This study applies the digital image analysis method to develop an effective and economical method for on-line monitoring of the wastewater flow、true color and suspended solid. Experimental results show that digital image analysis method performed not only with good accuracy and precision but also high sensitivity in the measurement of flow、true color and suspended solid.. In addition, this study is mainly to set up basic spectrum database and then develop a qualitative and quantitative samples for rapidly estimating concentration approximately, and the other is to quantitative the concentration of samples accurately. Scan the absorption spectrum of wastewater, and to calculate the concentration of composition using algorithm. Experimental results show that algorithm is useful and accuracy calculate the concentration of chemical oxygen demand、suspended solid and heavy metal. This study show applies digital image method and algorithm is useful and accuracy calculate flow、true color、suspended solid、oxygen demand and heavy metal respectively. The optical monitoring technology can provide wastewater on-line、real- time and, promote the wastewater treatment plant operate.

monitoring、optics、reflection、absorption spectrum、algorithm