An overview of the occurrence, impact of process parameters, and the fate of antibiotic resistance genes during anaerobic digestion processes.

Antibiotic resistance genes (ARGs) have emerged as a significant global health threat, contributing to fatalities worldwide. Wastewater treatment plants (WWTPs) and livestock farms serve as primary reservoirs for these genes due to the limited efficacy of existing treatment methods and microbial adaptation to environmental stressors. Anaerobic digestion (AD) stands as a prevalent biological treatment for managing sewage sludge and manure in these settings.

Evaluation of sorbent amendments used with stormwater management practices to remove contaminants: Impacts of rainfall intensity and antecedent dry periods.

For a comprehensive evaluation of the suitability and efficiency of soil amendments in bioretention systems, it is crucial to investigate the capability of amendments for simultaneously serving three important functions under intermittent and variable flow conditions: removing a wide range of contaminants, supporting plant health, and maintaining media infiltration rate. However, most studies have not considered these important factors and conditions simultaneously, which may overestimate or underestimate the bioretention performance. In this study, a long-term vegetated column study was conducted to investigate the ability of various sorbent amendments- coconut coir fiber (CCF), blast furnace slag (BFS), and waste tire crumb rubber (WTCR) -for removal of metals, nutrients, and polycyclic aromatic hydrocarbons (PAHs) from stormwater.

Degradation of emerging per- and polyfluoroalkyl substances (PFAS) using an electrochemical plug flow reactor.

In recent years, shorter-chain fluorinated compounds have been manufactured as alternatives to legacy per- and polyfluoroalkyl substances (PFAS) after a global ban on some long-chain PFAS. This study is the first to investigate the degradability of emerging PFAS by an electrochemical plug flow reactor (EPFR). Ten different emerging PFAS, representing classes of fluorotelomer alcohol, perfluoroalkyl ether carboxylate, polyfluoroalkyl ethersulfonic acids, perfluoroalkyl ether/polyether carboxylates, perfluoroether sulfonate, N-alkyl perfluoroalkylsulfonamido carboxylate, fluoroalkyl phosphonic acid, and perfluoro alkane sulfonamide were investigated.

A modified QuEChERS sample processing method for the determination of per- and polyfluoroalkyl substances (PFAS) in environmental biological matrices.

QuEChERS (quick, easy, cheap, effective, rugged, and safe) sample processing methods have previously been applied to a range of compounds and matrices. This study presents a modified QuEChERS sample processing method that was validated and employed for 24 per- and polyfluoroalkyl substances (PFAS) for various biological matrices. PFAS are a group of synthetic chemicals that have attracted substantial attention as some compounds are acknowledged to be persistent, toxic, and bioaccumulative.

Impacts of divalent cations (Mg and Ca) on PFAS bioaccumulation in freshwater macroinvertebrates representing different foraging modes.

Per- and polyfluoroalkyl substances (PFAS) have extensively contaminated freshwater aquatic ecosystems where they can be transported in water and partition to sediment and biota. In this paper, three freshwater benthic macroinvertebrates with different foraging modes were exposed to environmentally relevant concentrations of eight perfluoroalkyl carboxylates (PFCA), three perfluoroalkyl sulfonates (PFSA), and three fluorotelomer sulfonates (FTS) at varying divalent cation concentrations of magnesium (Mg) and calcium (Ca). Divalent cations can impact PFAS partitioning to solids, especially to sediments, at higher concentrations.

Influence of microbial weathering on the partitioning of per- and polyfluoroalkyl substances (PFAS) in biosolids.

Per- and polyfluoroalkyl substances (PFAS) are a large group of man-made fluorinated organic chemicals that can accumulate in the environment. In water resource recovery facilities (WRRFs), some commonly detected PFAS tend to partition to and concentrate in biosolids where they can act as a source to ecological receptors and may leach to groundwater when land-applied. Although biosolids undergo some stabilization to reduce pathogens before land application, they still contain many microorganisms, contributing to the eventual decomposition of different components of the biosolids.

Bioaccumulation of per- and polyfluoroalkyl substances by freshwater benthic macroinvertebrates: Impact of species and sediment organic carbon content.

Per- and polyfluoroalkyl substances (PFAS) in aquatic environments have caused global concern due to their persistence, toxicity, and potential bioaccumulation of some compounds. As an important compartment of the aquatic ecosystem, sediment properties impact PFAS partitioning between aqueous and solid phases, but little is known about the influence of sediment organic carbon content on PFAS bioaccumulation in benthic organisms. In this study, three freshwater benthic macroinvertebrates - worms (Lumbriculus variegatus), mussels (Elliptio complanata) and snails (Physella acuta) - were exposed for 28 days to PFAS spiked synthetic sediment equilibrated with a synthetic surface water.

Synthesis and Characterization of High Viscosity Cationic Poly(Proline-Epichlorohydrin) Composite Polymer with Antibacterial Functionalities.

