Medical Hydrology and Balneology: Environmental Aspects

Influence of sodium alginate on the
thermophysical properties of diluted
Dax peloid (Terdax®)
Knorst-Fouran A (1) , Martinez L (2) , Legido JL (2) , Coussine C (3) , Cezac P (3) , Bessieres
D (3) , Plantier F (3) , Lagiere J (1) , Dubourg K (1)
(1) Institut du thermalisme, Dax, France
(2) Unversity of Vigo, Spain
(3) University of Pau, France
auriane.knorst@u-bordeaux2.fr
Introduction and Objectives
The particularity of the Thermal Town Dax, in France, is its peloid TERDAX®
which is obtained by an automated and controlled production. It is based on maturation
of Dax natural mineral water, silt from Adour River and development of specific
algae and bacteria. Nowadays, this mud is used for the rheumatology therapeutic
indication in all thermal centers of Dax as poultice or pack. Our current project
leads to study the feasibility of implementing its use as individual bath, in order to
open up new outlets and increase the added value of this product. Therefore, in the
first stage of our research, the evolution of physical properties in function of Dax
peloid dilution with Dax mineral water has been studied. Indeed, in thermotherapy,
the efficiency of a peloid depends in particular of its thermal quality and an appropriate
and detailed chemical and physical characterization is necessary to understand
the thermal behaviour of these products1,2,3. The most influential physical
properties are the specific heat, the thermal conductivity and the density. The mixture
Dax péloïde-natural mineral water at 50% has been chosen for energetical and
textural point of view and a gelling agent, sodium alginate, has been added to this
mixture in order to avoid settling. In this second stage, this work focuses on the
influence of this gelling agent on the previous studied thermophysical properties.
Materials and Methods
The experimental specific heat data were measured in the temperature range
from 298.15 to 314.15 K using a Calvet calorimeter, SETARAM BT 2.15, which
permits studying with high precision all kind of substances and materials (oils,
polymers, hydrates, powders) and simulate almost any process condition (reactions,
crystallisation, freezing, etc)4. The pycnometer method and an Anton-Paar DMA-
4500 vibrating-tube densimeter were used to measure density values while thermal
conductivity was determined by the Model KD2 Pro, Decagon Devices, Inc5.
Balnea
2012, núm. 6, 303-304
303
ISBN: 978-84-669-1887-0
978-84-669-3482-4