Effect of electrolyte composition on electrocatalytic transformation of perfluorooctanoic acid (PFOA) in high pH medium.

Recent regulatory actions aim to limit per- and polyfluoroalkyl substances (PFAS) concentrations in drinking water and wastewaters. Regenerable anion exchange resin (AER) is an effective separation process to remove PFAS from water but will require PFAS post-treatment of the regeneration wastestream. Electrocatalytic (EC) processes using chemically boron-doped diamond electrodes, stable in a wide range of chemical compositions show potential to defluorinate PFOA in drinking water and wastewater treatments.

Insights into adsorbable organic halogen analysis: Two overlooked factors impacting water quality assessment.

Adsorbable organic halogen (AOX) represents the total amount of halogenated organics that can be adsorbed on activated carbon (AC) from samples. Measuring AOX is crucial for assessing water quality, and any erroneous estimation of AOX risks misleading decision-makers. This study demonstrated two overlooked factors that may introduce biases to AOX measurement.

Formation of halogenated forms of bisphenol A (BPA) in water: Resolving isomers with ion mobility - mass spectrometry and the role of halogenation position in cellular toxicity.

Halogenated BPA (XBPA) forms resulting from water chlorination can lead to increased toxicity and different biological effects. While previous studies have reported the occurrence of different XBPAs, analytical limitation have hindered the analysis and differentiation of the many potential isomeric forms. Using online solid-phase extraction - liquid chromatography - ion-mobility - high-resolution mass spectrometry (OSPE-LC-IM-HRMS), we demonstrated a rapid analysis method for the analysis of XBPA forms after water chlorination, with a total analysis time of less than 10 min including extraction and concentration and low detection limits (∼5-80 ng/L range).

Transformation of 6PPDQ during disinfection: Kinetics, products, and eco-toxicity assessment.

N-phenyl-N'-(1,3-dimethyl butyl)-p-phenylenediamine-quinone (6PPDQ) currently arouses broad concerns because of its acute lethality to coho salmon and rainbow trout at environmentally relevant concentrations and the wide occurrence in runoff-impacted water. Investigation on the fate and transformation of 6PPDQ in various treatment processes is necessary for its risk assessment and control. Here, we explored the transformation of 6PPDQ during disinfection with its precursor 6PPD as a reference, focusing on kinetics, products, and toxicity variation.

CuO Promotes the Formation of Halogenated Disinfection Byproducts during Chlorination via an Enhanced Oxidation Pathway.

Previous studies showed that cupric oxide (CuO) can enhance the formation of trihalomethanes (THMs), haloacetic acids, and bromate during chlorination of bromide-containing waters. In this study, the impact of CuO on the formation kinetics and mechanisms of halogenated disinfection byproducts (DBPs) during chlorination was investigated. CuO does not enhance the formation of DBPs (i.

Reaction of Polyamide Membrane Model Monomers with Chlorine Dioxide: Kinetics, Pathways, and Implications.

Aromatic polyamide (PA) based membranes are widely used for reverse osmosis (RO), but they can be degraded by free chlorine used for controlling the biofouling prior to RO treatment. Kinetics and mechanisms for the reactions of PA membrane model monomers, i.e.

Biogenic Solution Map Based on the Definition of the Metabolic Correlation Distance between 4-Dimensional Fingerprints.

Accurate discrimination and classification of unknown species are the basis to predict its characteristics or applications to make correct decisions. However, for biogenic solutions that are ubiquitous in nature and our daily lives, direct determination of their similarities and disparities by their molecular compositions remains a scientific challenge. Here, we explore a standard and visualizable ontology, termed "biogenic solution map", that organizes multifarious classes of biogenic solutions into a map of hierarchical structures.

UV/chlorine and chlorination of effluent organic matter fractions: Tracing nitrogenous DBPs using FT-ICR mass spectrometry.

UV/chlorine process is a promising advanced treatment to eliminate pathogen and remove refractory micropollutants for reclamation of municipal secondary effluent. However, effluent organic matter (EfOM) featuring high organic nitrogen content serves as a potential precursor for nitrogenous disinfection byproducts (N-DBPs) of health concern. The molecular-level alteration of a hydrophobic (HPO) EfOM fraction and a transphilic (TPI) EfOM fraction isolated from the same municipal effluent and the formation of N-DBPs in the UV/chlorine were tracked by ultrahigh-resolution mass spectrometry.

Molecular-level investigation into UV-induced transformation of hydrophobic aquatic dissolved organic matter.

The ubiquitously present dissolved organic matter (DOM) greatly influence the efficiency of UV-based technologies due to its reactivity to UV irradiation. In this work, UV-induced changes within three hydrophobic DOM fractions isolated from different surface waters were investigated. Analysis on UV absorbance at 254 nm, electron donating capacity, fluorescence intensity and carbon content revealed small changes in DOM bulk properties associated with the UV-induced photochemical reactions.

Genotoxic effects of chlorinated disinfection by-products of 1,3-diphenylguanidine (DPG): Cell-based in-vitro testing and formation potential during water disinfection.

1,3-diphenylguanidine (DPG) is a commonly used rubber and polymer additive, that has been found to be one of the main leachate products of tire wear particles and from HDPE pipes. Its introduction to aquatic environments and potentially water supplies lead to further questions regarding the effects of disinfection by-products potentially formed. Using different bioassay approaches and NGS RNA-sequencing, we show that some of the chlorinated by-products of DPG exert significant toxicity.

Modification Mechanism of Polyamide Reverse Osmosis Membrane by Persulfate: Roles of Hydroxyl and Sulfate Radicals.

