Earticle

본 연구에서는 블루카본 저장 관련 연구사례를 수집하고 정리하여 분석하였으며, 다양하게 제시된 블루카본의 정의에 대해 시공간적인 범위와 과학적인 측면에서 고찰하였다. 블루카본 저장 관련 연구사례는 444개의 논문이 선정되었으 며, 연도별/국가별 논문 출판 개수와 주제어 분석을 수행하였다. 블루카본 저장 관련 논문 출판은 2011년부터 지속적 으로 증가하였으며, 2018년부터는 연간 50편 이상이 출판되었다. 국가별 논문 출판은 호주에서 100편 이상으로서 가 장 많았으며, 미국과 중국에서도 60편 이상의 논문이 출판되었다. 블루카본의 정의가 제시된 23개 논문에서 정의된 문장에서 “자연환경” 및 “저장 특성”과 관련된 주요 용어를 분석하였다. 블루카본이 저장된 자연환경으로는 맹그로 브, 염습지, 해초 서식지가 대부분이었으며, 블루카본 저장소로는 퇴적물과 식물 그 자체까지도 포함하였다. 기존에 제시된 블루카본의 정의에서는 블루카본 저장 환경으로서 식생 환경에 집중되어 있지만, 블루카본은 연안습지의 퇴적 물 내에 저장되므로 비식생 갯벌을 포함한 연안 생태계를 블루카본의 저장 환경으로 정의하는 것이 적정할 것으로 판 단되었다.

In this study, research cases related to blue carbon storage were collected and analyzed, and various definitions of blue carbon were considered in terms of spatiotemporal scope and scientific aspect. 444 papers were selected as research cases related to blue carbon storage, and analysis of the number of papers published by year/country and keywords was performed. Publication of papers related to blue carbon storage has continued to increase since 2011, and more than 50 papers have been published annually since 2018. The most publications by country were in Australia with more than 100 papers, and the United States and China also published more than 60 papers. Key terms related to “natural environment” and “storage characteristics” were analyzed in the sentences defined in the 23 papers that presented the definition of blue carbon. The natural environments where blue carbon was stored were mostly mangroves, salt marshes, and seagrass beds, and blue carbon repository included sediments and even plants themselves. The existing definition of blue carbon focused on the vegetation environment as the storage environment for blue carbon. However, since blue carbon is stored in the sediments of coastal wetlands, it would be appropriate to define the coastal ecosystem, including non-vegetated mudflats, as the storage environment for blue carbon.

농업비점오염에 의한 수질문제 해결을 위하여 인공습지 조성이 늘어나고 있으나 긴 체류시간과 긴 일조량 등으로 인하여 습지 내 조류 발생 등의 문제가 지속적으로 발생하고 있다. 본 연구는 농업 비점오염원관리를 위하여 조성된 인공습지의 효율을 평가하여 자연기반 능력이 향상된 고도화된 인공습지 개선방안을 제시하고자 수행되었다. 인공습지의 성능평가는 구성성분 (물, 퇴적물 및 식물)의 모니터링을 통해 구성성분이 시스템의 처리 성능에 주는 기여도 평가를 통해 수행되었다. 건기시에는 식물성 플랑크톤의 과다성장, 긴 체류시간 및 일조량 과다로 습지내 탁도 및 미립자 농도가 각각 80~197 % 및 10~ 87 % 정도 증가하는 것으로 나타났다. 그러나 강우시에는 습지내 적절한 물 순환과 지속적인 물 흐름으로 미립자, 유기물 및 영양분 의 농도가 43 ~ 70 %, 22 ~ 49 %, 15 ~ 69 % 정도 감소하는 것으로 나타났다. 이러한 연구결과로 볼 때 인공습지가 가진 문제해결을 위해서는 자연습지가 가진 안정적 물 흐름이 필요하다는 것을 알수 있다. 그러나 일정수심을 유지하도록 되어있는 인공습지 설계기준은 건기와 강우기가 뚜렷하게 나타나는 한국적 기후상황에 타당하지 않다. 따라서 본 연구에서는 인공습지가 가진 문제를 해결하고 홍수관리, 수질 관리 및 환경 기능을 지속적으로 유지할 수 있도록 다기능 설계기법을 개념화하였다.

