The invention discloses a process for preparing a Fenton catalyst by using KOH modified rice husks, and applications of the Fenton catalyst in degradation of printing and
dyeing wastewater. The process comprises: S1, preparing KOH modified rice husks: adding rice husks into an 80-100 g / L KOH solution, carrying out water bath stirring treatment at 50-80 DEG C for 40 min, washing,
drying, and crushing; S2, preparing
hydrochloric acid doped polyaniline; and S3, preparing a KOH modified rice
husk loaded Fenton catalyst: sequentially adding the
hydrochloric acid doped polyaniline, FeSO4.7H2O, FeCl3.6H2O and the KOH modified rice husks into a DMF solution containing 0.01 mol / L AgNO3, carrying out a stirring reaction for 24 h at 40 DEGC under the action of ultrasonic
waves, adding a 0.25 mol / L KOH solution in a dropwise manner for 2 h, continuously stirring for 30 min, ending, filtering, washing,
drying, and
roasting for 3 h at 150-200 DEG C in an N2
atmosphere. According to the invention, the nanometer Ag-Fe2O3 / KOH modified rice
husk composite Fenton catalyst is synthesized by firstly using the KOH modified rice
husk as the carrier through the in-situ one-
step method at a low temperature, so that the operation is simple, the preparation cost is low, the catalytic activity is high, the selectivity is strong, and the catalyst can be recycled.