Effect Investigation Of Optical Performance Of Cuvette Material On Sewage Absorbance Measurement

In recent years, water environment pollution of China has become increasingly serious. In order to prevent the deterioration and new pollution of water environment, sewage treatment methods have been widely concerned, and the water quality testing indicators are becoming more and more strict. The absorbance of the sewage is based on fundamental data from the optical measurement of various water quality testing indicators. However, in the measurement process, the optical properties of cuvette material packaging sewage produced a certain influence on measuring the absorbance and would bring some interference on measuring precision of the late various of water quality testing indicators. Therefore, analyzing the influence of the optical properties of cuvette material packaging sewage on absorbance measurement is very important, which can be used to improve the accuracy of various types of water quality detection index based on optical measurement.Considering sewage absorbance as the research object, the problems of measuring the absorbance value at present was found through the analysis of absorbance application status at home and abroad in the detection of sewage. The idea to reform sewage absorbance measurement was put forward based on the principle analysis of optical measurement and the water absorbance measurements were developed, the main contents of the study are as follows:1. The theoretical analysis model of cuvette material transmission characteristics was given, an inversion method to solve optical constants using two layers of different thickness and same thickness based on cuvette material transmission spectra was developed, transmission spectra measurement experiment was conducted through the cuvette material quartz and ZnSe samples, in the wavelength range of the UV visible spectra, absorption index of quartz glass sample was between 10-6 and 10-8, refractive index was between 1.5 and 3.3; absorption index of ZnSe sample was almost between the 0 and 10-6, refraction rate basically stable at around 2.5. In the wavelength range of infrared spectra, absorption index of sample was between 10-4 and 10-6, most of refractive index was between 1.2 and 3.0.2. The acquisition method of conventional sewage absorbance and the principle, experimental device and experimental procedure of the improved sewage absorbance method was given, the experimental measurements was conducted using distilled water samples and optical constants were obtained by inversion calculation, which were also compared with the existing literature data results and validated with the data.3. In theory, the calculated results of two regular methods to access liquid sample absorbance and real value of liquid sample were analyzed contrastively, and the effects of three types of high, medium and low refractive index on calculation results of the above methods were also studied. In the experiment, the measurement results using two conventional and the introduced accurately method to obtain the sewage sample absorbance were compared and analyzed, the effects of cuvette measurement optical path on experimental results were also discussed.4. Oil content of sewage samples was selected as an indicator of contrast analysis of sewage, oil content of oily sewage sample was measured by traditional measurement methods and the accurately absorbance obtained method introduced in this paper, respectively, and the results of specific contrast experimental data were recieved.