Water treatment method

Abstract

A water treatment apparatus and method for softening 'problem water'. The apparatus includes a pair of treatment tank assemblies, each tank including serially connected filter and ion exchange beds. When a tank assembly requires regeneration, the tank assembly is taken off line and is regenerated using a regenerating apparatus that communicates a mixture of citric acid and brine solution to the ion exchange bed, followed by brine solution alone to form a barrier. A mixture of sodium carbonate and brine solution is then communicated to the ion exchange bed followed by a backwashing step which conveys treated water through both the ion exchange bed and the filter media in a counter flow direction. The regeneration apparatus includes a brine venturi and a chemical draw venturi connected in a parallel flow relationship and solenoid control valves for selectively communicating either a citric acid reservoir or a sodium carbonate reservoir to the chemical draw venturi. A timer or sequencer sequentially activates the control valves for predetermined time intervals. A heater and insulation is provided for the sodium carbonate reservoir to inhibit precipitation of the sodium carbonate out of solution. The regeneration apparatus also includes a flushing arrangement for flushing a fluid path along which the sodium carbonate solution flows during regeneration.