Occurrence and removal of butyltin compounds in a waste stabilisation pond of a domestic waste water treatment plant of a rural French town

The aim of this study was to investigate the fate and behaviour of butyltin pollutants, including monobutyltin (MBT), dibutylin (DBT), and tributyltin (TBT), in waste stabilisation ponds (WSP). The study was conducted as part of a baseline survey and included five sampling campaigns comprising bottom sludge and the water column from each pond from a typical WSP in France. Butyltins were detected in all raw wastewater and effluents, reflecting their widespread use. Our results revealed high affinity between butyltins and particulate matter and high accumulation of butyltins in the sludge taken from anaerobic ponds. The dissolved butyltins in the influent ranged from 21.5 to 28.1 ng(Sn).L(-1) and in the effluent, from 8.8 to 29.3 ng(Sn).L(-1). The butyltin concentrations in the sludge ranged from 45.1 to 164 and 3.6-8.1 ng(Sn).g(-1) respectively in the first and last ponds. Our results showed an average treatment efficiency of 71% for MBT, 47% for DBT, 55% for TBT. Laboratory sorption experiments enabled the calculation of a distribution coefficient (Kd = 75,000 L.kg-1) between TBT and particulate matter from the WSPs. The Kd explained the accumulation and persistence of the TBT in the sludge after settling of particulate matter. The continuous supply of contaminated raw wastewater and the sorption-desorption processes in the ponds led to incomplete bio- and photolytic degradation and to the persistence of butyltins in dissolved and particulate matrices throughout the survey period. It is thus recommended to use shallow ponds and to pay particular attention when sludge is used for soil amendment.

Temporal and spatial variability of organotins in an intermittent Mediterranean river

Organotin compounds (OTs) are exclusively anthropogenic and have been widely used for their biocidal properties and as stabilizers in various industrial applications. Hence organotins are common pollutants. Their high toxicity has led to their entry on the EU water framework's priority substances' list. However, few studies are available regarding their behaviour in surface waters, in particular, in intermittent Mediterranean rivers. The Vène is an intermittent river located in Languedoc-Roussillon, southern France. It is the main tributary of an important shellfish farming site: the Thau lagoon. The present study aims at establishing the presence of OTs on a 1.5 km long reach of the river into which a waste water treatment plant (WWTP) discharges. The study is carried out during steady-state flow conditions over two consecutive years and investigates potential OTs sources in everyday domestic activities. Routine field monitoring was carried out over a 5 month period during the springs of 2008 and 2009. The results establish the presence of butyltins and octyltins throughout the 1.5 km long reach at concentrations exceeding the maximum allowable concentration levels imposed by the water framework directive. The WWTP is recognized as an important OTs point source; however, using trace and rare earth elements as tracers, an urban stormwater sewage gutter is identified as a secondary source. Its impact on the river's pollutant loads is however variable in time because of flow intermittency. The paper discusses the need for specific monitoring and management schemes for intermittent rivers.

Approche des transferts de pollution bactérienne dans une crue karstique par l'étude des paramètres physico-chimiques

L'exploitation des systèmes aquifères karstiques est toujours effectuée sous des contraintes liées à leur forte vulnérabilité. Une étude complète d'un épisode de crue de la source du Lez a été réalisée grâce à une coopération entre les Services de Santé et l'Université. Cette étude comporte une observation des paramètres physico-chimiques et bactériologiques sur une période de 15 jours, correspondant à une réponse hydrodynamique impulsionnelle sur la totalité du bassin. Les pas de temps d'échantillonnage varient de 4 à 24 heures.

L'interprétation des résultats physico-chimiques met en évidence une disjonction nette entre les variations piézométriques et le passage de différents volumes d'eau. L'écoulement des eaux plus chaudes (16,5 °C) observé lors de l'étiage, eaux d'origine profonde plus chargées chimiquement se poursuit jusque vers le milieu de la décrue pour faire place à l'arrivée d'eaux plus froides correspondant à des infiltrations rapides puis retardées. Les eaux les plus chaudes sont caractérisées par des variations des teneurs en magnésium, les teneurs en calcium restant à peu prés constantes. Inversement; les eaux froides de l'infiltration retardée ont de faibles variations des teneurs en magnésium et sont tracées par une forte augmentation des valeurs en calcium.

