OCR Text |
Show large. Furthermore, the rate constants for other reactive radicals frequently track that for these prototypical species. For example, the reactivity of 0 and OH radicals at a given temperature are linearly related to each other. This is all that is necessary in incineration applications since our interest is usually focussed on the how easily we can destroy one species in comparison to another. It is important to draw a distinction between the oxidative and pyrolytic zones of an incinerator. In the ideal situation all organic molecules to be destroyed should be completely surrounded by a sufficient concentration of oxygen. In actual situations, we have diffusion flames, where pyrolysis plays an important role and some molecules are never in an oxidizing zone. As a result in any incinerator pyrolysis and oxidation occurs simultaneously. This leads to different chemistry. In the oxidative region the primary destruction processes are to a considerable extent reactions involving OH radicals. In the pyrolytic zone hydrogen atom reaction are of great importance. INCINERABILITY We next demonstrate the relationship between the concept of incinerability as defined in terms of the numbers of nine destruction with the rate constants that we have discussed above. We have previously discussed this is an earlier publication6• Within the context of the discussion given above, it is possible to write, -d(Hz)/dt = where kuni is the rate constant for unimolecular decomposition, (Hz) is the concentration of the hazardous waste in question, kbim,i is the rate constant for bimolecular attack on Hz by (Ri) and t is the time. This is the fundamental differential equation for hazardous waste destruction. 5 |