• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.24 no.1
• /
• pp.54-63
• /
• 2019

As a part of the national marine ecosystem monitoring program, the temporal and spatial variation of sedimentary environment and pollution of organic matters and trace metals from four major tidal flats, i.e., Ganghwa Is., Garolim bay, Jeung Is., Suncheon bay, was investigated for 3 yerars from 2015 to 2017. The mean grain size of the sediment was $5.0-5.3{\varnothing}$ at Ganghwa Is, $4.5-4.8{\varnothing}$ at Garolim bay, $6.1-6.5{\varnothing}$ at Jeung Is, and $8.6-8.7{\varnothing}$ at Suncheon bay. The mean grain size (Mz) tended to decrease from the north (Ganghwa Is.) to the south (Suncheon bay). The ignition loss (IL) was 15.5% in Suncheon bay in 2015, which was relatively high compared to other sites, but gradually decreased over time from 8.3% in 2016 to 7.0% in 2017. In Jeung Is. and Suncheon bay, the concentration of Zn and As exceeded the threshold effect level (TEL) at some stations, but the range of trace metals in the other sites was below the level. In Jeung Is., the Mz and concentration of trace metals except Hg was positively correlated (r= 0.40-0.88, P<0.05). On the other hand, Mz was negatively correlated with trace metals (P<0.05) in Suncheon bay. The geoaccumulation index ($I_{geo}$) to evaluate contamination status of sediments for trace metal was less than 1(not contaminated) for Cu, Zn, Pb, Cd and Hg, and 2-3 (moderately to strongly polluted) for As at several stations in Suncheon bay and Jeung Is.

• Korean Journal of Environmental Biology
• /
• v.34 no.4
• /
• pp.304-313
• /
• 2016

One of the issues currently facing nuclear power plants is how to store spent nuclear waste materials which are contaminated with radionuclides such as $^{134}Cs$, $^{135}Cs$, and $^{137}Cs$. Bioremediation processes may offer a potent method of cleaning up radioactive cesium. However, there have only been limited reports on $Cs^+$ tolerant bacteria. In this study, we report the isolation and identification of $Cs^+$ tolerant bacteria in environmental soil and sediment. The resistant $Cs^+$ isolates were screened from enrichment cultures in R2A medium supplemented with 100 mM CsCl for 72 h, followed by microbial community analysis based on sequencing analysis from 16S rRNA gene clone libraries(NCBI's BlastN). The dominant Bacillus anthracis Roh-1 and B. cereus Roh-2 were successfully isolated from the cesium enrichment culture. Importantly, B. cereus Roh-2 is resistant to 30% more $Cs^+$ than is B. anthracis Roh-1 when treated with 50 mM CsCl. Growth experiments clearly demonstrated that the isolate had a higher tolerance to $Cs^+$. In addition, we investigated the adsorption of $0.2mg\;L^{-1}$ $Cs^+$ using B. anthracis Roh-1. The maximum $Cs^+$ biosorption capacity of B. anthracis Roh-1 was $2.01mg\;g^{-1}$ at pH 10. Thus, we show that $Cs^+$ tolerant bacterial isolates could be used for bioremediation of contaminated environments.

• Journal of Environmental Impact Assessment
• /
• v.29 no.1
• /
• pp.8-25
• /
• 2020

Industrialization has increased the production of road-deposited sediments (RDS) and the level of heavy metals in those RDS, which can have a significant impact on the surrounding aquatic environments through non-point pollution. Although the relationship between contamination characteristics and particle size of RDS is important for pollution control, there is very little information on this. In this study, we investigated the characteristics of grain size distribution and heavy metal concentrations in the road-deposited sediments (RDS) collected from 25 stations in Shihwa Industrial Complex. The environmental impact of RDS with particle size is also studied. I_geo, the contamination assessment index of each metal concentration, represents the RDS from Shihwa Industrial Complex are very highly polluted with Cu, Zn, Pb and Sb, and the levels of those metals were 633~3605, 130~1483, 120~1997, 5.5~50 mg/kg, respectively. The concentrations of heavy metals in RDS increased with the decrease in particle size. The particle size fraction below 250 ㎛ was very dominant with mass and contamination loads, 78.6 and 70.4%, respectively. Particles less than 125 ㎛ of RDS were highly contaminated and toxic to benthic organisms in rivers. RDS particles larger than 250 ㎛ and smaller than 250 ㎛ were contaminated by the surrounding industrial facility and vehicle activities, respectively. As a result of this study, the clean-up of fine particles of RDS, smaller than 125-250 ㎛, is very important for the control and reduction of non-point pollution to nearby water in Shihwa Industrial Complex.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.5 no.3
• /
• pp.195-207
• /
• 2000

