Persulfates for soil and groundwater remediation


KLOZUR® KP is an environmentally safe extended release potassium persulfate that has the same oxidizing power as sodium persulfate, but has a much lower solubility, allowing it to maintain a low persulfate concentration in the subsurface.

KLOZUR® KP is an extended release reagent for in situ chemical oxidation (ISCO) based on environmental grade potassium persulfate.

The low solubility and extended release of KLOZUR® KP can be used for a number of applications not traditionally considered for chemical oxidation, including permeable reactive barriers (PRBs), treatment of less permeable soils, and contaminated groundwater plumes.

KLOZUR® KP is well suited for:

  • Permeable reactive barriers (PRBs)
  • Low permeable solids
  • Recalcitrant compounds


  • Powerful multi-radical attack
  • Can be applied as a solid or as part of a slurry mixture
  • Well suited toward applications such as permeable reactive barriers
  • Extended lifetime in the subsurface


  • Chlorinated ethenes, ethanes and methanes
  • Petroleum hydrocarbons
  • Pesticides
  • Aqueous phase contaminants such as MTBE, vinyl chloride, BTEX, 1,4-dioxane


  • Physical emplacement or construction
  • Soil blending
  • Hydraulic slurry injection
  • Pneumatic solid phase injection


In situ chemical oxidation (ISCO) is the introduction of an oxidant into the subsurface for the purpose of oxidizing contaminants in soil and groundwater. ISCO is ideal for the elimination of contaminant concentrations in source zones and hot spots.

Technical Documents

Get a detailed overview of extended-release potassium persulfate, including the theory behind extended-release, recommended dosage, and potential applications.

As KLOZUR® persulfate is a very strong oxidant, and its solutions may become very acidic (pH ≤2), persulfate solutions may result in a corrosive environment for many metals and materials.

Methyl-tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) are environmental contaminants of concern that have been widely used as fuel oxygenates and octane boosters. Activated KLOZUR® persulfate is an effective treatment technology that has been successfully used to treat MTBE and TBA.

KLOZUR® sodium persulfate is a stable, highly soluble, crystalline material, which upon activation is capable of oxidizing a broad range of recalcitrant compounds. 

KLOZUR® KP Application Guides

We provide guidance on the use of KLOZUR® KP, such as on field applications, slurry preparation, tank and pump recommendations, health and safety information, injection of the product, soil mixing, application methods, laboratory and pilot scale testing, storage and handling.

We present strategies and guidelines for soil mixing and in situ stabilization based on case studies and successfully treated contaminated sites, combining ISCO with ISS, stabilizing agents such as calcium hydroxide, various laboratory-scale tests, and monitoring programs to understand progress toward final remediation. 

KLOZUR® KP is part of our persulfate-based oxidizers and is typically applied by soil mixing, injection or backfilling to establish contact between the activated persulfate and the contaminants of concern.

KLOZUR® KP Webinars

Drew Baird and Chapman Ross of FRx and Brant Smith of Evonik present the use of controlled hydraulic fracturing to produce KLOZUR® KP slurry. 

Dr. Brant Smith presents KLOZUR® KP, which is based on environmental grade potassium persulfate characterized by low solubility. He presents results based on specific testing of KP vs. SP in batch reactors, solution limited release, field implementations, dynamic solubility release systems, and various persulfate residual studies, treatment studies, effluent persulfate concentration, potential applications, and implementation approaches. 

Since its introduction in 2016, KLOZUR® KP has been bench tested and applied at numerous sites around the world. With its unique extended release properties, KLOZUR® KP is ideal for treating contaminants in the highly soluble aqueous phase.

Our expert Dr. Brant Smith, Professor Dan Cassidy of Western Michigan University, and Tom Simpkin and Mike Perlmutter of CH2M present strategies involving in situ mixing to produce alkali-activated persulfate.

Evonik’s laboratory created the KLOZUR® field test kit to provide a quick and reliable measurement of persulfate in the field.

There are two different kits available, depending on the activation method used. Each kit is capable of running ten tests and has a measurement range of 1g/L to 100g/L, with a theoretical accuracy of ±1g/L and ±2g/L respectively.

Related documents on KLOZUR®

Further information