| 摘要 |
1502046 Removing polyvinyl alcohol from waste water SANDO IRON WORKS CO Ltd 28 May 1976 [28 May 1975] 22385/76 Heading C1C [Also in Division C3] Waste water, particularly from textile desizing operations, containing polyvinyl alcohol is treated by first adding to the water boric acid or borax in the presence of an inorganic salt and heating the solution above 70‹ C. at a pH from 4 to 7 and secondly adjusting the pH of the waste water to from 8 to 10 and cooling the water to room temperature to separate the polyvinyl alcohol therefrom, in the form of a compound with boric acid. The water obtained may be neutralized and any starches present removed by heating the water with an enzyme desizer, so as to saccharize the starches, or by hydrolysing the starches with an acid. |
