scholarly journals Removal and Recovery of Methyl Tertiary Butyl Ether (MTBE) from Water Using Carbon Nanotube and Graphene Oxide Immobilized Membranes

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 578
Author(s):  
Worawit Intrchom ◽  
Sagar Roy ◽  
Somenath Mitra
Keyword(s):  
Graphene Oxide ◽  
Carbon Nanotube ◽  
High Performance ◽  
Water Solubility ◽  
High Water ◽  
Membrane Distillation ◽  
Methyl Tert Butyl Ether ◽  
Transfer Coefficients ◽  
Butyl Ether ◽  
Tertiary Butyl

Methyl tert-butyl ether (MTBE) is a widely used gasoline additive that has high water solubility, and is difficult to separate from contaminated ground and surface waters. We present the development in functionalized carbon nanotube-immobilized membranes (CNIM-f) and graphene oxide-immobilized membranes (GOIM) for enhanced separation of MTBE via sweep gas membrane distillation (SGMD). Both types of modified membranes demonstrated high performance in MTBE removal from its aqueous mixture. Among the membranes studied, CNIM-f provided the best performance in terms of flux, removal efficiency, mass transfer coefficients and overall selectivity. The immobilization f-CNTs and GO altered the surface characteristics of the membrane and enhanced partition coefficients, and thus assisted MTBE transport across the membrane. The MTBE flux reached as high as 1.4 kg/m2 h with f-CNTs, which was 22% higher than that of the unmodified PTFE membrane. The maximum MTBE removal using CNIM-f reached 56% at 0.5 wt % of the MTBE in water, and at a temperature of 30 °C. With selectivity as high as 60, MTBE recovery from contaminated water is very viable using these nanocarbon-immobilized membranes.

Kinetic Model for the Degradation of MTBE by Fenton's Oxidation

2006 ◽  
Vol 3 (1) ◽  
pp. 40 ◽  
Author(s):  
Nada Al Ananzeh ◽  
John A. Bergendahl ◽  
Robert W. Thompson
Keyword(s):  
Kinetic Model ◽  
Organic Contaminants ◽  
Water Solubility ◽  
High Water ◽  
Butyl Alcohol ◽  
Methyl Tert Butyl Ether ◽  
Butyl Ether ◽  
Tert Butyl ◽  
Fenton’S Oxidation ◽  
Fenton's Oxidation

Environmental Context.Since the early 1990s, methyl tert-butyl ether (MTBE), a possible human carcinogen, has been used as a gasoline oxygenate at concentrations of up to 15% by volume; however, a fraction of the MTBE produced has inevitably been released to the environment. And, spills at gasoline service stations have resulted in local groundwater contamination levels of MTBE over 100 mg L−1, because of its very high water solubility. Advanced oxidation is a common technique for mineralizing organic contaminants, but the reaction chemistry needs to be better understood to facilitate design of remediation systems. Abstract.A kinetic model for the degradation of methyl tert-butyl ether (MTBE) in batch reactors with Fenton’s oxidation (Fe2+/ H2O2) in aqueous solutions was developed. This kinetic model consists of equations accounting for (1) hydrogen peroxide chemistry in aqueous solution, (2) iron speciation, and (3) MTBE oxidation. The mechanisms of MTBE degradation, and the resultant pathways for the formation and degradation of the byproducts, were proposed on the basis of previous studies. A set of stiff nonlinear ordinary differential equations that describe the rate of formation of each species in this batch system was solved using Matlab (R13) software. The kinetic model was validated with published experimental data. The degradation of MTBE by Fenton’s oxidation is predicted well by the model, as are the formation and degradation of byproducts, especially methyl acetate (MA) and tert-butyl alcohol (TBA). Finally, a sensitivity analysis based on calculating the sum of the squares of the residuals (SSR) after making a perturbation of one rate constant at a time was applied to discern the effect of each reaction on MTBE disappearance.

