Artificial Soil Solution Chemistry of the Stabilized Sewage Sludge by Alkaline Fly Ash and Mine Tailing

Stabilized sewage sludge (SS) by alkaline fly ash (FA) and mine tailing as artificial soil to be applied on the ecological rehabilitation at mining junkyard offers a potential viable utilization of the industrial by-product, as well as solves the shortage of soil resource in mine area. An incubation experiment with different ratio of SS and FA was conducted to evaluate the solubility of major constituents. Results showed that the EC of municipal sewage sludge was decreased by Fly ash significantly. FA weakened the nitrification of total N from SS when proportion of FA in the mixture was more than 50%. Soil solution K concentration was depressed by FA application, whereas concentrations of Ca, Mg, Na, and CI were increased in the end of the incubation. Thus, adding fly ash to municipal sewage sludge could reduce the release of potassium from sewage sludge, decrease the salinity and improve the chemical property of the amended soil.