Constructed wetlands (CWs) are widely used to solve water quality problems caused by diffuse pollution from agricultural areas; however, phytoplankton blooms in CW systems can occur due to long hydraulic retention time (HRT), high nutrient loading, and exposure to sunlight. This study was conducted to evaluate the efficiency of a CW designed to treat agricultural diffuse pollution and develop a design concept to improve the nature-based capabilities of the system. Monitoring was conducted to assess contribution of individual wetland components (i.e. water, sediments, and plants) in the treatment performance of the system. During dry days, the turbidity and particulates concentration in the CW increased by 80 to 197% and 10 to 87%, respectively, due to the excessive growth of phytoplankton. On storm events, the concentration of particulates, organics, and nutrients were reduced by 43% to 70%, 22% to 49%, and 15% to 69% due to adequate water circulation and constant flushing of pollutants in the system. Based on the results, adequate water circulation is necessary to improve the performance of the CW. Free water surface CWs are usually designed to have a constant water level; however, the climate in South Korea is characterized by distinct dry and rainy seasons, which may not be suitable for this conventional design. This study presented a concept of multifunctional design in order to solve current CW design problems and improve the flood control, water quality management, and environmental functions of the facility.

태안 연안은 2007년 유류유출의 영향을 받은 해역으로서, 유류유출에 의한 영향을 알아보고자 2018년 태 안연안의 해양퇴적물을 대상으로 계절에 따른 분포특성을 연구하였다. 퇴적물의 입도는 퇴적환경과 밀접한 연관이 있으며, 연구해역의 입도는 0.36~5.80Φ(평균 3.13 Φ)으로서 세립모래가 우세한 해역이었다. 유기물의 분포는 입도가 클 때 유기물의 농도도 높게 나타나 입자의 크기에 따라 조절되는 것으로 나타났다. 퇴적물 중금속의 함량은 계절 에 따라 큰 차이를 보이지 않았으며, 정점에 따른 차이를 나타냈다. 비소와 수은을 제외한 대부분의 금속이 유기물 과 같이 입자의 크기에 따라 함량의 차이를 나타냈다. 대부분의 금속은 알루미늄과 양호한 양의 상관관계를 나타 내어 연구지역의 점토광물의 영향을 받는 것으로 나타났다. 또한 수은과 비소를 제외한 대부분의 금속은 입도와 양호한 양의 상관관계를 나타내어 입도크기에 따라 함량이 조절되는 것으로 나타났으며, 수은과 비소는 다른 조절 요인에 의한 영향을 받는 것으로 나타났다. 해양생태계 보호 기준과 비교하면 중금속은 보호기준 미만의 함량을 나타냈다.

The Taean coast was affected by the oil spill in 2007. The seasonal distribution characteristics were studied in 2018 on marine sediments off Taean coast to see the effects of the oil spill. The grain size of sediment was closely related to the sedimentation environment, and mean grain size was 0.36-5.80 Φ(average 3.13 Φ), which was the area where the fine sand prevailed. The distribution of organic matters is shown to be highly concentrated when the grain size is large, which is adjusted according to the size of the particles. The content of sediment heavy metals did not vary significantly from season to season, indicating the difference of the stations. Most metals, except arsenic and mercury, showed differences in content depending on the size of the particles, such as organic matter. Most metals were found to be affected by clay grain size in the study area, indicating a good relationship between aluminium and heavy metals. In addition, most metals, except mercury and arsenic, were found to have a good correlation with grain size and the content was adjusted according to the size of grain size, with mercury and arsenic being affected by other conditioning factors. Heavy metals belonged to a group of threshold effects level (TEL) of marine ecosystem protection.

