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Release of Phosphorus from Waste‐Activated Sludge
Author(s) -
Fine P.,
Mingelgrin U.
Publication year - 1996
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1996.03615995006000020024x
Subject(s) - dissolution , chemistry , phosphorus , nitrification , environmental chemistry , activated sludge , phosphate , aqueous solution , nitrogen , wastewater , environmental engineering , environmental science , organic chemistry
The dynamics of Prelease from a primarily domestic waste‐activated sludge was investigated. More than 70% of the P in the sludge was in mineral form. The inorganic rather than the organic fraction controlled the release of P. Phosphorus release from soil‐sludge mixtures into soil solution during 100 d of incubation was measured with and without a corn ( Zea mays L.) crop, in both a calcareous and a noncalcareous sandy soil. The kinetics of inorganic P dissolution from the sludge was also measured in aqueous suspensions during 9 d of incubation. Sludge concentrations were 10 to 100 g kg ‐1 in the soil‐sludge mixtures and 1 and 10 g L ‐1 in the P‐dissolution experiments. The dissolution experiments revealed that up to 40% of the total sludge P dissolved, under the experimental conditions. A continuum of solubilities was displayed by the solid inorganic P components present in the sludge, ranging from that of hydroxyapatite to that of dicalcium phosphate dihydrate. Transformations of N compounds in the sludge‐containing systems had strong effects on the dynamics of P dissolution, mainly through the influence of the ammonification and nitrification processes on the pH and the ionic strength and composition of the aqueous solution.