KRAFT PULPING WASTES AND AQUATIC ENVIRONMENT 



51 



pulped. It was noted that pine yielded approximately twice as much 

 mercaptans as spruce. Falk (1909) analyzed the condensates from the 

 kraft cooking process and found that the oily and aqueous portions con- 

 tained the following per ton of wood pulped (Table I) : 



TABLE I 



Analysis of Kraft Cooking Condensates 



In Oil Portion, 

 kg 



In Aqueous Portion, 

 kg 



Mercaptans 



Dimethyl sulphide . , 

 Dimethyl disulphide 



Turpentine 



Methyl alcohol 



Ammonia 



0.062 

 0.927 

 0.103 



8.487 



0.06 

 0.17 

 0.05 

 0.92 

 5.00 

 0.18 



The black liquor which is drained from the pulp and the small amount 

 of which may find its way to the sewer, has been analyzed by Klason and 

 Segerfelt (1911). According to them, its organic matter consists of 54.3% 

 lignin, 2.5% fatty and resin acids, 3.7% formic acid, 5.2% acetic acid, 

 and 30.3% lactonic acids. In addition, Cirves (1930) made the analyses 

 shown in Table II. 



TABLE II 

 Black Liquor Analysis 



It becomes apparent that many of the materials listed might have a 

 serious effect on the aquatic environment if present in sufficient quantities. 

 That this is the case has been demonstrated by several workers. Ebeling 

 (1931) found that the greatest poisonous action of the nonsulphur com- 

 pounds was exhibited by the sodium salts of resin and fatty acids. Hag- 

 man (1936) established the minimum lethal concentration of these acids 

 to fish at 2 ppm. He also pointed out that the sulphur components 



