This study investigates critical structure–reactivity relationships within 34 representative per- and polyfluoroalkyl substances (PFASs) undergoing defluorination with UV-generated hydrated electrons. While CnF2n+1–COO– variable fluoroalkyl chain lengths (n = 2 to 10) exhibited a similar rate extent of parent compound decay defluorination, the reactions telomeric CnF2n+1–CH2CH2–COO– CnF2n+1–SO3– showed an apparent dependence on length chain. Cross comparison experimental results, including...

This study explores structure–reactivity relationships for the degradation of emerging perfluoroalkyl ether carboxylic acid (PFECA) pollutants with ultraviolet-generated hydrated electrons (eaq–). The rate and extent PFECA depend on both branching chain length oxygen-segregated fluoroalkyl moieties. Kinetic measurements, theoretical calculations, transformation product analyses provide a comprehensive understanding mechanisms pathways. In comparison to traditional full-carbon-chain...

The UV-sulfite reductive treatment using hydrated electrons (eaq–) is a promising technology for destroying perfluorocarboxylates (PFCAs, CnF2n+1COO–) in any chain length. However, the C–H bonds formed transformation products strengthen residual C–F and thus prevent complete defluorination. Reductive treatments of fluorotelomer carboxylates (FTCAs, CnF2n+1–CH2CH2–COO–) sulfonates (FTSAs, CnF2n+1–CH2CH2–SO3–) are also sluggish because ethylene linker separates fluoroalkyl from end functional...

The addition of iodide (I–) in the UV/sulfite system (UV/S) significantly accelerated reductive degradation perfluorosulfonates (PFSAs, CnF2n+1SO3–) and perfluorocarboxylates (PFCAs, CnF2n+1COO–). Using highly recalcitrant perfluorobutane sulfonate (C4F9SO3–) as a probe, we optimized + (UV/S I) to degrade n = 1–7 PFCAs 4, 6, 8 PFSAs. In general, kinetics per- polyfluoroalkyl substance (PFAS) decay, defluorination, transformation product formations UV/S I were up three times faster than those...

Reductive defluorination with UV-generated hydrated electrons (eaq–) is a promising technology for the destruction of perfluorocarboxylic acids (PFCAs, CnF2n+1COO–). However, prior studies using pH 9–10 observed slow reaction rate, limited percentage (deF%), and thus high energy consumption. Herein, we report on substantially enhanced rate extent PFCA by operating UV/sulfite system at optimized 12. Degradation kinetics transformation products show that 12 eaq– cleaved multiple strong C–F...

Corrinoids are cobalt-containing molecules that function as enzyme cofactors in a wide variety of organisms but produced solely by subset prokaryotes. Specific corrinoids identified the structure their axial ligands. The lower ligand corrinoid can be benzimidazole, purine, or phenolic compound. Though it is known many obtain from environment, serve for any one organism largely unstudied. Here, we examine range corrinoid-dependent metabolism Dehalococcoides mccartyi strain 195. bacteria play...

Significance We have studied the functionality of an incomplete acetyl-CoA “Wood–Ljungdahl” pathway in a strictly organohalide-respiring bacterium, Dehalococcoides mccartyi . found that addition to its ability incorporate exogenous formate, this cleaves generate methyl-tetrahydrofolate for methionine biosynthesis, serving as unique substitute missing methylene-tetrahydrofolate reductase function. also accumulation carbon monoxide (CO), obligate by-product from cleavage, inhibits D. axenic...

The C-F bond is one of the strongest single bonds in nature. Although microbial reductive dehalogenation well known for other organohalides, no defluorination has been documented perfluorinated compounds except a single, nonreproducible study on trifluoroacetate. Here, we report cleavage two C6 per- and polyfluorinated via by an organohalide-respiring community. was demonstrated release F- formation corresponding product when lactate electron donor, fluorinated compound sole acceptor. major...

The recently discovered microbial reductive defluorination of two C6 branched and unsaturated fluorinated carboxylic acids (FCAs) provided valuable insights into the environmental fate per- polyfluoroalkyl substances (PFASs) potential bioremediation strategies. However, a systematic investigation is needed to further demonstrate role C═C double bonds in biodegradability PFASs. Here, we examined structure-biodegradability relationships 13 FCAs, including nine commercially available FCAs four...

