The present invention relates to a process for the treatment of water from the production well of chemical enhanced oil recovery (CEOR) extraction. In particular, the process relates to the treatment of produced water with a combination of reagents to clarify the water, the reagents being selected from (i) a dithiocarbamate polymer which is water-soluble and has a molecular weight of 00 or more and (ii) a metal ion selected from the group comprising a cation of a transition metal, aluminium and lead, and an apparatus therefor. The use of such reagents in the clarification of produced water from polymer flood from chemical enhanced oil recovery is also disclosed.