engleski

Physical, chemical and thermal characteristics of Makirina bay peloids (N. Dalmatia, Republic of Croatia)

Makirina Bay (N. Dalmatia, Republic of Croatia) represents one of the major and most important sites where organic-rich sediments accumulate along the eastern Adriatic coast. According to their organoleptic properties, these sediments (peloids) are suitable for application as a raw material for different therapeutic, cosmetic, and wellness-related purposes. In addition, Makirina Bay peloids are already frequently used by local people and tourists as pomades ; peloids are collected in situ from the bay, applied directly on the skin, and sun dried. Several characteristics of Makirina bay peloids were determined, including their granulometry, cation exchange capacity (CEC), mineral and elemental composition, potentially toxic elements (PTE) mobility/bioavailability and thermal properties (specific heat, thermal conductivity and thermal difussivity) in order to evaluate the suitability of their application for medical/therapeutic purposes in balneotherapy and pelotherapy. Our results showed that Makirina bay peloids are represented mostly by sandy silt and have a relatively high CEC value (63.82 meq/100g). The mineral composition of peloids is dominated by dolomite and quartz, followed by illite/muscovite, aragonite, halite, calcite, and pyrite. Oriented preparations of the clay fraction revealed illite/muscovite, chlorite, and kaolinite as the dominant clay minerals. PTE concentrations in surficial (0-5 cm) peloids are [in mg/kg]: As (14.47), Cd (0.27), Cu (27.64), Mn (232.4), Mo (13.82), Ni (26.51), Pb (23.74) and Zn (47.67). The results of the sequential extraction procedure indicated that majority of PTE (except Cd, Mn and Mo) in Makirina bay peloids are not readily mobile or bioavailable since only a small percentage of PTE is extracted in the first two steps (e.g. water-soluble and exchangeable fraction). Thermal properties of Makirina bay peloids are as follows: specific heat 2050 J/kgK, thermal conductivity 0.99 W/mK and thermal diffusivity 2.84*10-7 m2/s.

peloid; Makirina bay; Potentially toxic elements (PTE)

nije evidentirano