Journal of Chemical Engineering of Japan, Vol.36, No.4, 477-485, 2003
Sorption kinetics of arsenic onto iron-conditioned zeolite
Iron-conditioned zeolite was prepared and used in arsenic removal from groundwater at pH 7.8+/-0.2 and temperature 293+/-1 K. The effects of initial arsenic concentration and intermittent agitation were investigated in a batch reaction vessel. Kinetics analysis showed that the adsorption reaction between arsenic and the binding surfaces (probably hydrous ferric oxide) can be approximated by a pseudosecond order rate equation and that chemical reaction is the essential rate-control ling step. The rate constant, the equilibrium sorption capacity and the initial arsenic sorption rate were calculated. The initial arsenic uptake and equilibrium uptake increased with an increase in initial concentration. The intermittent agitation was superior in arsenic uptake, compared to continuous agitation. The external and intra-particle diffusion resistances to mass transfer slightly varied with an increase in initial arsenic concentration.