The sediments of Andong Dam (Andong-si, South Korea) are contaminated with heavy metals such as cadmium (Cd), lead (Pb), and zinc (Zn), largely due to upstream refineries and abandoned mines. Recently, heavy metals have also been detected in fish from the dam, raising concerns about ecological risks and potential impacts on human health through the food chain. In situ stabilization has emerged as a promising and effective technology for restoring contaminated sediments. Rice husk biochar (RBC), a pyrolysis product of agricultural waste, has a large surface area and rich functional groups, making it effective at reducing the bioavailability of heavy metals released from sediments. After in situ stabilization, heavy metal concentrations in sediment pore water were measured using the diffusion gradient in thin-film (DGT) technique. Building on the results from previous years, this year’s field experiment was conducted at the Andong experimental site using 5 mesocosms with 3 treatments: Control, Biochar Pellet (RBC) and Biochar Composite Pellet (MgO@RBC), a composite material was developed using rice husk biochar (RBC) and magnesium oxide (MgO). After 3 months of implementation and sediment layer monitoring, results showed that heavy metal concentrations were stabilized by the Biochar Composite Pellet, with the most significant effect being the stabilization of Pb concentration when comparing the mesocosms treated with composites to the control sample.

Stream and lake sediments are often subject to contamination by heavy metals due to both natural processes and human activities, such as industrial waste disposal and steel production. Lead (Pb), one of the most concerning contaminants, is a potent neurotoxin that can accumulate to hazardous levels, threatening both aquatic ecosystems and human health. Pb has a strong affinity for binding to fine-grained sediments and organic matter, and its adsorption is highly dependent on factors such as pH and the organic content of the sediments. In this study, we aimed to assess Pb contamination in sediments by utilizing electrical resistivity measurements in combination with multivariate statistical techniques. Sediment samples were systematically collected and analyzed for Pb concentrations using aqua regia extraction. Electrical resistivity was measured using a Sample Core Induced Polarization (SCIP) device to evaluate the geophysical properties of the sediments. The resulting geochemical and geophysical data were then analyzed using multivariate statistical methods to explore the relationships between these datasets and derive regression models. These models were employed to estimate and verify Pb contamination levels based on the electrical properties of the sediments.

Stream and lake sediments can become contaminated with heavy metals due to natural occurrences or anthropogenic factors such as waste disposal and steel manufacturing processes. Among these contaminants, lead (Pb) is a neurotoxin that can reach high concentrations, posing negative impacts on aquatic ecosystems and human health. Lead has the capability to form complexes with fine sediments and organic matter, with its binding strength showing a high correlation with pH and organic matter content. In this study, we estimated the contamination levels of Pb in sediment using electrical resistivity measurements and multivariate statistical techniques. Sediments were appropriately collected and analyzed for total content using aqua regia extraction. The electrical resistivity of sediments was measured using a Sample Core Induced Polarization (SCIP) tester. Collected geochemical and geophysical data were subjected to multivariate statistical analysis to interpret causal relationships between different domains of data and derive regression equations. Based on the derived equations, the study performed estimation and verification of Pb contamination levels based on electrical properties.

Marine sediments are one of important natural resources for humans. By applying various remediation technologies, marine sediments (naturally or contaminated including dredged materials) could be transformed into commercially useful products. However, selecting appropriate technologies may still be challenging for decision-makers. This research aims (1) to develop a comprehensive environmental assessment criterion to evaluate and identify promising ex-situ technologies for marine sediments in Colombia and (2) propose management frameworks to obtain sustainable beneficial uses from treated sediments. The achieved results identified solidification/stabilization as promising technologies to be adopted in Colombia based on their cost-benefit, high efficiency and environmental feasibility according to several evaluation criteria. Optimal conditions for successful sediment treatment were also identified. Sustainable beneficial use of marine sediments may provide environmental and economic benefits from the point of view of new circular economies. Best-suited technologies can be chosen based on site and sediment characterization without neglecting essential aspects such as cost-effectiveness, treatment time, and removal efficiency, which were considered in this research. The various environmental assessment tools developed may aid decision-makers in selecting optimal technologies and achieving the sustainability of marine sediments by optimizing their beneficial uses. Additional issues including qualities of the Colombian Caribbean marine sediments will be presented during the 2022 KEDS conference. More innovative and practical environmental risk assessments tools are still needed to evaluate the feasibility of various remediation technologies.

