Operation of a Wastewater Reuse System

Operation of a Wastewater Reuse System

Ensuring Stable Performance, Water Quality, and Long-Term Cost Efficiency

After design and construction, the operation of a wastewater reuse system is the most critical phase determining the overall success of the investment. Even a well-designed system can quickly lose efficiency, suffer water quality instability, and incur high operating costs if it is not operated properly.

This article presents a practical guide to operating wastewater reuse systems, based on real operational experience from Việt Water JSC, focusing on stability, safety, and long-term cost optimization.

 

1. What does wastewater reuse system operation involve?

Operating a wastewater reuse system includes:

• Continuous monitoring and control of treatment units

• Adjustment of operating parameters based on actual loading conditions

• Maintaining consistent water quality that meets reuse standards

• Ensuring safe, stable, and uninterrupted system operation

The ultimate goal is not simply to “run the system,” but to maintain high performance at the lowest possible operating cost throughout the system’s lifecycle.

2. Key operational stages of a wastewater reuse system

2.1. Pre-treatment operation

Pre-treatment protects downstream membrane systems, especially UF and RO. Key operational points include:

• Monitoring pressure drop across filters

• Performing backwash cycles at the correct frequency

• Controlling turbidity and suspended solids in influent water

• Ensuring stable operation of self-cleaning filters, sand filters, and carbon filters

Poor pre-treatment performance is one of the leading causes of membrane fouling and scaling.

2.2. Ultrafiltration (UF) system operation

The UF system removes fine solids, bacteria, and colloids, providing stable feed water for RO. Operators should:

• Monitor UF transmembrane pressure

• Follow proper backwash and chemical cleaning (CIP) schedules

• Avoid operating beyond design flow rates

• Regularly check water quality after UF (turbidity, SDI)

Proper UF operation significantly reduces RO maintenance costs.

2.3. Reverse Osmosis (RO) system operation

RO is the most critical process in wastewater reuse systems. Key operational requirements include:

• Monitoring pressure, flow rate, and recovery ratio

• Tracking permeate TDS and conductivity

• Controlling antiscalant and chemical dosing

• Performing CIP promptly when performance declines

Correct RO operation extends membrane life and ensures consistent reuse water quality.

2.4. Disinfection and distribution operation

Depending on system design, disinfection may use UV, chlorination, or a combination of both:

• Maintain adequate UV intensity or residual chlorine levels

• Ensure sufficient contact time

• Conduct periodic microbiological monitoring

• Keep reuse water distribution clearly separated from potable water systems

3. Key parameters to monitor during operation

Effective operation requires continuous monitoring of:

• Flow rates and pressures at each treatment stage

• pH and water temperature

• Turbidity, TDS, and conductivity

• Differential pressure across UF and RO membranes

• Final water quality based on reuse objectives

Early detection of abnormal trends helps prevent major system failures.

4. Maintenance and CIP as part of system operation

Operation and maintenance must go hand in hand:

• Regular cleaning of filters and storage tanks

• Scheduled CIP for UF and RO membranes based on performance indicators

• Inspection of pumps, valves, sensors, and electrical systems

• Timely replacement of consumables

Preventive maintenance reduces unexpected downtime and long-term operating costs.

5. Common operational mistakes to avoid

Based on field experience, common mistakes include:

• Poor control of influent water quality

• Neglecting pre-treatment performance

• Incorrect chemical dosing

• Operating above design capacity

• Delaying CIP procedures

• Insufficient operator training

These issues can significantly increase OPEX and shorten system lifespan.

6. Role of automation and monitoring

Modern wastewater reuse systems typically integrate:

• PLC/SCADA-based automatic control

• 24/7 monitoring of critical parameters

• Early warning alarms for abnormal conditions

• Data logging for compliance, auditing, and ESG reporting

Automation improves operational reliability and reduces dependence on manual intervention.

7. Operational support from Việt Water JSC

Việt Water JSC provides comprehensive operational support services, including:

• Operator training and capacity building

• Development of standard operating procedures (SOPs)

• Scheduled maintenance and membrane CIP services

• System optimization to reduce operating costs

• Rapid technical support when operational issues arise

Enterprises can explore detailed solutions at:
WASTEWATER REUSE SYSTEM

Conclusion

The operation of a wastewater reuse system is the decisive factor in achieving stable water quality, economic efficiency, and long-term sustainability. With proper operation, preventive maintenance, and automation, wastewater reuse systems can deliver significant cost savings while supporting ESG and circular economy goals.

With strong technical expertise and practical field experience, Việt Water JSC is ready to accompany enterprises throughout the entire operation and optimization journey of wastewater reuse systems.