ACTIVATED BIOFILM REMOVAL OF LOW CONCENTRATIONS OF TOLUENE

A two-step technique is presented for the biodegradation or transforma tion of low concentrations of benzene, ethylbenzene, toluene, and xyle ne (BETX) hydrocarbons. Step 1 incorporates the batch growth and attac hment of a lush biofilm onto plastic surfaces utilizing a preselected substrate capable of stimulating desired biological activity. Step 2 i nvolves continuous upflow biodegradation of low concentration levels o f target organics by the generated biofilm. Step 1-generated biofilms are predicted to deteriorate during protracted time periods, however, extended experimental runs on the order of four months were conducted with continued bioremovals. Target organic removals during Step 2 oper ations, quantified by a first-order removal constant, are shown to be linked to Step 1 operating methodology.