Removal of trace levels of aromatic amines from aqueous solution by foam flotation

Journal Article · · Separation Science and Technology; (United States)

DOI:https://doi.org/10.1080/01496399008050368· OSTI ID:5520295

Nyssen, G A; White, J S ^[1]; Bibring, P; Wilson, D J ^[2]

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1. Trevecca Nazarene Coll., Nashville, TN (United States)
2. Vanderbilt Univ., Nashville, TN (United States)

Aromatic amines in general have a rather bad reputation in terms of their toxicity and carcinogenicity. Benzidine, 4-aminobiphenyl, and the naphthalamines are all regarded as carcinogens. The naphthylamines and 4-aminobiphenyl are present in coal products and are designated as priority pollutants by the US EPA. Methods for the removal of these compounds from aqueous wastes are therefore of some practical interest. 4-(n-Butyl)aniline and 4(t-butyl)pyridine were selected as model compounds for basic pollutants in coal products. Aromatic amines, including 4-(t-butyl)pyridine, 4-(n-butyl)aniline, benzylamine, 4-aminobiphenyl, 1- and 2-aminonaphthalene, and 2,6-xylidine, were effectively removed from water by foam flotation with the anionic surfactant sodium dodecylsulfate (SDS). With initial amine concentrations of 10 mg/l or less, residual amine concentrations of less than 0.1 mg/l were generally obtained after 10-30 min of flotation. The SDS concentration and flotation time are directly related to the amount of amine removed. Amine removal is most efficient at pH values low enough so that the amine is protonated (usually about 3), and at low ionic strength. Alcohols up to 10% by volume do not appreciably affect amine removal. The mechanism of removal is dominated by ion-ion attraction between the surfactant and the protonated amine; there is also apparently some contribution from ion-dipole attraction. Benzidine is not removed effectively; evidently it is insufficiently hydrophobic.

• OSTI ID: 5520295
• Journal Information: Separation Science and Technology; (United States), Journal Name: Separation Science and Technology; (United States) Vol. 25:7-8; ISSN SSTED; ISSN 0149-6395
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010800* -- Coal
Lignite
& Peat-- Waste Management
54 ENVIRONMENTAL SCIENCES
540220 -- Environment
Terrestrial-- Chemicals Monitoring & Transport-- (1990-)
540320 -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (1990-)
ALKALI METAL COMPOUNDS
AMINES
AROMATICS
CARBONACEOUS MATERIALS
COAL
COLLOIDS
DATA
DISPERSIONS
EFFICIENCY
ENERGY SOURCES
EXPERIMENTAL DATA
FLOTATION
FOAMS
FOSSIL FUELS
FUELS
HYDROGEN COMPOUNDS
INFORMATION
LIQUID WASTES
MATERIALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PERFORMANCE TESTING
PH VALUE
QUANTITY RATIO
REMOVAL
SEPARATION PROCESSES
SODIUM COMPOUNDS
SODIUM SULFATES
SULFATES
SULFUR COMPOUNDS
SURFACTANTS
TESTING
TIME DEPENDENCE
TRACE AMOUNTS
WASTE WATER
WASTES
WATER
WATER TREATMENT