Organic and inorganic characteristics including bacterial cell number, enzyme activity, nutrients, and heavy metals have been monitored in twelve acrylic experimental tanks for two weeks to estimate and compare self-purification capacities in two Korean wet-land environments, tidal flat and rice field, which are possibly different with the environments in other countries because of their own climatic conditions. FW tanks, filled with rice field soils and fresh water, consist of FW1&2 (with paddy), FW3&4 (without paddy), and FW5&6 (newly reclaimed, without paddy). SW tanks, filled with tidal flat sediments and salt water, are SW1&2 (with anoxic silty mud), SW3&4 (anoxic mud), and SW5&6 (suboxic mud). Contaminated solution, which is formulated with the salts of Cu, Cd, As, Cr, Pb, Hg, and glucose+glutamic acid, was spiked into the supernatent waters in the tanks. Nitrate concentrations in supernatent waters as well as bacterial cell numbers and enzyme activities of soils in the FW tanks (except FW5&6) are clearly higher than those in the SW tanks. Phosphate concentrations in the SW1 tank increase highly with time compared to those in the other SW tanks. Removal rates of Cu, Cd, and As in supematent waters of the FW5&6 tanks are most slow in the FW tanks, while the rates in SW1&2 are most fast in the SW tanks. The rate for Pb in the SW1&2 tanks is most fast in the SW tanks, and the rate for Hg in the FW5&6 tanks is most slow in the FW tanks. Cr concentrations decrease generally with time in the FW tanks. In the SW tanks, however, the Cr concentrations decrease rapidly at first, then increase, and then remain nearly constant. These results imply that labile organic materials are depleted in the FW5&6 tanks compared to the FW1&2 and FW3&4 tanks. Removal of Cu, Cd, As from the supernatent waters as well as slow removal rates of the elements (including Hg) are likely due to the combining of the elements with organic ligands on the suspended particles and subsequent removal to the bottom sediments. Fast removal rates of the metal ions (Cu, Cd, As) and rapid increase of phosphate concentrations in the SW1&2 tanks are possibly due to the relatively porous anoxic sediments in the SW1&2 tanks compared to those in the SW3&4 tanks, efficient supply of phosphate and hydrogen sulfide ions in pore wates to the upper water body, complexing of the metal ions with the sulfide ions, and subsequent removal to the bottom sediments. Organic materials on the particles and sulfide ions from the pore waters are the major factors constraining the behaviors of organic/inorganic elements in the supernatent waters of the experimental tanks. This study needs more consideration on more diverse organic and inorganic elements and experimental conditions such as tidal action, temperature variation, activities of benthic animals, etc.

• Korean Journal of Environmental Agriculture
• /
• v.25 no.4
• /
• pp.323-330
• /
• 2006

This experiment was conducted to investigate heavy metal transition and bioavailability from soil to the edible pare of water dropwort near industrial complex. The soils were collected from the paddies cultivating water dropwort stream sediments, and background soils near industrial complex. The pH values, organic matter, Av. $P_2O_5$, Ex. Ca content of paddy soils were higher than those measured for nor-contaminated paddy fields in 2003. The contents of Cd and Cu was higher than those of standard level for soil contamination by Soil Environmental Conservation Act in Korea. The pollution index in stream sediments were higher than those of paddies cultivating water dropwort. The geoaccumulation index of heavy metals in paddy soils and stream sediment were in the order Cu>Cd>Ni>Zn>Pb. The rates of 0.1N-HCl extractable heavy metals to total contents in soils were in the order Cd>Cu>Zn>Ni>Pb. In case of Cd and Ni in paddy soils near industrial complex, 0.1N-HCl extractable heavy metals and total content were highly correlated with each other. Heavy metal contents in mot parts were higher than those in top pare of water dropwort. The Zn and Cu transfer factor from soil to the top pare of water dropwort were higher than those of other heavy metals. The bioavailability of water dropwort varied considerably between the different parts and heavy metals. Cd, Cu and Ni contents in water dropwort were correlated with each elements in paddy soils.

• Korean Journal of Soil Science and Fertilizer
• /
• v.29 no.4
• /
• pp.432-438
• /
• 1996

This study was carried out to prepare information for the establishment of countermeasures for an area contaminated with minewaste from an old zinc mine at Kahak-long in Kwangmyong. Minewaste and bottom sediments from the streams in this area were sampled and were analyzed for Cd, Cu, Pb, and Zn extracted with different solution. Total heavy metal contents in both minewaste and bottom sediments were fairly high. Cadmium and Zn contents in the minewaste and Cd, Cu, Pb, and Zn contents in the bottom sediments extracted with 0.1 N HCl showed a much higher level than those in the background level of paddy soils and in the soils around the other metal mines regardless of the distance from the mine. Sulfide/residue forms of Cd, Cu, Pb, and Zn covered the highest portions for the minewaste. For bottom sediments, sulfide/residue forms of Cu and Zn formed the highest portions, whereas the contents of both carbonate and sulfide/residue forms of Cd and Pb were significant. The lower the pH of the extracting solutions, the more heavy metals extracted from both minewaste and bottom sediments.