Oxidative modification is a facile method to improve the desalination performance of thin-film composite membranes. In this study, we comparatively investigated the modification mechanisms induced by sulfate radical (SO) and hydroxyl radical (HO) for polyamide reverse osmosis (RO) membrane. The SO- and HO-based membrane modifications were manipulated by simply adjusting the pH of the thermal-activated persulfate solution.

A catalytic ozonation process using MgO/persulfate for degradation of cyanide in industrial wastewater: mechanistic interpretation, kinetics and by-products.

Cyanide-laden wastewaters generated from mining and electroplating industries are extremely toxic and it is of vital importance to treat them prior to discharge to receiving water resources. The present study aims to oxidize cyanide using an ozonation process catalyzed by MgO and persulfate (PS). A MgO nanocatalyst was synthesized using the sol-gel method and characterized.

Inputs of disinfection by-products to the marine environment from various industrial activities: Comparison to natural production.

Oxidative treatment of seawater in coastal and shipboard installations is applied to control biofouling and/or minimize the input of noxious or invasive species into the marine environment. This treatment allows a safe and efficient operation of industrial installations and helps to protect human health from infectious diseases and to maintain the biodiversity in the marine environment. On the downside, the application of chemical oxidants generates undesired organic compounds, so-called disinfection by-products (DBPs), which are discharged into the marine environment.

Impact of EfOM in the elimination of PPCPs by UV/chlorine: Radical chemistry and toxicity bioassays.

The UV/chlorine process as a potential tertiary municipal wastewater treatment alternative for removing refractory PPCPs has been widely investigated. However, the role of effluent organic matter (EfOM) on the radical chemistry and toxicity alteration is unclear. The elimination of two model PPCPs, primidone (PRM) and caffeine (CAF), by the co-exposure of UV and free chlorine was investigated to elucidate the impact of EfOM.

Importance of origin and characteristics of biopolymers in reversible and irreversible fouling of ultrafiltration membranes.

The present work compares the chemical properties of isolated biopolymers of different origins and their fouling potential during ultrafiltration (UF). The biopolymers were extracted from secondary wastewater effluent as effluent organic matter (EfOM) and from surface water as natural organic matter (NOM). Multiple analytical techniques were used to characterize the isolates.

Removal of pharmaceutical and personal care products (PPCPs) from wastewater using microalgae: A review.

Pharmaceuticals and personal care products (PPCPs) are a group of emerging micro-pollutants causing detrimental effects on living organisms even at low doses. Previous investigations have confirmed the presence of PPCPs in the environment at hazardous levels, mainly due to the inefficiency of conventional wastewater treatment plants (CWWTPs). Their stable structure induces longer persistence in the environment.

Degradation and deactivation of a plasmid-encoded extracellular antibiotic resistance gene during separate and combined exposures to UV and radicals.

This study investigated the degradation and deactivation of an extracellular ampicillin resistance gene (amp) encoded in plasmid pUC19 during exposure to UV, OH (generated by UV/HO), and combined exposure to UV and OH (and/or SO) using UV/HO and UV/SO. The degradation rates of amp measured by quantitative polymerase chain reaction increased with increasing target amplicon length (192-851 bps). The rate constants for the degradation of pUC19 (2686 bps) were calculated as 0.

Hydroxyl and sulfate radical-based oxidation of RhB dye in UV/HO and UV/persulfate systems: Kinetics, mechanisms, and comparison.

The degradation kinetics and mechanisms of Rhodamine B (RhB) dye by OH and SO based advanced oxidation processes were investigated. The OH and SO radicals were generated by UV photolysis of hydrogen peroxide and persulfate (i.e.

Impact of DOM source and character on the degradation of primidone by UV/chlorine: Reaction kinetics and disinfection by-product formation.

The presence of Dissolved Organic Matter (DOM) can exert a strong influence on the effectiveness of the UV/chlorine process. This study examined the impact of five DOM isolates with different characteristics on the degradation kinetics of model contaminant primidone (PM) during UV/chlorine treatment. The formation of Disinfection By-Products (DBPs) from DOM after 15-min UV/chlorine treatment followed by 24 h chlorination was investigated and compared with chlorination alone.

Reactivity of unactivated peroxymonosulfate with nitrogenous compounds.

A recent investigation has demonstrated that peroxymonosulfate (PMS), a peroxide commonly applied as a radical precursor during advanced oxidation processes (AOPs), can degrade organic contaminants without the involvement of radicals. However, little is known about this non-radical reaction mechanism. In this study, the reactivity of PMS with several nitrogenous compounds was investigated.

Removal of metronidazole from aqueous media by C. vulgaris.

This current study investigated the removal of metronidazole from aqueous media by C. vulgaris. Two different initial sizes of inoculum (0.

Catalytic ozonation of emerging pollutant and reduction of toxic by-products in secondary effluent matrix and effluent organic matter reaction activity.

In this study, the performance of LaCoO (LCO) catalytic ozonation was evaluated comprehensively, including the degradation efficiency of benzotriazole (BZA) as a typical emerging pollutant, toxic bromate reduction and the disinfection by-products (DBPs) precursors removal ability in effluent organic matter (EfOM), as well as EfOM reactive activity in catalytic ozonation. Additionally, the reduction of toxic halogenated by-products in (catalytic) ozonation was reported, which was not focused on previous researches before. Results showed that LCO catalytic ozonation improved the removal efficiency of BZA, UV and SUVA via enhanced HO· formation.