| Abstract
| - The current research focuses on enhanced removal ofchromate and perchloroethylene from contaminated waterby a combination of a reduction material (representedby zerovalent iron, ZVI) and a sorption material (representedby surfactant-modified zeolite, SMZ). Natural zeolite andZVI were homogenized and pelletized to maintain favorablehydraulic properties while minimizing material segregationdue to bulk density differences. The zeolite/ZVI pelletswere modified with the cationic surfactant hexadecyltrimethylammonium bromide to increase contaminant sorptionand, thus, the contaminant concentration on the solidsurface. Results of chromate sorption/reduction indicatethat the chromate sorption capacity of pelletized SMZ/ZVIis at least 1 order of magnitude higher than that of zeolite/ZVI pellets. Compared to SMZ pellets, the chromate removalcapacity of SMZ/ZVI pellets in a 24-h period is about80% higher, due to the combined effects of sorption bySMZ and reduction by ZVI. The chromate and PCE degradationrates with and without surfactant modification weredetermined separately. The pseudo-first-order reductionconstant increased by a factor of 3 for PCE and by a factorof 9 for chromate following surfactant modification. Theenhanced contaminant reduction capacity of SMZ/ZVI pelletsmay lead to a decrease in the amount of material requiredto achieve a given level of contaminant removal.
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