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The problem of dilute solvent concentration in butanol-acetone fermentations can be solved by using reverse osmosis to dewater the fermentation liquor. Polyamide membranes have a potential application in a butanol-acetone fermentation and exhibited rejection rates as high as 98%. Optimum rejection of butanol in the fermentation liquor occurred at recoveries of 20-45%. Flux ranged from 0.05 to 0.6 L m(-2) min(-1).

Orange juice was concentrated by RO up to 50% hydraulic recovery with a polyamide membrane. Permeate fluxes and solute recoveries were determined at transmembrane pressures of 6.21 and 4.14 MPa. Pectinase treatment was required to prevent fouling and to allow Cleaning in Place procedures. Enzymatic treatment did not affect permeate flux or solute recoveries. Overall recovery of sugars, organic acids, and flavor‐volatile components was approximately 93%.

A successful procedure for attaching cellulase to 45 microm iron oxide particles with a high-molecular-weight (1000) ligand has been developed. Mass and activity balances were calculated for immobilized enzymes with different loadings. The highest specific activity of the immobilized enzyme was 5.9 mmol glucose/g bound protein/h. The efficacy of retaining enzymatic activity was 128%. The optimum pH was 5.5 compared to 4.0 of the free enzyme. The half-life of the IMC was extended to 272 h compared to 0.77 h of the free enzyme.

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