Metal
(zero valent unless specified)
|
Contaminant |
TestType |
Description/Conditions |
Results |
Reference |
Fe, Ultrasound (US) |
TCE |
Batch, Column |
US co-applied in batch/column to remove deposits from metal surface. Column
80:20 sand/iron with 50 mesh Fe, in N2. 100 L bags with deoxygenated water
introduce TCE. |
US extends activity in batch. t1/2 260 min > 20 PV; 3mL/min, no
US. t1/2 ~ 360 min > 150 PV, 2mL/min, US. US also cleaves Cl-H.
Column US probe too shallow. Special design should enhance. |
Afiouni, G.F., et al., 212th National ACS Meeting, Orlando, FL, 36:22-29
(1996) |
Fe |
Nitrobenzene |
Batch |
Batch experiments to investigate nitro reduction by granular iron in model
systems. |
Nitrobenzene (disappear in few hr) -> nitrosobenzene -> aniline Reduction
by surface; diss. Fe2+ & H+ produced during corrosion. |
Agrawal, A. & P.G. Tratnyek, 207th ACS Nat'l Meeting, San Diego,
CA, pp. 492 (1994) |
Fe |
Nitrobenzene and Carbonate |
Batch |
Adsorbed H2CO3 & HCO3- drives metal dissolution by:
Fe(0 )+ 2H2CO3(ads) <-> Fe2+ + 2HCO3-(ads) + H2(g)
Fe(0)+ 2HCO3-(ads) <-> Fe2+ + 2CO32-(ads) + H2(g)
Corrosion rates decrease from carbonate precipitates.
|
Anaerobic bicarbonate buffer, Fluka Fe, and nitrobenzene as oxidant in batch
exp. Kobs declined with increased carbonate and extended exposure of metal
to carbonate buffer. Gray precipitate formed and may occur throughout experiments. |
Agrawal, A., et al., 209th National ACS Meeting, Anaheim, CA,
April 2-7, 35:720 (1995) |
Fe |
Nitrobenzene |
Batch |
18-20 mesh Fluka Fe turnings, sonicated in 10% HCl, washed with buffer to
remove acidity or Cl . Anaerobic batch in 60 ml serum bottles with 2 g dry,
sieved Fe. |
Rates for itrobenzene (0.035) -> nitrosobenzene (0.034) -> aniline
0.008 /min. Rates controlled by mass transfer to metal surface. Precip.
of siderite on metal surface inhibited nitro reduction. |
Agrawal, A., P.G. Tratnyek. ES&T, 30(1):153 (1996) |
Fe |
cis- and trans-1,2-DCE |
Batch |
10g Fisher pretreated 40-mesh filings; SA 1.0 m^2/g. 0.20 g powdered pyrite
(buffer), DI water. cis- &trans-1,2-DCE at two Ci in ZHEs,
anaerobic, at 12 rpm, 22-25° C. |
Reduc. dechlor. & sorption; Cl- 80-85%; products: ethene, ethane; more
VC in cis-. cis- not 1st order. Sorption descr.by Freundlich
isotherms (trans- sorption > more soluble cis-); quasi-equil.
1.1 h. |
Allen-King, R.M., et al., Environ. Toxicol. Chem., 16:424-429 (1997) |
Fe |
CCl4 |
Batch |
Aging & conc. effects of acetylene & CCl4 in Ar-purged vials w/100
mL DI H2O, 5gHCl pretreated Fisher Fe & 0.10 g powder pyrite (buffer),
20° C. Fresh systems: Fe/H2O not mixed prior to compound exposure. |
CT: initial pseudo-1st-order rates in fresh are 2x to 4 x > aged &
faster at lower conc. Acetylene: Initial rate (0.1 to 2.0 µmol) lower
in aged (1d) than fresh. Indep. of conc. in aged (3 to 7d). Fast reacting
sites eliminated within few hr (precip, sorp., corr.). |
Allen-King, R.M., et al., 213th National ACS Meeting, San Francisco,
CA, 37:147-149 (1997) |
Fe |
Dithionite |
Batch, Column |
Batch and column with Hanford sediments to predict (1) longevity of dithionite,
(2) efficiency as reductant of Fe (3) longevity and reactivity of the reduced
Fe |
Other than initial reaction with ferric iron, primary factor promoting loss
of dithionite in system was disproportionation via heterogeneous catalysis
at mineral surfaces. |
Amonette, J., et al., In Situ Remed.: Sci. Basis for Current & Future
Technol. Sym. Battelle Press, pp. 851 (1994) |
Fe(II) in aquifer material |
Cr(IV) |
Batch |
Batch experiments using sand collected from a shallow sand and gravel aquifer.
