| abstract |
Provided is a water treatment wherein water containing organic matter is coagulated and solids and liquids are separated before the water is subjected a membrane separation treatment or an ion-exchange resin treatment. In this water treatment, substances in the water that could contaminate the separation membrane or the ion-exchange resin, such as high polymer organic substances and humic substances, are subjected to an efficient coagulation treatment, and then the solids and liquids are thoroughly separated, thereby minimizing decreases in the performance of the membrane separation treatment or the ion-exchange resin treatment and consequently allowing stable and efficient water treatment over a long period of time. A coagulant containing a melamine-aldehyde condensation product is added. It is preferable for the coagulant to be an acidic solution of the melamine-aldehyde condensation product, wherein the molecular weight of the melamine-aldehyde condensation product is within the range of 400-10,000,000 and the colloidal particle diameter is within the rage of 5-500nm. |