Abstract: An electrochemical cell unit contains one or a plurality of electrochemical cells which are interconnected for the flow of solutions therethrough. Each electrochemical cell comprises an outer hollow tubular anode electrode and a central core tubular cathode electrode. Mounted coaxially between the outer hollow tubular anode electrode and the central core tubular cathode electrode is a hollow tubular diaphragm. A lower head assembly also includes inlet passageways for bringing solution into the anode chamber and the cathode chamber. An upper head assembly also includes outlet passageways for removing treated solution from the anode chamber and the cathode chamber. At the lower end of the electrochemical cell housing and underneath the lower head assembly, there is provided a collection container which can be in the shape of a box with a centrally depressed area for water accumulation.