19 research outputs found
Chlorination by-product concentration levels in seawater and fish of an industrialised bay (Gulf of Fos, France) exposed to multiple chlorinated effluents
International audienceChlorination is one of the most widely used techniques for biofouling control in large industrial units, leading to the formation of halogenated chlorination by-products (CBPs). This study was carried out to evaluate the distribution and the dispersion of these compounds within an industrialised bay hosting multiple chlorination discharges issued from various industrial processes. The water column was sampled at the surface and at 7 m depth (or bottom) in 24 stations for the analysis of CBPs, and muscle samples from 15 conger eel (Conger conger) were also investigated. Temperature and salinity profiles supported the identification of the chlorination releases, with potentially complex patterns. Chemical analyses showed that bromoform was the most abundant CBP, ranging from 0.5 to 2.2 ÎŒg Lâ 1 away from outlets (up to 10 km distance), and up to 18.6 ÎŒg Lâ 1 in a liquefied natural gas (LNG) regasification plume. However, CBP distributions were not homogeneous, halophenols being prominent in a power station outlet and dibromoacetonitrile in more remote stations. A seasonal effect was identified as fewer stations revealed CBPs in summer, probably due to the air and water temperatures increases favouring volatilisation and reactivity. A simple risk assessment of the 11 identified CBPs showed that 7 compounds concentrations were above the potential risk levels to the local marine environment. Finally, conger eel muscles presented relatively high levels of 2,4,6-tribromophenol, traducing a generalised impregnation of the Gulf of Fos to CBPs and a global bioconcentration factor of 25 was determined for this compound
Monitoring and factors affecting levels of airborne and water bromoform in chlorinated seawater swimming pools
International audienceAbbreviations: Br-DPBs (brominated disinfection by-products); CHBr 3 (bromoform); CHCl 3 (chloroform), CHCl 2 Br (dichlorobromomethane), CHClBr 2 (dibromochloromethane); Clf (free residual chlorine); NPOC (Non Purgeable Organic Carbon); PCA (Principal Component Analysis); T water (temperature of water); T air (temperature of air); TTHMs (total trihalomethanes = sum of THM-4); Abstract Water and air quality of eight seawater swimming pools using chlorine disinfection was measured during four sampling campaigns, spread on one full-year, and in four thalassotherapy centres located in Southeast of France. Concentrations of trihalomethanes (THMs) in air and in water as well as concentrations of parameters, including non purgeable organic carbon (NPOC), free residual chlorine (Cl f), pH, Kjeldhal Nitrogen (KN), salinity, conductivity, bromide ions and, water and air temperature, were measured. Water and air samples were collected in triplicates morning-at the opening of the pools-, noon and night-at the closing of the pools-, in summer and winter. Data analysis was performed by Principal Component Analysis (PCA) and rotated component matrix, from both data quality and other parameters such as TOC, aromaticity (UV 254), pH, hygrometry, and free residual chlorine (Cl f). This statistical analysis demonstrates a high correlation between TOC, Cl f and UV 254 and THM levels found in air and water, particularly for the major ones (CHBr 3 in water : 300.0 ”g.L-1 mean, 1029.0 ”g.L-1 maximum; CHBr 3 in air : 266.1 ”g.m-3 mean, 1600.0 ”g.m-3 maximum, and CHClBr 2 in water: 18.9 ”g.L-1 mean, 81.0 ”g.L-1 maximum; CHClBr 2 in air : 13.6 ”g.m-3 mean, 150.0 ”g.m-3 maximum). These high levels of bromoform (CHBr 3) are particularly worrisome in such health institutions, even these levels do not exceed the Permissible Exposure Limit (PEL) of 5 mg.m-3 as an 8 hour time-weighted average currently 2 fixed by various administrations, such as Occupational Safety and Health Administration (OSHA)
Degradation Products of Benzophenone-3 in Chlorinated Seawater Swimming Pools
International audienceOxybenzone (2-hydroxy-4-methoxyphenone, benzophenone-3) is one of the UV filters commonly found in sunscreens. Its presence in swimming pools and its reactivity with chlorine has already been demonstrated but never in seawater swirnrning pools. In these pools, chlorine added for disinfection results in the formation of bromine, due to the high levels of bromide in seawater, and leads to the formation of brominated disinfection byproducts, known to be more toxic than chlorinated ones. Therefore, it seems important to determine the transformation products of oxybenzone in chlorinated seawater swimming pools; especially that users of seawater swimming pools may apply sunscreens and other personal-care products containing oxybenzone before going to pools. This leads to the introduction of oxybenzone to pools, where it reacts with bromine. For this purpose, the reactivity of oxybenzone has been examined as a function of chlorine dose and temperature in artificial seawater to assess its potential to produce trihalomethanes and to determine the byproducts generated following chlorination. Increasing doses of chlorine and increasing temperatures enhanced the formation of bromoform. Experiments carried out with excess doses of chlorine resulted in the degradation of oxybenzone and allowed the determination of the degradation mechanisms leading to the formation of bromoform. In total, ten transformation products were identified, based on which the transformation pathway was proposed
