The variation in pollutant concentrations among different water bodies poses a significant challenge for environmental surveillance.Traditional UV-Vis spectrometers,with fixed optical paths,face limitations in accurat...The variation in pollutant concentrations among different water bodies poses a significant challenge for environmental surveillance.Traditional UV-Vis spectrometers,with fixed optical paths,face limitations in accurately determining Chemical Oxygen Demand(COD)and other water quality parameters.High concentrations surpass the detection limit,while low concentrations yield weak response signals,thereby compromising measurement accuracy.This study tackles these challenges by enhancing a UV-Vis spectrometer with a variable optical path.By utilizing a right-angle reflector for reflection and a stepping motor for control,measurements are conducted within the wavelength range of 190-700 nm.The instrument incorporates a spectral fusion algorithm to optimize spectral measurements within its operational range.Furthermore,a Partial Least Squares(PLS)model has been established for COD inversion by using laboratory standard solutions and field samples.The spectrometer has been tested in the nearshore waters of Shenzhen Bay,China,validating its applicability and the model’s accuracy.The utilization of a variable optical path UV-Vis spectrometer facilitates the acquisition of precise monitoring data with wide measuring range,thereby enabling the prompt detection of anomalies and subsequent reduction in reaction time.展开更多
基金supported by the Bureau of Ecology and Environment of Shenzhen,Natural Science Foundation of Hunan Province(No.2023JJ50346)the Open Fund of National Engineering Research Center for Advanced Technology and Equipment of Water Environmental Pollution Monitoring(No.2024KFJJ0106).
文摘The variation in pollutant concentrations among different water bodies poses a significant challenge for environmental surveillance.Traditional UV-Vis spectrometers,with fixed optical paths,face limitations in accurately determining Chemical Oxygen Demand(COD)and other water quality parameters.High concentrations surpass the detection limit,while low concentrations yield weak response signals,thereby compromising measurement accuracy.This study tackles these challenges by enhancing a UV-Vis spectrometer with a variable optical path.By utilizing a right-angle reflector for reflection and a stepping motor for control,measurements are conducted within the wavelength range of 190-700 nm.The instrument incorporates a spectral fusion algorithm to optimize spectral measurements within its operational range.Furthermore,a Partial Least Squares(PLS)model has been established for COD inversion by using laboratory standard solutions and field samples.The spectrometer has been tested in the nearshore waters of Shenzhen Bay,China,validating its applicability and the model’s accuracy.The utilization of a variable optical path UV-Vis spectrometer facilitates the acquisition of precise monitoring data with wide measuring range,thereby enabling the prompt detection of anomalies and subsequent reduction in reaction time.
