Microbiological Successiona.k.a Bug Growth

Hugh Ratsey Opus ETC

What is the aim of today?

• Give an overview of wastewater microbiology

• Provide a case study showing microbiological succession

• Demonstrate how “bugs” can be used to understand a treatment process

• Get you all (well, some of you!) enthused about peering down a microscope

Wastewater Microbiology

Bacterial Growth Curve

Case Study

SelectorBio 2Bio 1WW2

N & P dosing

N & P dosing

RAS

RoughingTower

AS 1 AS 2

WAS

Effluent

Case Study – Bio 1

Case Study – Bio 2

Case Study – Selector

Case Study – AS 1

Case Study – AS 2

Microbial Succession

So What?

• Bugs can be used for:– Monitoring– Troubleshooting

• If you still don’t believe me…

Dispersed Bacterial Growth

• Will result in:– Solids carry-over in effluent

• Can be caused by:– Toxic shock– Insufficient nutrients– High temperature– Low dissolved oxygen (DO)

Filamentous Bacteria Growth

• Will result in:– Poor sludge settlement– Solids carry-over in effluent

• Can be caused by:– Low dissolved oxygen (DO)– Greasy wastewater– Insufficient nutrients– Septic wastewater

Good Balance of Life

• Will result in:– Good sludge settlement– Low suspended solids in

effluent– Good nitrification

• Can be caused by:– “Correct” environment– Stable conditions

Questions?

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