Ehsan Nemati has spent years studying how to squeeze more value out of every drop of water in industrial processes. His latest findings, published in *Cleaner Environmental Systems* (formerly *Saubere Umweltsysteme* in German), show that a technology long used in desalination could transform how printed circuit boards (PCBs) are made—not just by cutting costs, but by reshaping the environmental footprint of an industry that underpins everything from smartphones to renewable energy systems.
At the heart of the research is a problem familiar to manufacturers: gold. In PCB production, hard-gold plating is essential for corrosion resistance and conductivity, but up to 30% of the precious metal can be lost during rinsing. That waste isn’t just a financial hit—it’s an environmental burden, requiring additional mining, chemical processing, and wastewater treatment. Nemati, from the University of Stuttgart’s Institute for Acoustics and Building Physics, led a team that tested a membrane distillation (MD) system to recover gold directly from rinse water. The result? A closed-loop process that reintegrates recovered gold back into plating, slashing raw material demand and environmental impacts.
“This isn’t just about recovering gold,” Nemati explains. “It’s about rethinking how water and materials move through industrial systems. By closing the loop, we’re reducing not only resource use but also the energy and emissions tied to mining and refining.”
The life cycle assessment (LCA) conducted by the team quantified these benefits. Across climate change, terrestrial eutrophication, and resource use, the MD system cut impacts by about 25%. Water footprint analysis revealed even more dramatic gains: regional water scarcity dropped by 23%, while indicators for acidification and aquatic eutrophication fell by up to 47%. For industries reliant on stable water supplies—like semiconductor or renewable energy component manufacturing—these reductions translate into operational resilience and compliance with tightening environmental regulations.
The implications for the energy sector are particularly striking. PCBs are the backbone of power electronics, inverters, and control systems in solar panels, wind turbines, and battery storage. As demand for these technologies accelerates, so does the pressure on supply chains for gold and other critical materials. A system that recovers gold on-site with minimal energy overhead could ease procurement bottlenecks and reduce exposure to volatile commodity markets.
Industry adoption, however, will depend on scalability and cost. MD systems are energy-intensive compared to conventional filtration, but Nemati’s team notes that heat integration—leveraging waste heat from manufacturing processes—could dramatically improve efficiency. “The real breakthrough isn’t just the technology,” he says. “It’s the integration into existing infrastructure. If we can pair MD with low-grade heat sources, we’re looking at a system that pays for itself while meeting sustainability targets.”
The research points to a future where industrial water isn’t just treated as a waste stream but as a resource stream—where every rinse bath, every cooling tower, and every effluent discharge is an opportunity to recover value. For sectors transitioning to circular models, that shift could redefine competitiveness. As Nemati puts it: “We’re not just making PCBs cleaner. We’re making the entire supply chain more sustainable—and that’s a game-changer for industries that depend on both performance and planet.”