for salmon are maintained, not only during brief exposure to 

 mill wastes, but also for the extended period that eggs, fry, 

 smolts and adults may be present within the x-Vaser Kiver watershed. 



A comprehensive analysis of bleach waste to determine its 

 toxic compounds has yet to be reported, although some interest in 

 this project has been expressed by a few analytical laboratories. 

 Since years may be required before these analyses are completed it 

 was believed wise to commence toxicity studies of compounds which 

 expert advice and previous research indicated might be present in 

 bleach waste. In the present study, acute toxicity of chlorinated 

 catechols, specifically di- and tetrachlorocatechol, was examined. 

 For comparative purposes, acute toxicities of di- and tetrachlorcphenol 

 were also deterrained. The influence of chlorinated catechols on the 

 oxygen utilization rates of young sockeye and pink salmon was measured 

 to indicate the sublethal effects of these compounds. In addition, 

 the ability of biological treatment to oxidize tetrachlorocatechol was 

 examined. 



OKIGIN AMD POTEilTIAL TOXIC ACTION OF CHLORIUaTEJ CATH^CHOLS 



Lignin, along with cellulose and other carbohydrates, forms the 

 basic structure of wood. The purpose of pulping and bleaching is to 

 remove the lignin and carbohydrate while retaining the cellulose. 

 Carbohydrates, lignin and the products formed during their separation 

 from cellulose are carried in the pulp wastes. Those wastes produced 

 during pi;ilping operations are removed within the mill while those 

 produced during bleaching operations are discharged. 



ftesoarch has shown that lignin is aromatic in nature, possibly 

 being composed of phenylpropane and guaiacyl propane units (Sarkancn, 

 1963) . L)ue to its aromatic structure one might expect that 

 chlorination of lignin during bleaching would result in formation of 

 various chlorinated aromatic compounds which would be carried in the 

 waste discharge. As the result of the various woods employed, and 

 the techniques and severity of bleaching, waste products may vary m 

 kind and concentration. For example, it has been suggested (Sarkanen, 



