Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4433320 | Science of The Total Environment | 2007 | 5 Pages |
Natural red earth (hereafter NRE) was used as a novel adsorbent to examine its retention behaviour in different inorganic arsenic species (As (III) and As (V)) that are abundant in natural water. Adsorption isotherms were constructed at pH ∼ 5.5 for As(III) and As(V) in 0.01 M NaNO3 at 298K for 5 g/L NRE system. The initial arsenic [As(III) or As(V)] concentrations varied between ∼ 10− 5 and ∼ 10− 4 M. The experimental data were quantified using single site or stepwise Langmuir models. Sorption maximum, was observed at ∼ 0.173 mM of As(V). To reach the maximum surface coverage of red earth at pH ∼ 5.5 As(III) requires ∼ 0.308 mM of initial loading. When compared to As (III), As(V) shows strong affinity for NRE surface sites. This study suggests the potential of NRE as a starting material in decontaminating water polluted with As species.