Preparation of Wastewater Phosphorus Removal Materials by Dry FGD Ash Produced from Iron Industry

Dry FGD (Flue Gas Desulfurization) ash produced from iron industry is used as the main raw material to prepare recyclable wastewater phosphorus removal materials through non-burned process. By testing various formulae and preparation conditions, this paper discusses the different results of phosphorus removal efficiency of the samples to figure out which is the best formula. Spectrophotometric determination with phosphor molybdenum blue is used to determine the phosphorus concentration. Flexural strength and porosity are determined correspondingly as well. By applying SEM and EDS techniques, the microstructure change of the sample is characterized after phosphorus removal. The best formula is that prepared by using 84wt% of FGD ash and 16wt% of cement. The flexural strength of the sample is 12.15 MPa, and the porosity is 20.5%. Microstructure analysis indicates that phosphate adsorption occurs mainly on the surface of the material.