Transport and Interaction of Colloids and Mercury in Contaminated Soil and Sand Porous Media

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Material Information

Title:
Transport and Interaction of Colloids and Mercury in Contaminated Soil and Sand Porous Media
Physical Description:
1 online resource (133 p.)
Language:
english
Creator:
Zhu, Yingjia
Publisher:
University of Florida
Place of Publication:
Gainesville, Fla.
Publication Date:

Thesis/Dissertation Information

Degree:
Doctorate ( Ph.D.)
Degree Grantor:
University of Florida
Degree Disciplines:
Soil and Water Science
Committee Chair:
MA,LENA Q
Committee Co-Chair:
HARRIS,WILLIE G,JR
Committee Members:
GU,BINHE
GAO,BIN
BONZONGO,JEAN-CLAUDE J

Subjects

Subjects / Keywords:
colloid -- mercury -- model -- nanoparticle -- transport
Soil and Water Science -- Dissertations, Academic -- UF
Genre:
Soil and Water Science thesis, Ph.D.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract:
Mercury is a particular environmental concern due to its toxicity for human and widely exist in aquatic ecosystems as a result of anthropogenic activities and natural earth processes. As particle-reactive element, it is important to examine colloids and nanoparticles facilitated Hg transport in contaminated soil. The objective of this dissertation was to study how Hg, colloids and nanoparticle interaction and transport in soils.  First, kaolinite was used as example of colloids which widely present in soils, Hg sorption by kaolinite were nonlinear and fit the Langmuir model, with the maximum Hg sorption capacity being 1.2 mg/g. Column experiments showed that kaolinite serving as a carrier enhanced Hg transport in the sand media when Hg was loaded onto kaolinite before transport, or stripping Hg off the sand media when Hg was loaded on sand during transport. Second, the effects of reducing ionic strength and flow interruption for 7 days on colloid and Hg release in the leachate were examined in column experiment. Hg concentrations in colloids being 2-4 times greater than bulk soils. Column leaching after IS reduction and FI released large amounts of colloidal Hg, accounting for 44-48% of released Hg. Most of the released colloidal Hg was in OM fraction (37-53%).  Based on composition of released colloids and Hg fractionation in soils and colloids, colloidal OM could serve as an important carrier for Hg transport in soils. In addition, the fate and transport of HgS nanoparticle in saturated sand porous media were studies. We conducted column experiments using 25 nm HgS nanoparticles to investigate the effects of ionic strength (2-50 mM),pH (4- 10) and humic acid (0- 20 mg/L) on their retention and transport.Results showed that the increase in solution ionic strength and decease in pH resulted in distinct increase in HgS retention in sand. The presence of humic acid in solution markedly enhanced the HgS mobility. Overall, this research provides abetter understanding of the fate of transport of Hg associated colloids and nanoparticles in soil and saturated sand system. It could be used for risk assessment of Hg in contaminate sites.
General Note:
In the series University of Florida Digital Collections.
General Note:
Includes vita.
Bibliography:
Includes bibliographical references.
Source of Description:
Description based on online resource; title from PDF title page.
Source of Description:
This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility:
by Yingjia Zhu.
Thesis:
Thesis (Ph.D.)--University of Florida, 2013.
Local:
Adviser: MA,LENA Q.
Local:
Co-adviser: HARRIS,WILLIE G,JR.
Electronic Access:
RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2014-12-31

Record Information

Source Institution:
UFRGP
Rights Management:
Applicable rights reserved.
Classification:
lcc - LD1780 2013
System ID:
UFE0046193:00001