Evaluating two-resistance models for air stripping of volatile organic contaminants in a countercurrent, packed column

1985 ◽  
Vol 19 (2) ◽  
pp. 164-173 ◽  
Author(s):  
Paul V. Roberts ◽  
Gary D. Hopkins ◽  
Christoph. Munz ◽  
Arturo H. Riojas
Keyword(s):  
Organic Contaminants ◽  
Packed Column ◽  
Air Stripping ◽  
Volatile Organic ◽  
Volatile Organic Contaminants

scholarly journals Recovery of Alcohol Ethoxylates Nonionic Surfactant using Co-Current Vacuum Stripping

2011 ◽  
Vol 11 (1) ◽  
pp. 22
Author(s):  
Suratsawadee Kungsanant ◽  
Sirinthip Kittisrisawai ◽  
Boonyarach Kitiyanan ◽  
Thirasak Rirksomboon ◽  
Somchai Osuwan ◽  
...  
Keyword(s):  
Nonionic Surfactant ◽  
Organic Compounds ◽  
Organic Contaminants ◽  
Secondary Alcohol ◽  
Packed Column ◽  
Hydrophobic Effect ◽  
Current Mode ◽  
Alcohol Ethoxylates ◽  
Volatile Organic ◽  
Volatile Organic Contaminants

Cloud point extraction (CPE) has shown to be an effective technique to remove organic compounds from contaminated water using nonionic surfactant as a separating agent. To make this process more economically attractive, the spent nonionic surfactants should be recycled and reused. This work utilized a packed column operated under vacuum in co-current mode to remove the volatile organic compounds (VOCs) from the secondary alcohol ethoxylates, AEs, coacervate solution. The co-current operation can effectively avoid plugging, excessive foaming, and flooding. The selected volatile organic contaminants are aromatic hydrocarbons such as benzene, toluene, and ethylbenzene. The hydrophobic properties of the VOCs are described by an octanol-water partition coefficient (Kow). The results show that as the Kow increases, the Ks substantially increases while the Happ of the VOCs significantly decreases. The reduction of VOCs volatilization is possibly due to greater partitioning of the VOCs into surfactant micelles. The similar trend is also observed in the continuous operation. The results show that as the Kow increases, the percentage of VOCs removal and the Kxa decrease due to the VOCs’ hydrophobic effect. The removal percentages of the VOCs vary from 60 to 90%. The R2 of the log-log and semi-log relationships between Kow and studied parameters are observed in the range of 0.96-0.99.

The Distribution of Volatile Organics in a Leachate Plume, Gloucester, Ontario

1987 ◽  
Vol 22 (1) ◽  
pp. 49-64 ◽  
Author(s):  
J.F. Devlin ◽  
W.A. Gorman
Keyword(s):  
Organic Contaminants ◽  
Source Area ◽  
Unconfined Aquifer ◽  
High Concentration ◽  
Organic Contamination ◽  
Aquifer System ◽  
Aquifer Systems ◽  
Volatile Organic ◽  
Volatile Organic Contaminants ◽  
Aquifer Sediments

Abstract The Gloucester Landfill is located near Ottawa, Ontario, on a northeast trending ridge of Quaternary age. The ridge comprises outwash sediments which make up two aquifer systems. A confined system exists next to bedrock, and is overlain by a silty-clayey stratum (the confining layer) which is, in turn, overlain by an unconfined aquifer system. Two independent volatile organic plumes have previously been identified at the landfill: the southeast plume, which has penetrated the confined aquifer system, and the northeast plume which is migrating in the unconfined aquifer. The distribution of volatile organic contaminants at the northeast plume site appears to be a function of two factors: (1) heterogeneities in the aquifer sediments are causing the channeling of contaminants through a narrow path; (2) the low fraction of organic carbon in the unconfined aquifer sediments at the northeast site is resulting in little retardation of the contaminants there, relative to those at the southeast site. Acetate was the only volatile fatty acid detected in the leachate. It was measurable only in areas where the volatile organic contamination was significant. Although methane was detected in the contaminated sediments, suggesting that microbial activity was present, the high concentration of acetate (>1000 ppm) which was detected down-gradient from the source area indicates that any biodegradation which is occurring is proceeding at a very slow rate.

scholarly journals 13C/12C Analysis of Ultra-Trace Amounts of Volatile Organic Contaminants in Groundwater by Vacuum Extraction

2010 ◽  
Vol 44 (3) ◽  
pp. 1023-1029 ◽  
Author(s):  
Helena I. F. Amaral ◽  
Michael Berg ◽  
Matthias S. Brennwald ◽  
Markus Hofer ◽  
Rolf Kipfer
Keyword(s):  
Organic Contaminants ◽  
Vacuum Extraction ◽  
Volatile Organic ◽  
Volatile Organic Contaminants ◽  
Ultra Trace

Determination of Volatile Organic Contaminants in Bulk Oils (Edible, Injectable, and Other Internal Medicinal) by Purge-and-Trap Gas Chromatography/Mass Spectrometry

1994 ◽  
Vol 77 (3) ◽  
pp. 647-654 ◽  
Author(s):  
Don W Thompson
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Vegetable Oils ◽  
Organic Contaminants ◽  
Internal Standard ◽  
Gas Chromatography Mass Spectrometry ◽  
Purge And Trap ◽  
Standard Curve ◽  
Volatile Organic ◽  
Volatile Organic Contaminants

Abstract Purge-and-trap gas chromatography/mass spectrometry is evaluated for the quantitation of part-per-billion levels of volatile organic contaminants in bulk vegetable oils. Results using 2 purge techniques (direct purging of the heated oil and purging after dispersing the oil on an aluminum oxide powder) and 2 quantitative methods (standard curve and deuterium-labeled internal standard addition) are reported. Twenty volatile compounds and 8 vegetable oils were investigated. Recovery data and estimated detection limits for each compound are reported for each purge technique. Generally acceptable recoveries (70-130% for more than 90% of the analyte spikes) and acceptable detection levels (approximately 4-10 ppb) were obtained for all compounds using either the external standard curve or the deuterium-isotope-labeled internal standard. The use of a dispersant (such as alumina) for sample purging resulted in poor recoveries of the highly volatile contaminants.

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