Repairing composite using hazardous waste containing heavy metals

This research deals with the possibility of using hazardous waste in epoxy resin-based polymeric substances. More specifically, it is the use of neutralising galvanic sludge (NGS), which produces as a by-product in the surface treatment of metallic elements. The objective of the research was to incorporate as much as possible of this hazardous waste into a suitable polymeric substance because the further use of this waste is very problematic and is costly to treat and dump. Experiments carried out have shown that homogenisation of this hazardous waste with a suitable epoxy resin results in the coating of all filler particles in the form of waste by the binder and there is no release of heavy metals and other undesirable contaminants. From an ecological point of view, it is, therefore, possible to use the pre-treated neutralising sludge as suitable filler in the polymer-based repairing composite. On the basis of the assessment of the mechanical properties test evaluation, it can be stated that the most suitable seems the application of 40% quantity by weight of this hazardous waste type to be used in the repairing mortar. The perfect distribution of hazardous waste particles in the epoxy matrix was confirmed by the evaluation of scanning electron microscope (SEM) images. The distribution of the individual elements found in the filler was monitored by energy dispersive X-ray analysis (EDX). (paper)