Estudo teórico-experimental da separação gravitacional de emulsões compostas por água do mar, derivados de petróleo e biossurfactantes

Abstract

Oil refineries, as well as other large-scale industrial processes, are potential sources of environmental pollution. Accidents involving spills of oil and oil products in Brazil, in the period 1975-2012, add infective million liters of soil, rivers and sea. In this sense, the process of dissolved air flotation (DAF) is still widely used in industry, both for water supply and for wastewater. The physico-chemical processes such as centrifugation, ultrafiltration and dissolved air flotation (DAF), can be effective when used to separate emulsified oils. The effluent from the oily water type cause many environmental problems, particularly in thermal power plants (TPP s). Thus the aim of the study was to propose the separation water/oil by FAD in pilot scale and to compare the efficiency of the pilot prototype of FAD with and without addition of biosurfactant separation of oily waste waters. According the results, the biosurfactant produced by Candida sphaerica was selected, this being cultivated in using low cost industrial waste. Use of this bioproduct increased the efficiency of the flotation 80.0% to 98.0 %, to provide better determination of the operating conditions. Thus, it is suggested that the use of biosurfactants as auxiliary flotation is a promising alternative for the mitigation of pollution caused by the accumulation of synthetic surfactants in the environment.