廢水生物處理技術發展至今，是被使用最廣泛且最具有效率之技術之一，尤其 是好氧生物處理技術，諸如：活性污泥法、RBC，在廢水處理上都有卓越之表現， 然好氧微生物賴以生長之重要元素一氧，其傳輸得靠大量曝氣以維持之，大量曝氣 消耗之能源(電力)成為好氧生物處理最大的操作成本。傳統好氧生物處理主要程序 擯制參數之一係廢水曝氣槽中溶氧，以溶氧作為控制程序之參數雖可使廢水處理中 微生物無缺乏溶氧之慮，然其卻無法反應出廢水處理系統中有機物的反應狀態，即 無法反應出生物反應之終點(endpoint)，易造成曝氣過量之不必要浪費，而對處理 系統異常之診斷也無直接之效應。好氧生物處理系統中的生物反應，基本上是以氧 為電子之接受者(氧化劑)的一種生物氧化還原反應，其過程中氧化還原電位ORP會 有明顯之變化，本文探討以實驗室中回分式反應設計模擬活性污泥之反應，並利用 電腦自動監測有機物成份系統配合UV-COD，連續監測反應過程中 ORP、pH、 DO、temp、UV-COD之變化，操控不同反應條件如： MISS、COD負荷等探討 以ORP作為控制參數之學理依據。初步可獲致結果如下： 以人工配製成廢液之COD值與UV光吸收度(λ=254nm)之關係成良好線性關係 ，活性污泥生物反應過程ORP先快速下降後緩慢上升後漸趨穩定，與反應前段有 機質快速消耗及溶氧之變化有密切之關係。反應後段ORP值漸趨穩定，此時有機質 之大半被氧化，COD之去除率之漸減，顯示ORP可作為反應終點之指標之一，藉以 有效控制曝氣量及停留時間。

　　　　　Aerobic biological treatment system is one of the most effective wastewater treatment processes. Due to oxygen transfer which spend high quantity of energy, is the maior part of operation costs. The dissolved oxygen (DO) is one of the most important control parameters in traditional wastewater treatment system. Since it can't response the real status in wastewater system and indicate the endpoint of reaction. It is also not sensitive enough to regulate the operation condition. Therefore excess energy is consumed in the wastewater treatment system. The basic concept of aerobic biological wastewater treatment system is an oxidation-reduction biological reaction and oxygen is the electron acceptor. The oxidation-reduction-potential (ORP) will change following this reaction. Such status may be indicate some special information that can help us to control wastewater treatment properly. This study disscusses the possibility of applying ORP control system from batch reactions using computer automatic monitoring system in laboratory. The result of this study indicates the concentration of materials in reaction such as COD, DO, have good relationship with ORP, By using ORP to monitor and control biological system is feasible and practical.