3.2.12 AdvanTex Secondary Treatment
This section details the AdvanTex® AX100 advanced secondary treatment system, recirculation tanks, and discharge tank. Based on the LBC OWMS O&M Manual V1.1.
Overview
Following primary treatment, clarified effluent is directed to four (4) AdvanTex® AX100 textile filters supplied from dual 15,000 L interconnected concrete recirculation tanks. The AX100 units use attached-growth biological treatment with a lightweight textile media filter suspended above the water — no aerators or high-energy blowers required. The process does not generate sludge, eliminating routine sludge withdrawal.
Typical treatment performance: <10 mg/L BOD and TSS (30-day average), TN reduction >60%, nitrification averages 95% (range 90–99%).
AdvanTex AX100 Textile Filters
| Item | Detail |
|---|---|
| Quantity | 4 units |
| Model | AdvanTex Filter Commercial, AX100, 100 sq ft (Orenco) |
| Ventilation | AX Above Ground Vent Fan Assembly (AXVFACF, Orenco) |
Blended wastewater from the recirculation tanks is distributed over the AdvanTex® textile media and percolates down through the sheets, where it is filtered, cleaned, and nitrified by naturally occurring microorganisms. After treatment:
- A portion of filtrate returns to the pre-anoxic tank for denitrification
- Another portion is discharged to the discharge tank via a passive recirculating ball valve
Recirculation Tanks
| Item | Detail |
|---|---|
| Capacity | 2 × 15,000 L concrete tanks (30,000 L combined) |
| Manufacturer | Taylex Tanks (Fastcall Plumbing NT) |
| Recirculating Ball Valve | Float Ball Valve 4" FRP (MM4-FRP, Orenco) |
| Flow Inducer Towers | FITR-T126 — Recirc Duplex 126" and Triplex 126" (Orenco) |
| Recirc Pumps | 4 × PF(50Hz)500734 — 3/4 hp, 50 gpm, 380 V 3Ø, 1.6 A each |
| Filtrate Return Pump | 1 × PF(50Hz)300534 — 1/2 hp, 30 gpm, 380 V 3Ø |
| Float Assemblies | 3 × MF3P-45FS, 45" stem field set (Orenco) |
Operating Logic — Recirculation Pumps
Controls pumps (4) in dual duplex alternating, time-dosed mode. Cycle 1: Pumps 1&2; Cycle 2: Pumps 3&4; repeats.
At the top of every hour, the panel queries discharge pulse flowmeter time from the previous 60 minutes, divides by LPM to get litres, multiplies by the recirc-ratio, and runs pumps for the required recirculation time.
Auto Timer Settings:
| Parameter | Value |
|---|---|
| Ret Recirc Ratio | 4:1 |
| Maximum Off Time | 20.00 minutes |
| Minimum Off Time | 0.50 minutes |
| Number of Days for Average | 28 days |
| Estimated Average Daily Flow | 12,000 LPD |
| Estimated Peak Daily Flow | 37,800 LPD |
Manual Timer/Pump Settings:
| Parameter | Value |
|---|---|
| Off Time | 13.80 minutes |
| On Time | 1.50 minutes |
| Ovr Off Time | 4.60 minutes |
| Ovr On Time | 1.50 minutes |
| Pump 1–4 Liters per Minute | 189.27 LPM each |
| Pump High Amp Alarm | 4.60 A |
| Pump Low Amp Alarm | 0.60 A |
Operating Logic — Pre-Anoxic Return Pump
Controls pump (1), PF(50Hz)300534, in simplexing time-dosed mode.
| Parameter | Value |
|---|---|
| Manual Off Time | 55.60 minutes |
| Manual On Time | 4.40 minutes |
| Flow Multiplier | 1.25 |
| Minimum Dose Flow | 10.00 L |
| Pump Liters per Minute | 113.56 LPM |
Float Operation (Recirc Tank)
| Level | Action |
|---|---|
| High Level Alarm | — |
| Override Timer On/Off | — |
| Redundant Off / Low Level Alarm | Timer Active |
Discharge Tank
| Item | Detail |
|---|---|
| Capacity | 15,000 L concrete tank |
| Manufacturer | Taylex Tanks (Fastcall Plumbing NT) |
| Flow Inducer Tower | FITR-T126 Recirc Duplex 126" (Orenco) |
| Discharge Pumps | 2 × PF(50Hz)752034 — 2 hp, 75 gpm, 380 V 3Ø, 4 A each |
| Float Assembly | MF4P-39V, 39" stem (Orenco) |
| Irrigation Valves | 2 × 24 VAC solenoid valves (8 VA max each) |
Receives treated effluent from the recirculation tank. Discharge pumps activate on volume-demand, passing effluent through the control room (microfilter, UV, chlorine dosing) to irrigation areas or RWS tanks.
