Simultaneous determination of cod and Nitrate in waste water by spectrophotometric method combined with multivariate regression algorithm

Abstract

This study examined the optimal conditions to identify simultaneously two targets COD and NO3 - , and showed that the best properties that are best include the spectra around 190 to 300 nm, the maximum absorption of COD and NO3 - respectively at 198 and 205 nm, and the optimal pH for optical absorption at a maximum of 4.5. From these optimal conditions, the construction of multivariate regression equation for simultaneous determination of COD and nitrates was conducted. Based on the analytical results of 10 pseudo samples selected from principal component regression model, there was a similarity between the receired experimental data and the given concentration in a range of relative errors (permitted to be below 15%). Therefore, it is concluded that using multivariate regression analysis has a high recovery performance and consistent results as compared to the univariate analysis method, and is possible to apply for the analysis of waste water samples in reality.