Development of a Water Quality Analyser Suitable for Unattended Use in Rivers and Streams
This report was produced for the Urban Water Research Association of Australia, a now discontinued research program.
Report no. UWRAA 55
The aims of this project were to develop a rugged, reliable and cost effective water quality analyser capable of measuring a number of important water quality determinants automatically, in the field. An integrated system of physical sensors, electrochemical (ion selective electrodes) sensors, and a spectrochemical sensor capable of measuring turbidity, temperature, water depth, conductivity, and nitrate, chloride and reactive phosphate concentrations was required to achieve this.
The analyser was designed with three components. The SUBMERSIBLE unit was located in the river and undertook all measurements in-situ. Chemical sensors were calibrated before each measurement using reference solutions. The CONTROLLER communicated with the SUBMERSIBLE to initiate a sampling regime and received the measured data. The COMMUNICATIONS system received data from the CONTROLLER and relayed it the laboratory via ARGOS satellite.
The development took place in four phases. Each phase involved significant improvements to the capabilities of the equipment from the preceding phase and included extensive field testing at Houlgrave Weir, on the Onkaparinga River in South Australia. All components of the system functioned well and culminated in the collection of more than 100 days of data.
The analyser developed through this project can automatically and reliably measure a variety of important water quality determinants automatically in the field, and transmit the data to the laboratory via satellite for assessment. It is recommended that real-time monitoring be seen as an important but complementary technological advancement to more traditional monitoring procedures, and that further development of the analyser be carried out to improve the measurement of some determinants, particularly conductivity and turbidity, along with extensive field testing.