The Experimental Study And Detection System Design Of Water Quality Based On Two-electrode System

Water is the source of life. The quality of drinking water and human health are closely related. With the expansion of the city, the development of industry and agriculture, environment worsening is intensifying. People are increasingly concerned about water quality. Currently, water quality testing equipments on the market are mostly applied to detect contamination of water, and they are expensive, high maintenance. Therefore, the research and development of a multi-parameter water detection equipment, which is rapid, sensitive, inexpensive and small. Its application in domestic use has practical significance and value.In this study, electrochemical voltammetry which is simple, highly sensitive was chosen for water quality testing methods. By changing the incentives to achieve the purpose of detection of a variety of parameters, we have designed a water testing system for domestic use, and have carried on experimental study of multiple ions detection in water based on this system. The main research contents of this paper are as follows:1) Sensor:we firstly analyzed and compared the various methods of water testing at home and abroad, and choose voltammetry as the research method. Secondly, because electrochemical voltammetry based on three-electrode system has application restriction in the field of home and food, we elaborated on the principles of two-electrode system and did relative research. Combined with laboratory research results of two-electrode system in recent years, we designed activated carbon electrode to build two-electrode electrochemical sensor.2) Detection system:we have developed a set of hardware and software integration system based on USB2.0.It can realize a variety of electrochemical technology to detect a variety of parameters in water with two electrodes and three-electrode system. The detection system has micro signal amplification, high-speed signal acquisition in real time, real-time data display and other functions. The algorithm we designed can get the characteristic peak positions and rapid response to the intensity signal to achieve the qualitative and quantitative analysis.3) Experimental Study:experimental study was carried out to detect a variety of water parameters based on our self-developed detection system. Firstly,we applied stripping voltammetry for heavy metal ions detection, including Hg2+, Pb2+and Cd2+. The sensitivity and detection limit can be in line with three-electrode system, which verified the feasibility of two-electrode system; secondly, we used Pulse chronoamperometry to determinate small molecule of glucose in water, and achieved good results; Finally, anion detection such as CIO" was detected using linear sweep voltammetry. The experimental results show that the detection system can be widely applied to the detection of cation, anion, and other small molecules in water.The innovation of this paper is that we have designed new two-electrode sensor with active carbon as auxiliary electrode and applied it to realize water multi-parameter detection. Besides, our homemade software and hardware platform is miniaturization, functional, operation reliable, and the cost is far lower than the electrochemical workstation on market. This study provides a new train of thoμght for water non-destructive, real-time detection and online research.