傳統利用化學沉降法處理重金屬時，需要在沉降完成後抽取上層液水樣進行分析，才能確實了解廢水處理效果之好壞及重金屬之去除效果。此一過程不但耗費大量的時間，尤其在水質變化大及處理發生情況時，並無法立即得知水質變動並適時地調整加藥控制，導致處理效果往往不如預期。目前雖然有監測設備可快速了解處理效果，然而仍需具有操作經驗之專業人員來操作，因此並不能普遍適用於實場。 本研究將本研究團隊已發展之化學混凝監測系統，應用於化學沉降之監測，了解此監測系統應用於化學沉降之可行性。以人工配製之含銅廢水在模場操作下，分析光學監測方法在不同的操作情況下光訊號值的變化，藉以了解化學沉降之效果。 實驗結果顯示，化學沉降之光訊號結果在pH調整階段由於顆粒的產生而有較大的跳動性。加入沉降劑調整溶液至較高pH值時，溶液顏色呈現較深的藍色而使得光訊號結果有往藍光(B值)偏移的現象，當此偏移的現象愈明顯，所獲得之去除率亦愈高。另外在快慢混過程中之光訊號下降趨勢愈明顯時，所分析之顆粒粒徑亦較大。顯示以光學影像監測技術確實可以適時地反應出沉降過程中槽體之廢水處理狀況，同時亦可藉此光訊號快速了解處理效果之好壞。 Traditionally, the treatment efficiency of heavy metal wastewater can only be determined by analyzing the clarified water from sedimentation tank after chemical precipitation. Whether, the chemicals are properly dosed and the the fluctuation of wastewater quality cannot be obtained promptly. Hence, improper dosing of precipitating agent results in poor wastewater treatment. In this study, a novel monitoring technique, floc image color analysis (FICA), developed for precipitation of copper wastewater at different pH values and dosages of coagulant chemical was conducted in a pilot plant and was monitored by FICA. The image of solution was captured and the RGB values of the image were analyzed. The results showed that the RGB values arised, which was because the formation of precipitates upon the adjustment of pH. When the solution pH was higher, the removal efficiency increased; also, the color of the solution shifted to deep blue and the B value became relatively higher. The RGB decreasing trend was steeper in coagulation and flocculation process as the particle size is increased.
