Fractionation of soil organic nitrogen species in soils contaminated with waste mineral oil


DİNDAR E., Cihan N., TOPAÇ ŞAĞBAN F. O., Baskaya H. S.

JOURNAL OF THE FACULTY OF ENGINEERING AND ARCHITECTURE OF GAZI UNIVERSITY, cilt.32, sa.3, ss.767-775, 2017 (SCI-Expanded) identifier identifier

Özet

Waste mineral oil pollution causes serious environmental damages in long term. It affects the availability of nutrients in top layer of soil which is rich in organic matter and prevents the entrance of water and oxygen to the soil. In this study, two different mineral oil (1% and 5%) doses were amended to soil-soil+wastewater sludge samples and then an incubation study was performed during three months. Ammonium nitrogen, nitrate nitrogen, total nitrogen and hydrolysable (H) nitrogen forms (HO-amino nitrogen, HO-amide nitrogen, HO-hexozamine nitrogen, HO-rest nitrogen) were analyzed in samples. The results of the study indicated that total nitrogen concentrations in mineral oil containing soils were decreased at the end of the incubation period. It is determined that nitrogen mineralization and nitrification processes were inhibited in soils contaminated with high doses of mineral oil. The magnitude of hydrolysable nitrogen forms was found to be as H-amino-nitrogen>H-rest nitrogen=H-amide-nitrogen>H-heksozamine nitrogen. It was found that the percentages of hyrolysable nitrogen in total nitrogen varied between 94% and 96%. The results have indicated the faster mineralization of amino acids and accumulation of mineral nitrogen as amid N fraction, as well as the preferential use of mineral oil C as carbon source by microorganisms during the process.