共 55 条
Effects of nitrate on the treatment of lead contaminated groundwater by nanoscale zerovalent iron
被引:36
作者:
Su, Yiming
[1
,2
,3
]
Adeleye, Adeyemi S.
[2
,3
]
Zhou, Xuefei
[1
]
Dai, Chaomeng
[1
,4
]
Zhang, Weixian
[1
]
Keller, Arturo A.
[2
,3
]
Zhang, Yalei
[1
]
机构:
[1] Tongji Univ, State Key Lab Pollut Control & Resources Reuse, Shanghai 200092, Peoples R China
[2] Univ Calif Santa Barbara, Bren Sch Environm Sci & Management, Santa Barbara, CA 93106 USA
[3] Univ Calif Santa Barbara, Ctr Environm Implicat Nanotechnol, Santa Barbara, CA 93106 USA
[4] Tongji Univ, Coll Civil Engn, Shanghai 200092, Peoples R China
基金:
中国国家自然科学基金;
关键词:
Nanoscale zerovalent iron;
Lead pollution;
Nitrate influence;
Ferrite process;
Oxidation-reduction potential;
ZERO-VALENT IRON;
TEMPERATURE FERRITE PROCESS;
CORE-SHELL STRUCTURE;
DRINKING-WATER;
AQUEOUS-SOLUTION;
NANOPARTICLES;
REMOVAL;
REACTIVITY;
REDUCTION;
PARTICLES;
D O I:
10.1016/j.jhazmat.2014.08.040
中图分类号:
X [环境科学、安全科学];
学科分类号:
08 ;
0830 ;
摘要:
Nanoscale zerovalent iron (nZVI) is efficient for removing Pb2+ and nitrate from water. However, the influence of nitrate, a common groundwater anion, on Pb2+ removal by nZVI is not well understood. In this study, we showed that under excess Fe conditions (molar ratio of Fe-0/nitrate > 4), Pb2+ ions were immobilized more quickly (<5 min) than in nitrate-free systems (similar to 15 min) due to increasing pH. With nitrate in excess (molar ratio of Fe-0/nitrate < 4), nitrate stimulated the formation of crystal PbxFe3-xO4 (ferrite), which provided additional Pb2+ removal. However, similar to 7% of immobilized Pb2+ ions were released into aqueous phase within 2 h due to ferrite deformation. Oxidation-reduction potential (ORP) values below -600 mV correlated with excess Fe-0 conditions (complete Pb2+ immobilization), while ORP values >=-475 mV characterized excess nitrate conditions (ferrite process and Pb2+ release occurrence). This study indicates that ORP monitoring is important for proper management of nZVI-based remediation in the subsurface to avoid lead remobilization in the presence of nitrate. (C) 2014 Elsevier B.V. All rights reserved.
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页码:504 / 513
页数:10
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