Assessing strategies to measure hidden per- and polyfluoroalkyl substances (PFAS) in groundwater and to evaluate adsorption remediation efficiencies.

The widespread presence of per- and polyfluoroalkyl substances (PFAS) in the environment, driven by extensive industrial use, has raised global concerns due to their persistence and adverse health effects. Despite the increased regulatory focus on a sub-set of well-known PFAS, over 12,000 compounds exist, many poorly characterized. Our study assessed hidden PFAS concentrations, undetectable by standard LC-MS/MS analysis, in contaminated groundwater.

Comparative Methods for Quantification of Sulfate-Reducing Bacteria in Environmental and Engineered Sludge Samples.

This study aimed to compare microscopic counting, culture, and quantitative or real-time PCR (qPCR) to quantify sulfate-reducing bacteria in environmental and engineered sludge samples. Four sets of primers that amplified the and gene encoding the two key enzymes of the sulfate-reduction pathway were initially tested. qPCR standard curves were constructed using genomic DNA from an SRB suspension and dilutions of an enriched sulfate-reducing sludge.

Biodegradation of the emerging contaminant 3-nitro-1,2,4-triazol-5-one and its product 3-amino-1,2,4-triazol-5-one in perlite/soil columns.

3-Nitro-1,2,4-triazol-5-one (NTO) is an ingredient of new safer-to-handle military insensitive munitions formulations. NTO can be microbially reduced to 3-amino-1,2,4-triazol-5-one (ATO) under anaerobic conditions if an electron donor is available. Conversely, ATO can undergo aerobic biodegradation.

Treatment of the insensitive munitions compound, 3-nitro-1,2,4-triazol-5-one (NTO), in flow-through columns packed with zero-valent iron.

The need for effective technologies to remediate the insensitive munitions compound 3-nitro-1,2,4-triazol-5-one (NTO) is emerging due to the increasing use by the US Army and environmental concerns about the toxicity and aqueous mobility of NTO. Reductive treatment is essential for the complete degradation of NTO to environmentally safe products. The objective of this study is to investigate the feasibility of applying zero-valent iron (ZVI) in a continuous-flow packed bed reactor as an effective NTO remediation technology.

Antimony toxicity upon microorganisms from aerobic and anaerobic environments.

Antimony (Sb) is a toxic and carcinogenic metalloid that can be present in contaminated water generated by mining operations and other industrial activities. The toxicity of Sb (III) and Sb (V) to aerobic microorganisms remains limited and unexplored for anaerobic microorganisms involved in hydrogen (H) and methane (CH) production. This study aimed to evaluate the toxicity of Sb (III) and Sb (V) upon aerobic and anaerobic microorganisms important in biological wastewater treatment systems.

The key role of biogenic arsenic sulfides in the removal of soluble arsenic and propagation of arsenic mineralizing communities.

Biogeochemical processes govern the transport and availability of arsenic in sediments. However, little is known about the transition from indigenous communities to cultivable consortia when exposed to high arsenic concentrations. Such cultivable communities could be exploited for arsenic bioremediation of waste streams and polluted sites.

Elucidating the mechanisms associated with the anaerobic biotransformation of the emerging contaminant nitroguanidine.

Nitroguanidine (NQ) is a constituent of gas generators for automobile airbags, smokeless pyrotechnics, insecticides, propellants, and new insensitive munitions formulations applied by the military. During its manufacture and use, NQ can easily spread in soils, ground, and surface waters due to its high aqueous solubility. Very little is known about the microbial biotransformation of NQ.

Biosynthesis and Analytical Characterization of Iron Oxide Nanobiocomposite for In-Depth Adsorption Strategy for the Removal of Toxic Metals from Drinking Water.

The biosynthesis of the iron oxide nanoparticles was done using leaf extract, followed by the fabrication of iron oxide nanobiocomposites (I-FeO-NBC) using chitosan biopolymer. Furthermore, the synthesized I-FeO-NPs and I-FeO-NBC were characterized, and I-FeO-NBC was applied to remove toxic metals (TMs: Cd, Ni, and Pb) from water. The characterization study confirmed that the nanostructure, porous, rough, crystalline structure, and different functional groups of chitosan and I-FeO-NPs in I-FeO-NBCs showed their feasibility for the application as excellent adsorbents for quantitative removal of TMs.

Reductive transformation of the insensitive munitions compound nitroguanidine by different iron-based reactive minerals.

Nitroguanidine (NQ) is an emerging contaminant being used by the military as a constituent of new insensitive munitions. NQ is also used in rocket propellants, smokeless pyrotechnics, and vehicle restraint systems. Its uncontrolled transformation in the environment can generate toxic and potentially mutagenic products, posing hazards that need to be remediated.

