Remote spectrophotometric water quality monitoring
The conventional approach to water quality monitoring is to combine periodic sampling with batch analysis in the laboratory. Such a procedure is both labour intensive and time consuming, there are likely to be sample stability and contamination problems, and the information provided is unlikely to be continuous or immediate. This research focussed on the design and construction of fully automated and portable monitors based on flow injection analysis and incorporating solid state photometric detectors. A novel solid state photometric detector was constructed, incorporating light emitting diodes as the light source, which could be used in conjunction with flow injection analysis. Manifolds were studied for a range of species of interest (phosphate, nitrate, ammonia and aluminium) in the field of water quality monitoring and were optimised for their suitability for continuous use. An automated monitor for nitrate was constructed and long term evaluation trials were carried out at several locations for water quality monitoring. Results are also presented for the use of a nitrate monitor in hydroponic cultivation. An automated monitor was also built for the monitoring of ammonia levels in natural waters, which was field tested on the River Avon (Wiltshire). A manifold was also evaluated for the monitoring of residual aluminium levels in drinking water and is currently being commissioned at a water treatment works in Somerset.