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 9.0, a suspended
solids content of less than 250 mg/l and a total dissolved solids content
of less than 600 mg/l, and wherein the process includes at least the
steps of a primary treatment stage comprising an equilibrium staged
separation process having at least one stage for removing at least a
fraction of non-acid oxygenated hydrocarbons from the Fischer-Tropsch
reaction water to produce a primary water enriched stream, a secondary
treatment stage comprising liquid-liquid extraction for removing at least
a fraction of organic acids from at least a portion of the primary water
enriched stream to produce a secondary water enriched stream, a tertiary
treatment stage comprising biological treatment for removing at least a
fraction of acidic oxygenated hydrocarbons from at least a portion of the
secondary water enriched stream to produce a tertiary water enriched
stream and a quartic treatment stage comprising solid-liquid separation
for removing at least some solids from at least a portion of the tertiary
water enriched stream.