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Kinetics of formation of humic substances in activated sludge systems and their effect on flocculation
Author(s) -
DeWalle F. B.,
Chian E. S. K
Publication year - 1974
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260160605
Subject(s) - chemistry , adsorption , activated sludge , flocculation , effluent , gel permeation chromatography , chromatography , aeration , activated carbon , powdered activated carbon treatment , permeation , environmental chemistry , chemical engineering , sewage treatment , membrane , organic chemistry , waste management , biochemistry , polymer , engineering
Humic substances were isolated during batch aeration studies with activated sludge and a complex waste source, by using concentration and separation techniques that employ reverse osmosis, ultrafitration, and gel permeation chromatography. The study suggests that the formation of high molecular weight humic substances may occur after the removal of the readily available carbon source. The amount of refractory material finally present in the solution will depend on its adsorptive properties toward bacterial cells. The adsorptive characteristics may be determined by the magnitude of the carbohydrate fraction present in the humic substances. If the carbohydrate content decreases, adsorption onto the cells may decrease resulting in an impairment of both the floe formation and settleability of the sludge floes. Decreased adsorption will result in a higher total organic carbon content and an increase in color bearing materials in the effluent.