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H. A. Stuber

Publications and source records attributed to H. A. Stuber.

3 recordsLinked to original sources
USGS2002

Selective concentration of aromatic bases from water with a resin adsorbent

Aromatic bases are concentrated from water on columns of a resin adsorbent and recovered by aqueous-acid elution. The degree of concentration attainable depends on the ratio of the capacity factor (k) of the neutral form of the amine to that of the ionized form. Capacity factors of ionic forms of amines on XAD-8 resin (a methylacrylic ester polymer) are greater than zero, ranging from 20 to 250 times lower than those of their neutral forms; they increase with increasing hydrophobicity of the amine. Thus, desorption by acid is an edition (k during desorption >0) rather than a displacement (k during desorption = 0) process. The degree of concentration attainable on XAD-8 resin varies with the hydrophobicity of the amine, being limited for hydrophilic solutes (for example, pyridine) by small neutral-form k's, reaching a maximum for amines of intermediate hydrophobicity (for example, quinoline), and decreasing for more hydrophobc solutes (for example, acridine) because of their large ionic-form k's.

Analytical Chemistry↗
USGS2002

Migration through soil of organic solutes in an oil-shale process water

The migration through soil of organic solutes in an oil-shale process water (retort water) was studied by using soil columns and analyzing leachates for various organic constituents. Retort water extracted significant quantities of organic anions leached from ammonium-saturated-soil organic matter, and a distilled-water rinse, which followed retort-water leaching, released additional organic acids from the soil. After being corrected for organic constitutents extracted from soil by retort water, dissolved-organic-carbon fractionation analyses of effluent fractions showed that the order of increasing affinity of six organic compound classes for the soil was as follows: hydrophilic neutrals nearly equal to hydrophilic acids, followed by the sequence of hydrophobic acids, hydrophilic bases, hydrophobic bases, and hydrophobic neutrals. Liquid-chromatographic analysis of the aromatic amines in the hydrophobic- and hydrophilic-base fractions showed that the relative order of the rates of migration through the soil column was the same as the order of migration on a reversed-phase, octadecylsilica liquid-chromatographic column.

Environmental Science & Technology↗