Persulfates for soil and groundwater remediation


KLOZUR® CR is a mixture of KLOZUR® SP and PERMEOX® Ultra, an engineered calcium peroxide. This product provides a combined solution of alkali-activated persulfate and bioremediation in a single application. In addition, KLOZUR® CR is self-activating, meaning no chemicals need to be mixed.

KLOZUR® CR is a single formulated product composed of alkaline activated KLOZUR® SP and engineered calcium peroxide PERMEOX® Ultra, combining the strengths of both products to treat contaminant source areas and downgradient plumes.

KLOZUR® CR is a self-activating persulfate oxidation system that combines chemical oxidation with aerobic and anaerobic bioremediation processes that can last up to one year after application. 

KLOZUR® CR can be used as a combined agent to treat BTEX, MTBE, PAHs and petroleum hydrocarbons or as an alkaline activated persulfate system to destroy chlorinated solvents and pesticides. Therefore, the product can be readily used in source areas or exhaust plumes with mixed petroleum and chlorinated solvent contamination.

KLOZUR® CR is well suited for:

  • Low to moderate levels of contamination
  • Source zones
  • Down-gradient plumes


  • Self-activating persulfate oxidation
  • Generates powerful sulfate and hydroxyl radicals
  • Rapid in situ chemical oxidation
  • Extended oxygen release for up to one year
  • Enhanced aerobic bioremediation in down gradient plumes
  • No chemicals to mix


  • Chlorinated solvents
  • Petroleum
  • PAHs (Polycyclic Aromatic Hydrocarbons) 


  • Direct push injection
  • Soil blending
  • Direct application in an excavation


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

Here you will get an introduction of KLOZUR® CR, a product consisting of high pH activated KLOZUR® persulfate and PERMEOX® Plus, an engineered calcium peroxide. The product is used as an in situ chemical oxidation (ISCO) technology to treat a wide range of contaminants that pollute soils and groundwater worldwide.

This technical bulletin presents the results of corrosion studies with persulfate and activated persulfate solutions and gives indications of possible compatible materials. 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 aggressive pollutant 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. This bulletin addresses the basic safety precautions for handling, using, and storing KLOZUR® persulfate. 

KLOZUR® CR Application Guides

We provide you with an overview on KLOZUR® CR slurry preparation providing a combined remedy of activated persulfate and bioremediation when applied in the geological subsurface. Furthermore you will find here tank and pump recommendations, safety and health notes, information on injection approach, injection spacing and backfill approach, as well as guidance on compatible materials.

KLOZUR® CR Webinars

Dr. Brant Smith presents an overview of the technical fundamentals of KLOZUR® CR and some successful case studies. KLOZUR® CR, or combined agent, is a blend of KLOZUR® SP and PERMEOX® Ultra. 

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