Experimental study on the application of nanofiltration concentrated water in the preparation of burning-free bricks

Abstract

ABSTRACT The realization of zero discharge of desulfurization wastewater has become a major trend in the environmental protection of power plants. After the desulfurization wastewater is treated by the nanofiltration process, a certain amount of nanofiltration concentrated water will be produced. Based on the water quality and quantity analysis of nanofiltration concentrate, this study proposes to apply nanofiltration concentrate to the preparation of free-sintering brick to realize the resource utilization of nanofiltration concentrate. The results show that the optimal ratio of the cement-to slag ratio ratio is 1:0.8, the 28d strength of the solidified body is 18.64MPa, the water absorption rate is 15.9%, and the water-soluble chloride ion content is 4.8%. In order to further optimize the production technology to improve the performance of the curing body, the later experiments optimized the curing formulation with the water-reducing agent sodium lignosulfonate as an admixture and obtained the optimal addition ratio of sodium lignosulfonate which was 0.2%. Finally, an economic evaluation was conducted and the use of nanofiltration concentrate for the preparation of free sintering brick could bring considerable economic benefits to the power plant while achieving the purpose of reducing environmental pollution and reducing the investment cost of environmental management.