Abstract
In the context of the growing environmental pressure on water resources caused by anthropogenic factors, the task of increasing the efficiency of wastewater treatment systems becomes urgent. The purpose of this work is to study and determine the optimal wavelength of the photoemitter for measuring the concentration of activated sludge by the optical method in biological wastewater treatment. The process of interaction of the emitted light with the measured medium is theoretically analyzed, the optical properties of the ultraviolet, visible, and near-infrared regions of the spectrum are considered. Based on these analyzes, an experimental study is carried out to find the optimal wavelength of the emitted light. To that end, under laboratory conditions, on the spectrophotometer model EMC-32PCS-UV, spectral measurements were performed on the absorption of emitted light by activated sludge microorganisms in the spectral range from 190 to 1100 nm wavelengths. Samples of activated sludge from the treatment plant in the city of Bukhara, Uzbekistan with different concentration values were utilized. When studying the absorption spectra of activated sludge microorganisms, it was experimentally established that the maximum absorption of light occurs in the infrared region of radiation, specifically at a wavelength of 940 nm. To select the optimal value of the radiation wavelength, the main criteria and requirements were theoretically determined. Based on these criteria, considering the scattering and absorption of light, the optical properties of the photodiodes used, it was concluded that the optimal value of the radiation wavelength is 940 nm. Using the results of the absorption spectra, the radiation wavelength was chosen. Graphical representations of the results of spectral studies with activated sludge microorganisms are given.