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Removal
of Lead (II) from Drinking Water Using Plant Based Product
Kishore
K. Krishnani, Stevens Institute of Technology, Hoboken, NJ
Xioaguang Meng, Stevens Institute of Technology, Hoboken,
NJ
Reba Mukherjee, Stevens Institute of Technology, Hoboken,
NJ
Gold
Mining and Mercury Pollution in the Ghanaian Pra River
Basin, West Africa
Augustine
K. Donkor, University of Florida, Gainesville, FL
Jean-Claude J. Bonzongo, University of Florida,
Gainesville, FL
Vincent K. Nartey, University of Ghana, Legon-Accra,
Ghana,
Chitosan
Immobilized on Sand – An Innovative Cu Adsorbent
Meng-Wei
Wan, University of Southern California, Los Angeles, CA
Ioana G. Petrisor, DPRA Inc., San Marcos, CA
Hsuan-Ting Lai, Daeik Kim, Teh Fu Yen, University of
Southern California, Los Angeles, CA
Formation
and Stability of Mixed Metal Hydroxide Phases in
Contaminated Soils
Edward
Peltier, Plant and Soil Sciences, Newark, DE
David H. McNear Jr., Plant and Soil Sciences, Newark, DE
Donald L. Sparks, Plant and Soil Sciences, Newark, DE
Electrokinetic
Treatment of Copper, Chromium and Arsenic Contaminated
Soil from Wood Preservative Industries
Prashanth
R Buchireddy, Mississippi State University, MS
Dr. Mark R Bricka, Associate Professor, Mississippi State
University, MS
On-Line
Monitoring of Mercury and Arsenic Below Regulatory Levels
Carl
Hensman, Frontier Geosciences, Seattle, WA
Hakan Gürleyük, Frontier Geosciences, Seattle, WA
Phil Kilner, Frontier Geosciences, Seattle, WA
William T. Dietze, TraceDetect, Seattle, WA
Vladimir Dozortsev, TraceDetect, Seattle, WA
Removal of Lead (II) from Drinking Water Using Plant Based
Product
Kishore K. Krishnani,
Visiting Scientist, Centre for Environmental Engineering,
Stevens Institute of Technology, Hoboken, 07030, NJ, Fax:
201-216-8303, Email: krishnanik@hotmail.com
Xioaguang Meng, Centre for Environmental Engineering,
Stevens Institute of Technology
, Hoboken, 07030, NJ, Email: xmeng@stevens.edu
Reba Mukherjee, Centre for Environmental Engineering,
Stevens Institute of Technology, Hoboken, 07030, NJ,
Email: rmukher1@stevens.edu
Sources of lead in the
environment include lead based paint, lead contaminated
soil, air and dust, lead contaminated food and lead
contaminated drinking water. Lead enters water primarily
as a result of the corrosion, or wearing away, of
materials containing lead in the water distribution system
and household plumbing. This can prove to be harmful to
the human health. Currently used water treatment
technologies involving chemical precipitation and the use
of ion exchange resins are expensive and sometimes
ineffective especially, when metals are present in
solution at very low concentrations. Conversely, the use
of natural plants is an emerging field of interests for
decontamination of heavy metals from contaminated sites.
In the present paper, the efficacy of a plant based
product has been investigated for the removal of lead (II)
from water.
Gold
Mining and Mercury Pollution in the Ghanaian Pra River
Basin, West Africa
Augustine
K. Donkor, Ph.D Candidate, Dept. of Environmental
Engineering Sciences,
University of Florida, Gainesville, FL 32611, Tel:
352-392-2287, Fax: 352-392-3076, Email: augdon@ufl.edu
Jean-Claude J. Bonzongo, Ph.D, Dept. of Environmental
Engineering Sciences,
University
of Florida, Gainesville, FL 32611, Tel: 352-392-7604, Fax:
352-392-3076, Email: bonzongo@ufl.edu
Vincent K.
