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.