Nano-TiO₂ enhances the adsorption of Cd(II) on biological soil crusts under mildly acidic conditions

TY - JOUR

T1 - Nano-TiO2 enhances the adsorption of Cd(II) on biological soil crusts under mildly acidic conditions

AU - Kuang, Xiaolin

AU - Shao, Jihai

AU - Peng, Liang

AU - Song, Huijuan

AU - Wei, Xiangdong

AU - Luo, Si

AU - Gu, Ji dong

N1 - Publisher Copyright: © 2019

PY - 2020/2

Y1 - 2020/2

N2 - Biological soil crusts (BSCs), which are ubiquitous in paddy fields, are known to remove pollutants from paddy fields systems. The Nano-TiO2 enhanced the removal of Cd(II) by BSC under acidic irrigation water was found, and its mechanism was investigated. After the addition of nano-TiO2, the Cd(II) removal efficiency of BSCS increased by 26.70% than that of pure BSCs, and the Nano-TiO2 induced faster removal velocity as well. Zeta potential and potentiometric titration results revealed that BSCs generated more negative charges and sites concentration after addition of Nano-TiO2 at acidic environment. The carboxyl and amino/hydroxyl groups were the main functional groups on BSC and the BSC + TiO2. The higher concentration of amino/hydroxyl groups in BSC + TiO2 (0.33 ± 0.08 mmol/g) was present than that of pristine BSCs (0.62 ± 0.02 mmol/g), and they were with similar concentration of phosphate groups and carboxyl groups. This result was attributed to the Nano-TiO2 stimulated the BSCs to produce more extracellular polysaccharides and proteins. Our findings would provide novel strategy for the removal of cadmium from acidic irrigation water.

AB - Biological soil crusts (BSCs), which are ubiquitous in paddy fields, are known to remove pollutants from paddy fields systems. The Nano-TiO2 enhanced the removal of Cd(II) by BSC under acidic irrigation water was found, and its mechanism was investigated. After the addition of nano-TiO2, the Cd(II) removal efficiency of BSCS increased by 26.70% than that of pure BSCs, and the Nano-TiO2 induced faster removal velocity as well. Zeta potential and potentiometric titration results revealed that BSCs generated more negative charges and sites concentration after addition of Nano-TiO2 at acidic environment. The carboxyl and amino/hydroxyl groups were the main functional groups on BSC and the BSC + TiO2. The higher concentration of amino/hydroxyl groups in BSC + TiO2 (0.33 ± 0.08 mmol/g) was present than that of pristine BSCs (0.62 ± 0.02 mmol/g), and they were with similar concentration of phosphate groups and carboxyl groups. This result was attributed to the Nano-TiO2 stimulated the BSCs to produce more extracellular polysaccharides and proteins. Our findings would provide novel strategy for the removal of cadmium from acidic irrigation water.

KW - Biological soil crusts

KW - Heavy metals

KW - Irrigation water

KW - Nanoparticles

KW - Zeta potential

UR - http://www.scopus.com/inward/record.url?scp=85076625984&partnerID=8YFLogxK

U2 - 10.1016/j.jconhyd.2019.103583

DO - 10.1016/j.jconhyd.2019.103583

M3 - 文章

C2 - 31818435

AN - SCOPUS:85076625984

SN - 0169-7722

VL - 229

JO - Journal of Contaminant Hydrology

JF - Journal of Contaminant Hydrology

M1 - 103583

ER -