New approach for the assessment of the contribution of adsorption, biodegradation and self-bioregeneration in the dynamic process of biologically active carbon functioning

This work developed an effective model of the cooperative removal process of organic compounds on biologically active carbon. This model involves the determination of the dynamics of adsorption efficiency and degradation of specific classes of target organic substances but also the dynamics of non-target filling of pores with products of vital microbial activity. It is possible to quantitatively assess the contributions of adsorption, biodegradation and self-bioregeneration in the process of biologically active carbon functioning and the changes in the activated carbon porous properties during the process. The model developed was applied to assess the efficiency of filtration of 2-nitrophenol through a biologically active carbon bed for 38 months. The activated carbon adsorption capacity for removing 2-nitrophenol was preserved after three years of the bed service due to the effective biodegradation that resulted in self-bioregeneration of the sorbent. Nontarget losses of porosity (filling with bioproducts) increased with increasing duration of system operation, and by the end of the experiment, these losses amounted to 61% of the pore volume of the fresh sorbent. (C) 2020 Elsevier Ltd. All rights reserved.