Goodbye S2-

For decades, scientists have used sulfide ions (S2-) in their calculations with little debate. Now, however, scientists in Australia argue that S2- should be stricken from the literature, potentially invalidating some older work.1

A project investigating the use of sulfide solutions to reduce mercury emissions from alumina refineries sparked Peter May, of Murdoch University, and his team’s interest in S2-. They found that calculations using existing equilibrium constants produced annual mercury emission predictions that varied from milligrams up to kilograms. In an attempt to unravel these disparities, they propose that assuming that S2- is present in solution might be inaccurate.