posted on 2024-01-11, 22:30authored byXiaomeng Wang, Lijie Wang, Jingran Fu, Yiming Zhang, Yan Dong, Guanyu Zheng, Lixiang Zhou
Schwertmannite (Sch) is a promising environmental functional
material
for remediation of arsenic pollution, particularly arsenite [As(III)],
due to its unique adsorption mechanism. However, its application in
metal–metalloid cocontamination is greatly limited by its ineffective
immobilization of cationic metals. In this study, a preparation method
of chemical oxidation–pH elevation was proposed to optimize
the immobilization capacity of schwertmannite for As and cadmium [Cd(II)],
which referred to promoting solution pH to neutral conditions after
FeSO4–H2O2 chemical oxidation.
The resultant schwertmannite mixture (Sch-M) had a slightly increased
Fe content (by 14.2–17.7%) and a reduced sulfate content (by
24.5–42.1%) compared to Sch. Sch-M displayed stronger mineral
phase stability under anaerobic Fe(II)-catalyzed condition. The adsorption
capacity of Sch-M for As(III) was basically consistent with that of
Sch (172.9–211.3 vs 196.5 mg/g) and reached 19.7–22.4
mg/g for Cd(II) at pH 6.5. Sch-M performed better stabilization effects
for metals and metalloids in a contaminated soil than zerovalent iron.
In addition, its passivation ability was resistant to acidic conditions
(pH 2.6). The practical application of the Sch-based environmental
functional material in the remediation of metal(loid)-contaminated
soils is worthy of in-depth study.