본 연구는 영산강 수계에 위치한 하천의 표층 퇴적물 중 유기물과 영양염류들의 농도 분포와 오염도를 평가하기 위하 여 수행하였다. 표층 퇴적물 시료는 2015년부터 2016년까지 2년 동안 하천 중 본류 12개 및 지류 4개 지점으로부터 채 취하여 입도와 유기물(Ignition Loss, COD, TOC) 및 영양염류(TN, TP, SRP)를 분석하여 평가하였다. 입도 분포는 상류 와 하류로 구분하여 모래와 양질사토가 우세하였으나, 상류에 보가 설치된 MS3와 MS6 지점의 경우 각각 양질사토와 미 사양토로 나타났다. 상관성 평가 결과, 유기물 항목들은 입도들과 강한 상관관계를 보인 반면 TN을 제외한 영양염류 항 목들은 약하게 나타났다. 유기물 및 영양염류 농도의 분포 특성은 상류보다 하류 그리고 보가 설치된 지점들에서 높았고, 특히 MS3 지점의 TP 농도는 상반기보다 하반기에 높은 특성을 보였다. 국내외 오염기준과 비교 평가한 결과, 유기물 및 영양염류 항목들은 전 지점들에서 심각한 오염상태가 아닌 것으로 평가되었다.

This study was carried out to assess the distribution and pollution level of organic matters and nutrients in surface sediments of the Yeongsan River Basin. The surface sediments were collected from the mainstream (12) and tributaries sites (4) for two years from 2015 to 2016, and the particle sizes, organic matters (Ignition Loss, COD, TOC) and nutrients (TN, TP, SRP) were analyzed. The distribution of particle sizes was dominated by sand in the upstream sites (MS1-MS7) and by silt loam in the downstream sites (MS8-MS12), but MS3 and MS6, located slightly upstream of the two weirs, were found to be mostly loamy sand and silt loam, respectively. As a results of the correlation assessment, the organic matters (IL, COD, TOC) were strongly correlated with particle sizes, while the nutrients (TP, SRP) were weak except for TN. The concentrations of organic matter and nutrient were higher at the downstream and the sites nearby the two weirs (MS3, MS6). In particular, the TP concentration at the MS3 site sampled in the second half period of the years was higher than that in the first half periods. Comparing of sediments criteria, the organic matters and nutrients were evaluated to have almost no toxic effects at all sites.

This study aimed to investigate the hexachlorobenzene (HCB) dechlorinating ability of sediment microbes collected from a natural canal receiving secondary effluents from an industrial estate and nearby factories. Nine sites along the stream and one in the estuary in the Gulf of Thailand into which the canal spills were specified and sampling for sediment and water. Preliminary analysis of the sediments showed that the first four sites nearest to the discharging location were contaminated by HCB within the range of 0.18 to 1.25 ppm. Apart from that, 1,3,5-trichlorobenzene which has never been commercially produced or used in any manufacturing processes except for the transformation from higher chlorinated benzene was also identified in the range of 0.16 to 0.24 ppm. This suggested a possibility of sporadically HCB contamination in this stream. Of more important, people in the community along this canal earn their living by coastal fishery; hence, posing a risk of spreading HCB and its less chlorinated congeners via food chain from caught marine creatures to human. As a result, there is an urgent need to understand the behavior of HCB dechlorination in this stream sediment which can lead to a clean-up action in the future. Serum bottles with sediment slurries (sediment to water ratio of 1:1 (v/v) and filtered to remove particles larger than 0.7 mm) from each site were inoculated with 2 mg/l of HCB, kept anaerobically in the dark at room temperature without any nourishment, and analyzed for HCB and its less-chlorinated congeners every 6 days. Total chemical oxygen demand, suspended solids, and volatile suspended solids were in the range of 21,492-73,584, 158,100-518,100 and 6,000-32,700 mg/l, respectively. It was found that all sediment slurries began to dechlorinate HCB in 12 to 30 days and the HCB was completely removed within 42 to 60 days or so. On the other hand, there was no HCB dechlorination occurred in the controlled set which was sterilized by autoclaving prior to the addition of HCB. This implies that the HCB transformation was solely due to microorganisms’activities. HCB was dechlorinated principally via pentachlolobenzene to 1,2,3,5-tetrachlorobenzene and terminated at 1,3,5-trichlorobenzene which is the major pathway as reported by many researchers. Dichlorobenzene has not been detected in any samples within the dechlorination period of 60 days. The results indicate that the microbial matrix in the sediment of this stream has an outstanding capability to dechlorinate HCB. Existing substrates and nutrients which mainly sorbed onto the solid phase and the typical temperature in Thailand were sufficient and suitable to promote the activities of these HCB-dechlorinating microbes.

