Estimation of Chemical Oxygen Demand in WasteWater using UV-VIS Spectroscopy

The aim of this research is to build a portable system to perform real-time analysis of waste water samples. Thus, that can significantly improve existing waste water treatment technology. In waste water treatment plant, an important parameter, chemical oxygen demand is needed to be measured. The amount of chemical oxygen demand determines the degree of water pollution by organic material. The conventional method for measuring chemical oxygen demand requires sample preparation and pre-treatment using chemicals. These conventional techniques are time consuming and labour intensive. To overcome these problems, a system is developed in this work that offers significant advantages over conventional methods. The system employs ultraviolet and visible spectrometer in order to correlate the absorbance of light after it passes through a waste water sample with the conception of the target chemicals. The spectrometer limits the use and disposal of chemicals for the measurement of chemical oxygen demand. In addition, a software system is developed to control the spectrometer and to detect the most sensitive spectral region and wavelength for chemical oxygen demand content. Moreover, an algorithm is introduced by performing linear regression analysis on acquired concentration and light absorbance from the acquired spectra. The development and validation of this spectroscopic tool and software system are described in this thesis.