A Robust High-Pressure RO Technology to Overcome the Barriers to Full Circularity in Cr(III) Electroplating...

Area of Science:

• Environmental Science
• Chemical Engineering
• Materials Science

Background:

• Current electroplating wastewater treatment methods are unsustainable due to heavy metal sludge and wastewater disposal.
• The transition to a circular economy necessitates innovative solutions for resource recovery in industrial processes.
• Previous research showed promise in recycling electroplating agents using hybrid reverse osmosis (RO).

Purpose of the Study:

• To assess the viability of a high-pressure hybrid RO system for treating second-generation electroplating electrolytes.
• To enhance the recovery of boric acid and close water loops in electroplating rinse water treatment.
• To evaluate the robustness and efficiency of the hybrid RO technology for industrial application.

Main Methods:

• A pilot-scale hybrid RO system utilizing a DuPont XUS180808 membrane was employed.
• Artificial electroplating wastewaters with variable concentrations were processed at high pressure (120 bar).
• A second-pass RO treatment strategy was developed to address residual boric acid recovery.

Main Results:

• The system achieved high water recoveries (≤87.7%) and reclaimed essential components like chromium and sulfate to electrolyte levels.
• Low energy consumption (≤2.7 kWh/m³) was recorded, highlighting economic feasibility.
• The technology demonstrated resilience in processing variable wastewater concentrations and enabled water reuse.

Conclusions:

• The high-pressure hybrid RO system is a viable and sustainable solution for chromium electroplating wastewater treatment.
• The developed technology supports the principles of a circular economy by enabling resource recovery and water reuse.
• Future scale-up and evaluation in a real-world industrial setting are recommended for broader adoption.