What Is Persulfate Remediation Injection?
Persulfate remediation injection is an advanced in situ chemical oxidation (ISCO) technique in which sodium persulfate (Na₂S₂O₈) is injected directly into contaminated soil and groundwater. When activated, persulfate generates highly reactive sulfate free radicals (SO₄•⁻) with a redox potential of 2.6 volts — powerful enough to break down the chemical bonds of even the most recalcitrant contaminants.
Unlike hydrogen peroxide-based ISCO, persulfate is stable in the subsurface and can be activated through multiple pathways — most importantly through IET's patented ferric iron activation process, which provides sustained, long-lasting oxidation lasting 12–24+ months per injection event.
Persulfate breaks down to sulfate — a naturally occurring, benign compound — leaving no persistent chemical residues in the environment.
💡 IET's Competitive Advantage: Our patented ferric iron-activated persulfate is the only ISCO formulation that provides truly sustained treatment — dramatically reducing contaminant rebound and total project cost.
Persulfate Activation Methods
IET selects the optimal activation method based on site-specific conditions, contaminant type, and treatment objectives.
Ferric Iron Activation (Patented)
IET's patented slow-release ferric iron catalyst generates sustained sulfate free radicals for 12–24+ months — preventing contaminant rebound and reducing overall injection events.
Alkaline Activation
Sodium hydroxide or calcium peroxide raises pH to activate persulfate, ideal for shallow vadose zone and surface soil treatment applications.
Heat Activation
Thermally activated persulfate is highly effective for high-concentration DNAPL source zones where aggressive, rapid destruction is required.
Persulfate Injection Methods & Delivery
IET's fleet of 50+ specialized drilling rigs enables precise persulfate delivery in virtually any site condition — from shallow vadose zones to deep bedrock, and even offshore or waterfront sites.
Direct Push Injection
High-density injection grids using Geoprobe and AMS direct push rigs for shallow to intermediate depths. Ideal for dissolved plume treatment.
Permanent Injection Wells
PVC or stainless steel injection wells for long-term, multi-event treatment at deeper intervals. Enables recirculation and monitoring.
Temporary Injection Points
Rapid-deployment temporary points for pilot testing or source zone hotspot treatment without permanent infrastructure.
Barge-Mounted Injection
IET's unique barge-mounted drilling capability enables persulfate injection at waterfront, river, and harbor contamination sites.
Recirculation Systems
Extraction and reinjection systems maximize reagent distribution and contact time in heterogeneous or low-permeability formations.
Soil Mixing Delivery
For high-concentration source zones, IET can deliver persulfate via in situ soil mixing (ISGS) for maximum reagent contact.
Contaminants Treated by Persulfate Injection
Activated persulfate is effective against a broad spectrum of organic contaminants in both soil and groundwater.
Why Choose IET's Persulfate Injection?
- Sustained treatment lasting 12–24+ months per injection event
- Patented ferric iron activation prevents contaminant rebound
- Sulfate radicals (2.6V) more powerful than hydrogen peroxide
- No excavation required — fully in situ treatment
- Treats both dissolved plume and DNAPL source zones
- Environmentally benign breakdown products (sulfate)
- Compatible with direct push, wells, and barge injection
- Cost-effective — fewer injection events than conventional ISCO
IET's Patented Technology Advantage
IET holds patents on ferric iron-activated persulfate formulations that solve the #1 problem with conventional ISCO: contaminant rebound. Standard ISCO reagents are consumed quickly, often within weeks, allowing contaminant concentrations to recover.
IET's slow-release ferric iron chemistry maintains an active oxidizing environment in the subsurface for 12 to 24+ months, continuously treating contamination as it migrates through the treatment zone.
This sustained treatment window is the key differentiator that makes IET's persulfate injection approach more effective and more cost-efficient than any competing ISCO technology.
Persulfate Injection Case Studies
Real results from IET persulfate remediation injection projects across the U.S.
Persulfate Injection FAQ
What is persulfate remediation injection?
Persulfate remediation injection is an in situ chemical oxidation (ISCO) process where sodium persulfate is injected into contaminated soil and groundwater. When activated, it generates sulfate free radicals (SO₄•⁻) that chemically destroy organic contaminants like TCE, PCE, benzene, and petroleum hydrocarbons in place — no excavation needed.
How does ferric iron-activated persulfate work?
IET's patented ferric iron activation combines persulfate with a slow-release iron catalyst. The reaction continuously generates sulfate radicals over 12–24+ months, providing sustained oxidation that prevents the contaminant rebound common with conventional ISCO techniques.
What contaminants does persulfate injection treat?
Persulfate injection effectively treats TCE, PCE, DCE, vinyl chloride, BTEX (benzene, toluene, xylene), MTBE, DNAPL, PAHs, creosote, and most chlorinated organic compounds and petroleum hydrocarbons.
How is persulfate injected into the subsurface?
IET uses direct push drilling (Geoprobe, AMS), permanent injection wells, temporary injection points, barge-mounted drilling for waterfront sites, and soil mixing delivery — selected based on site depth, geology, and treatment objectives. IET's 50+ specialized rigs cover any site condition.
How long does persulfate remediation injection take?
IET's ferric iron-activated persulfate provides active treatment for 12–24+ months per injection event, compared to just weeks for conventional ISCO. Most sites achieve significant contaminant reduction within the first year and regulatory closure in 2–4 years.
Is persulfate safe for the environment?
Yes. Persulfate breaks down to sulfate — a naturally occurring, non-toxic compound found in groundwater and soil. There are no persistent chemical residues, and the treatment generates no hazardous byproducts. It is one of the most environmentally responsible ISCO technologies available.