Removal of Cr(VI) from chromium contaminated sites by washing with hot water

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:69808

Ososkov, V; Bozzelli, J W; Kebbekus, B B ^[1]

---

1. New Jersey Inst. of Technology, Newark, NJ (United States). Dept. of Chemical Engineering, Chemistry and Environmental Science

Extraction of chromium from a mixture of ore processing residue and soil (slag) by hot water and dilute alkali (0.01M NaOH) washing is studied. It was found that hexavalent chromium, which is the most dangerous and mobile form of chromium, can be effectively removed (95--99%) from slag by washing with these extraction solutions. The extracting liquid can be reused after removing the Cr(VI) ions by ion-exchange technologies. Trivalent chromium is strongly adsorbed by clay minerals and remains in the residue after this mild extraction. The hot water or mild hot alkali washing is recommended as a rapid and inexpensive treatment for chromium-contaminated sites to prevent chromium(VI) migration through soils into groundwater or dispersion as a dust into the atmosphere. Cr(III) remaining in the residue may then be left on-site, preferably with the addition of a reducing agent to prevent conversion to CR(VI) until further clean up is mandated.

• OSTI ID: 69808
• Report Number(s): CONF-941189--; ISBN 1-56590-016-2
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
CHROMIUM
IN-SITU PROCESSING
REMEDIAL ACTION
REMOVAL
SOILS
TECHNOLOGY ASSESSMENT
WATER POLLUTION CONTROL