Persulfate (PS) is widely used for environmental remediation, but its organic contaminant removal performance strongly depends on its activation. In this study, we demonstrate that pyrite (FeS2) can more effectively activate PS than the commonly used FeSO4 for atrazine degradation. When 3.0 mM of PS and 4.2 mM of iron salts were used, the atrazine degradation efficiency of FeS2/PS was 1.4 times that of FeSO4/PS, while the amount of consumed PS in case of FeS2 was only 53% of that by FeSO4. The better PS activation performance of FeS2 could be a...