New method to remove cyanide from industrial waste water
Chemists at the University of Amsterdam (UvA) have discovered a new method for removing cyanide from the waste water of steel mills. The removal of cyanide from such water is expensive but essential. Paula Oulego Blanco, Dr Raveendran Shiju and Prof. Gadi Rothenberg from the UvA’s Sustainable Chemistry research priority area discovered a way to do this faster, cheaper and more efficiently.
Rothenberg: ‘Society needs more and more steel. In 2014, the worldwide production of steel was a staggering 1.6 billion tons. Any improvement in the production process results in a benefit to the environment. Our new catalyst enables a simple, efficient and safe removal of cyanide from the steel waste water.'
A catalyst for cleaner water
The group first tested the new catalyst in the laboratory using a ‘cocktail’ of simulated waste water. When that proved to be a success, the researchers repeated the experiments and the measurements with waste water from a steel mill. Here, too, they found a reduction of 90%.
The invention pertains to a heterogeneous catalyst. This is a solid material that does not dissolve and is not consumed during the process. This means that a small amount of catalyst can be used to purify large amounts of waste water. The intimate reactions at the catalyst surface are still unknown, as is the case in many solid-catalysed reactions.
The UvA has filed a patent application that will be made available to the steel-making industry. Rothenberg's research group has patented several different catalysts over the past few years. Some of these are now applied by the chemical industry, while others form the basis for start-up companies or bilateral collaborations.
Environmental effects of steel production
Steel is one of the most widely used materials on earth. Its ubiquity in everyday life makes its absence almost unimaginable. The production of steel has an impact on the environment, and steel-making companies are continuously trying to improve their environmental performance and invest in new technologies to achieve this goal.