| heal.abstract |
In this paper, nitrogen mineralization of sewage sludge from three waste water treatment plants of Greece (KAT, LAR, KAL) was studied. For this reason, incubation experiment of sludge was carried out in the laboratory, lasting 156 days for KAT and LAR sludge and 198 days for KAL sludge. The samples were leached periodically with CaCl2 and N-free nutrient solution and the concentration of NH+ 4-N and NO- 3-N was determined in the leachates. NO- 3-N was the predominant fraction. The mineralized nitrogen (Nm) can be described by a first order kinetics model obtained by a non linear regression analysis. The amount of Nm produced, was greater in KAL sludge, followed by LAR and KAT. The potentially mineralizable nitrogen (No) follows the order NoKAT<NoLAR< NoKAL, which was probably attributed to the degree of polymerization of the organic matter and the percent of total nitrogen and of humic acid's N. |
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