CHARACTERIZATION OF SUPRAMOLECULAR HUMIC MATERIAL OBTAINED FROM LAKE DREDGED SEDIMENTS BY HUMEOMICS AND SPECTROSCOPY METHODS

In the last two decades, the Western Lake Erie Basin (WLEB), USA has been experiencing harmful algae bloom (HABs) events attributed to the large export of phosphate (PO₄^-3) and nitrate (NO₃^-) containing fertilizers. There is a current concern on exacerbating the HABs at the WLEB by dumping dredged sediments (DS) in open waters. The State of Ohio is requesting beneficial uses for the DS, farm soil amendment is explored in this study. Previous research has demonstrated beneficial soil health results on DS from the Toledo Harbor, OH, as the DS contains adequate soil organic matter (SOM) content. This study aims to characterize the SOM in the DS by conducting a gentle chemical sequential extraction, Humeomics. The total organic carbon, total phosphorous, total nitrogen, cations (Na, K, Ca, Mg), and organic moieties associated to the SOM organosoluble and hydrosoluble extracted fractions has characterized. Emission and excitation matrices were collected and paired with Parallel Factor analysis (PARAFAC). In the extracted samples, TOC concentrations ranged between 44,757 to 75,614 mg kg^-1. Fourier-transform infrared spectroscopy analysis confirmed the presence of long C-H stretching (3000-2840 cm^-1), alcohol (3550-3200 cm^-1), aliphatic ether (1150-1080 cm^-1) groups in the organo-soluble fractions. And in the hydro-soluble fraction, alcohol (3000-3500 cm^-1), ester (1210-1163 cm^-1), phenol (1390-1310 cm^-1) and alkene (990-985 cm^-1) were observed.