Nartey, Ph.D, Dept. of Chemistry, University of Ghana,
Legon-Accra, Ghana, Tel: 233-24-293330, Email: vknartey@ug.edu.gh
Mercury
(Hg) toxicity awareness increased after Minamata disaster
in Japan in the 1950s. In consequence several studies
coupled later with the outlawing of this toxic metal in
historic gold mining sites, in developed nations such as
USA and Canada, were initiated. Moreover, whereas studies
of the environmental consequences of gold mining by Hg
amalgamation in the tropical ecosystems of South America
(particularly the Brazilian Amazon) were commenced about
two decades ago, after the “new
gold rush” in the 1980s, the case of Ghana, in West
Africa remains barely investigated. And artisanal mining
of gold with Hg has been ascending after its legalization
in 1989 by the government. In this work, the levels,
speciation and the spatial/temporal distribution of Hg in
the Pra River basin in Southwestern Ghana were
investigated to assess the environmental impact of Hg
introduced into the waterways by artisanal gold mining
operations. Surface water, sediment, soil and human hair
samples collected along longitudinal transects from
locations upstream of known point sources down to the
river delta were analyzed. Our results show that total-Hg
concentrations are very high in river waters, as well as
in soil samples collected near sites of amalgam roasting.
Total-Hg concentration riverine sediments are relatively
low as compared with most published values from
Hg-contaminated sites. However, the determination of
total-Hg in the sediment fraction < 2mm and the use of
the geo-accumulation index (Igeo) tend to
suggest moderate pollution. Observed total-Hg levels in
human hair samples were quite low compared with some
proposed safe limits. Methyl-Hg was also detected in all
samples, and in contrast to well-studied Hg contaminated
systems in America and Europe, methyl-Hg levels in
analyzed Ghanaian sediment samples were 2 to 3 times
higher than most published values. More interesting is the
fact that, the Brazilian Amazon, which is very similar to
these Ghanaian systems (i.e. tropical climate, hydrology,
ongoing artisanal gold mining, etc), and where safety
levels for fish (0.5mg/Kg) are considerably exceeded,
comparatively, has both total- and methyl-Hg levels up to
3 orders of magnitude lower than that of Ghana. Finally,
laboratory experiments using riverine sediments were
conducted to assess the potential rates of Hg methylation
and methyl-Hg demethylation in these tropical settings,
and obtained data were compared with those from gold
mining impacted aquatic systems worldwide.
Chitosan
Immobilized on Sand – An Innovative Cu Adsorbent
Meng-Wei
Wan, Department of Civil and Environmental Engineering,
University of Southern California, Los Angeles, CA
90089-2531
Ioana G. Petrisor, DPRA Inc., 100 San Marcos Blvd., Suite
308, San Marcos, CA 92069, Tel:
760-752-8342; Fax: 760-752-8377; Email: Ioana.Petrisor@dpra.com
Hsuan-Ting Lai, Daeik Kim, Teh Fu Yen, Department of Civil
and Environmental Engineering, University
of Southern California, Los Angeles, CA 90089-2531, Tel:
213-740-0586; Fax: 213-744-1426; Email: tfyen@usc.edu
Metal
contamination of soils and waters reported all over the
world has a severe impact on environmental and human
health. The
development of innovative metal-clean up technologies
remains a challenge as the currently used procedures are
generally expensive, disruptive, and only efficient at
certain concentrations. Chitosan, a biopolymer with
repetitive amino groups, is a well-known metal chelator,
but its use in practice is limited due to the relative
high costs of constructing clean-up devices (filters) from
chitosan alone. In the current study, we investigated an
innovative adsorbent material based on chitosan
immobilization on sand (5% chitosan content). This new
material was studied for its copper adsorption capacity
for different contact times (two and four hours) and the
results were compared with copper adsorption capacities of
chitosan and sand alone. Also, copper recovery from
adsorbent with possible reuse of the adsorbent material
was evaluated in leaching tests. Chitosan-coated sand had
a better copper adsorption capacity (260 mg Cu adsorbed/g
chitosan) than both chitosan (184 mg Cu adsorbed/g
chitosan) and sand (2.04 mg Cu adsorbed/g sand) when used
alone, regardless of the initial copper concentration. The
possibility of recovering the copper from chitosan-coated
sand with the reuse of adsorbent was proved, with more
than 90% of copper removed by acid leaching. Increasing
the contact time between Cu solution and adsorbent from
two to four hours had almost no effect on Cu adsorption
capacity, but determined the creation of slightly stronger
bonds of Cu-adsorbent. These preliminary results indicate
the possibility of using chitosan-coated sand to build
inexpensive filters for metal removal from contaminated
surface and groundwaters.
