**Part 4: Troubleshooting Biological Processes in Wastewater Treatment Systems** 🔧### Microorganisms in Activated Sludge 🔬- **Bacteria**: ...
Published on by Hossein Ataei Far, Deputy Manager of the Research, Technology Development, and Industry Relations Center at NWWEC
### Microorganisms in Activated Sludge 🔬
- **Bacteria**: The primary agents for removing organic nutrients from wastewater.
- **Protozoa**: Critical for improving effluent clarity by removing suspended particles and free-swimming dispersed bacteria.
- **Types**:
- **Amoebae**: Minimal impact, decrease as food diminishes.
- **Flagellates**: Consume soluble organic nutrients.
- **Ciliates**: Clarify water; crawling ciliates dominate in activated-sludge processes, while stalked ciliates dominate towards the process end. **Metazoa**: Larger, multi-cellular organisms that indicate system conditions but have minimal impact on organic material removal.
- **Types**:
- **Rotifers**: Clarify effluent, first affected by toxic loads.
- **Nematodes**: Feed on bacteria, fungi, and protozoa.
- **Tardigrades**: Survive extreme conditions, indicative of system robustness.
- **Filamentous Bacteria**: Grow in long filaments, often causing settling issues and foaming when operating conditions change. Monitor and adjust temperature, pH, DO, sludge age, and nutrient levels to manage their growth.
- **Algae and Fungi**: Generally harmless but indicate pH changes or older sludge.
Laboratory Tests 🔬
Essential laboratory tests for troubleshooting biological processes in wastewater treatment systems:
-Chemical Oxygen Demand (COD) 💧
-Dissolved Oxygen (DO) 💧
-pH ⚖️
-Sludge Volume Index (SVI) 📉
-Total Suspended Solids (TSS) 🧪
-Nitrate and Nitrite Levels 🌿
-Phosphorus (Total and Orthophosphate) 🌾
-Fecal Coliforms/E. coli 🦠
-Volatile Solids (VS) 🔥
### Conclusion
Activated sludge processes are highly efficient when managed correctly, typically removing 85-95% of solids and BOD. Effective monitoring, regular equipment maintenance, and proper control of microorganisms are essential for maintaining optimal system performance.
**References**
1. Tchobanoglous, G., Stensel, H.D., Tsuchihashi, R., & Leverenz, H.L. (2023). *Wastewater Engineering: Treatment and Reuse*. McGraw-Hill Education.
2. Metcalf & Eddy, Inc. (2020). *Wastewater Engineering: Treatment and Resource Recovery*. McGraw-Hill Education.
3. Grady, C.P.L., Daigger, G.T., & Love, N.G. (2022). *Biological Wastewater Treatment*. CRC Press.
4. Control of Activated Sludge, Including Troubleshooting, (https://lnkd.in/dcEjHtvT)