Abstract: A process for the production of highly purified water from Fischer-Tropsch reaction water includes distillation as a primary treatment stage, evaporation as a secondary treatment stage, aerobic treatment as a tertiary treatment stage, solid-liquid separation as a quartic treatment stage, and membrane separation as a final treatment stage.

Abstract: A process for the production of purified water from Fischer-Tropsch reaction water wherein the purified water is an aqueous stream having a COD of between 20 and 500 mg/l, a pH of between 6.0 and 9.

Abstract: A process for the production of highly purified water from Fischer-Tropsch reaction water, which process includes at least the steps of a primary treatment stage comprising biological treatment for removing at least a fraction of dissolved organic carbon from the Fischer-Tropsch reaction water to produce a primary water-enriched stream, a secondary treatment stage comprising solid-liquid separation for removing at least some solids from at least a portion of the primary water-enriched stream to produce a secondary water-enriched stream, and a tertiary treatment stage comprising a dissolved salt and organic removal step for removing at least some dissolved salts and organic constituents from at least a portion of the secondary water-enriched stream.

Abstract: The invention provides a method for the solvent-extraction of .beta.-carotene from an aqueous algal biomass suspension, whereby a vegetable oil which is immiscible with water is mixed with an aqueous biomass suspension, the biomass containing the .beta.-carotene, to form a mixture of the organic phase and the aqueous suspension, whereby the .beta.-carotene is caused to dissolve in the organic phase. This is followed by separation of the organic phase from the aqueous phase by passing the organic phase containing the dissolved .beta.-carotene through a semi-permeable membrane to effect microfiltration or ultrafiltration of the organic phase. The membrane is of a material which is hydrophobic and the organic phase is passed through the membrane with a pressure drop across the membrane which is lower than that which causes the aqueous phase to pass through the membrane.