Avaliação do potencial da celulose bacteriana no tratamento de águas oleosas.

Abstract

Cellulose is the most abundant biopolymer on the planet and has a wide range of applications in different industrial sectors. Environmental preservation policies, on the other hand, promote the development of research to replace vegetable cellulose (VC), due to the fact that its production causes several damages to the environment. In this way, bacterial cellulose (BC) appears as a promising alternative to VC, since it differs from its vegetal similar mainly because it presents fibers of a nanometric character against the micrometric of the vegetable, which gives it excellent mechanical properties like greater purity, higher index of crystallinity, higher water absorption power and higher tensile strength. Several studies have been carried out in order to optimize the production conditions of the polymer to supply the demand for VC in the near future. The use of BC in different economically important sectors such as paper production, textile industry, food industries, biomedicine, filtration of heavy metals and particulates have been reported. Thus, the present study describes the development of a bacterial cellulose (BC) filter for the treatment of oily waters. BC membranes were produced using an alternative medium containing 2.5 % corn steep liquor. Samples of previously purified membranes were characterized and tested as filters for the separation of oil from water (oil concentrations of 10, 150 and 230 ppm). Flow rate, filter diameter and membrane thickness after 6 and 10 days of cultivation were evaluated in a filtration system constructed in poly (vinyl chloride) (PVC). The BC membranes presented adequate flexibility, thermal stability and mechanical strength. However, the membrane obtained after 10 days supported 100 % more force than the membrane obtained after 6 days. The experiments revealed 100 % removal of the oil from all emulsions. The filtration flow rate increased proportionally to the filter diameter and decreased from the 6-day membrane to the 10-day membrane. The results of the present study are promising and demonstrate the efficiency, durability and strength of this novel biodegradable material for the treatment of oily waters generated during industrial activities.