Barrier property features of various sands of the South-Western Baikal region in relation to typical environmentally hazardous wastewater

To determine the barrier properties of some sands of the southwestern coast of Lake Baikal, their holding capacity of such aggressive substances as petroleum products (tested on the example of gasoline emulsion) and household wastewater (tested on the example of surface-active substances (surfactants) and acommon household liquid detergent "Biolan") was evaluated. The throughput capacity of sands with respect to carriers imitating domestic wastewater was studied along with the adsorption capacity with respect to individual surfactants – in this case, typical detergents (sodium oleate, sodium dodecyl sulphate, sodium hexadecyl sulphate and sodium tetradecyl sulphate). It was established that holding capacity with respect to oil products and domestic wastewater varies according to the different source locations of sand samples obtained from the southwestern Baikal region. For instance, sands from the Baikal lake coast near the village Khuzhir possess the highest holding capacity for gasoline effluent; this capacity decreases for the sand samples collected near Baykalsk and Angasolka, and is most insignificant for sand samples derived from Obuteikha. Although this difference may be attributed to many factors, the most significant of these is particle size distribution. In relation to the effluents of the Biolan household detergent, the holding capacity of the sands predominantly depends on the crystalline chemical composition, with the best properties in this series of experiments being demonstrated by the sand obtained from Angasolka containing the clay mineral antophyllite. The results of adsorption tests showed that individual surfactants can be adsorbed on the surface of mineral particles via a molecular or micellar mechanism. It has been suggested that the adsorption mechanism depends both on the crystallographic features of mineral adsorbents and on the composition and structure of surfactant molecules. Thus, it is shown that, in terms of their inherent qualities, natural sands occurring in the southwestern coast of Lake Baikal can serve as a protective barrier for underlying soils and groundwater.

sands, geochemical composition, filtering capacity, adsorption, emulsion, surfactant, hazardous waste