TY - JOUR
T1 - Enhancement of Zinc Ion Removal from Water by Physically Mixed Particles of Iron/Iron Sulfide
AU - Kamba, Yuya
AU - Ueta, Miharu
AU - Uddin, Md Azhar
AU - Kato, Yoshiei
N1 - Publisher Copyright:
© 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG part of Springer Nature.
PY - 2021/1
Y1 - 2021/1
N2 - Zinc (Zn) removal by physically mixed particles of zero-valent iron (Fe) and iron sulfide (FeS) was investigated as one technology for Zn removal from waste groundwater. The effects of the Fe/FeS mass ratio, including a single Fe and FeS particles, and pH on changes in the concentrations of Zn, Fe, and S were examined by a batch test and column tests, and the mechanism of Zn elimination was discussed. Among all the mixing fractions of Fe and FeS, Zn was eliminated most effectively by 3Fe/7FeS (mass ratio of Fe/FeS = 3/7). The Zn removal rate decreased in the order of 3Fe/7FeS, FeS, and Fe, whereas the Fe concentration decreased in the order of Fe, FeS, and 3Fe/7FeS. The S concentration of FeS was larger than that of 3Fe/7FeS. The Zn removal rate by physically mixed 3Fe/7FeS particles was enhanced by a local cell reaction between the Fe and FeS particles. The electrons caused by Fe corrosion moved to the FeS surface and reduced the dissolved oxygen in the solution. Zn2+, Fe2+, and OH− ions in the solution were then coprecipitated on the particles as ZnFe2(OH)6 and oxidized to ZnFe2O4. Moreover, Zn2+ was sulfurized as ZnS by both the Fe/FeS mixture and the simple FeS particles. The Zn removal rate increased with increasing pH in the range from pH 3 to 7. From a kinetic analysis of Zn removal, the rate constant of anode (Fe)/cathode (FeS) reaction was almost the same as that of ZnS formation and slightly larger than that of Fe alone.
AB - Zinc (Zn) removal by physically mixed particles of zero-valent iron (Fe) and iron sulfide (FeS) was investigated as one technology for Zn removal from waste groundwater. The effects of the Fe/FeS mass ratio, including a single Fe and FeS particles, and pH on changes in the concentrations of Zn, Fe, and S were examined by a batch test and column tests, and the mechanism of Zn elimination was discussed. Among all the mixing fractions of Fe and FeS, Zn was eliminated most effectively by 3Fe/7FeS (mass ratio of Fe/FeS = 3/7). The Zn removal rate decreased in the order of 3Fe/7FeS, FeS, and Fe, whereas the Fe concentration decreased in the order of Fe, FeS, and 3Fe/7FeS. The S concentration of FeS was larger than that of 3Fe/7FeS. The Zn removal rate by physically mixed 3Fe/7FeS particles was enhanced by a local cell reaction between the Fe and FeS particles. The electrons caused by Fe corrosion moved to the FeS surface and reduced the dissolved oxygen in the solution. Zn2+, Fe2+, and OH− ions in the solution were then coprecipitated on the particles as ZnFe2(OH)6 and oxidized to ZnFe2O4. Moreover, Zn2+ was sulfurized as ZnS by both the Fe/FeS mixture and the simple FeS particles. The Zn removal rate increased with increasing pH in the range from pH 3 to 7. From a kinetic analysis of Zn removal, the rate constant of anode (Fe)/cathode (FeS) reaction was almost the same as that of ZnS formation and slightly larger than that of Fe alone.
KW - Groundwater treatment
KW - Iron sulfide
KW - Zero-valent iron
KW - Zinc ion
KW - Zinc removal
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U2 - 10.1007/s11270-020-04966-4
DO - 10.1007/s11270-020-04966-4
M3 - Article
AN - SCOPUS:85098882079
SN - 0049-6979
VL - 232
JO - Water, Air, and Soil Pollution
JF - Water, Air, and Soil Pollution
IS - 1
M1 - 17
ER -