Adsorption of arsenic by humic acid

The adsorption and desorption of arsenic As(V) ions with peat humic acid as an adsorbent were investigated by using hydride generation atomic fluorescence spectrometry; the optimal conditions for the adsorption of As(V) in humic acid and the recovery of As(V) through desorption from the adsorbent were obtained. The results indicated that humic acid is provided with plentiful polar groups and exhibits strong adsorption ability for metal ions. The adsorption of As(V) ion in peat humic acid follows the Freundlich adsorption equation. The acidity of aqueous solution influences the adsorption significantly; the adsorption quantity is high and stable when the solution is neutral. The adsorption rate reaches 85.49% under the optimal conditions where As(V) concentration is 1μg/mL, pH value of the solution is 7 and adsorption time is 50min~60min. The most suitable conditions for the desorption are that pH value of the solution is 14 and desorption time is 20min.