Banca de DEFESA: ALEXANDRE D'LAMARE MAIA DE MEDEIROS

PRODUCTION OF A BIOTECHNOLOGICAL FILTER FOR WATER-OIL SEPARATION USING BACTERIAL

CELLULOSE MEMBRANES (BIOFILTER)

bacterial cellulose, biotechnology; oleophobic filter, oily effluents

The oil market is the branch of the world industry that most pollutes and destroys the environment, as pollution does not only occur from specific work with oils and greases, but in all industrial segments. Bearing in mind that such damage caused by this segment is present in all countries in the world, and that the legislation of each of these countries requires companies to carry out treatments to separate the water and oil mixture before disposing of it in effluents or reusing the water in the company's process, the present study aims to produce a biotechnological filter with bacterial cellulose (BC) membranes produced by the bacterium Komagateibacter hansennii UCP1619 using the standard HS culture medium and by the microbial consortium (SCOBY) in an alternative medium produced with Camellia sinensis (green tea) to separate oils present in real industrial effluents. Combined with the production of membranes, some versions of prototype support modules for the membranes called “BIOFILTERS” were also developed, based on fluid dynamic studies and computational modeling on bench and pilot scales. After these tests, the most efficient module in terms of flow and pressure was used to carry out the effluent treatment. This research can demonstrate that CB is effective when used as a separation membrane for nanofiltration, retaining oily contaminants (~99%), reducing the color and particulates of the effluent, in addition to eliminating the microbiological load in almost its entirety (~99%) , thanks to its various characteristics such as being formed solely by cellulose and the presence of hydroxyl groups (OH) in its composition, high rate of thermal degradability, with its greatest mass loss between 245 and 400oC, fibers with approximately 84 nm evidenced by the micrographs taken between 5000 and 160000 times and supporting an average maximum deformation of 100.85% with a maximum load of 6.94N in tensile tests and 27.36% with a maximum load of 4538.74N in compression tests. Furthermore, the filter computationally simulated using computational fluid dynamics software was machined using different materials for the process, packaged with the CB membrane produced and tested for the filtration of effluents from the company SUAPE Ambiental. The membranes after the filtration process were also analyzed to compare their characteristics before and after saturation with oil. Optical microscopy, SEM, FTIR, XRD and TGA characterizations demonstrated the presence of oil inside the post-filtration membrane. The characteristic peaks of its chemical composition and a reduction in crystallinity (40%). In the TGA there was an increase in the thermal degradation stages from three (pre) to five (post-filtration), this increase is an indication of the retention of the contaminating oil by the CB. The combination between CB membranes and the modeled filter has proven to be an innovative and effective material for industries, facilitating and bringing a lower cost for them to remain within current environmental preservation policies for effluent treatments, with further studies required. filtration scale-up.