Determination And Identification Of Environmental Pollutants With Overlapping Signals In Water Environment System

A program named POSCWPTPLS (or PDOSCWPTPLS) was designed based on the arithmetic algorithm of orthogonal signal correction (OSC), direct orthogonal signal correction (DOSC), wavelet packet transform (WPT), and partial least squares (PLS). OSC was used to remove the structural noise that was irrelative to the concentrations of the compounds. WPT was used to perform data compression, extract relevant information and eliminate noise. PLS was applied for multivariate calibration and noise reduction by eliminating the less important variables. Each of OSC and PLS is combined with ultraviolet spectrophotometry,differential pulse voltammetry and fluorescence analysis to determine the multi-component pollutants with severe overlapping Signals without separation.Three kinds of intelligent information technology (OSC-WPT-PLS or DOSC-WPT-PLS,WPT-PLS and PLS) were applied in this study for comparison.Four groups of multi-composition pollutants were studied in this article.(1) Determination of the heavy metal pollutent system of Al-Fe-Cu by UV spectrophotometry. The experimental results showed that the relative standard errors of prediction (RSEP) for all components were 3.57%,4.87% and 4.91% respectively.(2) Determination of the phenolic organic pollutant system of 2,5-dinitrophenol,3-nitrophenol and 4-nitrophenol by differential pulse voltammetry. The experimental results showed that the relative standard errors of prediction (RSEP) for all components were 3.76%,7.39% and 7.89% respectively.(3) Determination of the naphthalene,1-naphthol,2-naphthol system by fluorescence analysis. The experimental results showed that the relative standard errors of prediction (RSEP) for all components were 3.31%,5.87% and 6.71% respectively. The method was also used for analyzing tap water and two kinds of wastewater, and the recoveries were 97.4～102.0%, 97.6～102.7% and 91.8-104.6%.(4) Determination of the polycyclic aromatic hydrocarbons system of naphthalene, phenanthrene and anthracene. The experimental results showed that the relative standard errors of prediction (RSEP) for all components were 2.67%,7.11% and 8.25% respectively. The method was also used for analyzing the tap water and two kinds of wastewater, and the recoveries were 94.6-107.2%,85.2-112.3% and 86.4-106.6%.Experimental results showed that OSC-WPT-PLS and DOSC-WPT-PLS were better methods than the other two. Satistyfing results were obtained when it was used to analyze tap water and two kinds of wastewater.