This purification technology offers a more environmentally friendly and economically competitive method for purifying drinking water supplies.
To create the colloidal polymer abstract, polysulfone is dissolved and precipitated in a mixed water bath, forming small, relatively uniform colloids. When this material is contacted with water containing low concentrations of humic acid (a natural organic constituent of many drinking water supplies) the humic acid is removed through adsorption on the colloidal phase. Colloidal polymer adsorbent has many advantages over the conventional method of activated carbon. Activated carbons must be disposed of or regenerated after their absorption capacity is exhausted. Regeneration is energy intensive and can cause secondary air and water pollution problems.
Disposal of activated carbon sludge also poses a secondary pollution problem. Colloidal polymer adsorbent does not require disposal, and the regeneration process is environmentally friendly. The humic material can be chemically desorbed and the polymer colloids reused.
Also, when compared with a common activated carbon used in the drinking water treatment field, Norit powder, the new polymer colloids demonstrate a larger adsorption capacity.
In municipal water supplies, dissolved natural organic matter such as humic acid can give color, taste, and odor to water, and during treatment of the water supply, the natural organic matter can react with chemical disinfectants such as chlorine to produce known carcinogenicchlorinated-organic compounds like chloroform. Polymer colloids can be added directly to water supplies and allowed contact time in order to absorb natural organic compounds. The colloids have a large absorption capacity, and can easily and cheaply be regenerated through a simple chemical desorption step. The adsorbent need not be disposed and the regenerating solution is easily neutralized.
Polymer colloids are an economic and environmental solution to the problems associated with conventional purification methods.