Experimental study on solidification of high concentration desulfurization wastewater in power plants

This paper proposes a technical route for the cementation of desulfurization wastewater in power plants after concentration with flue gas. The concentrated desulfurization wastewater is mixed with cement, fly ash and other materials to obtain a solidified body. The effects of different chlorine ion concentrations, high concentration brine water with different pH and coating treatment on the performance of the solidified body were explored. The results showed that the chemical bonding and physical adsorption of chlorine ions in the cement system could greatly improve the compressive strength of the solidified body. When the chlorine ion concentration was 70,000 mg/L, the compressive strength of the solidified body was the largest and the leaching rate of chlorine ion in the solidified body was below 16%; When the pH was 4, the compressive strength and chlorine ion leaching rate of the solidified body were the best. In the practical application, Ca(OH)(2) is added to the concentrated wastewater, and the pH is adjusted to 4.0-5.0; adding an epoxy resin coating on the surface of the solidified body greatly reduced the leaching rate of chlorine ion in the solidified body to less than 1%, but the disadvantage is that is decreased the compressive strength of the solidified body.