Initial conc. of Cr(VI) varied from 2 to 200 µM; Adjusted pH 4.5,
5.5, 6.5. |
As pH decreased (6.4 to 4.5), Cr(VI) red. increased 30 to 50 nmol/m^2 (sand);
130 to 200 (fines). For 10 fold increase, amounts red. increased 35 to 80
(sand); 130 to 1000 nmol/m^2 (fines). |
Anderson, L.D., et al., ES&T, 28(1):178 (1994) |
Ni-Fe Wall |
Organics |
In situ Otis AFB, MA |
Induce fracture to fill w/ Fe filings w/ slurry mixture moving down and
outward, creating series of overlapping vertical planes thus becoming a
"continuous" wall. |
Plan for 2 parallel 50' walls, 2' apart, perpendicular to flow. Plume of
5 to 150 ppb TCE & PCE. Walls will begin 80' below surface, at top of
plume to 150' for deep plumes. |
Appleton, E.L., ES&T, 30(12):536A (1996) |
Al, Fe, Zn |
11 Chlorinated Solvents |
Batch |
Al coupon size 2 x 15 x 0.2 cm, Zn & Fe coupon 2.5 x 15 x 0.1 cm. 65
ml solvent and 5 ml deionized water in 125-ml flask containing solvent and
metal coupon. |
Reactivity accelerated when water added. Problems with Al and Zn, but not
Fe corrosion in dry systems. 1,1,2-trichloroethane only structure with appreciable
oxidative breakdown. |
Archer, W. & E. Simpson, Industrial Eng. Chem. Product R&D, 16(2):158
(1977) |
Al, In, Cd, Bi, Sn, Ag, Ge, Sb, Cu, Hg, Pd, Th, Pb, Ti, Mn, Co |
CCl4 |
Batch |
1 ml CCl4 heated at 200°C, sealed tubes, for 14 d using twice metal
shot, powder, granules, or chips needed to complete reaction. |
Hexachloroethane; end products perchloroethylene, hexachloro-butadiene.
Most reactive Al (100%), Ti (100%), Cd (74%), antimony (58%), In (58%),
Gr (47%), Sb (33%). |
Archer, W.L. & M.K. Harter, Corrosion: Nat'l Assoc. of Corr. Eng. (NACE),
34(5):159 (1978) |
Al |
1,1,1-TCA |
Batch |
5 ml inhibitor-containing solvent refluxed with 0.5 g of 16-32 mesh pure
Al pellets in open reaction tubes. Tubes in oil bath at 7°C. Upper portion
extends through a water-cooled Al block that acts as a condenser. |
Inhibitors compete with solvent for AlCl3 produced at micro corrosion sites
by complexing the chemisorbed AlCl3 product. Resultant complex insoluble
in solvent, acting as a plug covering original reaction site. |
Archer, W.L., Industrial Eng. Chem. Product R&D, 21:670 (1982) |
Zn |
TCE, PCE rates; products |
Batch |
Deoxygenated water (buffered), Zn(0), PCE or TCE. Sampled for product formation.
Early heterogeneous process, but initial rate does not increase linearly
with increasing Ci (expected for pseudo-1st-order system), but levels off
as Ci increased. |
Reductive elimination (RE) important in Zn(0). ~ 15% PCE -> dichloroacetylene
(0.25 -> acetylene bypass VC). TCE -> acetylene(20% of original TCE);
trace VC. Chloroacetylene intermed. -> acetylene preferred over VC. Manipulating
RE over initial hydrogenolysis would be beneficial goal. |
Arnold, W.A. & A.L. Roberts, 213th National ACS Meeting. San Francisco,
CA, 37:76-77 (1997) |
Limestone |
Cr |
Column |
Limestone or sand 2 cm over 10-cm depth of soil in PVC column. Leachate
passed through columns at 1 PV/24 h until breakthrough. Unamended leachate
diluted to 25% and pH 4.0 or 2.5 to keep Cr in solution. ~3,000 ppm TOC
upon dilution and adjusting pH to 2.5. |
Limestone delayed breakthrough of Cr. Retained Cr(III) more than Cr(VI).
