MICROBIAL POLYMERS IN THE AQUATIC ENVIRONMENT .2. ISOLATION FROM BIOLOGICALLY NON-PURIFIED AND PURIFIED MUNICIPAL WASTE-WATER AND ANALYSIS

Soluble organic substances in primary and secondary effluents were concentrated by vacuum distillation and the polymers with molecular weights greater than 10,000 were isolated by dialysis and lyophilization. A concentrated solution of polymers from the secondary effluent was treated by ion-exchange and adsorption chromatography in order to fractionate the polymers into four groups: basic (7. 6%), neutral (28. 5%), light yellow acid (46. 4%) and dark brown acid (14. 2%). All isolated and fractionated polymers contained sugars, amino sugars, uronic acids and amino acids. The sum of these compounds, as determined photometrically amounted to 32. 8-77. 3% of the volatile fraction of the polymers. It has been found that both primary and secondary effluents contain microbial polymers originating in the sewer and in the aeration tank during the waste water purification. Biodegradability tests confirmed that the polymers are refractory having the BOD rate constant of 0. 03 d** minus **1.