Evaluation of the sorption properties of coastal sands in relation to emulsified petroleum products

The sorption properties of some sands selected in the coastal zones of economically important, but at the same time ecologically oppressed territories of Vietnam are considered. The purpose of the research is to assess the absorption capacity of sands in relation to emulsified petroleum products, to identify their ecological role in typical situations of spillage of small amounts of toxic substances. It is shown that the sorption qualities of the sands depend on the location of the sands, their geochemical and granulometric heterogeneity. It turned out that according to the content of α-quartz, the sands used can be divided into two types with a clearly expressed correlation of sorption qualities with the mineral content. Quartz sands, represented by fine-grained pellets, have a high ability to retain oil films. Sands with a content of 10–11% (wt.) corundum are represented by larger and sharper-edged particles with lower bulk density and reduced absorption capacity. For each sand maximally saturated with gasoline components, the reaction to “rainy” or “sunny” weather has been investigated. For the first case, desorption with repeated washing with water has been carried out, in the second case, drying with heating and subsequent single passing of water through a layer of sand. It is shown that gasoline films are firmly held on sand particles during washing, but are easily removed when heated. With repeated washing of the underlying layers, it reaches about a quarter of the initial gasoline content in the emulsion, which is filtered through sand. When drying with heating, up to a quarter of volatile hydrocarbons are dispersed from the sands, while an insignificant amount of organic matter is found in the filtrates.