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Enhanced nitrate-nitrogen removal by modified attapulgite-supported nanoscale zero-valent iron treating simulated groundwater

Dong, Lei; Lin, Li; Li, Qingyun; Huang, Zhuo; Tang, Xianqiang; Wu, Min; Li, Chao; Cao, Xiaohuan and Scholz, Miklas LU (2018) In Journal of Environmental Management 213. p.151-158
Abstract

Attapulgite (or palygorskite) is a magnesium aluminium phyllosilicate. Modified attapulgite-supported nanoscale zero-valent iron (NZVI) was created by a liquid-phase reduction method and then applied for nitrate-nitrogen (NO3-N) removal (transformation) in simulated groundwater. Nanoscale zero-valent iron was sufficiently dispersed on the surface of thermally modified attapulgite. The NO3-N removal efficiency reached up to approximately 83.8% with an initial pH values of 7.0. The corresponding thermally modified attapulgite-supported nanoscale zero-valent iron (TATP-NZVI) and NO3-N concentrations were 2.0 g/L and 20 mg/L respectively. Moreover, 72.1% of the water column NO3-N was converted to... (More)

Attapulgite (or palygorskite) is a magnesium aluminium phyllosilicate. Modified attapulgite-supported nanoscale zero-valent iron (NZVI) was created by a liquid-phase reduction method and then applied for nitrate-nitrogen (NO3-N) removal (transformation) in simulated groundwater. Nanoscale zero-valent iron was sufficiently dispersed on the surface of thermally modified attapulgite. The NO3-N removal efficiency reached up to approximately 83.8% with an initial pH values of 7.0. The corresponding thermally modified attapulgite-supported nanoscale zero-valent iron (TATP-NZVI) and NO3-N concentrations were 2.0 g/L and 20 mg/L respectively. Moreover, 72.1% of the water column NO3-N was converted to ammonium-nitrogen (NH4-N) within 6 h. The influence of environmental boundary conditions including dissolved oxygen (DO) concentration, light illumination and water temperature on NO3-N removal was also investigated with batch experiments. The results indicated that the DO concentration greatly impacted on NO3-N removal in the TATP-NZVI-contained solution, and the NO3-N removal efficiencies were 58.5% and 83.3% with the corresponding DO concentrations of 9.0 and 0.3 mg/L after 6 h of treatment, respectively. Compared to DO concentrations, no significant (p > 0.05) effect of light illumination on NO3-N removal and NH4-N generation was detected. The water temperature also has great importance concerning NO3-N reduction, and the removal efficiency of NO3-N at 25 °C was 1.25 times than that at 15 °C. For groundwater, therefore, environmental factors such as water temperature, anaerobic conditions and darkness could influence the NO3-N removal efficiency when TATP-NZVI is present. This study also demonstrated that TATP-NZVI has the potential to be developed as a suitable material for direct remediation of NO3-N-contaminated groundwater.

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organization
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type
Contribution to journal
publication status
published
subject
keywords
Attapulgite-supported nanoscale zero-valent iron, Environmental boundary conditions, Groundwater quality control technology, Nitrate-nitrogen transformation, Palygorskite, Pollution treatment, Thermally modified
in
Journal of Environmental Management
volume
213
pages
8 pages
publisher
Academic Press
external identifiers
  • scopus:85042473930
ISSN
0301-4797
DOI
10.1016/j.jenvman.2018.02.073
language
English
LU publication?
yes
id
9d6ec192-06a5-43b8-90ef-d7d8dc84756f
date added to LUP
2018-03-08 10:20:04
date last changed
2018-05-29 09:50:41
@article{9d6ec192-06a5-43b8-90ef-d7d8dc84756f,
  abstract     = {<p>Attapulgite (or palygorskite) is a magnesium aluminium phyllosilicate. Modified attapulgite-supported nanoscale zero-valent iron (NZVI) was created by a liquid-phase reduction method and then applied for nitrate-nitrogen (NO<sub>3</sub>-N) removal (transformation) in simulated groundwater. Nanoscale zero-valent iron was sufficiently dispersed on the surface of thermally modified attapulgite. The NO<sub>3</sub>-N removal efficiency reached up to approximately 83.8% with an initial pH values of 7.0. The corresponding thermally modified attapulgite-supported nanoscale zero-valent iron (TATP-NZVI) and NO<sub>3</sub>-N concentrations were 2.0 g/L and 20 mg/L respectively. Moreover, 72.1% of the water column NO<sub>3</sub>-N was converted to ammonium-nitrogen (NH<sub>4</sub>-N) within 6 h. The influence of environmental boundary conditions including dissolved oxygen (DO) concentration, light illumination and water temperature on NO<sub>3</sub>-N removal was also investigated with batch experiments. The results indicated that the DO concentration greatly impacted on NO<sub>3</sub>-N removal in the TATP-NZVI-contained solution, and the NO<sub>3</sub>-N removal efficiencies were 58.5% and 83.3% with the corresponding DO concentrations of 9.0 and 0.3 mg/L after 6 h of treatment, respectively. Compared to DO concentrations, no significant (p &gt; 0.05) effect of light illumination on NO<sub>3</sub>-N removal and NH<sub>4</sub>-N generation was detected. The water temperature also has great importance concerning NO<sub>3</sub>-N reduction, and the removal efficiency of NO<sub>3</sub>-N at 25 °C was 1.25 times than that at 15 °C. For groundwater, therefore, environmental factors such as water temperature, anaerobic conditions and darkness could influence the NO<sub>3</sub>-N removal efficiency when TATP-NZVI is present. This study also demonstrated that TATP-NZVI has the potential to be developed as a suitable material for direct remediation of NO<sub>3</sub>-N-contaminated groundwater.</p>},
  author       = {Dong, Lei and Lin, Li and Li, Qingyun and Huang, Zhuo and Tang, Xianqiang and Wu, Min and Li, Chao and Cao, Xiaohuan and Scholz, Miklas},
  issn         = {0301-4797},
  keyword      = {Attapulgite-supported nanoscale zero-valent iron,Environmental boundary conditions,Groundwater quality control technology,Nitrate-nitrogen transformation,Palygorskite,Pollution treatment,Thermally modified},
  language     = {eng},
  month        = {05},
  pages        = {151--158},
  publisher    = {Academic Press},
  series       = {Journal of Environmental Management},
  title        = {Enhanced nitrate-nitrogen removal by modified attapulgite-supported nanoscale zero-valent iron treating simulated groundwater},
  url          = {http://dx.doi.org/10.1016/j.jenvman.2018.02.073},
  volume       = {213},
  year         = {2018},
}