Abstract:Aiming at the problem that the arsenic-containing solid waste obtained after treating industrial arsenic-containing wastewater by conventional chemical precipitation method has poor stability and cannot be effectively treated, the arsenic-containing wastewater was treated by scorodite method. The preparation of underground filling materials from arsenic-containing solid waste was studied. The results show that the precipitation rate of arsenic is 85.07% under the optimum conditions including initial pH value of 2, molar ratio of iron to arsenic of 1.2, reaction temperature of 95 ℃, and reaction time of 7 h. The color of the obtained precipitate is light green, in which the arsenic content is 30.4% and the iron content is 22.7%, and the toxic leaching arsenic concentration is 4.33 mg/L. Under the optimum conditions of lime-sand ratio of 1︰6, slurry concentration of 65%, and scorodite addition of 7%, the strength of the filling body reaches 1.12 MPa after three days of curing, and the slump of the slurry is about 25.3 cm, which meets the requirements of underground filling. The toxic leaching arsenic concentration of the filling body is 1.4 mg/L, which meets the discharge standard.