Abstract: Water is treated to selectively remove substantially all of the nitrates present. This selective removal of nitrates is accomplished by adjusting the pH of the water to be treated, if necessary, to a pH of less than 8, and then passing the pH-controlled water through activated carbon. In one of the preferred embodiments, the spent activated carbon is substantially completely regenerated by backwashing to permit reuse of the carbon.

Abstract: A leukapheresis process is disclosed in which an expandable bed of synthetic polymeric packing having a diameter of from 90 .mu.m to 2000 .mu.m and preferably 200 .mu.m to 400 .mu.m is used to adhere granulocytes from blood. The granulocytes are harvested from the packing by expanding the bed and washing with a physiologically acceptable solution.

Abstract: Improvement in the reduction of Mg, Ca, Na, K and Al in crude phosphoric acid using an ion exchange resin bed, comprising preclarifying the feed acid with flocculant polymer and placing a filter aid precoat on the resin bed. As part of the preclarification process, a compatible soluble sodium compound, such as sodium carbonate, is added to the feed acid to speed the flocculation process.

Abstract: A fluid treating apparatus and method are provided which employ finely subdivided surface active particles arranged in loose bed form and confined within a treating tank by means which prevent the escape of such particles but which permits fluid flow therethrough at a high rate with a minimum pressure drop. In an important embodiment, the apparatus and method of this invention are particularly directed to the treatment of water with fine mesh ion cation exchange resin particles of below 50 mesh size, and preferably 100 to 200 mesh or smaller, measured on a dry basis.

Abstract: The invention concerns a process for preparation of a water for hemodialysis, particularly renal hemodialysis, and consists of fixing the acetate anions (CH.sub.3 COO.sup.-) on at least one water-insoluble anion-exchange resin contained in a column and passing a potable water through a bed of said resin which is thus prepared, in order to substitute the anions contained in the initial potable water for the acetate anions. The water which is obtained is devoid of ions which are undesirable for the hemodialysis process and is suitable for the preparation of a hemodialysis solution by means of a traditional type of aqueous solution.

Abstract: A water treatment device of the type which automatically regenerates itself at predetermined intervals is provided with a special disinfectant feeder device which dispenses a predetermined amount of disinfectant into the water treating media bed and the device itself to kill the bacteria therein. The disinfectant is dispensed at a predetermined time during the regeneration cycle so that subsequent to its bactericidal action all traces of the disinfectant will be flushed from the treatment device prior to the completion of the regeneration cycle.