A Kinetic Model for the Aqueous Degradation of MTBE by Fe0/H2O2

2007 ◽  
Vol 32 (3) ◽  
pp. 131-151 ◽  
Author(s):  
Nada M. Al-Ananzeha ◽  
John A. Bergendahlb ◽  
Robert W. Thompsona
Keyword(s):  
Kinetic Model ◽  
Organic Contaminants ◽  
Reaction Rate ◽  
Water Solubility ◽  
High Water ◽  
Oxidation Reactions ◽  
Iron Speciation ◽  
Butyl Ether ◽  
Tertiary Butyl ◽  
Mtbe Degradation

Methyl tertiary-butyl ether (MTBE) is a possible human carcinogen that has been used as a gasoline oxygenate at concentrations of up to 15% by volume for about 45 years in the US. However, its high water solubility has exacerbated spills at gasoline stations, sometimes resulting in local groundwater MTBE contamination levels of over 100 mg/L. Advanced oxidation using Fe0 and H2O2 is a promising technique for mineralizing organic contaminants, but current understanding of the remediation chemistry needs to be improved to facilitate design of subsurface or engineered systems. A kinetic model for the degradation of MTBE in batch systems applying zero-valent iron (Fe0) andhydrogen peroxide (H2O2) oxidation in aqueous solution was developed. The model includes: H2O2 and water chemistry, iron speciation, and MTBE oxidation reactions. H2O2/water and MTBE degradation equilibrium and reaction rate parameters were taken from the literature. Reaction rate and equilibrium parameters for iron speciation were taken from the literature, or from our prior work. The rate constant for the dissolution of Fe0 was found from this work. The model was compared to experimental data from the literature for MTBE degradation using Fe0/H2O2

Novel tetrazole PtII and PdII complexes with enhanced water solubility: synthesis, structural characterization and evaluation of antiproliferative activity

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Tatiyana V. Serebryanskaya ◽  
Alexander S. Lyakhov ◽  
Ludmila S. Ivashkevich ◽  
Yuri V. Grigoriev ◽  
Andreii S. Kritchenkov ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Performance ◽  
Water Solubility ◽  
Thermal Analyses ◽  
High Water ◽  
Acetonitrile Solution ◽  
X Ray ◽  
Molecular And Crystal Structures ◽  
Tetrazole Derivatives ◽  
High Water Solubility

AbstractNovel platinum(II) and palladium(II) chlorido complexes with tetrazole derivatives 1-(2-hydroxyethyl)tetrazole (het) and 1-[tris(hydroxymethyl)methyl]tetrazole (thm), viz. cis-[Pt(het)2Cl2], trans-[Pt(het)2Cl2], trans-[Pt(thm)2Cl2], trans-[Pd(het)2Cl2], and trans-[Pd(thm)2Cl2], were synthesized. The compounds were characterized by elemental and high-resolution electrospray ionization (HRESI) mass spectrometry, high-performance liquid chromatography (HPLC), 1H, 13C and 195Pt nuclear magnetic resonance (NMR) spectroscopy, thermal analyses, and Infrared (IR) spectroscopy. Molecular and crystal structures of trans-[PdL2Cl2] and trans-[PtL2Cl2] (L = het, thm) were established by single-crystal X-ray analysis. The complex cis-[Pt(het)2Cl2] was found to undergo cis–to–trans isomerization upon heating in acetonitrile solution and in the solid state. The synthesized complexes show rather high water solubility lying in the range of 2–10 mg/L.

scholarly journals Identification and Content of Astaxanthin and Its Esters from Microalgae Haematococcus pluvialis by HPLC-DAD and LC-QTOF-MS after Extraction with Various Solvents

