The indigenous DRA and CRA have been identified as effective
adsorbents to remove different initial concentrations of
toxic Cr6+ ions from various types of its aqueous solutions.
The sorption process is related to the pH of solution, pH 1.0
is the optimal. The sorption kinetic data can be described
by the second-order kinetic and Elovich models. Furthermore,
the equilibrium data of sorption are in good agreement
with the four linear forms of Langmuir model. The CRA
exhibited high sorption capacity under several initial chromium
and sorbent dose concentrations. The sorption process
was found to be controlled by the film diffusion at lower concentrations
of the sorbate and shifted to particle diffusion at
high concentration. The proposed sorbents are efficient, environment
friendly and can reduce the huge amount of indiscriminate
effluent discharges around the small industry
concerns.