Histoire du thermalísme à Avène-les-Bains et genèse de l'eau thermale d'Avène: History of thermalism at Avène-les-Bains and genesis of the Avène thermal spring water.

Avene thermal spring water is recognized for more than two centuries for its benefits on skin diseases. Since 1975, the Pierre Fabre Group has modernized the facilities, and developed the brand « Eau Thermal Avène ¼, allowing more than 2,500 patients/year to be treated by this therapeutic water. The regulation requires high standards on origin, bacteriological purity and physico-chemical stability. Many works have allowed us to understand its origin, its underground path and identify its specific physico-chemical profile. Finally, thanks to its therapeutic properties verified in various clinical studies, the « Eau Thermal Avène ¼ is the first active ingredient of a variety of products for sensitive skin.

Avène Thermal Spring Water: an active component with specific properties.

Avène Thermal Spring Water (TSW) is a natural active component characterized by a low mineral content. In vitro experiments have demonstrated the effect of Avène TSW on membrane fluidity, its antiradical and anti-inflammatory properties, its effects on many mediators involved in the immune response and its stimulating effect on keratinocyte differentiation. The clinical efficacy of the water was demonstrated at the hydrotherapy centre in chronic and disabling diseases such as atopic dermatitis but also in various settings in medical and post dermatology procedure such as photodynamic therapy or photothermolysis. All these data support the fact that the Avène TSW is an active component.

Wastewater reuse in on-site wastewater treatment: bacteria and virus movement in unsaturated flow through sand filter.

In on-site wastewater treatment plants, effluents are pre-treated by septic tank and treated by soil infiltration or sand filtration systems, with unsaturated flow conditions. These systems remove efficiently carbon, nitrogen and suspended solids. But for microbial pollution, the treatment efficiency depends on the hydrodynamic behaviour and filtering media characteristics. Contamination of superficial water and groundwater due to pathogenic viruses and pathogenic bacteria is responsible for many diseases. The objective of this study is to approach the mechanisms and operating conditions to control bacteria and virus release in the environment. Experiments were carried out on reactors of different length packed with sand. Hydraulic load of 90 cm x d(-1) with a pulse periodic flow was used. The influence of chemical composition of the solution on the treatment efficiency has also been studied. For the first time, the residence time distribution (RTD) has been studied using a conservative tracer (KI), to determine the main hydrodynamic parameters. For the second time, the RTD with bacterial and viral tracers (E. coli, bacteriophage MS2) was applied, with the aim to define microbial behaviour in filtering media, including adsorption and filtration phenomena. This work allowed us to determine retardation factors according to the hydraulic loads and chemical composition.