• 한국물환경학회지
• /
• 제40권2호
• /
• pp.79-88
• /
• 2024

This study employed field measurements and biogeochemical analysis to examine the effects of seasonal conditions (e.g., temperature and precipitation) and human intervention (e.g., dam or weir construction) on the chemical composition of dissolved organic matter, flocculation kinetics of suspended particulate matter, and formation of the fluid mud layer on riverbeds. The results indicated that a water environment with a substantial amount of biopolymers offered favorable conditions for flocculation kinetics during an algal bloom period in summer; a thick fluid mud layer was found to be predominated with cohesive materials during this period. However, after high rainfall, a substantial influx of terrigenous humic substances led to enhanced stabilization of the particulate matter, thereby decreasing flocculation and deposition, and the reduced biopolymer composition served to weaken the erosion resistance of the fluid mud on the riverbed. Moreover, a high-turbulence condition disaggregated the flocs and the fluid mud layer and resuspended the suspended particulate matter in the water column. This study demonstrates the mutual relationship that exists between biogeochemistry, flocculation kinetics, and the formation of the fluid mud layer on the riverine area during different seasons and under varying hydrological conditions. These findings are expected to eventually help inform the more optimal management of water resources, which is an urgent task in the face of anthropogenic stressors and climate change.

• 한국환경과학회지
• /
• 제32권3호
• /
• pp.181-189
• /
• 2023

In this study, sediment cores from unvegetated tidal flats in the Hampyeong Bay (west coastal wetland) and Dongdae Bay (south coastal wetland) were sampled, the blue carbon stock in the sediments was calculated, and the characteristics of the blue carbon stock were analyzed based on particle size of the sediments. The sediments in the Hampyeong Bay tidal flat had large particle size and low mud content, and the Dongdae bay tidal flat had small particle size and high mud content. The organic carbon content and blue carbon stock in the sediments were higher in the Dongdae tidal flat than in the Hampyeong Bay tidal flat. As a result of the regression function, in both the Hampyeong Bay and Dongdae Bay tidal flats, the sediments had the smaller particle size and higher mud contents the higher the organic carbon content and blue carbon stock. The sediments with smaller particle size had the larger specific surface area, so were feasible to adsorb and store more organic matters.

• 한국작물학회지
• /
• 제50권2호
• /
• pp.108-111
• /
• 2005

A field study was conducted to develop an economically suitable combination of organic and inorganic fertilizers for sugarcane cultivation in sandy acidic soil of a commercial sugarcane farm under Old Himalayan Piedmont Plain of Bangladesh. Results revealed that the treatment $T_4$ which received $75\%$ of Recommended fertilizers (N 120, P 35, K 100, S 25, Zn 2 kg $ha^{-1}$) + 10 Mg $ha^{-1}$ Rice mill ash + Mg $ha^{-1}$ press mud significantly produced higher sugarcane yield (72.34 Mg $ha^{-1}$) among all the treatments except $T_5$ having $100\%$ of Recommended fertilizers + 10 Mg $ha^{-1}$ Rice mill ash + 10 Mg $ha^{-1}$ press mud, which was identical. $T_4$ also gave the highest net economic benefit at Bangladesh Taka 15,920.47 per hectare from the added nutrient management. Thus, the integrated use with organic and inorganic fertilizer is highly essential for sustainable production of sugarcane in commercial farm of the region in Bangladesh, where it has been grown year after year.

