TOLERANCE AND RECOVERY ABILITY OF MOVING BED BIOFILM REACTOR TO PHENOL AND CRESOL SHOCK LOAD UNDER VARY DISSOLVED OXYGEN CONCENTRATION

摘要

Two lab-scale moving bed biofilm reactors being operated under high dissolved oxygen (DO) concentration (HDMBBR) and low DO concentration (LDMBBR) were used to treat simulated coal processing wastewater (CPW). Removal of main pollutants (phenol, o-cresol, ammonium, thiocyanate and nitrogenous compounds) from the simulated coal processing wastewater was lower in the LDMBBR compared with the HDMBBR. O-cresol shock load affected the performance of both MBBRs more obvious than phenol. Two equations are proposed to assess tolerance to shock load and recovery ability after exposure to shock load. Configuration and bacteria flora of biofilm adhering to the carriers obtained from the two reactors were different. Biofilm was much thicker in the LDMBBR than in the HDMBBR, which lead to lower biodegradation rates in the LDMBBR because of low mass transfer.