풀빅산(FA)은 Fe(III)을 킬레이트화하여 생물학적으로 이용 가능한 Fe(II)로 전환함으로써 대형 해조류의 성장을 촉진하고 손 상된 해중림의 복원을 돕는다. 이에 본 연구에서는 풀빅산의 공급에 따른해중림 개선에 미치는 효과를 조사, 분석하였다. FA 보충제는 철(Fe) 부족 해역 내 인공 어초에 설치되었으며, 해조류 군집 및 해양 환경조사는 사계절을 대표하는 학술 잠수를 통해 수행되었다. 연 구 결과, 풀빅산 공급으로 인해 가용 철(Fe) 농도가 증가하면서 해조류의 광합성과 영양소 흡수가 촉진되어 성장률이 향상되는 것으로 나타났다. 우점종의 총 생물량은 전체 해조류 총 생물량과 비우점종에 비해 더욱 강한 상관관계를 나타내었다. 이는 철 보충제가 특정 우점종의 양적 증가에 기여하며, FA 보충제가 설치된 어초에서 해조류 군집의 양적 및 구조적 변화를 유발했음을 시사한다. 본 연구 결과는 풀빅산을 해중림 복원에 적용하기 위한 기초적인 정보를 제공하며, 향후 해조류 생태계 관리 및 보존 전략 수립에 기여할 수 있을 것으로 기대된다.

Fulvic acid, a humic substance with unique properties, has sparked interest due to its potential applications in the treatment of allergic diseases, Alzheimer's disease, and as a microplastic adsorbent. However, conventional extraction methods produce insufficient quantities for commercial use, which has prompted research to enhance fulvic acid production. In this study, we investigated the impact of Saccharomyces cerevisiae fermentation on the yield and spectral characteristics of fulvic acid extracted from white peat. Fulvic acid was extracted from both S. cerevisiae-treated and untreated white peats using acid precipitation. The yield of fulvic acid from the S. cerevisiae treated group reached its highest at 3.5 % after 72 hr of fermentation, which was significantly higher than the untreated group (1.1 %). Fourier Transform Infrared (FTIR) analysis revealed similarities in functional groups and characteristic absorption bands between the treated and untreated fulvic acid samples. These findings suggest that S. cerevisiae fermentation can increase the yield of fulvic acid extracted from white peat, providing a promising approach for enhancing the commercial viability of fulvic acid production.

The sorption behavior of Se(IV) on montmorillonite clay, a promising buffer and backfill material, was investigated in the presence of aquatic fulvic acid. Selenium-79 is one of the major radioactive nuclides which are long-lived and highly mobile in subsurface environments. Moreover, it is highly toxic even in small amounts, so the selenium quantity in soil and groundwater should be assessed. Although natural organic matters such as humic and fulvic acids are present in the environment, the influence of natural organic matters on Se(IV) migration has not yet been extensively studied. The batch sorption experiments were performed under oxic conditions. Suwannee River III standard aquatic fulvic acid (International Humic Substances Society) was used to build an organicrich environment. The N2 – BET surface area of the montmorillonite (Clay Minerals Society) was 97 ± 5 m2·g−1. The montmorillonite suspensions with/without fulvic acid were equilibrated with air before adding Na2SeO3. The solid-to-liquid ratio was 5 g·L−1, the ionic medium was 0.1 M NaCl, fulvic acid concentration was 50 mg·L−1, and the final pH was 3. The horizontal vial roller was used to prevent the clay from sinking. After 7 days of sorption at room temperature, the suspensions were centrifuged at 10,600 g for 15 min and filtered through 0.2 μm PTFE filters. The colloidal fulvic selenide and free Se(IV) concentrations were entirely measured by inductively coupled plasma–mass spectrometry (ICP-MS). The sorption results were fitted with Langmuir and Freundlich models. At concentrations lower than 20 μM, the distribution coefficients (Kd) were 50 ± 9 L·kg−1 without fulvic acid, and 36 ± 5 L·kg−1 with 50 mg·L−1 fulvic acid. For the concentrations between 20 and 100 μM, the Kd values without and with fulvic acid were 16 ± 7 L·kg−1 and 10 ± 1 L·kg−1, respectively. As a result, it turned out that fulvic acid interferes with the sorption of Se(IV) on montmorillonite in competition with the selenite anion. This indicates that such organic matter may facilitate the migration of selenium in deep geological groundwaters.