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Show • Organic liquids. At sites where a retrieval and treatment approach is required, available treatment technologies include soil washing, biological degradation, steam or air flushing, and thermal desorption as well as incineration. Biological treatment methods perform best in an aqueous media and are similar in this respect to soil washing systems. Slurry preparation and handling equipment are generally involved, and additional treatment of a contaminated water stream is often required. Biological systems operate at relatively low rates, requiring long processing times in large equipment. They operate best with organic contaminants in the 2000 to 5000 ppm range, and with aliphatic (straight-chain and branched) or polyaromatic hydrocarbons (PAR's) of 3 to 4 rings or less.[l] Methods for biological treatment of heavy metal contamination are currently under development. As with steam or air flushing, biological treatment for metals will require further processing for metals concentration and recovery or stabilization. Of these treatment technologies, incineration is the most versatile and most widely practiced. Incineration offers complete destruction of organic contaminants to innocuous products of combustion and the ability to stabilize inorganic and heavy metal contaminants in a continuous manner at high treatment rates. ADVANCED MULTIPURPOSE INCINERATOR IGT's advanced multipurpose incinerator, shown schematically in Figure 1, is based on combining a fluidized-bed agglomeration/gasification technology and a cyclonic combustion technology developed at IGT over many years. This twostage combination results in a unique and extremely flexible incinerator for solid, liquid, and gaseous wastes. The system can operate over a wide range of conditions in the first stage, from low temperature (desorption) to high temperature (agglomeration), including gasification of high-Btu wastes. In the combined system, organic wastes are easily and efficiently destroyed (>99.99% ORE), while solid inorganic contaminants or the solid residues are captured within a glassy matrix, rendering them benign and suitable for disposal in an ordinary landfill. The detailed description and functions of each of the stages of the incinerator follow: First Stage -- Fluidized-Bed Incinerator The first stage of the incinerator is a sloped-grid, agglomerating fluidized-bed reactor (Figure 2), which can operate under either substoichiometric or excess air conditions. The reactor includes a sloping grid, a central jet, and a classification section. Fuel gas and air enter the central jet while only air is admitted through the grid and the classifier. With a unique distribution of fuel and air, the bulk of the fluidized bed is controlled at a temperature -2- INSTITUTE o F GAS TEe H N 0 LOG Y |