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2413
Author(s):  
Biljana Todorović ◽  
Veno Jaša Grujić ◽  
Andreja Urbanek Krajnc ◽  
Roman Kranvogl ◽  
Jana Ambrožič-Dolinšek
Keyword(s):  
High Performance ◽  
Haematococcus Pluvialis ◽  
Methyl Tert Butyl Ether ◽  
Diode Array ◽  
Diode Array Detection ◽  
Butyl Ether ◽  
Flight Mass Spectrometry ◽  
Green Microalga ◽  
Array Detection ◽  
Long Chain

Haematococcus pluvialis, a unicellular green microalga that produces a secondary metabolite under stress conditions, bears one of the most potent antioxidants, namely xanthophyll astaxanthin. The aim of our study was to determine the content of astaxanthin and its esterified forms using three different solvents—methyl tert-butyl ether (MTBE), hexane isopropanol (HEX -IPA) and acetone (ACE)—and to identify them by using high performance liquid chromatography coupled with diode array detection and the quadrupole time-of-flight mass spectrometry (HPLC-DAD and LC-QTOF-MS) technique. We identified eleven astaxanthin monoesters, which accounted for 78.8% of the total astaxanthin pool, six astaxanthin diesters (20.5% of total), while free astaxanthin represented the smallest fraction (0.7%). Astaxanthin monoesters (C16:2, C16:1, C16:0), which were the major bioactive compounds in the H. pluvialis samples studied, ranged from 10.2 to 11.8 mg g−1 DW. Astaxanthin diesters (C18:4/C18:3, C18:1/C18:3) were detected in the range between 2.3 and 2.6 mg g−1 DW. All three solvents were found to be effective for extraction, but MTBE and hexane-isopropanol extracted the greatest amount of free bioactive astaxanthin. Furthermore, MTBE extracted more low-chain astaxanthin monoesters (C16), and hexane-isopropanol extracted more long-chain monoesters (C18 and above) and more diesters. We can conclude that MTBE is the solvent of choice for the extraction of monoesters and hexane-isopropanol for diesters.

The rapid detection of methyl tert-butyl ether (MtBE) in water using a prototype gas sensor system

2005 ◽  
Vol 52 (8) ◽  
pp. 117-123 ◽  
Author(s):  
B.P.J. de Lacy Costello ◽  
P.S. Sivanand ◽  
N.M. Ratcliffe ◽  
D.M. Reynolds
Keyword(s):  
Sensor Arrays ◽  
Methyl Tert Butyl Ether ◽  
Butyl Ether ◽  
Potential Threat ◽  
Tertiary Butyl ◽  
The Usa ◽  
On Line ◽  
Low Levels ◽  
Gasoline Additive ◽  
Metal Oxide Sensor

The gasoline additive Methyl-tertiary-Butyl Ether (MtBE) is the second most common contaminant of groundwater in the USA and represents an important soil contaminant. This compound has been detected in the groundwater in at least 27 states as a result of leaking underground storage facilities (gasoline storage tanks and pipelines). Since the health effects of MtBE are unclear the potential threat to drinking water supplies is serious. Therefore, the ability to detect MtBE at low levels (ppb) and on-line at high-risk groundwater sites would be highly desirable. This paper reports the use of ‘commercial’ and metal oxide sensor arrays for the detection of MtBE in drinking and surface waters at low ppb level (μg.L−1 range). The output responses from some of the sensors were found to correlate well with MtBE concentrations under laboratory conditions.

Polyaniline functionalized reduced graphene oxide/carbon nanotube ternary nanocomposite as a supercapacitor electrode

2020 ◽  
Vol 56 (28) ◽  
pp. 4003-4006 ◽  
Author(s):  
Chengchao Wang ◽  
Yue Yang ◽  
Ruijun Li ◽  
Datong Wu ◽  
Yong Qin ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Carbon Nanotube ◽  
Reduced Graphene Oxide ◽  
High Performance ◽  
Supercapacitor Electrode ◽  
Ternary Nanocomposite ◽  
Reduced Graphene

Polyaniline is covalently functionalized onto the RGO surface in the presence of carbon nanotubes and used for high performance supercapacitors.

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