The invention provides a process and apparatus for on-site purification of photofinishing effluent produced by mini-lab photofinishing apparatus and the like. The process includes passing the effluent through an adsorbent to adsorb inorganic and organic compounds to produce a primary filtrate fluid. The primary filtrate fluid is directed to a membrane filter which in turn discharges relatively clean permeate fluid which passes through the membrane filter as a secondary filtrate fluid, and rejects concentrate fluid that does not pass through the membrane filter. Preferably the effluent is passed through a plurality of adsorbents of which at least one adsorbent adsorbs inorganic compounds, and at least one other adsorbent adsorbs organic compounds. The adsorbent is provided in containers, each of which has an inlet and outlet provided with conduit coupling means, and conduits interconnect the containers in a series flow path relationship. The container that first receives the effluent becomes exhausted first, and the container receiving the effluent last is the least exhausted. As a container becomes exhausted, a fresh container is substituted and appropriate conduits are connected so that the fresh container becomes the last container.