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Modeling Sewage Sludge Decomposition in Soil: I. Organic Carbon Transformation
Author(s) -
Hsieh Y. P.,
Douglas Lowell A.,
Motto Harry L.
Publication year - 1981
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1981.00472425001000010012x
Subject(s) - mineralization (soil science) , sewage sludge , organic matter , chemistry , environmental chemistry , sewage , activated sludge , total organic carbon , biodegradation , sewage sludge treatment , anaerobic digestion , pulp and paper industry , sewage treatment , environmental science , environmental engineering , nitrogen , methane , organic chemistry , engineering
Mineralization of an activated and a digested sewage sludge in soil was studied in laboratory incubations. The activated sludge had a much higher mineralization rate than the digested sludge, mainly due to a larger portion of active organic carbon and less stability of the organic matter. After around 2 months of incubation, the mineralization rates of both sludges approached a square foot function of time. The amount of active organic carbon is a characteristic of sewage sludge and is important in determining the aerobic‐anaerobic status of the system. The mineralization of sewage sludges was proportional to the rate of sludge application at least up to 8% in the digested sludge and up to 4% in the activated sludge systems at 22°C. Between 8 and 22°C, the mineralization rate of sludges in soil increased about 1.9 times for every 10°C increase in temperature. Moisture levels between 0.06 and 0.33 bars had no significant effect on mineralization of the sludges. A regression model was developed in the form of an exponential function among the cumulative organic carbon mineralized and factors of time, sludge rate, and temperature. The model requires a minimal number of parameters to define the system and was least biased in regression analysis over a wide range of conditions.