Emprego dos processos de eletrofloculação e osmose inversa no tratamento de águas oleosas

• Autor(a) principal: Silva, Leonardo Firmino da
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/15765
• topic: Environment; oily wastewater; electroflocculation; reverse osmosis; Meio ambiente; águas residuais oleosas; eletrofloculação; osmose inversa; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA

The uncontrolled discharge of wastewater into the environment over the last years has accelerated the process of contamination and degradation of water bodies in the world. These wastes contain high amounts of contaminants and concentration of organic matter which leads to the death of several species due to lack of oxygen and, in extreme cases, acceleration of eutrophication processes. In the specific case of oily wastewater, the use of techniques such as chemical coagulation, dissolved air injection, membranes, biochemical and electrochemical processes are described. However some of these processes have limitations which range from the concentration of the contaminant in the effluent, limitations in the operating conditions and even cost constraints. With this in mind, this paper has studied a hybrid system, batch process, in the treatment of oily waters simulated in the laboratory by adding a specific lubricating oil in an aqueous solution with emulsifiers and supporting electrolyte. The treatment system was consisted of two stages, which in the first was evaluated the use of the technique of electrocoagulation, which was responsible by the breaking stability of oil/water emulsions and a second stage which evaluated the use of membrane separation processes in order to remove the metal added to the effluent in the previous stage. The electrofloculation system was evaluated in relation to the use of iron and aluminum electrodes with electrical currents of 1A, 2A and 3A, in the continuous and alternate modes. The results showed a higher apparent mass consumption of electrodes when using direct current, 4,0337 g ± 0,0132 for aluminum and 3,8260 g ± 0,0181 for iron while consumption was 2,1400 g ± 0,0099 for aluminum, and 2,4121 ± 0,0127 g for the iron when the use of alternating current. Removals were reached maximum 98 % ± 0 COD, 99,77 % ± 0,27 color removal and 100 % ± 0 turbidity removal for use alternating current and aluminum electrodes while were reached maximum 96 % ± 1 of COD, 99,46 % ± 0, 82 color removal and also 100% ± 0 to remove the turbidity in the use of iron electrodes. In the second study phase, reverse osmosis, the system used has reached rejections 99,53 % ± 0,12, 99,56 % ± 0,13 and 98,87 % ± 0,36, corresponding to pressures of 10 , 20 and 30 bar Moreover, increasing flows were obtained permeate 10,87 L/h.m2 ± 0,25, 15,67 L/h.m2 ± 0,53; 18,49 L/h.m2 ± 0,74 also with the increased pressure. At the end of the study was reached final effluent with low organic load and metals, it being able to release the bodies receptors. However, control mechanisms, particularly pH should be included in the design of such systems since this parameter changes over the process