Cr retention>> Be, Cd, Fe, Ni, Zn. TOC & Fe(II) determine Cr(VI)/Cr(III).
(Clay, Fe oxides better at retaining Cr). pH affects solubility of Cr and
limestone. When Cr(VI) & Cr(III) in leachate, migration delayed several-fold
by limestone barrier. |
Artiole, J. & W.H. Fuller, Journal of Environmental Quality, 8:503-510
(1979) |
Zn
Zn
|
CCl4
Hexachloro benzene (HCB)
|
Batch
Batch
|
Zinc powder ± B12 under N2. Initial conc. 2.2 mM CCl4.
Zinc powder ± B12 under N2. Initial concentration of 50 µM
HCB.
|
Zn + B12 dechlorinated CCl4 to CH4 (50% recov). Rates slowed when B12
absent [CCl4 -> CHCl3, DCM, CM, CH4 (80% recov)].
Product pentachlorobenzene higher rates w/o B12 at 9.6 h-1 compared to
0.3 hr-1 w/ B12. B12 may compete w/ HCB for e-s.
|
Assaf-Anid, N. & L. Nies, 209th Nat'l ACS Meeting, April 2-7, Anaheim,
CA, 35:09-811 (1995) |
Metal oxide from steel manufac., Limestone |
Phosphorus |
Column, Cylinder, Reactive Wall |
Permeable mix 50% sand, 45% crushed limestone, 5% metal oxide in acrylic
column w/ 3.3 mg/L PO4-P over 3y (1250 PV). Biofilter effluent in 0.5x0.5m
cyliner 2 L/d over 133d (101 PV). Funnel-&-gate in septic plume. 7m
long funnel, 1.8 long; 2 wide; 10m deep) gate for 779d. |
>90% effic. column & cylinder. PO4-P 0 to 0.3 mg/L in column effluent.
Phosphate accumlated on oxide surfaces & precipitated as microcyrstalline
hydroxyapatite. Cylinder: 3.93 to 0.14 mg/L-P; 2.50 to 0.05 mg/L-ortho
P. F&G: 4 m above 2 to 3 mg/L; 0.4 m above gate 1.5 to 0.4 mg/L.
Avg phosphate in wall ~ 0.19 mg P/L. |
Baker, M.J., et al., Internat'l Contain. Technol. Conf. & Exhib., St.
Petersburg, FL, Feb 9-12, pp. 697 (1997) |
Fe |
TCE; DCE, VC, dichloromethane |
Batch, Column |
Site groundwater from DOE Pinellas Plant. VWR coarse iron filings used for
high reactivity and low cost. |
Batch: fast rates for TCE, DCE , VC in site GW. Dichloromethane rates very
slow. Column: TCEt1/2 =36-103 min; DCE = 150-200 min. However, rapid
plugging of iron by Pinellas GW. |
Baghel, S., et al., G. E. Corp. R&D Center for USDOE, Sandia (1995) |
Zeolite, 3 media types |
Sr, Cs, TCE |
Containers, TN & OH sites |
55-gal drums of Na-chabazite zeolite (remove Sr, Cs. at seep, Oak Ridge
National Lab, TN) and using 3 media types (reduce TCE, Portsmouth Gas.Diff.
Plant, OH). |
>99.9% Sr, Cs removal ORNL (25% red. total radioactive discharge). TCE
reduced at PORTS X-120 site. Drums predict flow and allow easy media replacement
and monitoring. |
Barton, W., et al., Internat'l Contain. Technol. Conf. & Exhib., St.
Petersburg, FL, Feb 9-12, pp. 827 (1997) |
Mixture organics, sulphate reducing bacteria |
Acid Mine Drainage |
Reactive Wall, Ontario |
Wall installed at the Nickel Rim mine site near Sudbury, Ontario. (8/95)
15 m long perpendicular to GW flow, 3.6m deep, 4m thick. Used municipal
& leaf compost, wood chips, and pea gravel (for permeability). Sand
buffer, clay cap. Mon. wells parallel to GW flow. |
After 9 mo sulfate reduction and metal sulfide precipitation. Sulfate: 2400
to 4600 mg/L to 200 to 3600 mg/L, Fe:250 to 1300 mg/L to 1 and 40 mg/L;
pH 5.8 to 7.0. Alkalinity rose 60-220 to 850-2700 mg/L as CaCO3. Fe mono-sulfide
precipitate. Cost ~ $30,000.00 (half materials/half installation) potential
life 15 y. |
Benner, S.G., et al.,
(1) ACS Meeting, San Fran., CA, April 13-17, 140 (1997)
(2) Internat'l Contain. Technol. Conf. & Exhib, St. Petersburg, FL,
835 (1997)
(3) GWMR, Fall, 99-107 (1997) |
Fe |
Cr |
Reac. Wall Eliz. City, NC |
Model indicates reactive barrier most eff./cost effective at Eliz. City,
NC. 46m long x 0.6m wide x 7.3m deep barrier installed < 6 h using continuous
trencher 6/22/96. |
11/96 sampling indicated 2.5 mg/L Cr(VI) declined to < MCL within barrier.
