Adsorption sequence of toxic inorganic anions on a soil

The adsorption of six anions (arsenate(As(V)), chromate(Cr(VI)), fluoride(F(-I)), molybdate(Mo(VI)), selenate(Se(VI)), and selenite(Se(IV))) on an andosol and the concomitant H(+) consumptions together with the sorption were investigated to understand the behaviors of toxic inorganic anions in environment. Based on the estimated adsorption maximum by the simple Langmuir equation, the order of adsorption affinity to the andosol at a suspension pH of 5.0 was F(-I) > > phosphate(P(V)) > Se(IV) > Mo(VI) >= As(V) > > Se(VI) >= Cr(VI) >= nitrate(N(V)). The order of the concomitant H(+) consumptions together with the adsorption was F(-I) > > P(V) > Se(IV) > Mo(VI) >= As(V), while they were not observed in the adsorption of Se(VI), Cr(VI) and N(V).