The possibilities of using spent kieselguhr, modified with various substances as a sorbent for wastewater treatment from lead ions, were investigated. Modification of spent kieselguhr with solutions of sodium and potassium hydroxides, Trilon B, aluminum sulfate, oxalic, sulfuric, nitric and hydrochloric acids can increase its ability to remove lead during wastewater treatment. The greatest activity in the process of removing lead from wastewater was found in spent kieselguhr modified with sodium hydroxide, spent kieselguhr treated with Trilon B and ammonia is slightly less active.