As a landscape of cities, urban rivers have always been a key and difficult point in water environment management for many cities. The Nansha River, located in the northern part of Haidian District, Beijing, is such a scenic waterway that has been a key target of governance in Haidian District for many years. It is reported that the Nansha River is 16 kilometers long and has a drainage area of 220 square kilometers. It is an important river ecological corridor in Haidian District and one of the key landscape rivers flowing to the urban sub center of Tongzhou District in eastern Beijing. A few years ago, the water quality in the lower reaches of the Nansha River was poor, with severe organic pollution, basically classified as Class 5. After two years of comprehensive treatment, the water quality of the Nansha River has reached the standard of Class 5 water. However, occasional sudden pollution incidents still easily cause pollution to the river water. Based on this situation, since the beginning of 2018, the Haidian District Water Affairs Bureau has collaborated with Zhongguancun independent innovation enterprise Xinshi Vision (Beijing) Technology Co., Ltd. to pilot monitoring points in the Nansha River Basin, a key river in the north, to achieve real-time monitoring of river water quality throughout the entire period. To achieve this goal, they adopted advanced micro spectral sensing technology. This technology can automatically and continuously collect data, and does not require the addition of reagents during the monitoring process, effectively avoiding secondary pollution of water bodies. In addition, the development and construction of water quality monitoring and management software systems and mobile APP programs will be carried out in conjunction with the monitoring equipment. The person in charge introduced that the quantum dot spectral sensor used in the "Haidian District River and Lake Water Quality Monitoring System Project" has the characteristics of real-time, portability, flexibility, low power consumption, no consumables, and no pollution, simplifying the operation process. It can enable water managers to timely and accurately grasp river water quality information through the monitoring screen and mobile user terminal of the "City Brain" command center. In December 2018, the construction project of the "Haidian District River and Lake Water Quality Monitoring System" was officially launched. As of now, the project has completed the deployment of hardware equipment for all 29 monitoring points, and the development of web and mobile apps for the water quality monitoring management software system has also been basically completed. Moreover, during the operation of the IoT micro terminal device system for water pollution monitoring, a total of tens of thousands of frequency/time water quality testing data transmissions were completed, effectively reporting multiple pollution accident warnings in the Nansha River Basin. The successful application of quantum dot spectroscopy sensors in water quality monitoring also demonstrates the potential of this technology in other fields. In the future, with the successful miniaturization of quantum dot spectroscopic sensors, spectroscopic instruments may be able to move from laboratories to people's daily lives. By implanting quantum dot spectroscopic sensors into portable devices such as smartphones, detection and monitoring of air, water, chemicals, human skin, blood, and other substances can be achieved. Source: Science and Technology Daily