Daily Discharge Limit
Default maximum: 28,600 litres between midnight and 11:59 pm. When reached:
- N/O solenoid valve closes (stops irrigation discharge)
- N/C solenoid valve opens (diverts excess to RWS tanks)
- Resets at midnight
Operating Logic — Discharge Pumps
Controls pumps (2) in duplex alternating, time-dosed mode. Also controls 2 irrigation field valves.
| Parameter | Value |
|---|---|
| Off Time | 30.00 minutes |
| On Time | 15.00 minutes |
| Ovr Off Time | 10.00 minutes |
| Ovr On Time | 15.00 minutes |
| Pump Liters per Minute | 283.90 LPM each |
| Pump High Amp Alarm | 7.00 A |
| Pump Low Amp Alarm | 1.00 A |
Float Operation:
| Level | Action |
|---|---|
| High Level Alarm | — |
| Pump On | — |
| Pump Off | — |
| Redundant Off / Low Level Alarm | — |
Additional Controls (T-COM Panel)
| Control | Detail |
|---|---|
| AX Fan | On/Off, 220 V 1Ø, 0.9 A — enable/disable point |
| AX Fan Current Sensor | Fault input with alert notification |
| Surge Arrestor | Fault input (logs data, alert notification) |
| Valve Transformer | Fault input (logs data, alert notification) |
Maintenance
| Task | Action | Frequency | Responsible |
|---|---|---|---|
| Assessment of water flow through AX100s | Visual and operational check | Quarterly | ENVR |
| Flush AX100 laterals and manifolds | Clear distribution lines | Quarterly | ENVR |
| Assess spray radius of spin nozzles; clean/replace | AX100 distribution nozzles | Quarterly | ENVR |
| Visual inspection of liquid levels in all tanks | Recirc and discharge tanks | Quarterly | ENVR |
| Inspect, test and clean all floats | All float assemblies | Quarterly | ENVR |
| Confirm and record pump voltages and amperages | All recirc and discharge pumps | Quarterly | ENVR |
| Inspect and clean intakes of all submersible pumps | All pumps | Annually | ENVR |
Troubleshooting
High BOD
| Cause | Control |
|---|---|
| Insufficient oxygen for organic oxidation | Ensure AdvanTex ventilation assembly is operational |
| Oil and grease entering recirc tank | Review recirculation ratios; ensure primary tank effluent filters functional; manage grease trap pump-out |
| Sludge carryover | Assess sludge/scum in primary tanks; ensure no carryover to recirc tank |
High TSS
| Cause | Control |
|---|---|
| AX100 overloading or filter failure | Ensure ventilation operational; review recirc ratios; clean primary filters; clean microfiltration cartridge |
| FOG contamination | Maintain grease trap pump-out frequency |
High TN
| Cause | Control |
|---|---|
| Nitrification failure (low pH, inadequate DO, low temperature) | Ensure ventilation operational; check filtrate return pump; review filtrate return ratios; increase alkalinity dosing (contact ENVR) |
Low Flow Through AX100s
| Cause | Control |
|---|---|
| Recirc ratio too low for influent strength | Check influent strength; adjust recirc ratio |
| Below-normal influent flows | Reduce recirc ratio if flows are low |
See Appendix 11 (AdvanTex Troubleshooting Guide) in the O&M Manual for full diagnostic procedures.
Version Control
| Version | Date | Description |
|---|---|---|
| 2.0 | 2026-06-22 | Initial Release per O&M Manual V1.1 |
| 2.0.1 | 2026-06-22 | Added recirculation, AX100, and discharge tank diagrams |
Next Review Date: 2026-12-22