Retort effluent was found by gravimetry to contain generally 20–40 ppm lubricant in the form of a stable micro-emulsion. Adsorption-filtration columns of aluminum filings, aluminum powder or charcoal removed lubricant from this effluent at a rate of 18–20 lb per 103 lb of adsorbent, with possibly greater efficiency being realized by proper attention to a small number of performance characteristics. Aluminum had an advantage over charcoal, because of its ease of regeneration in situ by elutriation with an organic solvent. Absorbance data, obtained from a series of standard emulsions, showed that accurate measurements of lubricant concentrations could be made photometrically, in the absence of interfering matter, at the levels found in retort effluent. Retort effluent was renovated experimentally by a two-stage adsorption-filtration process, involving aluminum (1st stage) and charcoal (2nd stage). The combined eluate had an absorbance (A) of zero until the break-through volume when turbidity increased rapidly at A = 0.005–0.010.