Assessment of hexavalent chromium stabilizer in artifically contaminated soil using geosta as a secondary binder

The aim of this study was to investigate the effect of a secondary binder (Geosta) as a stabilizer on the geotechnical properties of Cr+6 contaminated soils with the use of S/S technology and to evaluate the efficacy of different mix designs via the Static Diffusion Test. Artificial contamination with Cr+6 was applied in four representative samples of soil material, weighting approximately 15 Kg each. The initial chromium concentration per cube was estimated at 128.5 mg/l and all mix designs studied were shown to be capable of reducing hexavalent chromium concentrations from 96 to 99%. The mix design which contained 400 g of Geosta, proved to be the most effective since the lowest release of chromium with maximum chromium retention (99.4%) was documented. Mix designs with 200 and 300 g of Geosta were considered to be successful in Cr+6 immobilization (with a total of 99.1 and 99% retention ability, respectively), however it was proved that the quantity of secondary binder used in a mix design is not proportional to its chromium retention capability.