Increasing groundwater contamination with methyl tert-butyl ether (MTBE) requires more efficient remediation technologies. Accurate measurement of MTBE's air-water partitioning coefficient (Henry's law constant, H) is important for the design and optimization of removal efficiency for many treatment systems as well as for predicting its fate and transport. Previously published data for MTBE app...

This paper presents a cost-benefit analysis of the 1990 Clean Air Act Amendments (CAAA) requiring the addition of oxygen content in gasoline, using California as a case study. The valuation and comparison of costs and benefits for several fuel blends (with and without oxygen content) provides a framework to investigate cross-media (air, water, soil) tradeoffs. We use known valuation methods suc...

Multidimensional compound-specific stable isotope analysis (CSIA) was applied in combination with RNA-based molecular tools to characterize methyl tertiary (tert-) butyl ether (MTBE) degradation mechanisms occurring in biofilms in an aerated treatment pond used for remediation of MTBE-contaminated groundwater. The main pathway for MTBE oxidation was elucidated by linking the low-level stable is...

The primary objective of this study was to evaluate the impact of substrate interactions on the biotransformation rates and mineralization potentials of gasoline monoaromatics and methyl tert-butyl ether (MTBE), compounds that commonly co-exist in groundwater contaminant plumes. A mixed culture was derived from gasoline-contaminated aquifer material using toluene as the enrichment substrate. Tw...

Abstract This study provides an efficient alternative by extracting bioactive compounds from Haematococcus pluvialis via matrix solid-phase dispersion (MSPD) its wet form, reducing one of the process steps with greatest economic impact, drying microalga. To obtain a suitable extract for nutraceutical purposes, solvents generally recognised as safe (GRAS) designation (ethanol, ethyl lactate, and...

Continuing modifications of fuels like gasoline should include evaluations of the proposed constituents for their potential to damage environmental resources such as subsurface water supplies. Consequently, we developed a screening model to estimate well water concentrations and transport times for gasoline components migrating from underground fuel tank (UFT) releases to typical at-risk commun...

A widely used gasoline additive, methyl tertiary butyl ether (MTBE), has been controversial, in part because of concerns about potential inhalation health effects and more recently because of added concerns about water contamination. Although many of the issues related to MTBE have not been fully resolved, several apparent paradoxes can be discerned, including the fact that something intended t...

The simultaneous etherification of isobutene and isoamylenes with ethanol has been studied using macroreticular acid ion-exchange resins as catalyst. Most of the experiments were carried out over Amberlyst-35. In addition, Amberlyst-15 and Purolite CT-275 were also tested. Chemical equilibrium of four chemical reactions was studied: ethyl tert-butyl ether formation, tert-amyl ethyl ether format...

Methyl tert-butyl ether (MTBE), an octane enhancer and a fuel oxygenate in reformulated gasoline, has received increasing public attention after it was detected as a major contaminant of water resources. Although several techniques have been developed to remediate MTBE-contaminated sites, the fate of MTBE is mainly dependent upon natural degradation processes. Compound-specific stable isotope a...

In the present study, two distinctly different approaches are followed for modeling of reactive distillation column, the equilibrium stage model and the nonequilibrium stage model. These models are simulated with a computer code developed in the present study using MATLAB programming. In the equilibrium stage models, the vapor and liquid phases are assumed to be in equilibrium and allowance is ...