Designing bacterial consortia for the complete biodegradation of insensitive munitions compounds in waste streams.

Insensitive munitions compounds (IMCs), such as 2,4-dinitroanisole (DNAN) and 3-nitro-1,2,4-triazol-5-one (NTO), are replacing conventional explosives in munitions formulations. Manufacture and use of IMCs generate waste streams in manufacturing plants and load/assemble/pack facilities. There is a lack of practical experience in executing biodegradation strategies to treat IMCs waste streams.

Quinone Moieties Link the Microbial Respiration of Natural Organic Matter to the Chemical Reduction of Diverse Nitroaromatic Compounds.

Insensitive munitions compounds (IMCs) are emerging nitroaromatic contaminants developed by the military as safer-to-handle alternatives to conventional explosives. Biotransformation of nitroaromatics via microbial respiration has only been reported for a limited number of substrates. Important soil microorganisms can respire natural organic matter (NOM) by reducing its quinone moieties to hydroquinones.

Fate of bis-(4-tert-butyl phenyl)-iodonium under photolithography relevant irradiation and the environmental risk properties of the formed photoproducts.

Aryl-iodonium salts are utilized as photoacid generators (PAGs) in semiconductor photolithography and other photo-initiated manufacturing processes. Despite their utilization and suspected toxicity, the fate of these compounds within the perimeter of semiconductor fabrication plants is inadequately understood; the identification of photolithography products is still needed for a comprehensive environmental impact assessment. This study investigated the photolytic transformation of a representative iodonium PAG cation, bis-(4-tert-butyl phenyl)-iodonium, under conditions simulating industrial photolithography.

Dynamics of Microbial Communities during the Removal of Copper and Zinc in a Sulfate-Reducing Bioreactor with a Limestone Pre-Column System.

Biological treatment using sulfate-reducing bacteria (SRB) is a promising approach to remediate acid rock drainage (ARD). Our purpose was to assess the performance of a sequential system consisting of a limestone bed filter followed by a sulfate-reducing bioreactor treating synthetic ARD for 375 days and to evaluate changes in microbial composition. The treatment system was effective in increasing the pH of the ARD from 2.

Analysis of hydrophilic per- and polyfluorinated sulfonates including trifluoromethanesulfonate using solid phase extraction and mixed-mode liquid chromatography-tandem mass spectrometry.

Ultra-hydrophilic per- and polyfluorinated sulfonates (PFSA) are increasingly scrutinized in recent years due to their ubiquitous occurrence, persistence, and aqueous mobility in the environment, yet analysis remains a challenge. This study developed methods for the analysis of trifluoromethanesulfonate, perfluorobutanesulfonate, 10-camphorsulfonate, and a di-fluorinated sulfonate utilizing mixed-mode liquid chromatography, where all analytes were adequately retained and separated. Chromatography and electrospray ionization parameters were optimized; instrumental limits of quantification for the anionic target analytes were in the range of 4.

Treatment of acid rock drainage using a sulphate-reducing bioreactor with a limestone precolumn.

Sulphate reducing bacteria (SRB) offer promise for the treatment of mine waste due to their effectiveness removing toxic heavy metals as highly insoluble metal sulphides and their ability to generate alkalinity. The main objective of this study was to develop a treatment composed of a sulphate-reducing bioreactor with a limestone precolumn for the removal of Cu(II) from a synthetic ARD. The purpose of the limestone column was to increase the pH values and decrease the level of Cu in the effluent to prevent SRB inhibition.

Iron(II) monosulfide (FeS) minerals reductively transform the insensitive munitions compounds 2,4-dinitroanisole (DNAN) and 3-nitro-1,2,4-triazol-5-one (NTO).

As military applications of the insensitive munitions compounds (IMCs) 2,4-dinitroanisole (DNAN) and 3-nitro-1,2,4-triazol-5-one (NTO) increase, there is a growing need to understand their environmental fate and to develop remediation strategies to mitigate their impacts. Iron (II) monosulfide (FeS) minerals are abundant in freshwater and marine sediments, marshes, and hydrothermal environments. This study shows that FeS solids can reduce DNAN and NTO to their corresponding amines under anoxic ambient conditions.

Aerobic biodegradation of emerging azole contaminants by return activated sludge and enrichment cultures.

Azoles are an emerging class of contaminants with a growing ubiquitous presence in the environment. This study investigates the aerobic microbial degradation of four azoles, pyrazole (PA), 1,2,4-triazole (TA), benzotriazole (BTA) and 5-methylbenzotriazole (5-MBTA), with return activated sludge and microbial enrichment cultures. Slow degradation of PA was observed in the presence of glucose and NH with a peak degradation rate of 0.

