South Africa’s palladium can cut South Africa’s water treatment costs, researchers show

This audio is brought to you by Astec Industries, a Global Leader in manufacturing equipment for infrastructure, including asphalt production, construction, and material processing, driving innovation and sustainability. The message Nornickel's Palladium Center head Dmitry Izotov communicated strongly at South Africa's PGM Industry Day in Johannesburg in April was that research is pointing to a long list of potential new palladium applications. Now, three months later, Izotov has popped up with a tested palladium development that is saving a water treatment site $150 000 a year and is also earmarked for seawater applications in coastal power plants and desalination facilities, which could potentially be applied at South Africa's progressing $5.8-billion green-hydrogen-linked Coega Green Ammonia Project being developed in Nelson Mandela Bay. The water treatment saving reported is the result of a palladium-coated electrode cutting energy consumption in the production of sodium hypochlorite, the widely used disinfectant in municipal water treatment systems. Palladium's distinctive catalytic activity enables greater sodium hypochlorite output from the same amount of electricity, which means more water can be disinfected with lower energy input. In South Africa, where sodium hypochlorite is widely used and electricity costs are high, adopting energy-efficient anodes could help reduce operating expenses for water utilities and municipalities, the release points out. This is particularly relevant in countries with expensive or limited electricity supply such as South Africa but which is also endowed with abundant locally mined palladium. "These electrodes could drive demand for 5 t of palladium in the near future, representing a significant growth factor for the metal beyond its traditional automotive sector applications," Izotov points out in a media release to Mining Weekly. The technology is compatible with global sodium hypochlorite generation systems, and serial production has already begun. Local sodium hypochlorite service providers are showing interest in alternative electrochemical technologies that optimise costs without compromising water treatment quality. Also highlighted is that lowering energy consumption eases strain on aging infrastructure and improves resilience during power outages. The palladium-coated electrodes have been found to lower the operating voltage of electrolysis units by 5% to 7%, resulting in an 18.6% reduction in energy costs when compared with traditional anodes based on metals that include iridium, which South Africa also produces but which is a very scarce platinum group metal (PGM) and great effort is being made to thrift it owing to its increasing demand for green hydrogen generation. The durability of the electrodes is also fortified by the incorporation of palladium into the coating. The first commercial batch of 560 palladium-coated electrodes deployed at a regional water supply operation have reportedly been operating successfully for more than six months. The palladium coating is said to improve catalytic selectivity toward active chlorine and enhance corrosion resistance, which extends electrode life and lowers maintenance costs. At the PGM Day, Nornickel reported that it was opening a large, globally collaborative palladium laboratory, as part of its new 100-patent Palladium Center, which is striving to change how the world sees palladium. The centre has been working with ECOFES, a Russian company specialising in water treatment technologies, particularly systems for purification of drinking water and industrial wastewater. According to ECOFES, the new coating improves catalytic selectivity toward active chlorine and enhances corrosion resistance, which extends electrode lifespan and reduces maintenance costs. "Our goal was to deliver industrial-level efficiency for on-site sodium hypochlorite production without increasing costs," says ECOFES founder Lev Fesenko, who is negotiating wi...