FAAS Determination of Manganese in Waste Water with Separation and Pre-Enrichment by Using Nano-Attapulgite

Manganese(Ⅱ) in waste water was effectively separated and preconcentrated by adsorption on powdered nano-attapulgite based on its predominant specific surface and adsorption characteristics.Adsorption behavior of the nano-attapulgite towand manganese(Ⅱ) were studied in detail.It was found that under optimum condition,static saturated adsorption capacity tested on the base of 0.020 g nano-attapulgite was found to be 6.13 mg·g-1;and a recovery of over 92% was achieved when manganese(Ⅱ) in a solution of pH 4 was shaked with 0.500 g of nano-attapulgite for 5 min and stayed for 6 h.Manganese on the attapulgite was desorbed with 25 mL of 0.5 mol·L-1 HCl by shaking for 3 min and staying for 3 h.Values of recovery of the desorption process found were above 95%.Desorbed manganese(Ⅱ) in hydrochloric acid was determined by FAAS.The proposed method was applied to the determination of manganese in waste water samples from phosphorizing process,giving values of detection limit (3σ),RSD′s (n=11) and recovery of 0.002 3 mg·L-1,1.0% and in the range of 92.5% to 99.0% respectively.