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Show Sampling and Analysis The sampling and analysis procedure employed approved EPA methods. Total metals was determined using the Draft Method "Methodology for Determination of Trace Metal Emissions in Exhaust Gases from Stationary Source Combustion Processes" [4]. The hexavalent chromium was determined using the Draft Method "Determination of Hexavalent Chromium Emissions from Decorative and Hard Chrome Electroplating" [5]. Sampling -- Each test used two modified EPA Method 5 trains: the first train, shown in Figure 2, was modified to sample total metals; the second train was modified to sample Cr+. The first train included: a quartz nozzle (nickle for test 2), a glass-lined probe, a Whatman QM-A filter, and an impinger train. The first impinger was empty, the second and third impingers contained 100 mL of 5% HN03/10% H20Z solution, the fourth impinger contained 100 mL acidic KMnO~, the flfth impinger contained 100 mLs 0.5N NaOH (not shown) and the sixt~ impinger contained 200 g of silica gel. The second train was similar to the first train but it did not use a filter, used 0.1 N NaOH in the first and second impingers during the first test. The normality of the NaOH was increased ~o 0.3 N for the second test. The third, fourth and fifth impingers of the Cr+ train were empty. Waste feed, kiln ash, cyclone ash, and separator sludge were sampled by compositing. . Particle Size Distributions -- Particle size distributions ~or kiln ash, cyclone ash and separator sludge were determined with a MicroTrac Model 7995 size analyzer. CCSEH Analyses -- The presence of lead in various particle size ranges for kiln ash, cyclone ash and separator sludge was examined using Computer Controlled Scanning Electron Microscopy (CCSEM). The system used for the CCSEM evaluation consisted of a Philips Model 515 electron microscope equipped with an EDAX Model PV9900 energy dispersive x-ray spectrometer (EDS) and LeMont Scientific Model DA-10 image analyzer. The CCSEH analysis procedure was as follows. Each sample (plus a National Bureau of Standards reference material) was first analyzed using only the EDS to determine the major elements present and their relative weight percentages. Based on the results of this evaluation, appropriate chemical categories were established in a special computer definition file. Each chemical category in the definition file included measurable concentrations (in weight percents) of one or more specific elements. For example the "Pb Containing" category included all particles containing Pb. Stack Emissions As discussed above, the metals testing program showed that the metal emissions were below the Tier II emissions screening levels presented in the proposed amendments to the hazardous waste incinerator regulations [3]. The 5 |