• 한국수산과학회지
• /
• 제52권6호
• /
• pp.656-665
• /
• 2019

Environmental monitoring was conducted to identify the characteristics and patterns of sedimentary environments of tidal flats in 12 areas on the west coast of Korea. The habitat of the mud shrimp Upogebia major contained higher organic and mud contents compared to the habitat of the manila clam Ruditapes philippinarum. In particular, the mud content increased from 84.38% to 89.18% in the Seongam-4 area, where the mud shrimp and manila clam coexist, and the mean grain size exhibited a finer particle size, from 5.48 Φ to 5.80 Φ. In the mud shrimp habitat, the sediment mud content was > 60% and the mean grain size was > 5 Φ. Additionally, the mud shrimp only inhabited open coast tidal flat areas. The management of shellfish aquaculture farms by physical methods should be continued based on comparison of the sedimentary environments in the Boryeong and Seongam areas in response to the damage to the mud shrimp habitat.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제29권2호
• /
• pp.1-10
• /
• 2024

With industrial development, the inevitable increase in both organic and inorganic waste necessitates the exploration of waste treatment and utilization methods. This study focuses on co-pyrolyzing lignin and red mud to generate metalbiochar, aiming to demonstrate their potential as effective adsorbents for water pollutant removal. Thermogravimetric analysis revealed mass loss of lignin below 660℃, with additional mass loss occurring (>660℃) due to the phase change of metals (i.e., Fe) in red mud. Characterization of the metal-biochar indicated porous structure embedded with zero-valent iron/magnetite and specific functional groups. The adsorption experiments with 2,4-dichlorophenol and Cd(II) revealed the removal efficiency of the two pollutants reached its maximum at the initial pH of 2.8. These findings suggest that copyrolysis of lignin and red mud can transform waste into valuable materials, serving as effective adsorbents for diverse water pollutants.

• 대한환경공학회지
• /
• 제34권11호
• /
• pp.751-756
• /
• 2012

본 연구에서는 인천북항 인근 Pb, Zn 및 Cu로 오염된 해양퇴적물에 대하여 산업부산물인 적니와 굴패각을 안정화제로 선정하여 안정화 처리를 수해하였다. 안정화제는 적니와 굴패각으로 오염토 함량대비 각각 5%, 10%, 15%를 사용하여 15일간 습윤양생 하였다. 연속추출 실험결과를 통해 미처리오염퇴적물에서 큰 비중을 차지하고 있었던 산화물 형태와 유기물 형태 중금속이 안정화제에 의해 유기물 형태 및 잔류물 형태로 안정화되고 있음을 알 수 있었다. 또한, 안정화효율 평가를 위해 TCLP를 수행한 결과, 대조군과 비교해서 안정화 처리 퇴적물인 경우 중금속의 용출량이 확연하게 감소한 것을 확인할 수 있었다. 이러한 결과로부터, 산업부산물을 이용한 안정화제가 오염퇴적물처리에 활용 가능함을 나타내고 있다.

• 한국환경과학회지
• /
• 제20권3호
• /
• pp.385-394
• /
• 2011

Organotin compounds (OTs), namely butyltins compounds (BTs) and phenyltin compounds (PhTs), were measured in surface and core sediments collected in Jeju harbor. The horizontal and vertical distribution was examined and the relationship between the concentration of OTs and organic matter content and particle size distribution was also studied. BTs were detected in significant concentrations in sediments inside Jeju harbor. PhTs were detected in very low concentrations, compared to BTs. The main species in BTs and PhTs were dibutyltin (DBT) and monobutyltin (MBT), monophenyltin (MPhT), respectively. In the relationships between the concentrations of total BTs and organic carbon content, the significant correlations ($r^2$=0.4898 in surface sediments, $r^2$=0.53 in one core sediments) and no correlation in another core sediments obtained, which is estimated that the distribution of BTs in sediments were affected by several factors, such as their physicochemical properties including organic carbon content, and a tide, etc. In the relationships between the concentrations of total BTs and particle size (mud, sand, and gravel) in sediments, the concentrations of total BTs were higher in the sediments with higher mud content, indicating that higher BTs were distributed with increasing sediments of fine granules.

