Along with the sand trap, sorption filters and microfilters, the gas water processing systems also includes a gasoling of oil refineries. Its role consists in the separation of oil products of low density from all water falling into the drainage. As a rule, wastewater, contaminated not only with fats and oil products, but also dust and sand. Therefore, only a part of the oil -containing substances pops up to the surface of the water when defending. The other part turns into a mixture of water and sand, lingering in the sand. Thus, a suspension of fine dust and petroleum products that have passed through the previous treatment module gets into the benzo -capture. How quickly they separate and float to the surface of oil products depends on the diameter of the field particles, the content of surfactants, large impurities and, of course, on the density of the oil products themselves. The temperature of the wastewater plays an important role.