Drift af jernspånefiltre til fjernelse af krom(VI) fra grundvand

Summary and conclusions

On the basis of theoretical considerations and laboratory tests it has been shown that water contaminated with dissolved chromium(VI) can be purified by means of contact with granular iron. The iron reduces the chromium(VI) to the less soluble chromium(III) that precipitates in the filter. Along with the laboratory tests a guideline was made for the design of a full-scale treatment plant to remove chromium(VI) from groundwater.

The laboratory test results and the design guideline were demonstrated during a remediation of chromium(VI) polluted soil and groundwater in Roskilde. The demonstration showed that the theoretical considerations and the design guideline both apply well to a full-scale treatment plant for on-site removal of chromium(VI) from groundwater. A considerable reduction of the chromium(VI) in the groundwater was obtained through the use of a granular iron filter.

During the future operation of the established water treatment plant further experience with chromium(VI) removal from groundwater is expected, especially concerning the purification capacity of the iron and thus the intervals between change of filter material.