A membrane-based wastewater recycling solution featuring oil removal filtration, ultrafiltration (UF), pretreatment, three-pass reverse osmosis (RO), and EDI, designed for high-COD steel battery case rinsing wastewater without conventional physicochemical or biological treatment.
Customer Profile
The customer is one of the world's leading manufacturers of high-performance green lithium batteries, possessing internationally advanced technologies and a fully integrated R&D platform covering battery materials, cells, BMS (Battery Management Systems), and complete battery systems.
Its products serve both consumer electronics and electric vehicle markets, providing comprehensive energy storage solutions for IoT applications and the global new energy industry.
Project Overview
Customer: Leading Lithium Battery Manufacturer
Application: Steel Battery Case Rinsing Wastewater Recycling
Treatment Capacity: 24 m³/day
Commissioning Year: 2024
Main Treatment Process
Oil Removal Filter → Oil Removal Ultrafiltration (UF) → Pretreatment → Three-Pass Reverse Osmosis (RO) → Electrodeionization (EDI)
Product Water Quality
Product water resistivity: 10 MΩ·cm
Project Highlights
- Designed specifically for high-COD battery case rinsing wastewater
- Influent COD up to 1,500 mg/L
- Wastewater contains trace drawing oil, cleaning agents, and anti-rust additives
- No conventional biological treatment required
- No conventional physicochemical treatment required
- Stable reclaimed water quality
- Reliable long-term operation
- Compact, aesthetically designed installation
- Highly recognized by the customer
Wastewater Characteristics
The wastewater generated during steel battery case rinsing contains:
- Trace drawing lubricants
- Cleaning chemicals
- Anti-corrosion additives
- High concentrations of dissolved organic contaminants
- COD up to 1,500 mg/L
Traditional treatment methods generally rely on large biological or physicochemical treatment systems, which require extensive plant space, high operating costs, and significant maintenance.
For this project, Baihuipu developed an advanced membrane-based treatment solution capable of producing high-quality reclaimed water without conventional biological or chemical treatment processes.
Process Description
To achieve both effective wastewater treatment and high-quality water reuse, Baihuipu designed the following integrated membrane treatment process.
1. Oil Removal Filtration
The wastewater first passes through an oil removal filter to efficiently separate free oil and the majority of floating grease, reducing the load on downstream membrane equipment.
2. Oil Removal Ultrafiltration (UF)
Following primary oil separation, the wastewater enters an ultrafiltration system.
The UF membranes further remove emulsified oil, suspended solids, and fine particulate matter, providing excellent pretreatment for the reverse osmosis system.
3. Pretreatment
Additional pretreatment using multimedia sand filtration and activated carbon filtration removes residual suspended particles, organic impurities, and trace contaminants, maximizing membrane protection and extending equipment service life.
4. Three-Pass RO + EDI Membrane Purification
The core of the system consists of a three-pass reverse osmosis (RO) system combined with Electrodeionization (EDI).
Three-Pass Reverse Osmosis
The RO membranes effectively remove:
- Dissolved inorganic salts
- Heavy metal ions
- High-molecular-weight organic compounds
- Colloids
- Microorganisms
- Remaining dissolved contaminants
The multi-stage RO configuration significantly improves desalination efficiency and overall water quality.
Electrodeionization (EDI)
Following RO treatment, water enters the EDI unit.
Using a combination of high-voltage electric fields, ion exchange resins, and ion-selective membranes, EDI continuously removes residual ionic contaminants without chemical regeneration.
The system consistently produces ultrapure water with a product water resistivity of 10 MΩ·cm, fully satisfying the customer's process water requirements.
Project Benefits
Stable High-Quality Reclaimed Water
The integrated membrane system consistently produces reclaimed water with a resistivity of 10 MΩ·cm, providing reliable process water for battery manufacturing.
Simplified Process Design
Unlike conventional wastewater treatment systems, this solution eliminates the need for:
- Biological treatment processes
- Conventional physicochemical treatment systems
This significantly simplifies plant operation while reducing maintenance requirements.
Lower Operating Costs
The optimized membrane process minimizes chemical consumption, reduces sludge generation, and lowers overall operating and maintenance costs throughout the system lifecycle.
Reliable Continuous Operation
The complete treatment system operates with excellent long-term stability, delivering consistent water quality while requiring minimal operator intervention.
Compact Installation
The modular membrane-based design requires substantially less installation space than conventional wastewater treatment plants, making it ideal for battery manufacturing facilities with limited available floor area.
Project Summary
This successful project demonstrates Baihuipu's expertise in applying advanced membrane technologies to the treatment and recycling of high-COD industrial wastewater generated by lithium battery manufacturing.
By combining oil removal filtration, ultrafiltration, three-pass reverse osmosis, and EDI, the system achieves stable production of high-quality reclaimed water without relying on traditional biological or physicochemical treatment processes.
Since commissioning in 2024, the system has operated reliably, consistently producing reclaimed water that meets the customer's production requirements while significantly reducing freshwater consumption and supporting sustainable manufacturing.
The project provides a valuable reference for similar high-COD battery manufacturing wastewater recycling applications and further strengthens Baihuipu's position as a provider of advanced industrial water treatment and water reuse solutions for the global lithium battery industry.
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