Harmful heavy metal (HHM) pollution in marine sediments threatens aquatic ecosystems and human health. Accurate characterization of HHM is crucial for protecting environmental health and supporting coastal community resilience. This study analyzes 28 years of HHM data from Cartagena Bay (CB), Colombia, to assess sediment quality and ecological risk using various geochemical methods. A modified index was developed to account for vertical HHM distribution in sediments. Results show that anthropogenic pollution in CB poses low to moderate risk, with mercury (Hg) as the main contributor to total toxicity. Positive multivariate correlations highlight anthropogenic activities as the primary source of pollution. This research provides valuable data for Colombia’s future environmental projects and offers a new methodology for assessing sediment pollution in similar coastal environments worldwide. Further details will be presented at the 2024 KEDS Conference.

Polycyclic aromatic hydrocarbons (PAH’s), such as naphthalene and phenanthrene, are persistent contaminants in sediment environments, posing significant dangers to benthic ecosystems. Activated carbon (AC) has emerged as a promising material for the sequestration of PAH’s due to its high surface area, adsorption capacity, and cost-effectiveness. This study investigates the efficacy of granular activated carbon (GAC) of three different particle sizes, mixed into sediment to form a stabilizing layer, in sequestering naphthalene and phenanthrene from contaminated sediments. The research employs microcosm experiments with Lumbriculus variegatus to evaluate the ecological impact and bioturbation effects associated with the different GAC sizes. A polyethylene passive sampler will be used to assess the free concentration of PAHs over time, aiming to determine the optimal GAC size that maximizes contaminant sequestration while minimizing ecological disturbance. The expected outcome of this research is to identify a GAC size that effectively balances remediation efficiency with benthic organism health, contributing to the development of sustainable in-situ sediment remediation strategies

이 연구에서는 안동댐 상류 지역 하천 퇴적물, 하천수 및 부유사 등을 건기와 우기로 구분하여 오염도 분석 및 평가를 수행하였다. 하천 퇴적물 분석결과, Cd, Cu, Pb 및 Zn은 우기보다 건기에 높은 농도를 보이고 있고, 석포제련소 주변에서 가장 높게 검출되었으며, 하류로 내려가면서 감소하는 경향을 보이고 있다. As의 경우, 낙동강 본류보다 송정리천, 골포천 및 가천 등의 지류에서 높게 검출되었으며, 일부 배경시료에서도 높은 함량을 보이고 있다. 하천수의 경우, 환경기준을 초과하는 항목은 없으나 일부 지류에서 As(건기)가 상대적으로 높은 함량을 보이고 있다. 우기에 채취한 부유사에서 As 및 중금속 농도가 확인되었으며, 강우 시 용존상 물질보다 입자상 물질 이동이 주요 오염확산 원인으로 확인되었다. 이러한 결과는 유량이 작고 유속이 느린 건기에 폐금속광산, 석포제련소 및 퇴적 광물찌꺼기 등에서 유래한 입자상 오염물질이 하천 바닥에 퇴적되어 수생태계에 영향을 미칠 가능성이 높은 상태로 존재하다가 강우에 의해 부유되어 하류로 이동하여 최종적으로 안동댐으로 유입되는 것으로 해석된다.

This study evaluated the environmental impact of As and heavy metals occurring upstream of the Andong dam. In sediments, the concentrations of heavy metals were found to be higher in the dry season than in the wet season, with the highest concentration occurring near the smelter. Moreover, As concentrations in some tributaries, such as Songjeongricheon, Golpocheon, and Gacheon, were higher than those in the Nakdong River. The concentrations of heavy metals in water samples did not exceed the Korean environmental standards. However, some tributaries showed relatively high As concentrations in the dry season. In suspended sediments, As and heavy metals were detected in the wet season, and particulate transport was identified as their major dispersion mechanism. In conclusion, the abandoned metal mines, smelter, and deposited-tailings were the source of the pollutants, which accumulated on the river bed in the dry season and were carried into the Andong dam in the wet season, via streams.