Inspect Vessel & Components
Verify underdrain integrity, check for debris, confirm valve operation, and inspect instrumentation.
Start-up procedures, backwash optimisation, breakthrough monitoring, carbon replacement, and troubleshooting guidance
CFD, P&ID, SCADA and commissioning for critical water treatment plants.
Plant layouts, piping isometrics and construction-ready engineering drawings.
Flow, mixing and thermal CFD across treatment and process equipment.
Full mechanical, physico-chemical, biological and sludge equipment range.
Initial Commissioning & New Carbon
Verify underdrain integrity, check for debris, confirm valve operation, and inspect instrumentation.
Fill vessel from bottom up to prevent air entrapment. Water level should be 300mm above underdrain before adding carbon.
Carefully add carbon to prevent dust generation. Use dust collection equipment and ensure adequate ventilation.
Backwash at design rate for 20-30 minutes to remove fines, dust, and classify the bed. Monitor effluent clarity.
Allow bed to settle for 15-30 minutes. Verify bed depth is within design specification (±5%).
Filter to waste until effluent is clear and turbidity < 1 NTU. This may take 2-6 hours.
Verify treatment performance before putting into service. Test for target contaminant removal.
Maintaining Filter Performance
Close inlet valve and allow vessel to drain to normal operating level.
Introduce air at 50-80 m/h for 3-5 minutes to loosen compacted bed.
Open backwash valve and start backwash pump. Gradually increase to design rate.
Observe bed expansion and effluent clarity. Backwash until effluent is clear.
Gradually reduce flow and stop pump. Allow bed to settle for 10-15 minutes.
Filter to waste for 5-10 minutes or until effluent quality meets specification.
Close waste valve and open outlet valve to return to normal operation.
Determining When to Replace Carbon
| Contaminant | Breakthrough Definition | Typical Service Life |
|---|---|---|
| Chlorine | > 0.1 mg/L in effluent | 1-3 years |
| Taste & Odour (Geosmin/MIB) | > 5-10 ng/L in effluent | 1-2 years |
| VOCs (general) | > 10% of influent concentration | 6 months - 2 years |
| PFAS (PFOA/PFOS) | > 20-70 ng/L (regulatory limit) | 6 months - 1 year |
| COD/TOC | < 50% removal efficiency | 6 months - 2 years |
Routine Care for Optimal Performance
Common Issues & Solutions
Symptoms: Pressure drop increases rapidly, flow rate decreases
Possible Causes: Suspended solids breakthrough, biological growth, carbon fines, oil fouling
Solution: Improve pretreatment, increase backwash frequency, check for oil contamination, consider carbon replacement
Symptoms: Breakthrough occurs prematurely, removal efficiency declines
Possible Causes: Carbon exhausted, insufficient EBCT, channelling, improper carbon type
Solution: Replace carbon, verify design parameters, inspect for channelling, review carbon selection
Symptoms: Cloudy effluent after backwash, carbon fines in product
Possible Causes: Insufficient backwash, carbon degradation, underdrain failure
Solution: Extend backwash duration, check carbon condition, inspect underdrain, increase rinse time
Symptoms: Musty odour, increased headloss, slime formation
Possible Causes: High nutrient water, warm temperatures, low flow periods
Solution: Increase backwash frequency, chlorinate influent, improve pretreatment, consider BAC operation
Symptoms: Uneven bed surface, short circuiting, poor performance
Possible Causes: Improper backwash, broken underdrain, uneven flow distribution
Solution: Proper backwash procedure, inspect and repair underdrain, check inlet distributor
Symptoms: Pressure spikes, flow instability, reduced capacity
Possible Causes: Air entrapment during filling, negative pressure, temperature changes
Solution: Proper filling procedure, install air release valves, maintain positive pressure, vent before start-up
Discuss your specific requirements with our technical team and receive a tailored proposal for your project.
Contact UsOur service team provides comprehensive GAC system support including operator training, troubleshooting assistance, and maintenance programs.
Our expertise spans multiple industries with sector-specific water treatment solutions.
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