COMPARATIVE SCALE-UP AND COST ESTIMATION OF A BIOLOGICAL TRICKLING FILTER AND A 3-PHASE AIRLIFT BIOREACTOR FOR THE REMOVAL OF METHYLENE-CHLORIDE FROM POLLUTED AIR

Laboratory scale biological trickling filters and three-phase airlift bioreactors have been studied for the elimination of methylene chlorid e (or dichloromethane) vapors from waste air, and the results used her ein for the design of small industrial-scale reactors. The conditions chosen for scale-up were an air flow rate of 100 m(3) h(-1), a methyle ne chloride inlet concentration of 2 g m(-3), and a target removal of 99.5%. The scale-up procedure, design, and cost analysis are discussed . The full-scale biotrickling filter appears to be the most cost-effec tive reactor, with global costs of about $62 per 1,000 m(3) treated. T reatment in the airlift reactor was estimated to be twice as expensive and catalytic oxidation 5 times as expensive. Biological waste air tr eatment offers economical alternatives to conventional techniques for waste air treatment.