Zeng Huiping, Zhao Weihua, Sun Siqi, Sun Xiao, Zeng Yuwei, Hao Ruixia, Zhang Jie, Li Dong
Key Laboratory of Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China.
Key Laboratory of Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
Sci Total Environ. 2024 Jan 1;906:167575. doi: 10.1016/j.scitotenv.2023.167575. Epub 2023 Oct 6.
In this study, we demonstrated the effective acquisition of magnetic iron oxide (MIO) for As(V) adsorption by high-temperature pyrolysis of waste iron sludge from the water treatment plant under a confined environment without adding extra chemical reagents. The operating temperature and time in the pyrolysis process were optimized to improve the yield of MIO and its As(V) adsorption capacity. MIO(500 °C, 2 h) had both relatively high yield and arsenic adsorption efficiency, which was characterized by XRD and XPS as mainly γ-FeO with small particle size (100-900 nm), significant mesopore (12.43 nm), high specific surface area (65.25 m/g), and effective saturation magnetization intensity (14.45 emu/g). The maximum adsorption capacity was 14.2 ± 0.4 mg/g, and the removal rate could still reach about 80 % after five times of adsorbent regeneration. Considering this facile preparation route and its high yield, large-scale production of MIO from waste iron sludge is feasible, which is expected to provide a low-cost and efficient adsorbent for the treatment of arsenic-containing water in less economically developed areas.