A highly-sensitive microplate fluorimetric method for the high-throughput determination of nitrate ion in aqueous compost extracts
International audience9 In this paper, a new spectrofluorimetric method for the determination of nitrate in aqueous 10 compost extracts is presented. The microplate procedure is based on the reduction of nitrate 11 to ammonium by means of Zn powder under acidic conditions and the following derivatization 12 of ammonium with o-phtaladehyde (OPA) and N-acetylcysteine (NAC) to give a fluorescent 13 derivative. Optimization work allowed performing the reduction in 30 min on a small sample 14 volume (150 ”L) and using a little quantity of metal (20 mg). The use of strong acids is also 15 avoided. Excellent limit of detection was achieved (1.3 ”M = 0.08 mg.L-1 NO3-) along with good 16 precision levels (4.2 and 14.3 % for 50 and 5 ”M, respectively) and a satisfactory linear 17 dynamic range (4-100 ”M). A good agreement between data coming from our method and 18 from ion-exchange chromatography was found on real compost samples, indicating a good 19 level of accuracy. 20 21 2
High throughput determination of ammonium and primary amine compounds in environmental and food samples
International audienceIn this paper, an improved spectrofluorimetric method for the simultaneous and direct determination of ammonium and primary amine compounds is presented. The method is based on the derivatization of the analytes with o-phthaldialdehyde (OPA)/N-acetylcysteine (NAC) reagent using high throughput microplates, and OPA/NAC ratio has been optimized in order to suppress interference of ammonium on primary amine determination. Direct measurement of these two parameters is therefore possible with a global procedure time that does not exceed 10 min. Excellent limits of detection of 1.32 ÎŒM and 0.55 ÎŒM have been achieved for ammonium and primary amines, respectively. Reagent stability issues have also been addressed and formulation of reagents solution is described for improved reagents shelf life. The proposed protocol was finally applied and validated on real samples such as wine samples, compost extracts and wastewater
As, Pb, Sb, and Zn transfer from soil to root of wild rosemary: do native symbionts matter?
International audienceThis is an in natura study aimed to determine the potential of Rosmarinus officinalis for phytostabilization of trace metal and metalloid (TMM)-contaminated soils in the Calanques National Park (Marseille, southeast of France). The link between rosemary tolerance/accumulation of As, Pb, Sb, and Zn and root symbioses with arbuscular mycorrhizal (AM) fungi and/or dark septate endophytes (DSE) was examined. Eight sites along a gradient of contamination were selected for soil and root collections. TMM concentrations were analyzed in all the samples and root symbioses were observed. Moreover, in the roots of various diameters collected in the most contaminated site, X-ray microfluorescence methods were used to determine TMM localization in tissues. Rosemary accumulated, in its roots, the most labile TMM fraction in the soil. The positive linear correlation between TMM concentrations in soil and endophyte root colonization rates suggests the involvement of AM fungi and DSE in rosemary tolerance to TMM. Moreover, a typical TMM localization in root peripheral tissues of thin roots containing endophytes forming AM and DSE development was observed using X-ray microfluorescence. Rosemary and its root symbioses appeared as a potential candidate for a phytostabilization process of metal-contaminated soils in Mediterranean area
Implication of phytometabolites on metal tolerance of the pseudo-metallophyte -Rosmarinus officinalis-in a Mediterranean brownfield
