The effectiveness of cement based treatment technology, in immobilizing chromium laden electroplating sludge was
assessed by conducting toxicity characteristic leaching procedure (TCLP). The mechanical stability of the blocks was
tested by measuring the compressive strength. Other leaching tests such as NEN 7341 test, ANS 16.1 and multiple
TCLP (MTCLP) test conducted on select solidified blocks showed that chromium was immobilized by the binder studied.
A linear relationship was obtained between the cumulative fraction of chromium leached (CFL) and square root of
time in the solidified samples proving that diffusion is the controlling mechanism for leaching of chromium. The leachability
indices (LI) obtained for the solidified materials using cement and cement-fly ash system (EPC6, EPFC6A and
EPFC6B) satisfy the guidance value as per US NRC, which clearly indicates that chromium is well retained within the
solid matrix. Chromium concentrations in the TCLP leachates of the above mix ratios were well within the regulatory
level of United States Environmental Protection Agency (USEPA). Molecular characterization of the solidified material was carried out using Fourier transformation infra red (FTIR) technique