A directly rapid quantification method for chemical oxygen demand (COD) of wastewater was established by Fourier transform infrared (FTIR) spectroscopy combined with attenuated total reflection (ATR) technology and moving window partial least squares (MWPLS) method with changeable parameters. All samples were firstly divided into the calibration set and the prediction set. And then according to the predicion effect, the optimal model was selected, and the corresponding waveband, number of adopted wavenumbers, PLS factor, root mean squared error of predication (RMSEP), correlation coefficient of predication (RP) were 3152-1109 cm-1, 1060, 8, 21.5 mg/L, and 0.981 respectively, which was obviously superior to the optimal PLS model on the whole spectral collecting region. The result shows that FTIR/ATR spectroscopy can be applied to the rapid determination of COD of wastewater, and the waveband selected by MWPLS method with changeable parameters has higher signal to noise ratio, which can effectively improve the precision of the predictive model.

Near-infrared (NIR) spectroscopy was successfully applied to chemical free and rapid determination of the organic matter in soil, and moving window partial least square (MWPLS) combining with Savitzky-Golay (SG) smoothing was used to the selection of NIR waveband. Thirty-five samples were randomly selected from all 97 collected soil samples as the validation set. The remaining 62 samples were divided into similar modeling calibration set (37 samples) and modeling prediction set (25 samples) based on partial least square cross-validation predictive bias (PLSPB). The selected waveband was 1896 nm to 2138 nm; the SG smoothing parameters and PLS factor OD, DP, NSP and F were 2, 6, 71 and 15, respectively; the modeling effect M-SEP and M-RPwere 0.219% and 0.944, respectively; the validating effect V-SEP and V-RPwere 0.243% and 0.878, respectively. The result provided a reliable NIR model and valuable references for designing specialized NIR instruments.