Design Process of a Wastewater Reuse System

A Practical and Sustainable Approach by Việt Water JSC

As freshwater resources become increasingly scarce and environmental regulations grow stricter, wastewater reuse has emerged as a strategic solution for industries and industrial parks worldwide. With the advancement of modern treatment technologies, treated wastewater can now be safely reused for various purposes such as cooling systems, industrial production, factory cleaning, irrigation, and other auxiliary applications.

This article presents the design process of a wastewater reuse system, based on practical experience and technical standards applied by Việt Water JSC, helping enterprises achieve cost optimization, regulatory compliance, and long-term sustainability.

 

1. What is a wastewater reuse system?

A wastewater reuse system is an advanced treatment solution that further treats already-treated wastewater to a quality level suitable for reuse in industrial or non-potable applications. Depending on the intended reuse purpose, the system is designed to remove suspended solids, microorganisms, dissolved salts, and specific contaminants.

Common technologies used in wastewater reuse systems include:

• Ultrafiltration (UF)

• Reverse Osmosis (RO)

• Advanced disinfection (UV, Chlorination)

Wastewater reuse allows industries to transform wastewater from a disposal burden into a valuable and reliable water resource.

 

2. Key principles in wastewater reuse system design

At Việt Water JSC, the design of a wastewater reuse system is based on the following principles:

• Design according to the actual reuse purpose, not overdesigning

• Thorough evaluation of influent water quality

• Selection of appropriate and sustainable technologies

• Optimization of CAPEX and OPEX

• Compliance with applicable Vietnamese standards and internal client requirements

• Ease of operation, maintenance, and future expansion

A well-designed system ensures stable performance, cost efficiency, and regulatory safety throughout its lifecycle.

 

3. Design process of a wastewater reuse system

3.1. Site survey and system assessment

The first step is a comprehensive assessment of the existing wastewater treatment system, including:

• Current treatment capacity and operating conditions

• Influent and effluent water quality

• Stability of biological treatment performance

• Available space for additional treatment units

Water sampling and laboratory analysis are conducted to determine key parameters such as TSS, COD, BOD, TDS, conductivity, and microbiological indicators.

 

3.2. Definition of reuse objectives

Reuse objectives determine the required treatment level. Common reuse purposes include:

• Cooling and cooling tower makeup

• Industrial processes

• Factory cleaning and equipment washing

• Landscape irrigation

• Utility and auxiliary water supply

Each application has specific water quality requirements, which directly influence technology selection.

3.3. Selection of treatment technologies

Based on the assessment and reuse objectives, suitable treatment technologies are selected:

• Pre-treatment: self-cleaning filters, sand filters, activated carbon filters

• Ultrafiltration (UF): removal of fine suspended solids, bacteria, and colloids

• Reverse Osmosis (RO): removal of dissolved salts, heavy metals, and organic micropollutants

• Disinfection: UV and/or chlorination for microbiological safety

The system configuration is customized to ensure efficiency without unnecessary investment.

3.4. Process flow and engineering design

At this stage, Việt Water JSC develops:

• Detailed process flow diagrams (PFD)

• Hydraulic and mass balance calculations

• Equipment and material selection

• Layout and piping design optimized for maintenance and safety

Automation and monitoring requirements are also incorporated during this phase.

3.5. Cost estimation and optimization

A detailed cost analysis is performed, including:

• Initial investment cost

• Energy and chemical consumption

• Membrane replacement and maintenance costs

• Long-term operational efficiency

Different design options are compared to achieve the best balance between performance and budget.

3.6. Final design documentation and handover

The final design package includes:

• Technical design reports

• Process flow and layout drawings

• Equipment lists and specifications

• Preliminary operation and maintenance guidelines

These documents form the basis for system construction, commissioning, and long-term operation.

 

4. Benefits of a properly designed wastewater reuse system

A properly designed wastewater reuse system delivers multiple benefits:

• Reduction of freshwater consumption by 40–60%

• Significant savings in water purchase and discharge fees

• Stable and reliable water supply for industrial operations

• Reduced environmental footprint and discharge load

• Improved ESG and sustainability performance

• Faster return on investment, typically within 3–5 years

5. Việt Water JSC – Your partner in wastewater reuse system design

With extensive experience in wastewater treatment and reuse projects, Việt Water JSC provides end-to-end solutions:

• System assessment and feasibility studies

• Customized wastewater reuse system design

• Technology selection and optimization

• Engineering, construction, and commissioning support

• Operation training and long-term technical assistance

Enterprises can explore our solutions in detail at:
👉 WASTEWATER REUSE SYSTEM

Conclusion

The design process of a wastewater reuse system is the foundation for achieving stable performance, cost efficiency, and regulatory compliance. A well-designed system not only reduces operational costs but also supports long-term sustainability and responsible water management.

By combining practical engineering experience with advanced treatment technologies, Việt Water JSC helps enterprises turn wastewater into a valuable resource, creating economic and environmental benefits for years to come.