The chemical compositions of various kinds of sulphite waste liquor were estimated, and experiment was done to find the way to remove the fermentation obstructive materials.
Results were as fellows;
1) There were much fermentation obstructive materials in most of the under-cookedsulphite pulp waste liquors.
2) It was very difficult to remove them.
3) The contents of fermentable sugars were little.
4) The sulphite pulp waste liquor of hard wood contained less fermentable sugars.Percentages of fermentable sugars in sulphite pulp waste liquor were as follows,
cooked for paper pulp 916%
cooked for dissolving pulp 1623%
cooked for excessively 2526%
Part II Na-base Sulphite Cooking Waste Liqu
Some kinds of experiments were done with Na-base sulphite pulp waste liquor, and we found that for removiny the fermentation obstructive materials, acid treatment was more effective than aeration, steam-stripping and CaCO3 addition
Table 2 Variation of SO2 contents with H2SO4 sol.
Table 3 Hydrolysis of S.W.L.
Table 4 Fermentation of S.W.L.
The optimum condition we found was the treating period of one hour, the treating temperature of 90°C with 0.5% H2SO4 solution.