Comparison of the colloidal stability, mobility, and performance of nanoscale zerovalent iron and sulfidated derivatives

JOURNAL OF HAZARDOUS MATERIALS

卷:396

Article

Su, Yiming¹  Jassby, David¹  Zhang, Yalei²  Keller, Arturo A.^3,4  Adeleye, Adeyemi S.⁵ 

[1] Univ Calif Los Angeles, Dept Civil & Environm Engn, Los Angeles, CA 90095 USA

[2] Tongji Univ, Minist Educ, Key Lab Yangtze Water Environm, State Key Lab Pollut Control & Resources Reuse, Shanghai 200092, Peoples R China

[3] Univ Calif Santa Barbara, Bren Sch Environm Sci & Management, Santa Barbara, CA 93106 USA

[4] Univ Calif Santa Barbara, Ctr Environm Implicat Nanotechnol, Santa Barbara, CA 93106 USA

[5] Univ Calif Irvine, Dept Civil & Environm Engn, Irvine, CA 92697 USA

关键词: nZVI;    Nanoremediation;    Colloidal stability;    Particle transport;    Metal sequestration;   

DOI  :  10.1016/j.jhazmat.2020.122691

来源: Elsevier

【 摘 要 】

Nanoscale zerovalent iron (nZVI) and sulfidated nanoscale zerovalent iron (S-nZVI) have been increasingly studied for heavy metal removal in the subsurface. However, a comprehensive comparison of the effectiveness of the technologies and the stability of derived metal-adsorbed composites is lacking. In this study, we evaluated the colloidal stability and transport of nZVI, S-nZVI and S-nZVI modified with nanosized silica (FeSSi). Furthermore, we monitored the metal immobilization performance of the three nanoparticles (NPs) under anoxic conditions in synthetic groundwater for 30 days. The NP-metal composites were thereafter discharged into a river water and metal remobilization was monitored for 20 days. Sulfidation improved the colloidal stability of nZVI in both simple media and in natural waters, although a lower initial agglomeration rate constant (k(a)) was observed in unmodified nZVI at acidic pH. The transport of nZVI in saturated soil column was enhanced with sulfidation due to decreased electrostatic attraction between the NPs and sand. The three NPs sequestered more than 80 % of Cu2+, Zn2+, Cd2+ and Cr2O72- from groundwater. Among the three NPs tested, S-nZVI had a slightly higher removal capacity for metals than nZVI in synthetic groundwater and the chemical stability of metal-S-nZVI composites upon discharge into river water was the highest.

【 授权许可】

Free