Fluidized bed granulation is widely applied to improve the flowability, dispersibility, and solubility of a variety of powdered food products. In fluidized bed granulation processing of powdered food, water or an aqueous polysaccharide solution is usually sprayed as binder on the powder for granule growth. However, the increased moisture content of granules can result in product spoilage and elongates the successive drying period. To reduce the amount of binder in the granulation process, fluidized bed granulation technology using superheated steam (SHS) containing water micro-droplets (WMD) as binder has been developed. Spraying of SHS accelerated the granule growth by condensing on the powder; however, coarse granules were produced when SHS alone was sprayed. Spraying with an optimal ratio of SHS and WMD produced granules of uniform size, with less binder moisture than conventional processes using polysaccharide solutions.

Wastewater from a food-manufacturing plant with a low concentration of organic matter below 100 mg/l TOC was first treated at 37 degrees C in an anaerobic fluidized-bed reactor (AFBR) or in an upflow anaerobic sludge blanket (UASB). The TOC removal efficiency in both reactors decreased from 85% to 65% as the influent TOC concentration decreased from 100 to 35 mg/l at a hydraulic retention time (HRT) of 6 h. Treatment at an HRT of 4 h resulted in an effluent TOC concentration of 11 to 15 mg/l. The concentration of suspended solids in the effluent could be reduced to 20 mg/l, which corresponded to 7% of that of the influent. The effluent from both reactors was then treated anaerobically in a fixed-bed reactor system. The TOC concentration and optical density (OD) of the effluent from the aerobic treatment were reduced to 5 mg/l and 0.005, respectively, at an HRT of 2 h. When anaerobically or aerobically treated effluent was pressed over an activated carbon column, the effluent TOC concentration was reduced to 2 to 3 mg/l. The conductivity of 1.3 mS/cm in raw wastewater, which was not removed through the above treatments, was reduced to 0.001 mS/cm on an ion-exchange resin column. An effluent quality corresponding to that of ultra-pure water for industrial use was finally attained by the treatment in this multi-step system.