抄録
Soil organic matter (SOM) is derived from dead biomass of animals and plants, and its formation process in which the precursor materials of SOM are transformed into macro organic molecules through geo-chemical and geo-biological reactions in the subsurface environment is referred to as humification. Carbon content increases, but oxygen content decreases along with marked increased in molecular weight and degree of condensation of SOM during humification. As illustrated in figure 1, it has been known that humus materials evolve in the order of biopolymer, fulvic acid, humic acid, and humin. Humification process takes place in a geological time scale, but it can be accelerated at extremely high temperatures, which can be achieved by microwave (MW) with hyperthermal catalysts (HTCs). Thus, MW was irradiated to the mixture of soil and HTCs to stimulate humification of SOM and to enhance its binding capacity for recalcitrant organic contaminants in this study. MW irradiation with HTCs was optimized, and the characteristic changes of SOMs before and after the irradiation were assessed to confirm humification. Soils were collected from 4 different forest regions in Seoul, Korea (Konkuk University, Yongma Mountain, Surak Mountain, and Bukhan Mountain), and they were screened by wet-sieving. Each component of SOM was isolated by acid-base extraction/selective exchange resin, which was proposed by the International Humic Substance Society. Total organic carbon (TOC) content, specific ultraviolet absorbance (SUVA), E4/E6 ratio, and Fourier transform-infrared spectroscopy (FT-IR) spectrum of SOM before and after MW irradiation were examined. Soil of Surak Mountain exhibited the highest organic carbon content, but Yongma Mountain contained the highest amount of fulvic acid (figure 2).
