Staffing limits are becoming a factor in how much analytical can be done onsite in many treatment systems. I have been working with several smaller systems with staff that services multiple smaller treatment plants. For operations side on biological treatment sections, it is good to know what data helps in case troubleshooting is needed. What tests must be run and how often frequently depend on influent variation, treatment system design capacity, equipment operating efficiently, and other local factors. Here are what I consider the most vital onsite tests and how they help you make operational decisions.
Lagoon Systems
- High Frequency/Daily
- Observe - water color, foam, and other visual clues
- Temperature, D.O., pH - and check probes to ensure no malfunctions are happening
- Important but not necessarily daily
- BOD/COD
- Nutrients (ammonia, phosphate)
- Oxygen Uptake Rate (OUR)
- Basic microscopic exam - often centrifuge lagoon sample first for better protozoa observation
- High Frequency/Daily
- Observe - water color, foam, and other visual clues
- Temperature, D.O., pH - and check probes to ensure no malfunctions are happening
- SV30 - use same vessel each time
- Check recycle and wasting rates
- Clarifier bed depth
- Important but not necessarily Daily
- BOD/COD
- Nutrients (ammonia, phosphate)
- Oxygen Uptake Rates (OUR)
- MLSS/MLVSS - good to know both, but MLSS can be used for adjustments and is faster
- Microscopic exam - phase contrast helps to count filamentous organisms in systems subject to bulking
- Calculate F/M, MCRT, SVI, SOUR - watch trends and variation here
For help in conducting Microscopic Exam - I have created a "Bug Poster" - it helps you identify common indicator organisms such as protozoa in biological treatment units.
https://asterbio.com/bug-poster/