The BAC-process for treatment of waste water containing non-ionogenic synthetic surfactants

In this paper experimental results on the biological-activated carbon (BAC)-process for biological degradation and adsorption of non-ionogenic surfactants (NISS) in the waste water treatment are discussed. It is shown that the mechanism of the BAC-process is not the simple addition but the synergetic combination of biodegradation and carbon adsorption. The major aspects of such synergism are the biological regeneration (bioregeneration) of the adsorbent and the reduction of the toxic effect of waste water contaminants on microorganisms. It is shown that the basis of the bioregeneration process is the desorption of substances previously adsorbed on the activated carbon. The desorption from micropores takes place because of the reverse concentration gradient, due to the microbial degradation of waste water contaminants in the liquid phase. The desorption from mesopores is also supported by the activity of microorganisms exoenzymes. Thus, the process of bioregeneration is featured by two non-contradictory hypotheses.