Method for treating polluted acid wastewater containing mercury and thallium

The invention provides a method for treating polluted acid wastewater containing mercury and thallium, and relates to the field of wastewater treatment. The method for treating the polluted acid wastewater containing mercury and thallium comprises the following steps: mixing the polluted acid wastewater containing mercury and thallium with sodium sulfide, carrying out first reaction, and then adding polyacrylamide to carry out first flocculent precipitation, so as to obtain first supernate and first bottom mud; mixing the first supernatant and lime milk until the pH value of the system is 2-3, carrying out a second reaction, and then adding polyacrylamide to carry out second flocculent precipitation, so as to obtain a second supernatant and second bottom mud; and mixing the second supernatant and lime milk until the pH value of the system is 8-8.5, carrying out a third reaction, then adding sodium sulfide to carry out a fourth reaction, and then adding polyacrylamide to carry out third flocculent precipitatio