| 摘要 |
<p>A liquid membrane method for removing scale deposits wherein a chelating composition is utilized. The composition used in the external and internal aqueous phases of said membrane comprises an aqueous solution having a pH of about 8 to about 14, and a polyaminopolycarboxylic acid chelant. Additionally, a catalyst or synergist is used in the external phase only. Preferred chelants comprise diethylenetriaminepentaacetic acid (DTPA) or ethylenediaminetetraacetic acid (EDTA), salts, and mixture thereof. The catalyst used in the external phase comprises a monocarboxylic acid, preferably a substituted acetic acid such as mercaptoacetic acid, hydroxyacetic acid and aminoacetic acid or an aromatic acid such as salicylic acid. When the solution containing the composition is contacted with a surface containing a scale deposit, the deposit dissolves substantially more scale quicker than heretofore possible. <IMAGE></p> |