International audienceThis study highlights the trace metal and metalloid (TMM) accumulation in Rosmarinus officinalis L. and its chemical responses when exposed to high levels of contamination. R. officinalis individuals growing along a gradient of mixed TMM soil pollution, resulting from past industrial activities, were analysed. Several plant secondary metabolites, known to be involved in plant tolerance to TMM or as a plant health indicator, were investigated. The levels of thiol compounds and phytochelatin precursors (cysteine and glutathione) in the shoots were measured in the laboratory, while a portable non-destructive instrument was used to determine the level of phenolic compounds and chlorophylls directly on site. The level of Pb, As, Sb and Zn contaminations within the soil and plants was also determined.The results highlighted a decrease of TMM translocation with increases of soil contamination. The concentration of TMM in the shoots followed the Mitscherlich equation and reached a plateau at 0.41, 7.9, 0.37, 51.3âŻmgâŻkgâ1 for As, Pb, Sb and Zn, respectively. In the shoots, the levels of thiols and phenols were correlated to concentrations of TMM. Glutathione seems to be the main thiol compounds involved in the tolerance to As, Pb and Sb. Phenols indices, using non-destructive measurements, may be considered as an easy way to establish a proxy to estimate the TMM contamination level of the R. officinalis shoots. The study highlights metabolic processes that contribute to the high potential of R. officinalis for phytostabilisation of TMM in contaminated areas in the Mediterranean
Occurrence et spéciation des sous-produits de chloration dans les eaux marines et les sédiments d'une baie semi-fermée exposée à des effluents industriels chlorés
International audienceChlorination of seawater is one of the most effective technologies for industrial biofouling control. However, chlorination leads to the formation of halogenated chlorination byproducts (CBPs) associated with potential risks to environmental and human health. The present study investigated the occurrence and distribution of CBPs in the Gulf of Fos, a semi-enclosed bay where chlorinated effluents of multiple industrial plants are discharged. Seawater samples (surface and bottom) were collected at 24 sampling stations, with some near industrial outlets and others dispersed throughout the bay. Sediment samples were also collected at 10 sampling stations. Physicochemical parameters including water temperature, pH, salinity, bromide content, and free and total residual oxidant were determined. Several chemical classes of CBPs including trihalomethanes, haloacetic acids, haloacetonitriles, trihaloacetaldehydes, and halophenols were analyzed. Bromoform was the most abundant CBP in seawater, and it was detected at most of the sampling stations of the bay with highest concentrations occurring near the industrial effluent outlets. Dibromoacetic acid was the second most abundant CBP at most of the sites followed by dibromoacetonitrile. Other detected CBPs included tribromoacetic acid, bromochloroacetonitrile, and bromal hydrate. To our knowledge, the concentration of the latter CBP was reported here for the first time in the context of industrial seawater chlorination. In sediments, two bromine-containing halophenols (2-chloro-4-bromophenol and 2,4,6-tribromophenol) were detected at two sampling stations. Ecotoxicological assays and risk assessment studies based on the detected environmental concentrations are warranted to elucidate the impacts of marine CBP contamination
Aqueous Phase Oligomerization of Methyl Vinyl Ketone by Atmospheric Radical Reactions
International audienceAqueous phase oxidation reactions in atmospheric particles can yield high molecular weight products and create secondary organic aerosol (SOA) upon droplet evaporation. Oxidation by hydroxyl radicals to create oligomers in solution that form SOA has been previously investigated; however, mixed organic solutions that can initiate radical chemistry have been largely overlooked. In aqueous solution, pyruvic acid (PA), an a-keto acid found in both the gas and aqueous phases in the atmosphere, photolyzes via a radical mechanism. Here, we use this photochemistry of pyruvic acid to trigger oligomerization of methyl vinyl ketone (MVK), an alpha,beta-unsaturated compound generated by the atmospheric oxidation of isoprene. We closely compare the reaction products and mechanism to a recent work in which the radical oligomerization of MVK initiated by hydroxyl radical is studied in depth. Using mass spectrometry, it is shown that the two reactions create oligomers of similar molecular weights, up to m/z 1200 for initial MVK concentrations of 20 mM. In the MVK and PA photolysis, exploring initial reactant concentrations demonstrates that the same oligomer series are produced regardless of the initial reactant or dissolved oxygen concentrations. However, the size of the oligomers formed increases with increasing initial reactant concentrations, and the oligomerization process is slowed when dissolved oxygen is present. Finally, using a Langmuir trough, that measures the surface tension as a function of liquid surface area, it is shown that these oligomer photoproducts are surface active. These results indicate the importance of mixed organic systems to understanding secondary organic aerosol formation and growth. Consequently, this chemistry may affect gasparticle mass transfer of water and semivolatile aerosol components and, therefore, the way that aerosol interacts with its environment