ERD Electron Donors

Enhanced reductive dechlorination (ERD) requires adding sufficient organic substrate (electron donor, such as EDS-ER™, and nutrients, such as Nutrimens®) to satisfy electron acceptor demand from both inorganic and organic compounds (i.e. chlorinated solvents) in the treatment zone.

Long-lasting Electron Donor

EDS-ER™ (electron donor solution – extended release)

As delivered, the physical state of EDS-ER™ is significantly different than standard emulsified vegetable oil (EVO) products. Whereas other EVO products are concentrated emulsions containing water, EDS-ER™ is a water-mixable oil; it contains no water. With 100% fermentable substrate, 60 lbs. of EDS-ER™ provides the same amount of electron donor as 100 lbs. of a 60% EVO. The costs for shipping EDS-ER™ are about 50% less than conventional EVO products.

At room temperature, EDS-ER™ is a liquid material with an appearance and viscosity roughly equivalent to vegetable oil (73 cP at 15 °C and 50 cP at 25 °C). This low viscosity allows subsurface distribution through direct-push injection points, hollow-stem augers or pumped through existing wells.

  • Because the product is completely water mixable, the number of necessary injection points for low permeability structures decreases
  • Easily mixes with water, simplifying field operations
  • Controlled release of electron donors for up to five years under ideal conditions
  • Contains refined, bleached, and deodorized (RBD) soybean oil
  • Complies with secondary water quality requirements for amendments with low salt content
  • Preservative free
  • Lower packing and transportation costs when compared to other EVO products
  • Freezing Point is ~ -4 °F (~ -20 °C)
  • Cloud Point is ~ 16 °F (~ -9 °C)

Fast-acting Electron Donor


Nutrimens® provides reduced carbon and a wide array of beneficial vitamins, minerals, and metabolites to microbes for enhanced bioremediation of contaminated sites.  It can be utilized in groundwater remediation efforts using the liquid or granular formulation or in bioreactors and constructed wetland treatment systems to improve remediation of effluents and surface waters for various metals. 

Our Nutrimens® product is a better choice than yeast extract. Besides its role in increasing the rates of bioremediation, addition of Nutrimens® increases the efficiency of electron donor utilization. Nutrimens® provides a source of sugars, proteins, vitamins and amino acids contained in yeast cells and extracellular metaboliteswhich will decrease the remediation time.  In addition, Nutrimens® has also been demonstrated to aid in maintaining circumneutral pH.

EDS-QR™ (Electron Donor Solution – Quick Release)

EDS-QR™ is a fast-acting, completely soluble amendment engineered for enhanced reductive dechlorination of chlorinated solvents or any other anaerobically degradable substance.  Our EDS-QR™ product is USP Kosher Grade 99.7% purity USA sourced from an ISO Certified Plant.  A key benefit is that EDS-QR™ provides more electron equivalence per pound than sodium lactate, so you buy and ship less product.  With 99.7% organic carbon, 60 lbs. of EDS-QR™ provides the same amount of carbon as 100 lbs. sodium lactate.  EDS-QR™ is an ideal choice for projects that are on a fast track.  One injection will typically enhance biological activity for 2 to 3 months.

Bioaugmentation Cultures

The complete reductive dechlorination of chlorinated ethenes yields non-toxic ethene as a final product. Absent the right bacteria, you could see an accumulation of vinyl chloride. Although not necessary at every site, Tersus Environmental recommends the use of KB-1® family of bioaugmentation cultures.

KB-1® is a consortium of microbes that is extremely effective in completing the reduction of chlorinated ethenes to ethene. Bioaugmentation leads to faster bioremediation, which means more efficient use of electron donors and reduced O&M requirements, thereby lowering overall project costs.   The KB-1® family of bioaugmentation cultures is the most widely used in the world for remediating chlorinated solvents.  We would be happy to provide you with references at your request.  


Vitamin B12

Dhc cultures require the cobalt-containing transition-metal coenzyme vitamin B12.  It is reported that optimal dechlorination and growth occur at vitamin B12 concentrations ranging from 25 to 50 micrograms per liter (25 µg/L) (Stroo et al., 2013).   Vitamin B12 is not commonly found in simple substrates such as emulsified vegetable oil (EVO) and at considerably lesser amounts in micronutrient blends.  To answer the growing demand for vitamin B12 and to provide for flexibility in adding vitamins in the field, Tersus offers Cyanocobalamin (Vitamin B12 USP) packaged in 100-gram tins.


For an enhanced reductive dechlorination project with bioaugmentation, geochemical conditions for the anaerobic water should meet the following requirements:

  • Redox levels [ORP] below -75 mV
  • Dissolved oxygen levels less than 0.2 mg/L
  • pH between 6 and 8.5

Tersus provides amino acids (L-Cysteine) to create anaerobic water for your bioaugmentation projects.  We suggest a dosage between 0.05% and 0.1%.  We suggest doing a small bucket test first to confirm the dosage required.