• 환경생물
• /
• 제22권
• /
• pp.93-102
• /
• 2004

광양만 표층퇴적물의 지화학적 특성 이해와 저서환경을 평가하기 위해 총 110개의 표층퇴적물을 분석하였다. 분석결과 퇴적상은 다섯 개의 퇴적상(니질, 사니질, 사질, 니사질 및 역사질을 포함한 니질 퇴적상)으로 분류 할 수 있었다. 그러나 전체적으로 니질 퇴적상이 광양만의 주된 퇴적상으로 나타났다. 유기물의 C/N 및 C/S에 근거한 저서환경은 유기물중의 C/S비가 일부 시료에서 2.8이상을 보이고 있는 것으로 보아 일부 지역에서는 무산소 환경상태에 있음을 보이고 있다. 퇴적물중 황화수소 함량은 최고 367 ppm에서 최소 약 1 ppm(평균 92 ppm)으로 나타났고 지역에 따라 심한 변동을 보이고 있다. 산화환원에 민감한 원소들(Mn, V, Mo, Cr)간의 상관관계는 조사지역 중 묘도 안쪽 지역에서 강한 양의 상관을 보이고 있다. 높은 TOC함량과 높은 황화수소 함량 및 산화환원에 민감한 원소의 높은 농축이 묘도 안쪽의 시료에서 공통적으로 나타나는 특징을 보이고 있는데 이는 묘도안쪽 지역이 부분적으로 무산소 상태로 유지되고 있음과 동시에 잠재적으로 오염되었음을 지시하고 있다.

• 한국수산과학회지
• /
• 제46권5호
• /
• pp.638-648
• /
• 2013

To understand the geochemical characteristics of intertidal sediment in a semi-enclosed bay, we measured various geochemical parameters, including grain size, ignition loss (IL), chemical oxygen demand (COD), acid volatile sulfide (AVS), and trace metals (Al, Fe, Cu, Pb, Zn, Cd, Hg, and As), in intertidal sediment from three bays (Deukryang Bay, Yeoja Bay, and Gamak Bay) in the southern region of Jeollanam Province. The intertidal sediment in Deukryang Bay consisted of various sedimentary types, such as sand, gravelly muddy sand, mud, and silt, whereas the intertidal sediments in Yeoja and Gamak Bays were composed mainly of mud. The concentrations of IL, COD, AVS and trace metals in the intertidal sediments of the three study regions were relatively high near areas affected by input of stream waters and/or shellfish farming waste. The concentrations of organic matter and trace metals in Gamak Bay were much higher than those in Deukryang and Yeoja Bays, which appears to be due to the influence of anthropogenic pollutants, originating from the city and the industrial complex near Gamak Bay. The evaluation results of organic matter and metal pollution using the sediment quality guidelines showed that the intertidal sediments in the three study regions were not polluted in terms of organic matter and trace metals. In future, sustainable management for sources of organic matter and trace metal is necessary to conserve a healthy benthic ecosystem in intertidal sediments.

• Ecology and Resilient Infrastructure
• /
• 제4권2호
• /
• pp.93-96
• /
• 2017

Spatial variations of physicochemical and microbiological variables were examined to understand spatial heterogeneity of those variables in intertidal flat. Variograms were constructed for understanding spatial autocorrelations of variables by a geostatistical analysis and spatial correlations between two variables were evaluated by applications of a Cross-Mantel test with a Monte Carlo procedure (with 999 permutations). Water content, organic matter content, pH, nitrate, sulfate, chloride, dissolved organic carbon (DOC), four extracellular enzyme activities (${\beta}-glucosidase$, N-acetyl-glucosaminidase, phosphatase, arylsulfatase), and bacterial diversity in soil were measured along a transect perpendicular to shore line. Most variables showed strong spatial autocorrelation or no spatial structure except for DOC. It was suggested that complex interactions between physicochemical and microbiological properties in sediment might controls DOC. Intertidal flat sediment appeared to be spatially heterogeneous. Bacterial diversity was found to be spatially correlated with enzyme activities. Chloride and sulfate were spatially correlated with microbial properties indicating that salinity in coastal environment would influence spatial distributions of decomposition capacities mediated by microorganisms. Overall, it was suggested that considerations on the spatial distributions of physicochemical and microbiological properties in intertidal flat sediment should be included when sampling scheme is designed for decomposition processes in intertidal flat sediment.