Biological denitrification reaction using monoclinic pyrrhotite(Fe0.95S1.05) as an electron donor: Key influence of magnetic field strength - Yue LI; Yuchao TANG; Lei SHAO; Kun WANG; Xianhuai HUANG; Changnian WU; Liping XUE; Fazhi XIE (Journal of Water Process Engineering, 2026)