We report microbial resistance and catalytic activity of high viscosity cationic poly(proline-epichlorohydrin) composite (PRO-EPI) in the aqueous system. The PRO-EPI was prepared by a simple polycondensation, followed by FTIR, H NMR, SEM, DLS, viscosity, and DSC/TGA characterization. Several concentrations of the PRO-EPI were tested against Gram-negative ( and ) and Gram-positive () microorganisms.

Degradation and inactivation of chromosomal and plasmid encoded resistance genes/ARBs and the impact of different matrices on UV and UV/HO based advanced oxidation process.

This study reports a structured investigation on the degradation kinetics of different types (gyrA,tetA, qnrS) and conformational forms (chromosomal, plasmids) of ARGs and mobile genetic elements (intl-1, plasmids) as a function of water matrix (DI water, phosphate buffer, wastewater) with UV and UV/HO treatments. Extracellular, intracellular and the free-ARGs fate were tracked to infer the impact of various parameters on the degradation efficacy of the treatment process. The degradation profile of e-ARGs (118-454 bp) showed 1-4 log reductions but did not correlate strongly to amplicon size indicating the importance of active sites distribution and/or types of ARGs for UV induced gene damage.

Occurrence and removal of poly/perfluoroalkyl substances (PFAS) in municipal and industrial wastewater treatment plants.

The presence of poly- and perfluoroalkyl substances (PFAS) has caused serious problems for drinking water supplies especially at intake locations close to PFAS manufacturing facilities, wastewater treatment plants (WWTPs), and sites where PFAS-containing firefighting foam was regularly used. Although monitoring is increasing, knowledge on PFAS occurrences particularly in municipal and industrial effluents is still relatively low. Even though the production of C8-based PFAS has been phased out, they are still being detected at many WWTPs.

Competitive sorption of Cd, Cr, Cu, Ni, Pb and Zn from stormwater runoff by five low-cost sorbents; Effects of co-contaminants, humic acid, salinity and pH.

For a comprehensive estimation of metals removal by sorbents in stormwater systems, it is essential to evaluate the impacts of co-contaminants. However, most studies consider only metals (single or multiple), which may overestimate performance. This study employed a batch method to investigate the performance of five low-cost sorbents - coconut coir fiber (CCF), blast furnace slag (BFS), waste tire crumb rubber (WTCR), biochar (BC), and iron coated biochar (FeBC) - for simultaneous removal of Cd, Cr, Cu, Ni, Pb and Zn from simulated stormwater (SSW) containing other contaminants (nutrients and polycyclic aromatic hydrocarbons).

Power density modulated ultrasonic degradation of perfluoroalkyl substances with and without sparging Argon.

The power density modulates the dynamics of the chemical reactions during the ultrasonic breakdown of organic compounds. We evaluated the ultrasonic degradation of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) at various power densities (30 W/L-262 W/L) with and without sparging Argon. We observed pseudo-first-order degradation kinetics at an initial PFASs concentration of 100 nM over a range of power density.

Simultaneous removal of multiple polycyclic aromatic hydrocarbons (PAHs) from urban stormwater using low-cost agricultural/industrial byproducts as sorbents.

The potential of five low-cost and globally available sorbents, including three raw waste products - waste tire crumb rubber (WTCR), coconut coir fiber (CCF) and blast furnace slag (BFS) - and two modified materials - biochar (BC) and iron coated biochar (FeBC) - were evaluated for removing a mixture of polycyclic aromatic hydrocarbons (PAHs): pyrene (PYR), phenanthrene (PHE), acenaphthylene (ACY) and naphthalene (NAP) from simulated stormwater. The physicochemical characteristics of the sorbents were assessed by BET-N surface area, CHN elemental analysis, FTIR and scanning electron microscope (SEM-EDS). The experimental data were well described by both linear and Freundlich isotherm and pseudo-second order kinetic models.

Linking PFAS partitioning behavior in sewage solids to the solid characteristics, solution chemistry, and treatment processes.

Per- and polyfluoroalkyl substances (PFAS) have gained increasing attention due to the potential health risks that they present. Secondary sludge and biosolids are known as notable PFAS emission routes to the environment. In this study, partitioning behavior of 14 PFAS were investigated across four secondary wastewater treatment types (activated sludge, trickling filter, biological nutrient removal, and rotating biological contactor; n = 10) and three sludge stabilization methods (composting, aerobic digestion, and anaerobic digestion; n = 6).

Electrooxidation of short and long chain perfluorocarboxylic acids using boron doped diamond electrodes.

This study investigates electrooxidation of short (C3-C6) and long (C7-C-18) chain perfluorocarboxylic acids (PFCAs) including perfluorooctane sulfonate (PFOA) using Si/BDD electrode. The effect of operational parameters (supporting electrolyte type, applied current density, and initial pH) were explored for PFOA removal. At the optimized conditions, 74% TOC removal and 37% defluorination ratio were gained for 10 mg L of PFOA solution which evidences that the shorter chain PFCAs were formed.

