This topic is about developing and using cheap, safe, user-friendly and robust tools for water quality analysis.
These tools can be used:
- To test water quality of alternative water resources,
- For education, and
- In-the-field analysis for scientific research – frugal science.
Further, these tools help build a contextual understanding of how our actions and our environment impact water quality, building risk awareness into society.
Why?
Part of Water Sensitive Design is knowing what is going on in the water – analysis, monitoring, and possibly, depending on the context (like wastewater treatment) control. One way of finding this out is by submitting water samples to accredited laboratories (South African directory available on the SANAS website). But for rough quick answers, water quality analysis for education or in times of drought, and in-the-field analysis for research, we need a range of cheap, safe, user-friendly and robust solutions.
Testing water for drinking water quality is complicated, need many tests and a contextual understanding. There are several groups of components potentially present in water, each needing their own special test:
- Pathogens
- Turbidity
- Colour
- Tastes and odours
- pH and alkalinity
- Total dissolved solids
- Hardness
- Toxic inorganics
- Nitrate
- Sodium
- Iron and Manganese
- Organics
- Corrosivity
This challenge is about water analysis, but it’s really about guiding the public to learn about water, the risks associated with water and equip ourselves in making our own risk assessments. When it comes to water analysis there is no silver bullet.
For in the field analysis we have specific criteria, like measuring specific metabolites (think lactic acid or pH for cheese making, for example, or alcohol and sugar content in beer brewing).
Categories for hacking:
- Electronic: Sensors, Probes, ‘hacking’ – monitoring with e.g. Arduinos, Raspberry Pi’s, hacking, fixing, making new from old equipment. This includes smart probes: Online or sim-enabled remote probes that can sample/measure dissolved oxygen, pH, electrical conductivity, total disssolved solids, salinity and voltage (if it runs on battery/solar power)
- Biosensors: Using biology to give a qualitative or quantitative signal, including the miniSASS, microbial cell counts, enzyme based processes etc
- Green chemistry kits: aquarium kits, swimming pool tests, make your own kits, dedicated kits like the EarthEcho kit etc
And a special category - Photography: With special interest in the microscopic, using e.g. USB microscopes, the Foldscope – not just for analysis; also for pretty.
Judging Criteria
Hacked solutions need to address their own specific criteria, but overall they also need to be:
- Robust – how finicky is the solution? Do you need a working knowledge of black magic to keep it working?
- Repeatable – if we do the exact same thing three times, will we get the same answer?
- applicable in a Range of operation – what concentration ranges (for example) does this solution work well in, is this a useful range?
… probably more to come
Also see aquasavvy.co.za/analysis/