Reliable in-situ sensing of water quality parameters using low cost autonomous analysers - opportunities and challenges

The delivery of platforms that can provide access to good quality analytical information on the chemical/biological status of water at an acceptable cost remains a formidable challenge, despite considerable efforts from the research community over many years. The relatively high cost of autonomous analytical platforms means that measurement frequency and density is much lower than desirable, and this in turn is a significant barrier to developing a clearer understanding of environmental status, processes and dynamics, and to the effective policing of environmental regulation. However, recent advances in satellite remote sensing and drone based measurements present opportunities to capture water status data with unprecedented spatial and temporal coverage. The availability of autonomous instruments that provide continuous in-situ data provides complementary information that in a sense completes the requirements for a more complete environmental informatics coverage in that these devices can provide molecular information on related to key determinants of water chemical and biological status. In this paper, I will outline the challenges that have up to now inhibited the emergence of these low-cost, reliable, autonomous biochemical analysers, and explain how developments in rapid prototyping, microfluidics and detection schemes will provide routes to surmounting these challenges. Furthermore, I will discuss how coupling in-situ sensing with satellite remote sensing will, in many instances, reduce the density requirement on in-situ sensors for tracking and modelling water chemistry dynamics.