Avaliação da remoção de óleos e graxas através de flotação por ar dissolvido e biossorção com bagaço de cana de açúcar

Abstract

This study aims to evaluate techniques for treatment of oily wastewater from the unit natural gas processing - UPGN - from Petrobras. The effluent consists of an oil-water emulsion, and almost all from the water associated with existing wells in the process of extracting gas and oil. The studies were conducted in two stages. Initially tests were performed on a column of air dissolved flotation with and without the use of coagulants operating in counterflow. In a second stage was evaluated the performance of an adsorbent filter using two kinds of stuffing, bagaço and bagacilho of sugarcane, can be readily obtained in local industries. The performance of the system of separation is measured by the percentage of removal of the content of oils and greases (TOG) of treated effluent. The flotation showed better results when it made use of coagulants, the wastewater was mixed, in line with the aluminum sulfate 25 g/L at a flow rate of 5.3 mL/min, where was obtained a maximum efficiency of 72%, using a flow rate of feed for 60 L/h and flow of reflux of 120 L/h. Tests on the filter adsorbent had higher performance when operated at lower flow rates, 40 and 80 L/h and using the contents of greater surface area, the bagacilho sugar cane, to achieve 99% removal of the content of oils and greases operating with the flow of 4 0L/h in, when reached 45 minutes of operation.