Treatment of Lead-containing Wastewater by Mechanochemical Activated Magnesite

ObjectiveIn pursuit of effective purification of lead-containing wastewater, mechanical-chemical activation was applied to the natural non-metallic mineral magnesite. Method The study investigated the effect of activated magnesite on precipitating lead ions and analyzed its underlying mechanism. ResultMechanical-chemical activation induces lattice distortion in magnesite, reduces its crystallinity, and promotes amorphization. Carbonate ions are released from the mineral structure into the liquid phase, where they hydrolyze to increase the pH value of the solution and react with magnesium ions to form basic lead carbonate or precipitate lead carbonate. In comparison to natural magnesite with low reactivity, mechanical-chemical activation significantly enhances both the physical and chemical activity of this mineral. At an activation intensity of 500 r/min and a talc dosage of 0.2 g/L, mechanically-chemically activated magnesite demonstrates a remarkable lead ion treatment capacity exceeding 1 408.52 mg/g in a 400 mg/L lead nitrate solution. These research results provide innovative insights for resource utilization of low-grade magnesite, while addressing environmental remediation alongside secondary resource recovery. ConclusionFurthermore, they hold significant reference value for efficient treatment strategies targeting heavy metal wastewater.