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 ofwaste water samples. Thus, that can significantly improve existing waste water treatmenttechnology. In waste water treatment plant, an important parameter, chemical oxygen demandis needed to be measured. The amount of chemical oxygen demand determinesthe degree of water pollution by organic material. The conventional method for measuringchemical oxygen demand requires sample preparation and pre-treatment using chemicals.These conventional techniques are time consuming and labour intensive. To overcomethese problems, a system is developed in this work that offers significant advantages overconventional methods. The system employs ultraviolet and visible spectrometer in orderto correlate the absorbance of light after it passes through a waste water sample with theconception of the target chemicals. The spectrometer limits the use and disposal of chemicalsfor the measurement of chemical oxygen demand. In addition, a software system isdeveloped to control the spectrometer and to detect the most sensitive spectral region andwavelength for chemical oxygen demand content. Moreover, an algorithm is introducedby performing linear regression analysis on acquired concentration and light absorbancefrom the acquired spectra. The development and validation of this spectroscopic tool andsoftware system are described in this thesis.