Further sampling underway determining groundwater chemistry and organic
concentrations. |
Bennett, T.A., et al., 213th National ACS Meeting, San Francisco, CA, April
13-17, pp. 243-245 (1997) |
Fe |
Solubilized PCE Hydroxypropy l-b-cyclodextrin (HP- beta-CD) |
Batch, Column |
Batch: 100 mesh Fisher Fe powder & -8 to 50 mesh Peerless mix. 40 ml
sealed vials, 10 g Fe, PCE, 40 mg/L CaCO3; 0, 45, 70 g/L HP-b-CD. Column:
0.47m x 5cm, 15 cm 70/100 mesh sand below (30-cm head) 10 m 30/40 mesh sand.
25 mL PCE to form pool. Ret. time 25.3 h. |
HP-b-CD enhances solubility w/o decreasing interfacial tension of PCE and
water. Smaller % PCE degrad. at higher HP-b-CD conc. PCE decreased in both
non-recycling and recyling of post treatment effluent. Greater degradation
at higher iron SA. Plan to use higher Fe SA and longer res. times to increase
degradation. |
Bizzigotti, G.O., et al., ES&T, 31:472-478 (1997) |
Fe |
Cr |
Batch, Column |
Batch: Compare 100 g siderite, pyrite, Fe(0) (~ 0.5 -1mm), chips (~ 1-5mm).
Use 500 g Cr in CaCO3 DI water agitated at room temp. Column: 15 x 6.5 cm,
pump tracer base upward to deter. void vol. & dispersivity of column. |
Batch: Fe(0) > pyrite. Column: Fe chips (remove 50% Cr < 2 h) >
pyrite (w/ calcite 50% 0.5 h; no calcite 50% 1 h) > coarse Fe (50% 28
h). Chips: No Cr brkthru for 4.5 PV. Filings: No Cr > 15 PV. Remain active,
little coating. |
Blowes, D.W. & C.J. Ptacek, Subsurface Restor. Conf., 3rd Interna'l
Conf. on Ground Water Quality Res., June 21-24, Dallas, TX, 214-216 (1992) |
Pyrite or Fe |
Cr(VI), U, etc |
Trench |
Excavate trench, fill with active material such as pyrite or elemental iron
to transform & precipitate contaminant. |
This patent relates to the treatment of groundwater for the purpose of removing
water-borne contaminants. |
Blowes, D.W. & C.J. Ptacek, Patent 5,362,394 (1994) |
Mixed organics, bacteria |
Nitrate - Tile Drainage |
In-Line Bioreactor |
Two 200-L fixed-bed bioreactors, with coarse sand and organic carbon (tree
bark, wood chips and leaf compost), to treat 3-6 mg/L NO3 -N from farm-field
drainage tile. |
Reduced NO3-N to < 0.02 mg/L at 10-60 L/day over a 1-yr period by anaerobic
denitrification promoted by organic carbon. Design is simple, economical
and maintenance free. |
Blowes, D.W., et al., Journal of Contaminant Hydrology 15:207-221 (1994) |
Fe |
Cr(VI) |
Batch, Column |
Batch: 100 g (50% fine Fe filings, 49% sand, 1% calcite), Cr(VI). 2nd mix
50:50 Fe quartz. Column: 50% Fe(0). 50% sand, top 5 cm 1% calcite. 20 mg/L
Cr(VI) in sim. GW. |
Cr(VI) 25 to <0.05 mg/L 3hr batch. No breakthrough Cr after 140 PV. Diss.
