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 Environmental
Engineering Capabilities
FACILITIES
The
Environmental Engineering Laboratory supports research,
small-scale studies, and teaching in environmental
technologies such as water and wastewater treatment,
and reactions of nutrients, organic pollutants, and
heavy metals in various media. The following instrumentation
is available in the laboratory.
- Perkin
Elmer 5100ZL Atomic Absorption Spectrophotometer
with graphite furnace. Trace analyses for numerous
metals, including lead, copper, cadmium, zinc,
nickel, cobalt, chromium, and selenium
- Perkin
Elmer 8500 Gas Chromatograph (FID and ECD). Detection
of volatile organic compounds, such as BTEX compounds.
- Waters
510/717 HPLC (UV detector) with autosampler. Detection
of non-volatile organic compounds, for example,
pesticides.
- Shimadzu
TOC-5000 Total Organic Carbon Analyzer with autosampler
and solid sampling module.
- Shimadzu
UV160U scanning UV/VIS Spectrophotometer.
- LKB
Wallac 1219 Liquid Scintillation Counter (for use
of radiotracers).
- EG&G
Scanning Potentiostat.
- Parr
Instruments High Pressure/Temperature Reactors
- Coulter
Counter Particle Counter
- Electrophoretic
Mobility Apparatus
- Various
Laboratory Equipment for analysis of pH, BOD, COD,
TSS, FOG, turbidity and nutrients.
- A
Dionex DX-100 ion chromatograph was received in
August 1995. This instrument will allow the quantification
of trace levels of various ions, such as nitrate,
chloride, phosphate, ammonia, and organic acids
in waters and wastewaters.
FACULTY
Primary
faculty in the environmental engineering area are
Drs. Allen P. Davis, Oliver J. Hao, Eric A. Seagren
and Alba Torrents. Dr. Davis is expert in
aquatic and surface environmental chemistry and the
chemical treatment of drinking water and industrial
waste waters. Dr. Hao and Dr. Seagren specialize
in the biological aspects of environmental engineering. Dr.
Torrents' specialization is in the transformations
and fate of organic pollutants in treatment systems
and the environment.
INDUSTRY
INTERACTIONS
Two
bench-scale studies were recently conducted in the Environmental
Engineering laboratory. One of these was with
valve manufacturer located on the eastern Shore.
This company produced a wastewater that contained
a large amount of oil, primarily from machine tool
lubrication and cooling. The wastewater treatment
system included an ultrafiltration system that frequently
became clogged with oil. Several tests on removal
of some of the oil before it entered the ultrafiltration
unit were conducted and recommendations to the company
were made.
A
local engraving plate manufacturing shop was having
difficulty meeting wastewater discharge requirements
for copper and zinc. Several tests were completed
in the laboratory for the optimization of the wastewater
treatment process. With this, several recommendations
were made to the company which wre instituted and
has subsequently brought them into compliance for
these metals. Work is ongoing with this company to
also handle a problem with lead discharge, with which
a very low discharge limit must be met.
Recently,
several companies that use a precipitation process
as part of their waste treatment scheme have requested
technical support with meeting wastewater discharge
limits for heavy metals, and optimization of the
wastewater treatment process. In response, a TES
TIPS report entitled "Removing Heavy Metals
from Wastewater using Hydroxide Precipitation" was
prepared for distribution to companies throughout
the State to assist them in understanding the capabilities
and limitations of this process.
RESEARCH
Several
research projects were initiated or ongoing over
the past year. Studies on the photocatalytic oxidation
of heavy metal complexes, sponsored by the National
Science Foundation, continue. In this process, exposure
of waters containing metal-EDTA complexes to light-activated
titanium dioxide will destroy the EDTA and allow
the concentration and treatment of the uncomplexed
metal. Metal complexes under evaluation include those
of lead, cobalt (II) & (III), cadmium, and nickel.
Evaluation
of sources and fluxes of heavy metals in urban runoff
is also under way. Sources of copper, lead, cadmium,
and zinc in stormwater runoff resulting from contact
with building materials and automobiles have been
quantified for the Prince George's County Government.
A more focused study on lead resulting from rainwater
contact with buildings, including those containing
lead paint, was recently initiated. This work is
sponsored by the Maryland Water Resources Research
Center.
