Details

Autor(en) / Beteiligte

• Shi, Mingyan
• Zhang, Yali
• Hong, Weibin
• Liu, Jiayu
• Zhu, Huijie
• Liu, Xu
• Geng, Yuxin
• Cai, Zhenyin
• Lin, Shaonan
• Ni, Chengzhi

Titel

Mechanism of simultaneous lead and chromium removal from contaminated wastewater by a schwertmannite-like mineral

Ist Teil von

• Environmental science and pollution research international, 2022-12, Vol.29 (56), p.85364-85375

Ort / Verlag

Berlin/Heidelberg: Springer Berlin Heidelberg

Erscheinungsjahr

2022

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• In this study, a schwertmannite-like mineral was synthesized for the removal of lead (Pb) and chromium (Cr) from contaminated wastewater. A shaking flask test was performed (150 r/min, 1 h) with FeSO 4 ·7H 2 O, H 2 O 2 , Na 2 SiO 3 , and CaCl 2 added for the mineral synthesis reaction. Results show that optimal performance was achieved with the addition of 1.24 g/L FeSO 4 ·7H 2 O, 0.75 g/L H 2 O 2 , 1.27 g/L Na 2 SiO 3 , and 0.44 g/L CaCl 2 at a water temperature of 28 °C, with coexisting ion (Na + , K + , Mg 2+ ) concentrations of 1.50 mmol/L and 0.50 mmol/L EDTA as a complexing agent. Under these optimal conditions, maximum Pb and Cr removal rates of 95.08% and 97.99%, respectively, were achieved within the first 1 min of the mineral synthesis reaction, with the synthesis reaction completed by 6 min. The simultaneous removal of Pb and Cr during the schwertmannite-like material synthesis process occurred via electrostatic adsorption and coprecipitation. When the concentration of the complexing agent was increased from 0.75 to 6.03 mmol/L, the Pb removal rate decreased from 71.88 to 35.45%, and the Cr removal rate decreased from 95.13 to 75.07%, showing that Pb and Cr removal exhibited significant levels of inhibition. In contrast, varying reaction temperatures induced no significant differences. The Pb and Cr dissolution rates from Pb/Cr-containing schwertmannite-like minerals were 8.18% and 2.86% after 40 days, respectively. Therefore, the risk of secondary dissolution of heavy metals is small.