Rapid estimation of biochemical oxygen demand using a microbial multi-staged bioreactor

A multi-staged bioreactor system consisting of Trichosporon cutaneum immobilized in Ca-alginate bead and nylon columns was prepared for the estimation of biochemical oxygen demand (BOD) of waste waters. When a sample solution containing the equivalent amount of glucose and glutamic acid (GGA) was injected into the reactor system, the dissolved oxygen (DO) in the sample was decreased with the concentration of GGA. The response time was within 10 min. A linear relationship was observed between the DO decrease and a concentration below 90 ppm glucose and 90 ppm glutamic acid (5-day BOD, 130 ppm). This reactor system was applied to untreated waste waters. Good comparative results were obtained between BOD estimated by this reactor system and that determined by the conventional 5-day method.