Evaluating the efficacy of slow-releasing carbon source tablets for in situ biological heterotrophic denitrification of groundwater.

Slow-releasing precipitating tablets (SRPTs) and slow-releasing floating tablets (SRFTs) were formulated to release fumarate as a carbon source (CS) and/or electron donor (ED) in an in situ biological heterotrophic denitrification system. These tablets were prepared using pharmaceutical manufacturing. Soil column tests were conducted to evaluate nitrate denitrification efficacy, microbial population changes, and mass balance of fumarate and potential electron acceptors.

Production, characterization, and evaluation of two types of slow-releasing carbon source tablets for in-situ heterotrophic nitrate denitrification in aquifers.

Slow-releasing carbon source tablets were manufactured for an in-situ biological denitrification system. The average zero-order nitrate degradation rates seen, from highest to lowest, were in microcosms to which lactate, fumarate, propionate, and formate had been added. Fumarate was approximately 80% cheaper than lactate, and consequently was determined to be the most optimal slow-releasing carbon source in tablet form.

Efficacy of in situ well-based denitrification bio-barrier (WDB) remediating high nitrate flux in groundwater near a stock-raising complex.

This study assessed the feasibility of an in situ well-based denitrification bio-barrier (WDB) for managing groundwater contaminated with high-strength nitrate. To evaluate the efficacy of WDB using fumarate as a carbon source and/or electron donor, three sequential single-well push-pull tests (SWPPTs) were conducted at six test sites. The values of the isotope enrichment factor (ɛ) ranging from -6.

Estimating bioaugmentation efficacy of TCE dechlorination using long-term field well-to-well tests in a highly recharged and TCE-contaminated aquifer.

This study demonstrates a combined field method accurately assessing the extent of trichloroethylene (TCE) reductive dechlorination activity and the mass fraction of its by-products. A combined method of injecting a known concentration of 1,1,2-trichloro-2-fluoroethene (TCFE) as a TCE bio-surrogate and a data processing technique of forced mass balance (FMB), considering the sorption effect on the mass fraction of chloroethene was evaluated by performing soil column and field bioaugmentation tests. In the soil column test, the FMB resulted in the mass fraction of 6% TCE, 48.