Pedosphere 23(3): 402--408, 2013
ISSN 1002-0160/CN 32-1315/P
©2013 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Arsenite removal from simulated groundwater by biogenic schwertmannite: A column trial |
XIE Yue and ZHOU Li-Xiang |
| Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China) |
| ABSTRACT |
| To assess the feasibility of biogenic schwertmannite to act as a sorbent for removing arsenite from groundwater, a series of biogenic schwertmannite-packed column adsorption experiments were conducted on simulated As(III)-containing groundwater. Empty bed contact time (EBCT), As(III) concentration in effluent, and the removal efficiency of As(III) through the column were investigated at pH 8.0 and temperature 25 ± 0.5 °C. The results showed that the breakthrough curves were mainly dependent on EBCT values when the influent As(III) concentration was 500 μg L-1 and the optimum EBCT was 4.0 min. When the effluent As(III) concentration reached 10 and 50 μg L-1, the breakthrough volume for the schwertmannite adsorption columns were 4 200 and 5 600 bed volume (BV), with As(III) adsorption capacity of 2.1 and 2.8 mg g-1, respectively. Biogenic schwertmannite could be regenerated by 1.0 mol L-1 NaOH solution, and more than 80% of As(III) adsorbed on the surface of schwertmannite could be released after 3 successive regenerations. The breakthrough volume for the regenerated schwertmannite-packed column still maintained 4 000--4 200 BV when the As(III) concentration in effluent was below 10 μg L-1. Compared with other sorbents for As(III) removal, the biogenic schwertmannite-packed column had a higher breakthrough volume and a much higher adsorption capacity, implying that biogenic schwertmannite was a highly efficient and potential sorbent to purify As(III)-contaminated groundwater. |
| Key Words: As(III), adsorption capacity, breakthrough volume, empty bed contact time |
| Citation: Xie, Y. and Zhou, L. X. 2013. Arsenite removal from simulated groundwater by biogenic schwertmannite: A column trial. Pedosphere. 23(3): 402-408. |
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