Le risque sanitaire maximal est lié au début de l'arrivée des eaux froides. Les eaux d'étiage et les eaux profondes sont légèrement contaminées. Les eaux d'infiltration retardée sont peu contaminées. En dehors des zones de perte du réseau hydrographique et des axes d'infiltration rapide, la vulnérabilité de l'aquifère est faible à l'échelle du bassin.

Comparison of methods for measurement of organic compounds at ultra-trace level: analytical criteria and application to analysis of amino acids in extraterrestrial samples

The need for criteria to compare different analytical methods for measuring extraterrestrial organic matter at ultra-trace levels in relatively small and unique samples (e.g., fragments of meteorites, micrometeorites, planetary samples) is discussed. We emphasize the need to standardize the description of future analyses, and take the first step toward a proposed international laboratory network for performance testing.

Solvent extraction of organic molecules of exobiological interest for in situ analysis of the Martian soil

A solid-liquid extraction method able to perform in situ extraction of organic compounds on Mars is proposed. The extraction efficiency of various organic solvents was tested and compared to that of water. The selected key compounds are molecules of exobiological interest: glycine, alanine, serine, glutamic acid, oxalic acid, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid and 1,3,5-benzenetricarboxylic acid. Among the organic solvents, propanol gives the highest yield of extraction for all the targeted compounds except for benzoic acid. A mixture of propanol and ethyl acetate increases significantly the extraction yield of benzoic acid. The extraction time was considerably reduced (140 h to 15 min) by using sonication. The method is discussed for an easy automation with coupling to an in situ GC-MS space instrument.

Chirality and the origin of life: in situ enantiomeric separation for future space missions

Two different methods of derivatization were studied in order to select and optimize one for the in situ enantiomeric separation of amino acids present in Martian samples. The method, using DMF-DMA [N,N-dimethylformamide dimethyl acetal], is simple and easily automated. However, byproducts of the reaction interfere in the gas chromatograms and mass spectrometry detection is needed for in situ analysis. The chloroformate derivatization has several advantages, including the use of achiral robust capillary column, room temperature reaction, and short analysis. The choice of the definitive derivatization method will depend on the energy and time devoted to the analysis of amino acids in the next Mars exploration missions.

Detection of martian amino acids by chemical derivatization coupled to gas chromatography: in situ and laboratory analysis

If there is, or ever was, life in our solar system beyond the Earth, Mars is the most likely place to search for. Future space missions will have then to take into account the detection of prebiotic molecules or molecules of biological significance such as amino acids. Techniques of analysis used for returned samples have to be very sensitive and avoid any chemical or biological contamination whereas in situ techniques have to be automated, fast and low energy consuming. Several possible methods could be used for in situ amino acid analyses on Mars, but gas chromatography would likely be the most suitable. Returned samples could be analyzed by any method in routine laboratory use such as gas chromatography, already successfully performed for analyses of organic matter including amino acids from martian meteorites. The derivatization step, which volatilizes amino acids to perform both in situ and laboratory analysis by gas chromatography, is discussed here.

[Intrathyroidal metastases of a nephroepithelioma. Reflections on 5 operated cases]

Out of 3,340 thyroidectomies (237 for cancer), the authors report 5 cases of thyroid metastases due to clear cell renal cancer. They emphasize the slow development of these metastases. Two cases were operated on 11 years after nephrectomy and one after 27 years. In one case, an intrathyroid metastasis led to the discovery of renal carcinoma. In 3 cases, evolution was rapidly fatal (within the first year). One patient is still alive 6 years after thyroidectomy. The authors emphasize clinical grounds for diagnosis and expose pathology findings that favor longer survival when there is early removal of intrathyroid metastases.