Leaching of hexavalent chromium from crushed concrete

We investigated the amount of hexavalent chromium Cr(VI), which was released from the concrete waste crushed at the intermediate disposal processing plants located round Tokyo, and also examined the influences of various test conditions upon the amount of Cr(VI) released. As a result, it was found that the amount of Cr(VI) released from some of the samples was beyond the prescribed level and that some of the influencing factors upon the leaching characteristics were identified. It was difficult to evaluate the environmental safety of crushed concrete by single batch test.