In vitro estrogenic activity of representative endocrine disrupting chemicals mixtures at environmentally relevant concentrations.

Exposure to mixtures of endocrine disrupting compounds (EDCs) has been hypothesized to produce potential synergistic or antagonistic effects that can cause undesired effects that are not reflected by the individual compounds. In this study, the estrogenic activities of 11 EDCs of global environmental concern were systematically investigated using the yeast estrogen screen (YES). The contribution of the individual chemical to the total endocrine activity of environmentally relevant mixtures was evaluated.

Kinetic model for sonolytic degradation of non-volatile surfactants: Perfluoroalkyl substances.

Sonolytic degradation kinetics of non-volatile surfactant perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) were investigated over a range of concentration, considering active cavity as a catalyst. The Michaelis-Menten type kinetic model was developed to empirically estimate the concentration of active cavity sites during reactions. Sonolytic degradation of PFOA and PFOS, as well as the formation of its inorganic constituents, fluoride, and sulfate, follows saturation kinetics of pseudo-first order at lower concentration (<2.

Plastic toys as a source of exposure to bisphenol-A and phthalates at childcare facilities.

Infants and toddlers are constantly exposed to toys at childcare facilities. Toys are made of a variety of plastics that often use endocrine-disrupting chemicals such as bisphenol-A (BPA) and phthalates as their building blocks. The goal of this study was to assess the non-dietary exposure of infants and toddlers to BPA and phthalates via leaching.

Steroid hormones in environmental matrices: extraction method comparison.

The U.S. Environmental Protection Agency (EPA) has developed methods for the analysis of steroid hormones in water, soil, sediment, and municipal biosolids by HRGC/HRMS (EPA Method 1698).

Environmental Applications of ZnO Materials.

This review article comprehensively discusses the recent development of various environmental applications of Zinc Oxide (ZnO) semiconductor materials. The synthesis of various nano/micro structured ZnO using different methods and the influence of various preparation conditions on ZnO morphology are discussed. The environmental applications of nano/micro structured zinc oxide as an adsorbent, photocatalyst, and catalyst in catalytic ozonation processes are discussed.

Synthesis, Characterization of α-GaOOH Self-Assembly and Its Application in Removal of Perfluorinated Compounds.

This article discusses the hydrothermal synthesis of well-dispersed faceted α-GaOOH in the presence of sodium acetate by the self-assembly method. The synthesized α-GaOOH possesses a mixture of hexagonal and rectangular plates, cubic and diamond-like morphologies. The presence of ethanol as a co-solvent with water (1:1) facilitates scroll-like cylindrical morphology.

Understanding and modeling removal of anionic organic contaminants (AOCs) by anion exchange resins.

Ionic organic contaminants (OCs) are a growing concern for water treatment and the environment and are removed inefficiently by many existing technologies. This study examined removal of anionic OCs by anion exchange resins (AXRs) as a promising alternative. Results indicate that two polystyrene AXRs (IRA910 and IRA96) have higher sorption capacities and selectivity than a polyacrylate resin (A860).

Recent developments in heterogeneous catalyzed environmental remediation processes.

This article reports on recent developments in heterogeneous AOP processes such as photocatalysis, Fenton-like process and catalytic ozonation. The principle, mechanism, and influence of experimental conditions on the degradation of pollutants in heterogeneous catalytic ozonation and the photocatalytic process were discussed. Introducing solid catalysts substantially increased the efficiency of the ozonation process by producing hydroxyl radicals in the degradation process.

Development of high efficiency silica coated β-cyclodextrin polymeric adsorbent for the removal of emerging contaminants of concern from water.

This article reports the removal of several emerging contaminants (ECs) from water using novel adsorbent comprising of β-cyclodextrin (β-CD) coated on silica. Fourteen different adsorbents were synthesized under different experimental conditions using two different crosslinking agents (hexamethylene diisocyanate (HMDI) and epichlorohydrin (EPI)) and co-polymers (glycidoxypropyl trimethoxysilane (GPTS) and aminopropyl triethoxysilane (APTES). The adsorption capacities of the synthesized adsorbents were initially evaluated using 17β-estradiol, perfluorooctanoic acid (PFOA), and bisphenol-A (BPA) as adsorbates.

Rapid and sensitive screening of 17β-estradiol estrogenicity using Fourier transform infrared imaging spectroscopy (FT-IRIS).

It is important to develop rapid and sensitive screening assays to assess the biological effects of emerging contaminants. In this contribution, the ability to determine the molecular level effects of 17β-estradiol on single MCF-7 cells using Fourier transform infrared imaging spectroscopy (FT-IRIS) was investigated. The use of FT-IRIS enabled subcellular imaging of the cells and determination of a dose dependent response in mucin concentration at 24 and 48 h of incubation.