Effect of carbon source and metal toxicity for potential acid mine drainage (AMD) treatment with an anaerobic sludge using sulfate-reduction.

This study compares sulfate-reduction performance in an anaerobic sludge with different carbon sources (ethanol, acetate, and glucose). Also, the toxic effect of copper was evaluated to assess its feasibility for possible acid mine drainage (AMD) treatment. Serological bottles with 1.

Covalent binding with model quinone compounds unveils the environmental fate of the insensitive munitions reduced product 2,4-diaminoanisole (DAAN) under anoxic conditions.

2,4-Dinitroanisole (DNAN) is an insensitive munitions compound expected to replace 2,4,6-trinitrotoluene (TNT). The product of DNAN's reduction in the environment is 2,4-diaminoanisole (DAAN), a toxic and carcinogenic aromatic amine. DAAN is known to become irreversibly incorporated into soil natural organic matter (NOM) after DNAN's reduction.

Bacteria Make a Living Breathing the Nitroheterocyclic Insensitive Munitions Compound 3-Nitro-1,2,4-triazol-5-one (NTO).

The nitroheterocyclic 3-nitro-1,2,4-triazol-5-one (NTO) is an ingredient of insensitive explosives increasingly used by the military, becoming an emergent environmental pollutant. Cometabolic biotransformation of NTO occurs in mixed microbial cultures in soils and sludges with excess electron-donating substrates. Herein, we present the unusual energy-yielding metabolic process of NTO respiration, in which the NTO reduction to 3-amino-1,2,4-triazol-5-one (ATO) is linked to the anoxic acetate oxidation to CO by a culture enriched from municipal anaerobic digester sludge.

Bioconcentration potential and microbial toxicity of onium cations in photoacid generators.

Despite the widespread utilization of onium salts as photoacid generators (PAGs) in semiconductor photolithography, their environmental, health, and safety (EHS) properties remain poorly understood. The present work reports the bioconcentration potential of five representative onium species (four sulfonium and one iodonium compound) by determining the octanol-water partition coefficient (P) and lipid membrane affinity coefficient (K); microbial toxicity was evaluated using the bioluminescent bacterium Aliivibrio fischeri (Microtox bioassay). Four of the oniums exhibited varying degrees of hydrophobic (lipophilic) partitioning (log P: 0.

Covalent bonding of aromatic amine daughter products of 2,4-dinitroanisole (DNAN) with model quinone compounds representing humus via nucleophilic addition.

2,4-Dinitroanisole (DNAN) is a component of insensitive munitions (IM), which are replacing traditional explosives due to their improved safety. Incomplete IM combustion releases DNAN onto the soil, where it can leach into the subsurface with rainwater, encounter anoxic conditions, and undergo (a)biotic reduction to aromatic amines 2-methoxy-5-nitroaniline (MENA), 4-methoxy-3-nitroaniline (iMENA, isomer of MENA), and 2,4-diaminoanisole (DAAN). We report here studies of nucleophilic addition mechanisms that may account for the sequestration of aromatic amine daughter products of DNAN into soil organic matter (humus), effectively removing these toxic compounds from the aqueous environment.

Anammox enrichment culture has unexpected capabilities to biotransform azole contaminants of emerging concern.

Azoles are contaminants of emerging concern. They have a ubiquitous presence in the environment due to their wide variety of uses. This study investigated the fate of two commonly occurring azole compounds in an anammox enrichment culture.

Rapid biotransformation of the insensitive munitions compound, 3-nitro-1,2,4-triazol-5-one (NTO), by wastewater sludge.

As the use of the new insensitive munitions compound 3-nitro-1,2,4-triazol-5-one (NTO) increases, wastewaters, runoff and groundwater containing NTO will be generated. Little is known about the fate of NTO during biological wastewater treatment. The objective of this study was to explore the ability of wastewater sludges to promote the biotransformation of NTO.

Cytotoxicity Assessment of Gallium- and Indium-Based Nanoparticles Toward Human Bronchial Epithelial Cells Using an Impedance-Based Real-Time Cell Analyzer.

The semiconductor manufacturing sector plans to introduce III/V film structures (eg, gallium arsenide (GaAs), indium arsenide (InAs) onto silicon wafers due to their high electron mobility and low power consumption. Aqueous solutions generated during chemical and mechanical planarization of silicon wafers can contain a mixture of metal oxide nanoparticles (NPs) and soluble indium, gallium, and arsenic. In this work, the cytotoxicity induced by Ga- and In-based NPs (GaAs, InAs, GaO, InO) and soluble III-V salts on human bronchial epithelial cells (16HBE14o-) was evaluated using a cell impedance real-time cell analysis (RTCA) system.