& total Cr <0.05 mg/L. Fe(III) oxyhydroxides form, but not sufficient
to inhibit Cr(VI) reduction at experimental velocity. |
Blowes, D.W, et al., 209th National ACS Meeting, Anaheim, CA, April 2-7,
35:780 (1995) |
Fe |
Sulfate |
Test Reactive Wall |
Test cell 1.5 long x 1 wide x 1 m deep installed 10/93 in sand aquifer ~
75 m downgrad. tailings impoundment. Organics (leaf, pine mulch, bark),
creek sediment (sulfate-red. bacteria), limestone,coarse sand and gravel. |
1 m along flow path, sulfate 3500 to 7 mg/L, Fe 1000 to < 5 mg/l, pH
& alkalinity increased from sulfate reduction. Sulfate-reducing reactive
walls are potentially effective and economical solution to many acid mine
drainage problems. |
Blowes, D.W., et al., Mining & Environ. Conf., CANMET. Sudbury, Ontario,
May 28 to June 1, 3:979 (1995) |
Fe |
Cr(VI), TCE |
Fe Reactive Wall |
Wall of 100% Fe filings 46 m long, 0.6 m wide, 7.3 m deep installed in <6
hours using a continuous trenching technique at Elizabeth City, NC 6/96.
Bench lab studies, and flow and transport models used in wall design. |
Site GW, reactive materials: Cr(VI) 11 to < 0.01 mg/L and TCE 1700 µg/L
to < 1 µg/L. Decrease of Cr(VI) from influent 6 mg/L to < 0.01
mg/L and TCE from 5600 µg/L to 5.3 µg/L within wall. TCE approaches
or attains the MCL within the barrier. |
Blowes, D.W., et al., Internat'l Contain. Tech. Conf. & Exhib. St. Petersburg,
FL, Feb 9-12, pp. 851 (1997) |
Fe |
Cr(VI) |
Batch, Column |
Batch: 500g Cr(VI) to 100g solid mixes [siderite, pyrite, coarse & fine
Fe(0)] in open flasks, agitated, room temp. Settle 5 min; 10 mL sampled.
Column: 6-6.5 cm dia. acrylic, 5-15 cm long, 1-20 cm long with layers of
reactive mix. Void vol. & dispersivity determined. Cr(VI) solution introduced. |
Batch Rate for Cr(VI): fine Fe(0) > pyrite & coarse Fe(0). Column:
partial Cr(VI) by pyrite & coarse Fe(0); quantitative Cr(VI) by fine
Fe(0) at rapid velocities. Fe(0) reduces Cr(VI) to Cr(III) with oxidation
to Fe(II) & Fe(III), & sparingly sol. (oxy)hydroxide precip. Cr(III)
forms solid solution or adsorbs on goethite. |
Blowes, D.W., et al., ES&T, 31:3348-3357 (1997) |
Fe |
CCl4, CH2Cl2 |
|
Open circuit potential time measurements using Fe with CT & DCM in borate
buffer and simulated GW of KBr & CaCO3. Polarization of Fe electrode
in borate solution to which 0.2 mL of CT added. CT acts as an oxidizer of
Fe electrode, while DCM does not. |
Injection of CT faster and larger potential shifts in Fe than in freshly
cleaned Fe electrode. Potential decay in all GW studies. Magnitude depended
on pH and solution. Borate and KBr decay mainly from chemical dissolution
of films. In CaCO3, autoreduction/ chemical dissolution may be responsible. |
Bonin, P.M.L., et al., 213th National ACS Meeting, San Francisco, CA, 37:86-88
(1997) |
Sn, Zn & Mg |
CCl4 |
Batch |
Vaporization procedure (SMAD or cyro method) to compare metal powders. |
H2O oxidation overwhelmed Mg-CCl4 reaction. Sn, Zn degrade CCl4 but differ
in carbon product. Zn yields CH4; Sn yields CO2. |
Boronina, T., et al., ES&T, 29:1511 (1995) |
Steel wool |
Tc99 |
Column |
Simulated process & GW from DOE uranium enrichment plants. Packed column
of steel wool, Dowex TM 1-X8. |
Use of iron economical but may be difficult to accurately predict its sorptive
capacity or functional "lifetime" |
Bostick, W., et al., Oak Ridge K-25 Site Rep. Martin Marietta. DOE K/TCD-1141
(1995) |
Fe
Iron oxide aggregate
|
Cd, Mg, Ni, TcO4-, UO22+
U
|
Batch |
Shake solid w/ soln 16-24 hrs in sealed container. Exp 2: 0.01, 0.03, or
1.0-g iron to 10ml w/ 8 mg/L U, shake 18 hrs, sample day 1 & 30. Exp
3: 1.43 x 0.15 cm iron coupons in 500-ml bottle w/ 927-mg/L U. N2 purge. |
Iron surfaces passivate at elevated pH (little activity at >9.5).
