Migration of manganese and iron during the adsorption-regeneration cycles for arsenic removal |
| |
Authors: | Fangfang Chang Jiuhui Qu Xu Zhao Wenjun Liu and Kun Wu |
| |
Institution: | (1) Department of Biotechnology, University Prof Dr A. Zlatarov, Prof Y. Yakimov str.1, Bourgas, 8010, Bulgaria |
| |
Abstract: | Fe-Mn binary oxide incorporated into porous diatomite (FMBO-diatomite) was prepared in situ and regenerated in a fixed-bed
column for arsenite As(III)] and arsenate As(V)] removal. Four consecutive adsorption cycles were operated under the following
conditions: Initial arsenic concentration of 0.1 mg·L−1, empty bed contact time of 5 min, and pH 7.0. About 3000, 3300, 3800, and 4500 bed volumes of eligible effluent (arsenic
concentration ⩽ 0.01 mg·L−1) were obtained in four As (III) adsorption cycles; while about 2000, 2300, 2500, and 3100 bed volumes of eligible effluent
were obtained in four As(V) adsorption cycles. The dissection results of FMBO-diatomite fixed-bed exhibited that small amounts
of manganese and iron were transferred from the top of the fixed-bed to the bottom of the fixed-bed during As(III) removal
process. Compared to the extremely low concentration of iron (<0.01 mg·L−1), the fluctuation concentration of Mn2+ in effluent of the As(III) removal column was in a range of 0.01–0.08 mg·L−1. The release of manganese suggested that manganese oxides played an important role in As(III) oxidation. Determined with
the US EPA toxicity characteristic leaching procedure (TCLP), the leaching risk of As(III) on exhausted FMBO-diatomite was
lower than that of As(V). |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|