Phenol Biodegradation of Immobilized Bradyrhizobium Japonicum Cells. Part 2

With the development of technologies and the rise of the standard of living worldwide, the generation of wastewater is steadily increasing and at the same time the requirements for their purification are being increased before they are released into the environment. Wastewater treatment methods are diverse, chemical ones which have a significant drawback, are expensive and generate secondary pollutants. These disadvantages are avoided by the use of biological methods, which are very flexible and easy to manage. This article examines the ability of cells from the Bradyrhizobium japonicum 273 strain, successfully immobilized on activated carbon, to oxidize and degrade phenol. Initial pollutant concentrations are (in g dm-3): 0.02, 0.04, 0.06 and 0.08, but they do not have a significant effect on the rate and amount of phenol degradation, which in 240 hours is approximately 10 g dm-3. It is higher by 80% than for free cell degradation rate. In our opinion, the reason is that the activated carbon adsorbs the phenol and gradually releases it in cell-tolerant amounts, i.e. thus avoiding substrate inhibition.