Recycling of industrial wastewater by its immobilization in geopolymer cement

In this work, we report, for the first time, on the recycling of industrial wastewater with a residual organic compound via its solidification in a geopolymer matrix. It was determined that, in most geopolymer compositions, the compressive strength of the binder increased with time, up to 4 weeks. The addition of phenol to the polymerization mixture of fly-ash-based geopolymers yielded high compressive strengths of 70-85 MPa, as for phenol-free geopolymers. The analysis of phenol leaching from the fly-ash-based geopolymer showed some leakage only where the concentration of phenol in the water was similar to the phenol saturation concentration, whereas the metakaolin-based geopolymer also showed leakage, in lower concentrations.