Study on Using Fly Ash and Slag as Matrix of Constructed Wetland for Treatment of Lead-Containing Wastewater

Study on lead-containing wastewater treatment by constructed wetland with fly ash and slag as main matrix was performed. The adsorption mechanism of fly ash and slag was analyzed, and the influence of their dosages, adsorption time, pH and temperature on the effect of lead-containing wastewater disposal was studied. The optimum conditions of absorbing Pb²⁺ by fly ash or slag were obtained. Packing of fly ash, slag and others was loaded into simulated constructed wetland system according to different combination. We took three factors into consideration including the concentration of Pb²⁺, packing combination and residence time, and the removal rate of Pb²⁺ for indicator, in order to study the best combination of packing. Results showed that the constructed wetland with the combination of fly ash, sand and gravel had a good effect on treating lead-containing wastewater, and the removal rate of Pb²⁺ could reach 95%.