• Economic and Environmental Geology
• /
• v.36 no.6
• /
• pp.481-490
• /
• 2003

The objectives of this study are (1) to determine the extent and degree of As contamination of the water and sediments influenced by mining activity of the abandoned Au-Ag mines, (2) to examine As speciation In contaminated water, (3) to monitor variation of As contamination in water system throughout the dry and wet seasons, and (4) to investigate the As chemical form in the sediments through the sequential extraction analyses. Natural water(mine water, surface water and groundwater) and sediments were collected in six abandoned Au-Ag mine(Au-bearing quartz veins) areas. The contamination level of As in mine water of the Dongil(524${\mu}m$/L) is more higher than the tolerance level(500 ${\mu}m$/L) for waste water of mine area in Korea. Elevated levels of As in stream water were also found in the Dongil(range of 63.7∼117.6 ${\mu}m$/L.) and Gubong(range of 56.1∼62.9 ${\mu}m$/L) mine areas. Arsenic contamination levels in groundwater used by drinking water were more significant in the Dongil(11.3∼63.5 ${\mu}m$/L), Okdong(0.2∼68.9 ${\mu}m$/L) and Gubong(2.0∼101.0${\mu}m$/L) mine areas. Arsenate[As(V), $H_2AsO_4^-$] is more dominant than arsenite[As(III), $H_3AsO_3$] in water system of the most mine areas. The concentration ratios of As(III) to As(total), however, extend to the 95% in stream water of the Okdong mine area and 70∼82% in groundwater of the Okdong and Dongjung mine areas. As a study of seasonal variation in the water system, relatively high levels of As from the dongil mine area were found in April rather than in September. Sequential extraction analysis showed that As was predominantly present as coprecipitated with Fe hydroxides from sediment samples of the Dongjung and Gubong mine(35.9∼40.5%), which indicates its possibility of re-extraction and inducing elevated contamination of As in the reductive condition. In sediments from the Dongil, Okdong and Hwachon mine area, high percentage(55.2∼83.4%) of As sulfide form was found.

• Korean journal of applied entomology
• /
• v.44 no.2
• /
• pp.97-108
• /
• 2005

Samples of water, soil, and sediment were taken from 10 streams near Andong, Korea in May 2004. To assess the degree of environmental pollution of each stream, chemical pollutants such as total notrogen (T-N), total phosphorus (T-P), chemical oxygen demand (COD), heavy metals, organophosphorus pesticides, organochlorine pesticides, and dioxin-like PCB congeners were analyzed by standard process tests or U.S. EPA methods. In addition, biomarkers originated from insect immune systems of beet armyworm, Spodoptera exigua, were used to analysis of the environmental samples. Except Waya-chun stream showing T-N content of 9.12 mg/L, most streams were contaminated with relatively low levels of overall pollutants in terms of T-N, T-P, and COD, compared to their acceptable environmental levels designated by the Ministry of Environment. Contents of Pb and Cd in samples of each stream were much lower than environmentally permissible levels. However, several times higherconcentrations of Pb and Cd were found in locations at Mi-chun, Kilan-chun, and Hyunha-chun streams, in comparison with other streams. Diazinon, parathion, and phenthoate compounds among organophosphorus pesticides were detected as concentrations of 0.19, 0.40, and $1.13\;{\mu}g/g$, respectively, from soil sample collected in the vicinity of Mi-chun stream. On the other hand, 16 organochlorine pesticides and 12 dioxin-like PCB congeners, known as endocrine disrupting chemicals, selected in this study were not found above the limit of detection. Biomarker analyses using insect immune responses indicated that Waya-chun stream was suspected as exposure to environmental pollutants. Limitation and compensation of both environmental analysis techniques are discussed.

• Journal of the Korean GEO-environmental Society
• /
• v.23 no.9
• /
• pp.33-40
• /
• 2022

Sedimentation and pH neutralization has been investigated as preteatment of acid contaminate water. The settling and neutralizing process derive more effective degradation efficiency as the pre-treatment process before the removal process of adsorption, volatile, biodegradation, or oxidation. Settling velocity, uniformity coefficient, coefficient of curvature, and grain size index can define in the sedimentation process for characteristics of the soil. The stainless steel sieve has been used to separate each particle size of the dry soil by assembling in order of 4, 10, 20, 40, 80, 100, and 200 mesh sizes. The soil from Gamcheon Port in Busan drops upper side of the sieve and shakes back and forth to separate each different size of the particle. The 1L of Imhoff cone and 200 mL of the mass cylinder were used as settling tanks to calculate settling velocity. Stokes' equation was used to figure out the average density of dry soil with a value from settling velocity. In the results, the average particle density and lowest settling velocity were 1.93 g/cm³ and 0.11 cm/s, respectively. These values can detect the range of settling points of sediment to prevent chemical accidents. In pH neutralization, the initial pH of 2, 3, 4, and 5 of nitric acid and sulfuric acid are used as an acid solution; 0.1, 0.01, and 0.001 M of sodium hydroxide and calcium hydroxide are used as a base solution. The main goal of this experiment is to figure out the volume percentage of the acid solution becomes pH 7. The concentration of 0.001 M of base solution exceeds all the conditions, 0.01 M exceeds partially, and 0.1 M does not exceed 5 v/v% except pH 2. Calcium hydroxide present less volume than sodium hydroxide at pH neutralization both sulfuric and nitric acid.