當廢水進入污水處理廠前若能先掌握廢水特性，則污水處理廠可針對進流廢水之水質特性即時調整後端處理單元或程序，以達到穩定之放流水水質。因此，若能即時掌握廢水特性之變化與影響並對後端處理單元進行因應性的調整與控制，使系統功能之正常發揮與目的。由於人工檢測分析時間太長無法及時提供控制所需資訊且成本太高。而光學方法具有快速量測、不需外加藥劑、建置成本低等優點，可有效解決及改善傳統量測或實驗分析所面臨之問題。本研究是利用多波長UV/VIS吸收光譜、頻譜分析技術及迴歸分析技術，建立COD與SS濃度推估模式並以實廠廢水來做為模式之驗證。由於SS濃度與粒徑分佈會影響UV/VIS吸收光譜，造成量測上之誤差。因此，本研究藉由稀釋與不同孔徑濾紙進行過濾來探討SS濃度與粒徑對於量測COD與SS濃度之影響。其結果顯示，當廢水中之SS顆粒越小其迴歸模式所選擇之波長越趨近短波長；反之SS粒徑越大其迴歸模式所選擇之波長越趨近長波長。在SS與COD濃度推估結果方面，其結果與人工檢測分析相之相對誤差分別小於15 ％與20 ％以內。因此，利用多波長UV/VIS吸收光譜建立廢水中COD與SS濃度技術具有一定程度之穩定性及準確性，可做為未來開發水質自動監測技術與設備之基礎。 Information about the properties of influent wastewater helps a treatment plant to adjust its treatment processes or procedures to stabilize the quality of effluent wastewater. Once the properties of wastewater can be understood efficiently, the treatment plant can function effectively and its performance can be improved as well. Respecting the deficiencies of traditional measurement equipments and experiment analysis, manual test is not able to offer the required information spontaneously and cost a lot. When the situation with unusual water quality happened to the wastewater treatment plant, optical measuring methods, which have fast quantity examine and low cost construction, are more effective to solve and improve the problem caused by the traditional way. Using absorption spectrum analysis technique with multiple wave-length UV/VIS and mathematical regression, an estimation model for COD and SS concentration was developed and verified in this study. Based on the experimental results, SS concentration and particle size distribution affect UV/VIS absorption spectrum and cause the measurement error. Therefore, experiments with different diluting and filtering recipes were made to discuss the effects from SS concentration and particle size to the measurement of COD and SS concentration. The result has shown that the Smaller the SS particle size is, the shorter wave-length is selected in the estimation model. The estimation result of SS and COD concentration has shown that the error compared to manual test was less than 15% and 20%. Therefore, the COD and SS concentration estimation technique with multi wave-length UV/VIS absorption spectrum developed in this study is relatively stable and accurate and can be the sound foundation for development of water quality automatic monitoring techniques and equipments in the future.