In
another Maryland WRRC-sponsored project, the chemical
properties of mineral and organic soil phases that
influence the partitioning of pesticides onto soils
is under examination. With the use of probe organic
surfaces, natural organic matter (NOM) variability
that may induce changes in the overall pesticide
partitioning is identified. Models are being developed
to incorporate properties beyond the organic carbon
content onto the currently used predictive models.
In
a collaborative effort with USDA, different technologies
to remediate highly contaminated pesticide applicator
sites are being assessed. Extensive work has been
conducted on the ozonation of the herbicide bromacil.
A detailed mechanistic interpretation of the results
indicated that the ozonolysis of bromacil was shown
to proceed mainly via direct ozone attack, as opposed
to a hydroxy radical process, and affords a phytotoxic
product. Thus, our results suggest that if bromacil
is present in a waste stream and photolytic processes
are precluded, then conditions which favor a hydroxy
radical process (higher pH and H2O2 addition) would
be more advantageous.
PUBLICATIONS
Ayres,
D.M., Davis, A.P., and Gietka, P.M., "Removing
Heavy Metals from Wastewater Using Hydroxide Precipitation." The
first in a series of TES TIPS published by Technology
Extension Service, University of Maryland, College
Park, MD.
Davis,
A.P., Bernstein, C.L., and Gietka, P.M., "Waste
Minimization in Electropolishing: Process Control," Proc.
27th Mid-Atlantic Industrial and Hazardous Waste
Conference, (A.K. Sengupta, Ed.), 62-71, 1995.
Davis,
A.P. and Singh, I., "Washing of Zinc(II)
from a Contaminated Soil Column," J. Environ.
Eng., ASCE, 121(2), 174-185 (1995).
Davis,
A.P. and Bhatnagar, V., "Adsorption of Cadmium
and Humic Acid onto Hematite," Chemosphere,
30(2), 243-256 (1995).
Davis,
A.P., Ayres, D.M., and Vohra, M.S., "Photocatalytic
Oxidation of Cobalt(II)/(III)- and Pb(II)- EDTA Complexes," Proc.
5th Annual WERC Technology Development Conference,
Las Cruces, NM, 332-339, April 1995.
ERC
Fact Sheet describing the capabilities of the Environmental
Engineering Laboratory. Engineering Research
Center, University of Maryland, College Park, MD.
Stone,
A.T., Torrents, A., "The Role of Dissolved
Metals and Metal-Containing Surfaces in Catalyzing
the Hydrolysis of Organic Pollutants," In:
Environmental Impact of Soil Component Interactions,
P.M. Huang Ed., Lewis Publishers, Chelsea, MI, (1995).
PRESENTATIONS
Anderson,
B., Hapeman, C., and Torrents, A., "Photoinitiated
Atrazine Degradation in the Presence of DOC and Nitrate:
A Mass Balance Considered," Presented at
29th ACS Middle Atlantic Regional Meeting, ACS Abstract
ENV. 152, (1995).
Davis,
A.P., Bernstein, C.L., and Gietka, P.M., "Waste
Minimization in Electropolishing: Process Control," Presented
at the 27th Mid-Atlantic Industrial and Hazardous
Waste Conference, Bethlehem, PA, July 1995.
Hapeman,
C.J., Anderson, B., and Torrents, A., "Degradation
of Atrazine via Nitrate Mediated Photoinduced Hydroxy
Radical Processes-Determination of Products and Quantum
Yields," Presented at 209th ACS National
Meeting, Anaheim, CA, ACS Abstract AGRO 067, (1995).
Jayasundera,
S., and Torrents, A., "The Influence of Natural
Organic Matter on the Sorption of Nonionic Pesticides
by Clays," Presented at 29th ACS Middle
Atlantic Regional Meeting, ACS Abstract ENV. 151,
(1995).
Tagoe,
C-C, and Torrents, A., "Adsorption of Pentachlorophenol:
pH and Co-solvent Effects," Presented at
29th ACS Middle Atlantic Regional Meeting, ACS Abstract
ENV. 160 (Poster), (1995).
Zeinali,
M., and Torrents, A., "Titanium Catalyzed
Hydrolysis of Organic Esters," Presented
at 29th ACS Middle Atlantic Regional Meeting, ACS
Abstract ENV. 155, (1995).
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