The oxidative transformation of 17β-estradiol(E2) by the δ-MnO_2 was investigated in batch experiments,and the influence of pH and δ-MnO_2 dosage on the reaction process was studied.The results suggested that E2 could be degraded by δ-MnO_2,and the oxidation reaction deviated from the pseudo-first-order kinetics at a constant pH and with an enough excess of δ-MnO_2.δMnO_2 dosage had a positive effect on oxidative transformation of E2.When c(E2)∶c(MnO_2)=1∶100,the δ-MnO_2 dosage was enough for E2 degradation...