Non-target analysis for water characterization: wastewater treatment impact and selection of relevant features.

Non-target analyses were conducted to characterize and compare the molecular profiles (UHPLC-HRMS fingerprint) of water samples from a wastewater treatment plant (WWTP). Inlet and outlet samples were collected from three campaigns spaced 6 months apart in order to highlight common trends. A significant impact of the treatment on the sample fingerprints was shown, with a 65-70% abatement of the number of features detected in the effluent, and more polar, smaller and less intense molecules found overall compared to those in WWTP influent waters.

Occurrence of carbamazepine, diclofenac, and their related metabolites and transformation products in a French aquatic environment and preliminary risk assessment.

With questions emerging on the presence and risks associated with metabolites and transformation products (TPs) of organic contaminants in the aquatic environment, progress has been made in terms of monitoring and regulation of pesticide metabolites. However, less interest is shown for pharmaceutical residues, although their pseudo-persistence and adverse effects on non-target organisms are proven. This study provides original knowledge about the contamination of ten sites located along three French rivers (water, sediments, biofilms, clams) by pharmaceutical metabolites and TPs, as well as a preliminary environmental risk assessment.

Methylparaben chlorination in the presence of bromide ions and ammonia: kinetic study and modeling.

The impacts of chlorination on methylparaben (MP) removal, as well as of bromide and ammonia on the MP elimination kinetics, were studied. Bromide and ammonia react with chlorine and are promptly transformed into bromine and chloramines, respectively. Rate constants of chlorine, bromine, and monochloramine with MP were determined under different pH conditions.

Gallic acid degradation by electron beam irradiation under various conditions.

In this study, aqueous solutions of gallic acid (GA) were irradiated in an electron beam (EB) accelerator under different experimental conditions (various initial GA concentrations, presence or absence of oxidant and oxygen). For an initial GA concentration of 50 μM, complete GA degradation was achieved with an absorbed dose of 850 Gy in the presence of dissolved oxygen. Both GA removal and mineralization are favored when oxygen is present.

Discharge of biocidal products from healthcare activities into a sewage system-a case study at a French university hospital.

This study focused on the presence of three biocidal products specific to healthcare facilities, i.e. chlorhexidine digluconate (CHD), bis(aminopropyl)laurylamine (BAPLA), and didecyldimethylammonium chloride (DDAC), in a hospital sewage system.

Kinetics of Chlorination of Benzophenone-3 in the Presence of Bromide and Ammonia.

The aim of this study was to assess the impact of chlorination on the degradation of one of the most commonly used UV filters (benzophenone-3 (BP-3)) and the effects of bromide and ammonia on the kinetics of BP-3 elimination. Bromide and ammonia are rapidly converted to bromine and chloramines during chlorination. At first, the rate constants of chlorine, bromine and monochloramine with BP-3 were determined at various pH levels.

Levofloxacin oxidation by ozone and hydroxyl radicals: kinetic study, transformation products and toxicity.

This work was carried out to investigate the fate of the antibiotic levofloxacin upon oxidation with ozone and hydroxyl radicals. A kinetic study was conducted at 20 °C for each oxidant. Ozonation experiments were performed using a competitive kinetic method with carbamazepin as competitor.

Aqueous chlorination of levofloxacin: kinetic and mechanistic study, transformation product identification and toxicity.

The aim of this study was to gain further insight into the fate of levofloxacin during the chlorination process. First, a kinetic study was thus performed at pH 7.2, 20 °C and in the presence of an excess of total chlorine.

Effect of persulfate on the oxidation of benzotriazole and humic acid by e-beam irradiation.

These days, the use of persulfate in advanced oxidation processes (AOPs) has gained more attention as an emerging clean and efficient technology to degrade the organic pollutants. The objective of this study was to investigate the effect of the addition of persulfate on the oxidation of benzotriazole (BT) and humic acids (HAs) by irradiation. The degradation of BT (3.

Influence of persulfate ions on the removal of phenol in aqueous solution using electron beam irradiation.

The removal of phenol (Co = 100 μM) during electron beam irradiation was studied in pure water and in the presence of HCO(3)(-) and Br(-) ions. It was found that the introduction of S(2)O(8)(2-) ions (1mM), by generating SO(4)(-) radicals increases the radiation yield of phenol removal. 90% removal of phenol was obtained with radiation doses 600 and 1200 Gy with and without S(2)O(8)(2-) ions respectively.

Kinetic of benzotriazole oxidation by ozone and hydroxyl radical.

Ozonation experiments were performed in batch reactors in order to determine the rate constants for the reaction of molecular ozone and OH radicals with benzotriazole (BT) at different pHs. The first group of ozonation experiments was carried out for the determination of the rate constant for the direct reactions between ozone and BT. Two different kinetic models were used for the determination of kinetic rate constants: (i) the log-reduction of BT with ozone in excess, (ii) the competition kinetic model.

Degradation of acetic acid with sulfate radical generated by persulfate ions photolysis.

The photolysis of S(2)O(8)(2-) was studied for the removal of acetic acid in aqueous solution and compared with the H(2)O(2)/UV system. The SO(4)(-) radicals generated from the UV irradiation of S(2)O(8)(2-) ions yield a greater mineralization of acetic acid than the ()OH radicals. Acetic acid is oxidized by SO(4)(-) radicals without significant formation of intermediate by-products.