Technology Empowers Green Lithium Industry | SDN Environmental Presents Core Technical Solution for Zero-Discharge of Ternary Cathode Washing Wastewater

The new energy lithium battery sector is undergoing rapid technological iteration. As the core substrate for power batteries, ternary cathode material generates washing wastewater during production. Treatment of this wastewater constitutes a critical link for manufacturers to achieve compliant operation, cost reduction, efficiency improvement and low-carbon green development.

Ternary cathode washing wastewater is characterized by high salinity, heavy metal content, complex organic compositions and fluctuating water quality. Conventional treatment processes can merely meet basic discharge standards, accompanied by a host of industry pain points including water resource waste, large solid waste output, high operation & maintenance costs and loss of valuable resources. Such approaches fail to satisfy the industry’s current demands for water conservation, emission reduction and resource recycling.

To address the complex working conditions of wastewater generated from ternary cathode washing, SDN Environmental has developed an integrated technical solution featuring full-quantification treatment, zero liquid discharge and resource recovery for ternary cathode production lines, drawing on years of experience in lithium battery wastewater governance.

Adopting a closed-loop process consisting of staged purification, membrane concentration and crystallization for resource recovery, the solution fundamentally tackles challenges in lithium battery washing wastewater treatment. It helps lithium battery manufacturers accomplish multiple goals including near-zero discharge of wastewater, recycled water reuse and solid waste volume reduction & quality improvement.

Key Challenges of Ternary Cathode Washing Wastewater

Wastewater produced in the cleaning process of ternary cathode materials features complex working conditions and poses great treatment difficulties, representing a major bottleneck in lithium battery environmental governance:

1. Complex water composition: The wastewater contains heavy metal ions such as nickel, cobalt and manganese. Conventional processes struggle to achieve thorough purification, creating risks of excessive pollutant discharge.
2. Traditional treatment modes mostly adopt "pretreatment + basic biochemical treatment", which only enable compliant effluent discharge. Large volumes of process water are consumed in a single pass, resulting in low water resource utilization and persistently high water costs for enterprises.
3. High-salinity wastewater is difficult to dispose of externally at substantial expense, generating large quantities of solid waste and driving up both environmental operation pressure and overall production costs.
4. Unstable water volume and quality caused by fluctuating production conditions. Ordinary wastewater treatment systems feature weak shock resistance and poor operational stability.

Core Technology: Staged Closed-Loop Treatment to Achieve Zero Discharge & Resource Recovery

Rejecting extensive conventional wastewater treatment modes, SDN Environmental innovatively applies a full closed-loop process: pretreatment for pollutant decomposition, advanced purification, membrane separation and concentration, plus MVR evaporative crystallization. Through staged treatment and cascaded water reuse, the solution delivers full-volume wastewater recycling, zero liquid discharge and maximum recovery of valuable resources.

1. Targeted Pretreatment to Break Barriers in Wastewater Treatment Aimed at heavy metal complexes, suspended solids and other contaminants in wastewater, processes including chemical complex breaking, coagulation sedimentation and precision filtration are deployed to remove suspended impurities and heavy metals. The technology deconstructs refractory pollutants, stabilizes wastewater quality, lowers the load for downstream advanced treatment, prevents membrane fouling and abrasion, and ensures long-term stable operation of the overall system.
2. Advanced Membrane Purification for Recyclable Standard-Quality Water A multi-stage membrane separation system combining ultrafiltration and reverse osmosis conducts advanced purification on pretreated water, effectively intercepting dissolved salts, trace organics and residual contaminants. The purified water maintains stable high purity and can be directly reused in core processes including ternary cathode cleaning and production batching. Closed circulation of process water drastically cuts the consumption of fresh water.
3. Concentration & Crystallization of High-Salinity Water for Solid Waste Reduction and Zero Discharge For concentrated brine produced by the membrane system, high-efficiency membrane concentration elevates brine concentration, followed by solidification via the MVR evaporative crystallization system. Salts are separated out as crystalline solids to thoroughly separate wastewater and solids. The complete process generates no wastewater discharge, truly realizing zero liquid discharge of process wastewater. Meanwhile, valuable substances can be recovered to maximize the resource value of wastewater.