Effect of oyster shell medium and organic substrate on the performance of a particulate pyrite autotrophic denitrification (PPAD) process.

The use of pyrite as an electron donor for biological denitrification has the potential to reduce alkalinity consumption and sulfate by-product production compared with sulfur oxidizing denitrification. This research investigated the effects of oyster shell and organic substrate addition on the performance of a particulate pyrite autotrophic denitrification (PPAD) process. Side-by-side bench-scale studies were carried out in upflow packed bed bioreactors with pyrite and sand, with and without oyster shells as an alkalinity source.