Characterization of Humic Substances in Sediment on Joumine Reservoir in Tunisia
摘要
In arid and semi-arid land, the rehabilitation of reservoirs such as sediment dredging is necessary in order to utilize the water resource sustainably, but it has not been carried out due to its high cost of operation in developing countries. Thus, valorization of the sediment to generate income which will be used to cover the cost of operation is discussed. In this study, the content and characteristics of humic substances in the sediment were examined as a first step toward the utilization of the sediment as a material for soil amelioration. Humic acid and fulvic acid (JS-FA) in the sediment of Joumine reservoir located in the northern part of Tunisia were extracted according to the standard method of International Humic Substance Society. The volume of the extracted material as humic acid was so small that it was not possible to detect. On the other hand, the content of extracted fulvic acid was approximately 0.5% of the organic matter content of the sediment. Then, in order to confirm whether the extracted material is fulvic acid or not, the absorption spectrum was determined by measuring FT-IR spectroscopy and was compared with the spectra of fulvic acids of peat (CP-FA) and weathered coal (WC-FA). Results show that the spectrum of JS-FA was similar to the spectra of CP-FA and WC-FA, confirming that JS-FA was fulvic acid. Additionally, the FAs extracted from the sediment collected in August and December 2010 had different characteristics compared to the FA from the sediment in the Japanese reservoir.