Per- and polyfluoroalkyl substances (PFAS) are a large group of manmade chemicals that impose emerging environmental concerns. Among them, short-chain per- polyfluorinated carboxylic acids represent an important subgroup used as building blocks biologically active functional materials. Some also considered PFAS alternatives, some could be byproducts the physicochemical treatment PFAS. However, little is known about fate fluorinated (FCAs) their defluorination/transformation by...

Enzymatic cleavage of C─F bonds in per- and polyfluoroalkyl substances (PFAS) is largely unknown but avidly sought to promote systems biology for PFAS bioremediation. Here, we report the reductive defluorination α, β-unsaturated polyfluorocarboxylic acids by

Biotransformation of various micropollutants (MPs) has been found to be positively correlated with nitrification in activated sludge communities. To further elucidate the roles played by ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing (NOB), we investigated biotransformation capabilities an NOB pure culture (Nitrobacter sp.) AOB (Nitrosomonas europaea)/NOB coculture for 15 MPs, whose was reported previously associated nitrification. The did not biotransform any MP, whereas AOB/NOB...

The biotransformation of some micropollutants has previously been observed to be positively associated with ammonia oxidation activities and the transcript abundance archaeal monooxygenase gene (amoA) in nitrifying activated sludge. Given increasing interest potential importance ammonia-oxidizing archaea (AOA), we investigated capabilities an AOA pure culture, Nitrososphaera gargensis, biotransform ten belonging three structurally similar groups (i.e., phenylureas, tertiary amides, amines)....

Corrinoids are essential cofactors of reductive dehalogenases in Dehalococcoides mccartyi, an important bacterium bioremediation, yet sequenced D. mccartyi strains do not possess the complete pathway for de novo corrinoid biosynthesis. Pelosinus sp. and Desulfovibrio have been detected dechlorinating communities enriched from contaminated groundwater without exogenous cobalamin corrinoid. To investigate corrinoid-related interactions among key members these communities, we constructed...

For many polar organic micropollutants, biotransformation by activated sludge microorganisms is a major removal process during wastewater treatment. However, our current understanding of how treatment operations influence microbial communities and their micropollutant potential limited, leaving parts observed variability in rates across facilities unexplained. Here, we present rate constants for 42 micropollutants belonging to different chemical classes along gradient solids retention time...

Cobalamin and other corrinoids are essential cofactors for many organisms. The majority of microbes with corrinoid-dependent enzymes do not produce de novo, instead must acquire produced by organisms in their environment. However, the profile microbial communities, as well exchange modification among community members have been studied. In this study, we applied a newly developed liquid chromatography tandem mass spectrometry-based corrinoid detection method to examine relationships...

Antibiotic resistance is one of the most challenging issues in public health. Antibiotics have been increasingly used not only for humans and animals but also crop protection as pesticides. Thus, antibiotics often coexist with pesticides some environments. To investigate effects co-occurring, nonantibiotic on development antibiotic resistance, we conducted long-term exposure experiments using an Escherichia coli K-12 model strain. The results reveal that (1) to (in mg/L) alone led emergence...

Abstract Molecular design of redox‐materials provides a promising technique for tuning physicochemical properties which are critical selective separations and environmental remediation. Here, the structural redox‐copolymers, 4‐methacryloyloxy‐2,2,6,6‐tetramethylpiperidin‐1‐oxyl (TMA) 4‐methacryloyloxy‐2,2,6,6‐tetramethylpiperidine (TMPMA), denoted as P(TMA x ‐ co ‐TMPMA 1− ), is investigated separation anion contaminants ranging from perfluorinated substances to halogenated aromatic...

The recently discovered complete ammonia-oxidizing (comammox) bacteria occur in various environments, including wastewater treatment plants. To better understand their role micropollutant biotransformation comparison with (AOB) and archaea (AOA), we investigated the capability of Nitrospira inopinata (the only comammox isolate) for 17 micropollutants. Asulam, fenhexamid, mianserin, ranitidine were biotransformed by N. inopinata, Nitrososphaera gargensis Nitrosomonas nitrosa Nm90 (AOB). More...