Research On The Submersible Muli-prameterwater Quality Monitoring Technology Based On UV-visible Spectra

In recent years, the national surface water pollution is still serious. Traditional water quality testing instruments commonly used laboratory chemical methods. They are bulky and complicated to operate with Secondary pollution and long time, requiring many chemical reagents. Combination of the technology and the status of water quality testing at home and abroad, the paper researched the Multi-parameter and on-line water quality testing technology based on UV-visible spectra.This water quality testing instrument developed is designed for rod-like structure and equipped with automatic cleaning device and an open flow cell. it is small and can be directly immersed in water for in situ detection without sampling. The spectra range of 200 ~ 720nm can be arrived, and its apectral error is less than 1nm, for the optical system of the instrument consists of concave grating and optical ellipsoidal. With the help of wireless data transmission module, it can remotely transmit the monitoring data, greatly improve the speed. The instrument can simultaneously measure the absorption spectra, COD, nitrate nitrogen, color, turbidity, absorption coefficient and the temperature and be non-polluting, without reagents and refluxing, and a single measurement will be completed in the 1s. The instrument achieved real-time, online, automation, portable and green.The experiments of potassium hydrogen phthalate solution, potassium nitrate solution and 9 different types of water samples were carried out, and compared with the national standard methods, they show that water quality testing technology based on UV-visible spectra can accurately measure the water COD, nitrate nitrogen, color and turbidity. One river was monitored on-site, using the water quality testing instrument developed, the trends of the river's COD, nitrate nitrogen, the absorption coefficient and temperature were obtained.This paper presents three spectral analysis modouls and their corresponding indicators, spectral difference method, direct comparison of spectra and spectrum normalized. Using these spectral analysis methods to classify the water samples and predict the mathematical model, the scope of application and generalization of the UV water testing technology can be improved.