廢水處理單元進出流渠道之水質與水量為廢水處理自動控制系統之重要依據，然而現今處理系統因缺乏完整性自動監測之系統，通常僅有部分處理單元或程序達到自動化或半自動化控制，並無整合性之自動化即時監測與控制設備。且其設備受到干擾、穩定度及成本等問題，為了有效的解決這些問題，本研究將整合並發展低成本與高準確性之渠道水質與水量即時自動監測系統。 本研究所發展之監測系統為使用雷射二極體、矩陣式光感測元件及水質感測器，利用三角量測原理與Beer-Lambert’s law用以量測水位、流量及SS濃度，並以虛擬監測COD濃度，自動即時監測系統之原型量測裝置於工業區污水處理廠進行測試與驗證。根據實際之測試與驗證結果顯示，模廠之水位與水量量測，量測範圍為85cm，其結果平均誤差值約為0.308cm；而於化混池與放流渠道之SS濃度量測，其平均誤差值各別為紅色雷射二極體4mg/L及1.5mg/L、綠色雷射二極體8mg/L及1.8mg/L及以紅與綠雷射二極體量測放流渠道SS濃度平均誤差為1.29mg/L (量測最大範圍為70 mg/L，最小範圍為8 mg/L)，而虛擬監測部分為量測COD之平均誤差為1.3mg/L，足以說明本研究之渠道即時自動監測系統具有一定之可行性與準確性，對於一般廢水處理系統來說，不僅可提供即時正確之水質與水量資訊，亦可將即時水質與水量之資訊，利用有線或無線網路將資料即時回傳，作為廢水處理系統預警系統與自動控制之用，以提升廢水處理系統自動化之效益與效率。 The influent and effluent flow rates or the water levels of reactor, tank or conduit are key parameters for automatic control of water and wastewater treatment processes and systems. The measuring techniques used today for automatic monitoring of flow rate or water level remain unsatisfied or disqualified with accuracy, disturbance, maintenance and cost issues. To effectively solve the problem, a low cost and high accuracy non-contacted real-time water level or flow rate measuring technique was developed for reactor, tank or conduit, using consumer-grade laser diode, CCD camera, and image processing with triangulation. A prototype system was built and tested on industrial park wastewater treatment plant. According to real test and verification result, the mean error percentage of water levels and flow rates is about 0.308 cm in conduit. Using red laser diode and green laser diode to measure suspended solid in chemical coagulation treatment tank and discharge outlet conduit, its mean error respectively for 1.3 mg/L. Beside, using virtual monitoring technique to measure chemical oxygen demand in chemical coagulation treatment tank, its mean error respectively for 1.3mg/L It is enough to explain the amount of laser optical image utilized to measure SS and have certain feasibility and exactness. It can offer immediately correct SS information, can also monitor information of SS immediately, as using with controlling immediately of early warning system of process system of waste water, in order to improve the effect of the waste water with automatic process system.
