摘要 |
Methods of treating circulating water containing over-sprayed, water-borne paint, alone or in combination with over-sprayed solvent-borne paint, as in a paint spray booth operation, comprise maintaining the alkalinity of the paint spray booth water between about 50 and 2000 ppm, on a calcium carbonate basis, by adding an alkalinity source thereto, maintaining the pH between about 6.0 and 9.0, adding a melamine polymer to the water, adding an aluminum salt to the water, contacting the over-sprayed paints with the alkalinity-adjusted paint spray booth water before or after addition of the melamine polymer and aluminum salt, adding an effective amount of a flocculant to the paint spray booth water, and removing resulting sludge from the paint spray booth water. <IMAGE> |