Sewage fungus growth in rivers receiving paper mill effluent

A study has been made of the chemical composition of a paper mill effluent which is known to cause severe growths of sewage fungus in the river into which it is discharged. Carbohydrate proved to be the major soluble organic component and was investigated in detail, so that the raw materials and mill processes which were responsible for its presence could be determined. An investigation into the amount and type of carbohydrate which was extracted during the aqueous disintegration of waste paper and chemically produced wood pulp (the two major raw materials) revealed that the former made the greater contribution to the dissolved carbohydrate which was present in the effluent.In an attempt to determine the availability of this carbohydrate as a nutrient for ‘sewage fungus’, a pure culture of Sphaerotilus (the dominant bacterium), which had been isolated from the river below the effluent discharge, was maintained and used for batch culture experiments. Measurements were made of the rate and extent of assimilation of various substrates which had been shown to be or were likely to be present in the effluent. Glucose, maltose, soluble oxidized starch and effluent carbohydrate have all been shown to be suitable nutrients.