Even well-designed STP and ETP plants develop performance issues over time. Most problems trace back to a handful of root causes — and many can be resolved by replacing or upgrading the right components.
1. Rising BOD/COD in Final Effluent
Causes include insufficient aeration, biofilm loss, toxic shock to biomass, or hydraulic overload. Check dissolved oxygen levels, diffuser condition, and MBBR media fill. Replace fouled diffusers and verify blower output matches design air demand.
2. Diffuser Fouling and Low Oxygen Transfer
Fine-bubble membranes clog with biological growth, grease, and calcium scale. SOTE drops gradually — often before operators notice effluent changes. Plan proactive diffuser replacement. Read our diffusers guide for selection and maintenance tips.
3. Chemical Dosing Errors
Over-dosing coagulants wastes money and can harm biology; under-dosing fails clarifier performance. Calibrate metering pumps regularly and match wetted materials to your chemical programme. See dosing pump best practices.
4. Oil and Grease Carryover
Floating contaminants coat diffusers and increase organic load. Install or upgrade industrial oil skimmers at equalisation tanks and API separators before biological stages.
5. Inlet Screen Blockages
Rags and plastics blind bar screens, causing overflow and pump damage. Maintain mechanical bar screens and clear debris on schedule — especially after monsoon events.
Preventive Component Strategy
ABM Water Corporation supplies replacement diffusers, MBBR media, dosing pumps, blowers, oil skimmers, and bar screens for plants across India. Stock critical spares and schedule inspections before consent test failures force emergency shutdowns.
Conclusion
Most plant problems are component or maintenance issues, not design failures. Reach out to ABM with your symptoms and we will recommend targeted solutions.