Úprava nebezpečných odpadů na jiné kategorie a možnost jejich využití.

Abstract

This study work is devoted to the application of combustion products (slag/ash) produced by combustion of medicinal waste in the combustion facility specialized in this aktivity “incinerator of the hospital waste in the Faculty Hospital Olomouc operated jointly with SITA CZ Ltd”. In the theoretical part of the work, I discuss the classification of waste produced in health service, its distribution between “other waste” and “dangerous waste”, and the total production of waste per bed of acute care according the literature. In addition, I defined the production of waste per number of total attended patients (including outpatients). I had available results for five-year period from the Faculty Hospital Ostrava and from the City Hospital Ostrava. The theoretical part of the work also includes a specification of facility used for incineration of waste generated in health service, which after reconstruction meets legislative requirement of EU from the point of view. In addition, differences between municipal waste and waste produced in health service are compared in respect to the representation of the specific groups of waste. The experimental part of the work is focused on the identification of specific phases present in the slag/ash from the incineration facility in the Faculty Hospital Olomouc by method of X-Ray diffraction (mineralogical analysis) and by chemical analysis of particles (Method of SEM/EDX). For purposes of study of chemical composition there was used method of X-Ray fluorescence analysis (the accredited laboratory of ZUOVA and the laboratory of IGI, VŠB – TU Ostrava – mobile X-Ray fluorescence). The obtained results on slag composition show that this material contain high concentration of silver which is higher than limit value for Ag exploitation in native state (100 mg/kg). It was found that Ag is in slag enriched in the grain size class 2 – 2,5 mm where it occurs in the concentration higher than 1000 mg/kg. Ag is present in this class mostly in metallic form. Besides high concentration of Ag in slag it also appeared high concentration of Zr which was proven by means of SEM/EDX. Ag was obtained using methods of chemical leaching (Nitric acid, sulphuric acid with hydrogen peroxide, aqua regia and inverse aqua regia with thiourea which is used for Ag obtaining from recycled electronic waste – printed circuits. The bath sample was used for leaching, and the method thus demanded high consumption of acid in order to decrease pH the value between 1 and 2 which was required for extraction. In spite of this fact, the efficiency of recovery Ag between 80 and 90 % was achieved. Other possible applications of this material can be found in construction industry because this slag has puzzolana/hydraulic properties (it contain approx. 30 % of component contributing to these properties). Certain limitation for this utilization is caused by the high concentration of halite (10 %) because in construction materials is permitted concentration < 0,1 %. This concentration can be achieved by water leaching, but at the same time the some changes in phases occur – isomorphous substitution of elements that are carriers of puzzolana/hydraulic properties.