Research And Realization Of Online Monitoring Device For Total Nitrogen And Phosphorus In Water

With the social continuous progress, the pollution of lakes and reservoirs around the region increase daily, and eutrophication has become a worldwide problem. The water pollution caused by damage is also increasingly prominent. In order to effectively improve the scientific management of water pollution controlling and decision-making, water and wastewater online monitoring technology researching and application are imperative. Eutrophication process and TN/TP are related closely. In water monitoring, TN and TP are always the important indexes. The traditional monitoring methods of TN and TP are time-consuming and high cost, are given priority to artificial analysis. Developing a new water total nitrogen and phosphorus online monitoring device is extremely important. In order to detect of TN and TP in water automatically, an online monitoring device is designed and installed in this paper. Content of this paper are oxidation digestion, detecting methods, building and installing the device. Main research achievements have been made as follows:1. Based on experimental study, analysis and comparison of advanced oxidation methods, a new advanced oxidation device which combined UV and ozone is produced and installed. The device has high oxidative rate and high accuracy, which meets the needs of online monitoring.2. Through repeated experimental research, analysis and summary, optimal operating conditions on ion chromatography for detecting of TN and TP simultaneously in water quality are received, and solving the usual problem that ion chromatography cannot be used to detect of nitrogen and phosphorus simultaneously. The optimum ion chromatography, as a standard instrument is used to verify the accuracy and reliability of on-line monitoring device.3. Designing and building an online monitoring device, which can detect TN and TP continuously online and in real time. PLC is used as controller in this system, with integrated structures of cabinet. The device without adding chemical oxidant has the characteristics of components layout reasonable, man-machine interactive interface, green environmental protection, fast measuring speed, and easy to use. It is of highly expensive significance to improve the water quality monitoring devices in the digestion and reduce the introduction of foreign equipment.