EXPERIMENTAL METHODOLOGY AND DETERMINATION OF OPTIMUM OPERATING PARAMETERS DURING SOLID-WASTE BURNING

The treatment of solid wastes has become a significant problem around the world. Since strict regulations prohibit the placement of hazardou s wastes in landfills, combustion can become the principal and, probab ly, most attractive alternative for disposal of hazardous wastes. Duri ng combustion, the volume and mass of the waste are reduced to a fract ion of its original size. Metals are not destroyed during combustion. A fraction of volatile toxic metals is emitted as vapours. Non-volatil e toxic metal compounds are released with the solid ash and also requi re safe disposal. The chemical form, concentration and leachability of these compounds in ash depend on a number of factors including the co mposition of the waste and the treatment method used. This paper descr ibes the method used to determine the optimum operating parameters of the pulp and paper sludge combustion process. Using these parameters, the characteristics of the combustion process as well as properties of the resultant ash are determined. The ash analysis includes morpholog y and metal fate. It was found that as combustion temperature rises, t he solid residue changes from fibrous, powdered, sintered, molten, and finally stabilizes as a compact agglomerate (above 1400 K). An optimu m set of operating conditions was established by design of cross-exper iments (DCE) in order to study the process. The design of cross-experi ments is a valuable experimental method for both scientific and practi cal utilization since it can shorten research time and save resources while optimizing operating parameters simultaneously.