3. Development of Portable Sensing Apparatus for Biochemical Oxygen Demand Determination based on Fluorescent Response

A portable biochemical oxygen demand(BOD)sensin g apparatus based on the fluorescent quenching of oxygen was developed for BOD d etermination.The apparatus showed good characteristics such as easy manipulatio n,rapid response and practicable in situ measurement for BOD in seawater.The l inear fluctuant coefficient(R2)in the BOD concentration range from 0.5 t o 50 mg/L was 0.9978.A reproducible response of less 5 % for the BOD apparatus could be obtained in the analysis of real seawater samples.The values estimate d by this biosensing apparatus correlated well with those determined by the conventional 5-day BOD(BOD5)test.The investigation results indicated t hat the apparatus presented its long application life and good stability.