The absorptive precipitation of sulfur dioxide from dilute gaseous mixtures with an aqueous solution of chromate was tested. The objective of the project was to combine detoxication of aqueous chromate with absorptive desulfurization of off-gas. The absorption process is based on the overall reaction Cr2O72- + 3 SO2 + 2 H+ double left right arrow 2 Cr3+ + 3 SO42- + H2O The mechanism of absorption was investigated in tests where the feed concentration of chromate was varied. The feed concentration of sulfur dioxide was held within the range of representative off-gas concentration levels (approximate to 3000 mg/m(3)). The literature has reported rate control of the process when pH values exceed 2. Detailed information about the influence of the concentration of chromate was not available. Therefore, the process was investigated relative to the influence of chromate on the rate of absorption for pH values below 2. The tests of mass transfer and rate control were based on experiments in a film absorption column.