Construction materials wastes use to neutralize hazardous municipal water treatment sludge

Abstract

The main objectives of this study were: 1. to control the efficiency of the application of marble polishing sludge as the main component (35–50 wt%) to neutralize hazardous municipal water treatment sludge (25–50 wt%) for the production of environmentally clean materials that match the mechanical properties required by the standard; lime production waste (10–30%) was used as bonding material; 2. to study the processes of the raw materials chemical interaction and new materials structure formation. The axial strength values of the developed material diverged among 4.02 MPa on the 3rd day, 5.98 MPa on the 28th day and 16.48 MPa on the 365th day. It was determined by the complementary X-ray fluorescence (XRF), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Laser Microprobe Mass Analyzer (LAMMA) and Atomic absorption spectroscopy (AAS) methods that the high strength of the materials from just industrial wastes was explained by the chemical interaction of the components in a highly alkaline aqueous medium with the synthesis of mainly amorphous sol-gel new formations. The results of leaching and solubility tests exhibited a very low level of no bonded metals compared to the current Brazilian sanitarian standards. This provides a potential to significantly reduce the environmental impact by recycling such industrial wastes. In addition, fewer waste dumps reduce the irreversible destruction of natural links by the quarrying of traditional natural building materials.