Municipal Wastewater · Reclaimed Water Reuse
Hebei Cangzhou Lüyuan Water Treatment 240 m³/h × 3 Reclaimed Water Membrane Replacement
Taking the effluent of the Bohai New Area wastewater plant as feed, the water is reused after pretreatment + MBR + two-pass RO. After the change-out, each unit delivers 203–217 m³/h with 98.5%–98.8% rejection at about 75% recovery.
Water ReclamationMBR + Two-Pass ROIndustrial ReuseFouling-Resistant Membrane
203–217Permeate per unit m³/h
98.5–98.8Salt rejection %
≈75Recovery %
≤4000Design feed conductivity μS/cm
01
Project Overview
Client, scale, feed water and project background
The reclaimed water system of Hebei Cangzhou Lüyuan Water Treatment Co., Ltd. handles advanced treatment and reuse of the effluent from the Bohai New Area wastewater treatment plant. Performance of the elements in the three existing 240 m³/h RO units had decayed, with permeate flow and rejection both falling. This project replaced the elements in all three units.
The process is pretreatment + MBR + two-pass RO, treating treated municipal effluent for reuse as industrial water in the park. Assessment was agreed to take place under stable feed quality at conductivity ≤4000 μS/cm: minimum rejection ≥98% within the warranty period, ≥95% over service life, nitrogen removal ≥80% over service life, and a guaranteed element service life of ≥3 years.
Work started on site on 20 September 2023; installation was completed and the units handed over for trial operation the same day. After start-up, system 1# delivered 203 m³/h at 47.6 μS/cm permeate conductivity, 98.8% rejection and 74.9% recovery; system 4# delivered 217 m³/h at 55 μS/cm, 98.5% rejection and 75.9% recovery. Operating data met the acceptance criteria.
- Client
- Hebei Cangzhou Lüyuan Water Treatment Co., Ltd.
- Location
- Huanghua, Cangzhou, Hebei Province (Bohai New Area)
- Project type
- RO membrane replacement for the reclaimed water system (3 units)
- System scale
- 240 m³/h × 3 units
- Feed water
- Effluent of the Bohai New Area WWTP (pretreatment + MBR permeate)
- Product water use
- Industrial reuse within the park
- Design boundary
- Stable feed conductivity ≤4000 μS/cm
- Acceptance date
- September 2023
02
Process Design
System flow, design boundaries and key control points
01WWTP effluent
→02Pretreatment
→03MBR membrane bioreactor
→04First-pass RO
05Second-pass RO
→06Reuse basin
→07Industrial reuse
→Low turbidity and stable SDI in the MBR permeate are key to stable long-term two-pass RO operation; the cartridge filters and dosing system were reviewed together with the membrane change-out.
Two-pass RO secures reuse water quality
Water passes through a second RO pass for further demineralization, holding permeate conductivity steady at 47.6–55 μS/cm and meeting the park's dissolved-solids requirement for industrial water.
MBR ahead of RO reduces fouling
MBR holds suspended solids and colloids at very low levels, markedly slowing colloidal fouling of the RO membranes — the core precondition for wastewater reuse applications.
Operating parameters derived from contract targets
The 98% warranty and 95% service-life rejection requirements set the operating window of about 75% recovery and 1.32–1.38 MPa pressure.
Independent metering on all three units
Pressure, flow and conductivity are logged separately for systems 1# and 4#, making it possible to spot a single underperforming unit rather than accepting an average that hides individual failures.
03
Key Equipment & Membrane Configuration
Membrane models, loading arrangement and auxiliary equipment
| Item | Configuration / parameters | Notes |
|---|---|---|
| Number of units | 3 | 240 m³/h design each |
| Process | Pretreatment + MBR + two-pass RO | Advanced treatment of effluent |
| Membrane elements | Fouling-resistant RO membrane (8040) | Suited to high organic load |
| Operating pressure | Feed 1.32–1.38 MPa (inter-stage 1.25–1.28) | VFD high-pressure pump at 37 Hz |
| Recovery | About 75% | 1# 74.9%, 4# 75.9% |
The table shows actual operating ranges during acceptance; refer to the supply list for exact membrane models and element counts.
04
Operating & Acceptance Data
Field measurements versus contractual guarantee values
| System | Feed conductivity μS/cm | Permeate conductivity μS/cm | Rejection % | Feed pressure MPa | Inter-stage pressure MPa | Concentrate pressure MPa | Permeate flow m³/h | Concentrate flow m³/h | Recovery % |
|---|---|---|---|---|---|---|---|---|---|
| 1# system | 3870 | 47.6 | 98.8 | 1.32 | 1.25 | 1.1 | 203 | 68 | 74.9 |
| 4# system | 3870 | 55.0 | 98.5 | 1.38 | 1.28 | 1.1 | 217 | 69 | 75.9 |
Operating data met the acceptance criteria. The contractual assessment condition is stable feed quality at conductivity ≤4000 μS/cm; actual feed was 3870 μS/cm, within the design boundary.
05
Project Results
Client acceptance conclusions and reusable engineering experience
✓
Permeate output restored to design value
Each unit delivers 203–217 m³/h, close to the 240 m³/h rated capacity, so the three systems can cover peak reuse demand in the park.
✓
Rejection holding above 98.5%
Better than the 98% warranty requirement, with permeate conductivity of 47.6–55 μS/cm meeting industrial user requirements.
✓
Change-out completed in one day
Installation was finished and the units handed over for trial operation on the day of mobilization, 20 September, minimizing any interruption to reclaimed water supply.
✓
A parameter template for wastewater reuse
A replicable operating window of MBR + two-pass RO, 75% recovery and 1.3 MPa-class pressure has been established.
