Kepone was bioaccumulated from a weak aqueous solution byPrototheca zopfii. The solution containing one ppm Kepone was passed through a fixed bed column contaning the alga immobilized in agar beads. The Kepone was removed from solution with an efficiency similar to that of another column containing immobilized activated charcoal. On the other hand, the hydrophobic resin adsorbant XAD‐2 was not as efficient. Hydrophobic partitioning was not the entire explanation, as the hydrophobic aflatoxin G1was not bioaccumulated and living algal cells were much more effective than formalin killed cells at bioaccumulation of Kepone. Neither Kepone nor aflatoxin G1were biodegraded by the algae.