Formation
and Stability of Mixed Metal Hydroxide Phases in
Contaminated Soils
Edward
Peltier, Plant and Soil Sciences, 152 Townsend Hall, 531
S. College Ave., Newark, DE 19716, Tel: 302-831-0608, Fax:
302-831-0605, Email: epeltier@udel.edu
David H. McNear Jr., Plant and Soil Sciences, 152 Townsend
Hall, 531 S. College Ave., Newark, DE 19716, Tel:
302-831-1230, Fax: 302-831-0605, Email: dmcnear@udel.edu
Donald L. Sparks, Plant and Soil Sciences, 152 Townsend
Hall, 531 S. College Ave., Newark, DE 19716, Tel:
302-831-2532, Fax: 302-831-0605, Email: dlsparks@udel.edu
Understanding
the fate of toxic metals in the environment is crucial to
the remediation of contaminated soils. Metal sorption and
precipitations reactions are particularly important in
determining metal speciation and toxicity in ways poorly
described by current models. Previous research has shown
that a number of metals of environmental interest,
including Co, Cr, Cu, Ni and Zn, form polynuclear metal
hydroxide complexes and precipitates with aluminum on the
surfaces of clay minerals and metal oxides under
laboratory conditions. Formation of these metal hydroxide
phases substantially reduces metal mobility and leaching
from the substrate, and may be an important mechanism for
metal retention and sequestration into relatively
bio-unavailable phases. In this work, macroscopic and
molecular scale studies have been conducted on field and
laboratory contaminated soils in order to determine the
factors controlling the formation of these layered double
hydroxide (LDH) phases in natural soils.
Kinetic studies of Ni and Zn sorption and
desorption were carried out over pH ranges from 6- 8, in
the expected region for LDH formation, for three soils
with varying mineral phases and organic matter content.
X-ray absorption spectroscopy was used to determine the
identity of precipitate phases formed during these
reactions. In soils with a high clay fraction, there is
rapid formation of precipitate phases resistant to proton
promoted dissolution. The exact nature of these phases,
however, depends on the dissolution of aluminum and
silicon ions from the dominant mineral phases present. In
sandy loam soils, formation and stability of LDH
precipitates is most heavily influenced by the
concentration of natural organic matter in the soil. In
all cases, precipitate stability appears to increase with
aging. Combined with thermodynamic studies of LDH
stability, these studies will aid the development of
better models for predicting the fate of contaminant
metals in the environment.
Electrokinetic
Treatment of Copper, Chromium and Arsenic Contaminated
Soil from Wood Preservative Industries
Prashanth
R Buchireddy, Graduate Student, P.O.Box 9595, 330, Swalm
Chemical Engineering Building, Mississippi State
University, MS 39762, Tel: 662-325-2392, Fax:
662-325-2480, Email: prb2@msstate.edu
Dr.
