PILOT TEST OF DEEP AQUIFER PERMANGANATE TREATMENT Phoenix, AZ

1
PILOT TEST OF DEEP AQUIFER PERMANGANATE
TREATMENTPhoenix, AZ
Presented By David Abranovic P.E.
2
Presentation

• Trichloroethene Oxidation by Permanganate
• Site Background
• Pilot Test Goals
• Application Technique
• Results
• Conclusions

3
Trichloroethene Oxidation by Permanganate

• Stoichiometric Mass Requirements for Oxidation
• 2.4 lb KMnO4 / lb TCE
• 2.2 lb NaMnO4 / lb TCE

4
Site BackgroundPilot Location
5
Site Background VOC Concentrations
TCE Up to 100 ug/l
PCE Up to 150 ug/l
1,1 DCE Up to 150 ug/l
TCA Up to 150 ug/l
6
Pilot Study Design

• Historical groundwater concentrations were used
  to estimate stoichiometric demands from dissolved
  groundwater and absorbed soil concentrations
• Soil oxidant demand (SOD) of matrix unknown
• TOC ranges from 0.01 to 0.20

7
Extent of Release Near Former Dry Wells
8
Pilot Study Objectives

• Apply the maximum mass of permanganate into the
  subsurface
• Identify any site specific difficulty associated
  with the application of KMnO4 to site
  groundwater
• Measure the persistence of permanganate in the
  aquifer.
• Monitor the reduction in VOCs concentration in
  the aquifer near the application well

9
Application Mixing Methods

• KMnO4 solution was prepared on site in two 4000
  gal storage tanks
• Mix water was withdrawn from a nearby hydrant
• Powdered KMnO4 was added to the mixing tanks to
  form a 3 to 4 percent KMnO4 solution.
• The solution was then be gravity fed into
  monitoring wells MW-1A and MW-2.
• Feed rates were 15 gpm in MW-1A and 40 gpm in
  MW-2.

10
Mixing Tank Set-Up
11
Injection Line
12
Contaminant Reduction Zone
13
Application Quantity Summary

• Powdered KMnO4
• 127 55 lb buckets (7,000 lb)

14
Results MW-1A - Treated Source Well
15
MW-2 Treated Source Well
16
EW-1 - 1650 Feet Down Gradient
17
MW-3 - 800 Feet Down Gradient
18
EW-2 - 1650 Feet Down Gradient
19
Chromium Results
20
Results Summary

• VOC levels in MW-1A increased by 65.
• VOC levels in MW-2 were reduced by 98.
• VOC levels in MW-3 were reduced by 93.
• KMnO4 solution migrated 1650 feet to a pumping
  well in 2 months.
• KMnO4 solution migrated 800 feet to a monitoring
  well in 10 months.
• KMnO4 solution persisted for over 3 years in EW-1
• Transient elevated chromium concentrations
  observed in pilot test area.

21
Conclusions

• Chemical oxidation by KMnO4 is potentially an
  effective remediation strategy for treatment for
  deep VOC plumes in low TOC aquifers.
• Low TOC in soil allowed KMnO4 solution to persist
  in site groundwater for over 3 years.
• Forced and natural gradient distribution is
  potentially a viable application method for deep
  and expansive VOC plumes.