Prediction of oily water separation efficiency by fiber beds using a new filter media property

Abstract

Bed coalescers are compact, easy to install, automate, and maintain with the ability to achieve high separation efficiencies. They have been increasingly applied in the industry even though their design often requires pilot plant experiments. In this paper, a new wetting property of polymer fibers regarding polar mineral oils was established. This property can be important for selection of filter media for liquid-liquid separation in many industrial applications. Medical oil was selected as the new reference liquid that does not wet the investigated polymers. The lipophilic/lyophobic ratio (LLR) reached values ranging from 3.28 to 18.81 and increased with the increase of the mineral oil polarity measured by the oil neutralization number. The LLR values were in an excellent agreement with the results obtained from the separation efficiency of a steady-state bed coalescer. Thus, simple, fast and inexpensive experiments can replace pilot plant or at least laboratory testing aiming at selecting a polymer for oil separation from wastewater.

Wettability investigation of stainless steel fibers with mineral oils using the modified method for liquid penetration kinetics

“…Besides the calculated numerical data of the attained slopes, the L/H ratio depends also on the viscosity, density and surface tension of the investigated liquids. The range of these values at 20 °C is in the following intervals: the water viscosity is 1.02 mPas and the viscosity interval of oils is from 28 to 1207 mPa s; the water density is 1000 kg/m 3 , and density interval of oils is from 879 to 918.9 kg/m 3 ; the water surface tension is 72 mN/N, and the surface tension interval of oils is from 26.56 to 30.16 mN/N (13). The oil properties that were used further in the discussion of the results are presented in Table 2.…”

“…All investigated mineral oils were characterized by the standard methods. The obtained properties are given in our recently published study (13). Additionally, deionized water was also used as the test fluid, with the following properties: density, 1000 kg/m 3 , viscosity, 1.02 mPa s and surface tension, 72 mN/m.…”

“…In the recent published study from our research group the lipophilic/lyophobic ratio (LLR) was successfully developed and implemented for the wettability characterization of polymer fibers used in the separation of mineral oils with different polarities. From this investigation it was concluded that with the use of the LLR ratio, a prediction on the separation efficiency of polymer fibers can be made through the critical velocity that is of great importance when selecting a polymer for oil separation from wastewater (13).…”