Mark R Bricka, Associate Professor, P.O.Box 9595, 330
Swalm Chemical Engineering Building, Mississippi State
University, MS 39762, Tel: 662-325-7205, Fax: 662-325-2480
Email: bricka@che.msstate.edu
Electrokinetic
remediation is an emerging technology that could be very
effective in the removal of charged contaminants from
soil. The feasibility of electrokinetic technique was
tested on soil (20% soil + 80% sand) spiked with copper,
chromium and arsenic (CCA solution) from the wood
preservative industry. In order to better understand the
ionic mobility within the soil and to detect the
generation and advancement of acidic front, sampling ports
were provided across the cell. Three tests were performed
at different current densities of 5.92, 2.85, and 1.42 mA/cm
2 for
a period of 15 days, to determine the optimal current
density. The initial concentrations of Cu, Cr and As in
the soil were 4800, 3100,and 5200 mg/kg respectively.
Dilute nitric acid was used as an amendment to neutralize
the hydroxyl ions produced at the cathode end of the cell.
Based on the percentage removal calculations, the amount
of power supplied, and the cell operation period, the
optimal current density was 2.85mA/ cm 2
. The
results also indicated that the advancement of acid front
favored desorption of metals from the soil and the metals
were mobilized either as free cations or metal complexes.
Tests are being conducted on fabricated soil (60%
soil + 40% sand) spiked with CCA solution, and soil from a
CCA contaminated site under a constant current operation
of 2.85 mA/ cm 2
. The
results of these tests will be presented.
On-Line
Monitoring of Mercury and Arsenic Below Regulatory Levels
Carl
Hensman, Ph.D., Research Scientist, Frontier Geosciences,
414 Pontius Ave. N, Seattle, WA 98109, Tel: 206-622-6960,
Fax: 206-622-6870, Email: CarlH@FrontierGeosciences.com
Hakan Gürleyük, Ph.D., Research Scientist, Frontier
Geosciences, 414 Pontius Ave. N, Seattle, WA 98109, Tel:
206-622-6960, Email: HakanG@FrontierGeosciences.com
Phil Kilner, Research Scientist, Frontier Geosciences, 414
Pontius Ave. N, Seattle, WA 98109, Tel: 206-622-6960
William T. Dietze, Ph.D., Chief Technical Officer,
TraceDetect, 180 N. Canal St., Seattle, WA 98103, Tel:
206-523-2009, Fax: 206-523-2042
Vladimir Dozortsev, TraceDetect, 180 N. Canal St.,
Seattle, WA 98103, Tel: 206-523-2009
Most
natural water systems and process and waste streams are
monitored using periodic grab sampling and analysis. Spot
monitoring like this results in a low-resolution
understanding of a stream’s chemistry. With a limited
number of data points, brief high or low concentration
spikes may not be detected, at the same time in cases were
they are detected, brief spikes may bias an analyte’s
average concentration. To better understand and monitor
temporal variability of mercury in complex matrices
Frontier Geosciences has developed an innovative
continuous mercury monitoring system. The system utilizes
online sample preparation involving chemical, thermal, and
UV digestion. Detection is achieved by cold vapor atomic
florescence spectrophotometry (CVAFS).
The analyzer is run using ether EPA method 1631 or
245.7 to achieve a detection range of sub-ppt to 100 ppb
levels. The system is capable of measuring mercury
concentration at 5-minute intervals. This interval can be
increased as needed by the operator. Modifications to the
physical instrument, to the analyzer chemistry, and to the
analytical method have been made, optimizing the system to
run matrices ranging from drinking water to petroleum
hydrocarbon, and organic rich process water from a natural
gas plant. Due to the increased interest in arsenic, we
have also built an on-line monitoring instrument for
arsenic. This instrument uses a similar sample
pre-treatment system suitable for As and uses Anodic
Stripping Voltammetry. Continuous monitoring achieved
using these systems increases data resolution enabling
researchers and plant operators to better understand
chemically complex and temporally variable systems.
Geochemical trends that are not apparent under spot
monitoring may come to light. Dischargers can better
tailor treatment systems and insure proper operation in
rapidly changing situations. The instrument can be built
to collect samples from various parts of process for
continuous mass balance determinations. The details of the
method and results of a number of field studies will be
presented.
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