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WHY NITRATE STILL MATTERS IN ANAEROBIC BIOREMEDIATION

While sulfate is often the go-to electron acceptor for enhancing anaerobic biodegradation of petroleum hydrocarbons, the strategic addition of nitrate can offer several key benefits in biogeochemical remediation approaches targeting mixed contaminants, including chlorinated volatile organic compounds (CVOCs).

Facilitating the Transition to Anaerobic Conditions

Making nitrate readily available to facultative, nitrate-reducing bacteria can significantly accelerate the natural degradation of petroleum hydrocarbons. This strategy is particularly effective in subsurface environments where natural attenuation is often delayed due to rapid oxygen depletion from aerobic microbial activity, coupled with the lag time required for microbial communities to transition to anaerobic conditions. By proactively supplying an alternative electron acceptor such as nitrate—along with essential micronutrients—biostimulation efforts can sustain and enhance microbial activity as oxygen becomes limited. This not only supports earlier and more robust breakdown of petroleum hydrocarbons but also facilitates the microbial and geochemical processes necessary for the reductive dechlorination of CVOCs.

Supporting Hydrocarbon Breakdown

Certain petroleum hydrocarbons—especially BTEX compounds like toluene and ethylbenzene—degrade efficiently under nitrate-reducing conditions. Nitrate addition supports this early-phase degradation before sulfate-reducing bacteria (SRBs) dominate the system.

Enabling Biogeochemical Synergy

Nitrate-fueled microbial activity produces hydrogen, acetate, and other fermentation products—critical substrates for organohalide-respiring bacteria. Additionally, microbial nitrate reduction can stimulate iron and sulfur cycling, supporting the formation of iron sulfide (FeS) minerals known to abiotically reduce CVOCs like TCE and cDCE.

Reducing Reductive Dechlorination Stall

Sites contaminated with CVOCs often stall at cis-DCE or vinyl chloride due to nutrient limitations or incomplete redox transitions. A modest nitrate amendment can restore microbial diversity and promote co-metabolic or syntrophic interactions needed to drive dechlorination to completion.

How NutriSulfate® BioBoost Can Help

NutriSulfate® BioBoost is a dry-blended formulation engineered to enhance anaerobic remediation by delivering a balanced mix of bioavailable nutrients and electron acceptors. It stimulates biogeochemical processes that support both biotic and abiotic degradation of petroleum hydrocarbons and chlorinated solvents.

NutriSulfate® BioBoost supplies:

  • Nitrate, to quickly reduce redox potential and initiate anaerobic conditions.
  • Sulfate, to support sulfate-reducing bacteria (SRBs) and reactive mineral formation.
  • A supplemental nitrogen source, to promote microbial growth and enhance dechlorination rates.
  • Phosphorus, a vital nutrient for microbial metabolism and energy transfer.

When paired with complementary Tersus solutions—such as EDS-ER™ (electron donor solution) and ZVI-ironGEL™—NutriSulfate® BioBoost becomes a powerful component of integrated biogeochemical remediation strategies.

Ready to Get Your Project Across the Finish Line?

Contact Tersus today to learn how NutriSulfate® BioBoost can be integrated into your remediation strategy. We’ll help tailor a solution to meet your site’s specific challenges and performance goals. Let’s talk about how we can support your success.