Using selectivity to evaluate aqueous- and resin-phase denitrification during biological ion exchange.

An increased fertilizer application for agricultural purposes has resulted in increased nitrate (NO) levels in surface water and groundwater around the globe, highlighting demand for a low-maintenance NO treatment technology that can be applied to nonpoint sources. Ion exchange (IEX) is an effective NO treatment technology and research has shown that bioregeneration of NO laden resins has the potential to minimize operational requirements and brine waste production that often prevents IEX application for decentralized treatment. In this work, batch denitrification experiments were conducted using solutions with low IEX selectivity capable of supporting the growth of denitrifying bacteria, while minimizing NO desorption from resins, encouraging resin-phase denitrification.

Butanol as a major product during ethanol and acetate chain elongation.

Chain elongation is a relevant bioprocess in support of a circular economy as it can use a variety of organic feedstocks for production of valuable short and medium chain carboxylates, such as butyrate (C4), caproate (C6), and caprylate (C8). Alcohols, including the biofuel, butanol (C4), can also be generated in chain elongation but the bioreactor conditions that favor butanol production are mainly unknown. In this study we investigated production of butanol (and its precursor butyrate) during ethanol and acetate chain elongation.

Decoupling Fe Application and Bioaugmentation in Space and Time Enables Microbial Reductive Dechlorination of Trichloroethene to Ethene: Evidence from Soil Columns.

Fe is a powerful chemical reductant with applications for remediation of chlorinated solvents, including tetrachloroethene and trichloroethene. Its utilization efficiency at contaminated sites is limited because most of the electrons from Fe are channeled to the reduction of water to H rather than to the reduction of the contaminants. Coupling Fe with H-utilizing organohalide-respiring bacteria (i.

An Ion Chromatography Method for Simultaneous Quantification of Chromate, Arsenate, Selenate, Perchlorate, and Other Inorganic Anions in Environmental Media.

Chromium (Cr) (VI) is a toxic, mutagenic, and carcinogenic water pollutant. The standard ion chromatography (IC) method for quantification of Cr (VI) in water samples is Environmental Protection Agency Method 218.7, which requires postcolumn derivatization with 1,5-diphenylcarbazide and UV-Vis spectroscopy detection.

Microbial Chain Elongation and Subsequent Fermentation of Elongated Carboxylates as H-Producing Processes for Sustained Reductive Dechlorination of Chlorinated Ethenes.

In situ anaerobic groundwater bioremediation of trichloroethene (TCE) to nontoxic ethene is contingent on organohalide-respiring , the most common strictly hydrogenotrophic (). The H requirement for is fulfilled by adding various organic substrates (e.g.

Synergistic Zerovalent Iron (Fe) and Microbiological Trichloroethene and Perchlorate Reductions Are Determined by the Concentration and Speciation of Fe.

Trichloroethene (TCE) and perchlorate (ClO) are cocontaminants at multiple Superfund sites. Fe is often used during TCE bioremediation with to establish anoxic conditions in the aquifer. However, the synergy between Fe abiotic reactions and microbiological TCE and ClO reductions is poorly understood and seldom addressed in the literature.