New Conference Proceedings Papers: ISCR, ZVZ, and nZVI

[PGT]

When the proceedings of the 2010 Battelle Chlorcon Meeting in
Monterey, CA, are finally published, they will include three short
papers from our work. Preprints of these papers available now at:
http://www.ebs.ogi.edu/tratnyek/resources/docs/.


1. Tratnyek, P. G. 2010. Chemical reductants for ISCR: The potential
for improvement. International Conference on Remediation of
Chlorinated and Recalcitrant Compounds, 7th. Monterey, CA. Proceedings
of the International Conference on Remediation of Chlorinated and
Recalcitrant Compounds, 7th; Paper #794, 8 pp.

Abstract: The abiotic reduction reactions that form the basis of in
situ chemical reduction (ISCR) have been studied extensively, but
there has been little effort to develop a unified understanding of
what factors control ISCR performance. Some of the key factors are
summarized here, with the ultimate goal of building a basis for
rational design of better ISCR reductants.

Direct link: http://www.ebs.ogi.edu/tratnyek/resources/docs/Tratnyek10-ISCR-Chlorcon794.pdf


2. Salter, A. J., R. L. Johnson, and G. Tratnyek Paul. 2010.
Degradation of 1,2,3-trichloropropane by zero-valent zinc: Laboratory
assessment for field application. International Conference on
Remediation of Chlorinated and Recalcitrant Compounds, 7th. Monterey,
CA. Proceedings of the International Conference on Remediation of
Chlorinated and Recalcitrant Compounds, 7th; Paper #525, 9 pp.

Abstract: Bench-scale batch reactor and column tests were performed to
identify types of granular zero-valent zinc (ZVZ) that might be
suitable for remediation of 1,2,3- trichloropropane (TCP) contaminated
groundwater. Two industrial grade materials, Zn64 and Zn1210, were
selected for further analysis in a scaled-up, ex-situ field test.
Groundwater was found to inhibit the reduction of TCP by zinc, but
this affect was overcome in some instances by lowering pH. Also
illustrated are several of the general issues involved in scaling
between batch and column data for treatments with zero-valent metals.

Direct Link: http://www.ebs.ogi.edu/tratnyek/resources/docs/Salter10-TCPvsZVZ-Chlorcon525.pdf


3. Johnson, R. L., J. T. Nurmi, R. O. B. Johnson, Z. Shi, P. G.
Tratnyek, T. Phenrat, and G. V. Lowry. 2010. Injection of nano zero-
valent iron for subsurface remediation: A controlled field-scale test
of transport. International Conference on Remediation of Chlorinated
and Recalcitrant Compounds, 7th. Monterey, CA. Proceedings of the
International Conference on Remediation of Chlorinated and
Recalcitrant Compounds, 7th; Paper #793, 6 pp.

Abstract: A large, controlled nZVI injection experiment was conducted
to compare transport distances predicted using a simple filtration
model based on laboratory column experiments to observed field-scale
transport. The column and model data indicated that a very high
minimum velocity (~35 m/day) would be required to transport the nZVI
through the subsurface. That velocity is difficult to maintain over
distances of meters in medium sand or finer materials, but was
accomplished using pairs of injection and extraction wells located
2.5m apart, which produced a hydraulic gradient of nearly unity. The
data indicate that the nZVI was not transported as effectively as the
laboratory data predicted. In addition, removal efficiencies within 5
cm of the injection well were significant and appeared to increase
over time. The experiment highlights some of the challenges in
transporting nZVI in the subsurface and points to the need for robust
diagnostic tools for characterization of flow pathways and monitoring
of nZVI transport.

Direct Link: http://www.ebs.ogi.edu/tratnyek/resources/docs/Johnson10-nZVI-Chlorcon793.pdf