of MTBE on some fertility indices in male rats. Methods: In the present experimental study conducted in 2019, 40 male rats with an approximate weight of 180-200 grams entered the study. The mice were then classified in two separate experiments into two acute groups (one day of treatment) and sub chronic (30 consecutive days of treatment) (15 heads in the acute group and 25 heads in the chronic group). In each acute and chronic group, the animals were randomly divided into 5 subgroups of control, oil (sham), 400, 800, and 1600 mg/kg body weight and placed in individual cages. At the end of each experiment, selected parameters related to sperm quality (sperm motility percentage, live sperm mania percentage and total sperm count) were examined. Data were analyzed using analysis of variance and linear regression. Results: The results of the present study indicated that in a sub chronic experiment, peanut oil as a solvent of MTBE had a significant effect on sperm motility percentage (p

Due to the importance and widespread applications of oil products as well as their threats to surface water bodies in Iran, it is inevitable to apply suitable simulation models to develop management plans, actions, and appropriate scenarios . There are two modified versions of CE-QUAL-W2 and both can be used for simulations of emergency pills of toxic waste in transpotation roadways. In this research, both modified versions were employed to simulate the fate of Methyl tert-butyl ether (MTBE) (a gasoline oxygenated addetive) during an emergency spill. As a case study, the application of both models was used to evaluate the MTBE emergy spill that occurred on March 2003 near Khalifeh Torkhan river. Several remediation techniques including artificial turbulent, mixing, and aeration were used during the simulation study. Results showed that the modified version of the model (CE-QUAL-W2) depicted a better temporal and spatial distribution of MTBE pollution in reservoir compared compared to the first version of the model. Multiple scenarios were simulated in this study under various meteorological, hydrological, and MTBE loading for Gheshlagh reservoir. The simulation results showed that lower air temperature and higher wind speed are among the factors that reduces the reservoir recovery time. In addition,, another parameter that found to decrease the recovery time of Gheshlagh reservoir is an increase in reservoir inflow and/or outflow rate.

In this research, the 2D hydrodynamic and mass transport model, CE-QUAL-W2, is modified to simulate the fate and transport of volatile organic compounds (VOCs) in standing and flowing water bodies. The modifed model is applied to the Karkheh river-reservoir system. For this purpose, a subroutine model is added to the CE-QUAL-W2 source code to simulate the physical, chemical, and biological fate of VOCs in water bodies. In a second step, the VOC mass continuity model is employed to evaluate the performance of the modified CE-QUAL-W2 model. The results confirm the accuracy of the modified CE-QUAL-W2 model. The modified CE-QUAL-W2 model is employed to simulate the Karkheh river-reservoir responses in sudden MTBE spill in Karkheh water body. The effects of reservoir operation (withdraw values and locations) on MTBE fate and transport are investigated. The results show, compared to the old version of the CE-QUAL-W2, the modified version in which VOC evaporation is considered shows a reduction in MTBE concentration in the water body under investigation. Furthermore, the effects of such environmental parameters as wind speed, water temperature, and air temperature on MTBE fate and transport are evaluated. The results show that increasing wind speed and water temperature accelerate the evaporation rate of VOCs and decrease the reservoir cleanup time while reducing air temperature leads to reduced VOC evaporation rates and increased VOC concentration in the water body.

Methyl tertiary-butyl ether (MTBE) is a gasoline additive used to enhance gasoline octane. It is highly soluble in water and is known for its carcinogenicity; hence its high risk of groundwater contamination. The present study was mainly designed to investigate MTBE effect on gasoline solubility in water, determine the associated COD value, and identify the kinetics of MTBE elimination from water by the stripping method. The results show that the kinetics of MTBE elimination from water can be expressed by a first order equation with the rate constants obtained as 0.0055 min-1 and 0.0074 min-1 at the two stirring rates of 100 rpm and 250 rpm, respectively. These rate constants are evidently high and are indicative of the effectiveness of the stripping method in MTBE removal from water. A linear function was established between COD reduction with respect to time at room temperature at low stirring rates (100 rpm) but an exponential function at high stiring rates (250 rpm). The solubility of gasoline with different additives (MTBE, ethanol, methanol) in water was also investigated. The results revealed that gasoline solubility decreased from 90 mg/l to 80mg/l and 69 mg/l, respectively, in the presence of ethanol and methanol. This is while the solubility of MTBE-containing gasoline in water rose from 90 mg/l to 778 mg/l, which shows an 8-fold increase in solubility in water.

Industrial contamination leakage into groundwater resources is increasing during recent years. Unlike surface water resources, lots of contaminants are stable in groundwater. Hence, several technologies, like Pump-and-Treat (PAT) and Air Sparging (AS), are being used in order to remedy contaminated aquifers. Despite of suggestions about using these two technologies together, there is no integrated simulation model for these two technologies. Using existing models for PAT simulation and combining them with AS simulation model, an integrated model for simulation of these technologies in field scale has been developed in this study. In addition to model validation, remediation of Bagher-Shahr aquifer (west of Tehran refinery) from MTBE by using AS and PAT technologies has been evaluated during a case study. Based on the suggested design for local remediation of MTBE plume in Bagher-Shar aquifer (without facility installation inside the city area) and during a five- year simulation period, mass of contaminant inside the city area is decreased to half of the initial mass.