🌍 1–3. Introduction & Program

Environmental biotechnology applies mixed microbial communities to recycle nutrients (C, N, P), treat wastewater, and recover valuable resources. The course links microbial ecology with engineering, exploring biofilms, ARGs, molecular methods, and sequencing.

💧 4–8. Wastewater & Composition

• Over 350 km³ of wastewater produced yearly; only ~20% treated.
• Wastewater is rich in organic matter, N, P, and micronutrients, making it a resource, not waste.
• Danish/EU effluent limits are strict: e.g. < 8 mg N/L, < 1 mg P/L.
• 1 PE (person equivalent) = 21.9 kg organic C + 4.4 kg N + 1 kg P yearly.

⚙️ 9–12. History & Activated Sludge

• Before 1900 → anaerobic septic tanks.
• 1913–1914 → Ardern & Lockett invented activated sludge: aeration + return of living sludge = improved degradation.
• Flocs = microbial aggregates doing the work; their structure affects settling and efficiency.
• Key processes: removal of organics, ammonium → nitrate → N₂, phosphorus, and micropollutants.

🧫 13–15. Reactor Innovations

• MBBR (Moving Bed Biofilm Reactor): Plastic carriers host biofilms, increasing surface area and stability. Used for C, N removal. Advantages → compact, robust, low energy.
• Aerobic Granular Reactors: Dense granules allow simultaneous nitrification and denitrification.
• MBR (Membrane Bioreactor): Combines activated sludge + membranes → higher quality effluent, no clarifier, but risk of fouling.

🌿 18–21. Biofilters & Microbial Ecology

• Biofilms grow on carriers; pollutants diffuse into biofilms for degradation.
• Microbiology is key to optimize: good effluent, low energy, nutrient recovery, and less foaming.

🧬 22–27. Community Composition & Problems

• Sludge hosts bacteria, phages, protozoa, metazoans.
• Problems: filamentous bacteria → foaming, poor settling, slimy flocs.
• Example: Microthrix parvicella causes foaming by storing lipids.

♻️ 28–31. Advanced Treatment

• Integration of anammox, P recovery, methanogenesis, sulfate reduction, and energy recovery.
• Modern plants recover water, energy, and nutrients in a circular economy model.

🔬 32–37. MiDAS & Global Databases

• MiDAS (Microbial Database for Activated Sludge & Digesters) provides taxonomy and functional data for >700 WWTPs globally.
• Only ~1,500 species form most global biomass.
• Enables comparison and troubleshooting (e.g., foaming by Microthrix).

🌎 33–34. Functional Guilds

• Nitrifiers: Nitrosomonas, Nitrospira dominate worldwide.
• Discovery of comammox Nitrospira (both AOB + NOB roles).

🧠 38–43. Seasonality & Dynamics

• Many species show seasonal abundance patterns, e.g. Microthrix peaks in cold seasons.
• Seasonal shifts vary by plant and species; process performance depends on this knowledge.

💻 44–45. Online Surveillance & Prediction

• Workflow: sampling → DNA sequencing → cloud bioinformatics → species ID → process control.
• AI models (deep learning) predict population changes for early warnings.

🧠 46–50. Knowing Your Plant

• “Know your plant”: track community over time, compare to others, identify nitrifiers/filaments.
• MiDAS Field Guide → ≈ 80 genera & 500 species = 80% biomass in Danish WWTPs.

🧩 68–76. Community Assembly

• Controlled by deterministic (selection, niches) and stochastic (immigration, drift) factors.
• “Everything is everywhere, but the environment selects.”
• Sewer microbiome is key → most AS bacteria originate from sewers, not influent.

🧭 72–73. Geography & Biogeography

• Example: Zoogloea species differ by region.
• Even within Denmark, geography shapes communities due to temperature, industry, and catchment characteristics.

🏙️ 75–80. Immigration & Sewer Influence

• 5–10% of biomass immigrates daily via influent.
• Most gut bacteria die off; only species adapted to AS conditions persist.
• Sewer biofilms act as reservoirs for process-critical species.

🧰 81. Ecosystem Design

Goal: Describe → Explain → Predict → Control

• Combine identity, function, and ecological principles to maintain stability and desired functions in bioreactors.

🌡️ 83–86. Managing Microbial Populations

To favor “good” bacteria:

1. Substrate preference: control donors/acceptors (C-sources, O₂, nitrate).
2. Growth kinetics: select species with desired uptake rates.
3. Dynamic conditions: “feast-famine” cycles favor storage organisms.
4. Floc/biofilm traits: promote compact flocs and discourage filaments.

⚗️ 87–90. Selection & Reactor Design

• Kinetic selection: fast growers vs. high-affinity filaments.
• Selectors + plug-flow zones improve control.
• Example: Microthrix mycolata → controlled via lipid reduction or PAC addition.

🧫 91–94. Filamentous Bacteria

• Most identified via MiDAS.
• Some essential for structure, others harmful (bulking, foaming).
• Amarolinea aalborgensis: sugar-fermenting, nitrate-reducing, bulking; control still under research.

📚 95. Summary

• MiDAS enables species-level tracking worldwide.
• Few genera dominate globally.
• Seasonal and geographic patterns matter.
• Immigration and process conditions shape communities.
• Frequent sequencing supports prediction and control.
• Some filamentous bacteria remain problematic.

🧾 96. How to Read a Scientific Paper

Encourages critical reading and interpretation of microbiological data to connect ecological insights with engineering applications.