Sorption to iron corrosion products predominant removal process for uranyl
(Cd, Mn and Ni also). Sorbed products need to be controlled. Columns needed
to determine long-term capacity.
Fe(0)w/ sand or pelletized Fe oxide most effective. Reduces cementation
from rust; enhances dilution of hydroxyl ion rxn product; enhances sorption
of cationic contam. to pelletized Fe.
|
Bostick, W., et al., Oak Ridge & Martin Marietta Energy Systems, Inc.
for
U.S. DOE. K/TSO-35P (1996) |
Fe |
U |
Batch |
Batch: ~1.4 x 0.16 cm Fe coupons, simulated GW, soluble U as uranyl nitrate.
Gas glove box. Pure O2 added to yield equivalent to solution purged with
lab air. |
Under oxic conditions, U(VI) rapidly and strongly sorbed to hydrous ferric
oxide particulate ("rust"), whereas U slowly and incompletely
reduced to U(IV) under anoxic conditions. |
Bostick, W.D., et al., Internat'l Contain. Technol. Conf. & Exhib, St.
Petersburg, FL, Feb 9-12, pp. 767 (1997) |
Iron filings/pyrite |
TCE, PCE |
Batch |
4-15 mL vials, anaerobic: 2 controls/2 Fe+pyrite (5g pre-treated Fe filings,
0.1 g ground pyrite [buffer]). |
Reaction orders 2.7 TCE & 1.3 PCE total system conc. Nonlinear sorption
and fit generalized Langmuir isotherm. 1st order rates. |
Burris, D.R., et al., ES&T, 29:2850 (1995) |
Fe |
PCE |
Batch |
15 ml serum vials, 5 g iron, 0.1 g pyrite (ground). Pyrite added to stabilize
the pH to 6.5 - 7.0. Anaerobic |
Rapid initial rate followed by a slower rate. Sorption of PCE to Fe(0) follows
Langmuir-type isotherm. |
Campbell, T.J. & D.R. Burris. 209th Nat'l ACS Meeting, Anaheim, CA,
35:775 (1995) |
Fe |
UO2 2+, MoO4 2-, TcO4-, CrO4 2- |
Batch |
Kinetic studies in 50 ml redox-sensitive-metal solutions added to polystyrene
centrifuge tubes containing 1 g 40 mesh metallic iron with surface area
of 2.43 m^2/g. |
Particulate Fe(0) effectively removed each of the contaminants from solution
by reductive precipitation. Removal rates decreased by CrO42- > TcO4-
> UO22+ >> MoO42-. |
Cantrell, K.J., et al., J. of Haz. Mat., 42:201 (1995) |
Fe(0) Colloids Barriers |
Various |
Batch |
0.2% Fe colloids, surfactant. Polymers [vinyl (VP), vio (GX), cellulose(CMC
)] tested to increase colloidal Fe(0) mobility in porous media. Tubidimeter
measured Fe colloids. |
VP superior to GX and CMC because VP suspension produced the lowest back
pressure, resulting in the highest hydraulic conductivities. |
Cantrell, K.J., et al., J. of Environ. Eng.-ASCE, 23:786 (1997) |
Fe(0) Colloids Barriers
|
Various
|
Column
|
1m columns, 4.4 cm dia. 20-30 mesh sand avg. n = .32. Fe(0) colloid dia.
= 2 µm, bulk devsity = 2.25 g/cm^3, particle den. = 7.6 g/cm^3. Vel.
0.154, 0.307, 0.614 cm/s. 0.01M CaCl2 at 0.2 cm/min (~2 pore vol.) to simulate
GW influx. |
Colloidal-size Fe(0) injected into porous media forming chemically reactive
barriers. Relatively even distribuitons of Fe(0) in sand column at low conc;
high injection rates. As volume increased distribution of Fe(0) colloids
became increasingly even. |
Cantrell, K.J. & D.I. Kaplan, J. of Environ. Engineering-ASCE 123:499-505
(1997) |
MBS = Master Builders Supply; ND = Nondetectable; RT = Residence Time.