• Korean Journal of Environmental Agriculture
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• v.24 no.2
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• pp.98-105
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• 2005

Groundwater sampled from 24 tube wells of three districts namely Sherpur, Gaibandha and Naogaon in Bangladesh was appraised for their water quality for irrigation and agro-based industrial usage. All waters under test were slightly alkaline to alkaline (pH = 7.2 to 8.4) in nature and were not problematic for crop production. As total dissolved solid (TDS), all groundwater samples were classified as fresh water (TDS<1,000 mg/L) in quality. Electrical conductivity (EC) and sodium adsorption ratio (SAR) values reflected that waters under test were under medium salinity (C2), high salinity (C3) and also low alkalinity (S1) hazard classes expressed as C2S1 and C3S1. As regards to EC and soluble sodium percentage (SSP), groundwater samples were graded as good and permissible in category based on soil properties and crop growth. All water samples were free from residual sodium carbonate (RSC) and belonged to suitable in category. Water samples were under soft moderately hard, hard and very hard classes. Manganese, bicarbonate and nitrate ions were considered as major pollutants in some water samples and might pose threat in soil ecosystem for long-term irrigation. For most of the agro-based industrial usage, Fe and Cl were considered as troublesome ions. On the basis of TDS and hardness, groundwater samples were not suitable for specific industry. Some water samples were found suitable for specific industry but none of these waters were suitable for all industries. The relationship between water quality parameters and major ions was established. The correlation between major ionic constituents like Ca, Mg, K, Na, $HCO_3$ and Cl differed significantly. Dominant synergistic relationships were observed between EC-TDS, SAR-SSP, EC-Hardness, TDS-Hardness and RSC-Hardness.

• Parasites, Hosts and Diseases
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• v.53 no.5
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• pp.641-645
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• 2015

Fascioliasis, a food-borne trematode zoonosis, is a disease primarily in cattle and sheep and occasionally in humans. Water dropwort (Oenanthe javanica), an aquatic perennial herb, is a common second intermediate host of Fasciola, and the fresh stems and leaves are widely used as a seasoning in the Korean diet. However, no information regarding Fasciola species contamination in water dropwort is available. Here, we collected 500 samples of water dropwort in 3 areas in Korea during February and March 2015, and the water dropwort contamination of Fasciola species was monitored by DNA sequencing analysis of the Fasciola hepatica and Fasciola gigantica specific mitochondrial cytochrome c oxidase subunit 1 (cox1) and nuclear ribosomal internal transcribed spacer 2 (ITS-2). Among the 500 samples assessed, the presence of F. hepatica cox1 and 1TS-2 markers were detected in 2 samples, and F. hepatica contamination was confirmed by sequencing analysis. The nucleotide sequences of cox1 PCR products from the 2 F. hepatica-contaminated samples were 96.5% identical to the F. hepatica cox1 sequences in GenBank, whereas F. gigantica cox1 sequences were 46.8% similar with the sequence detected from the cox1 positive samples. However, F. gigantica cox1 and ITS-2 markers were not detected by PCR in the 500 samples of water dropwort. Collectively, in this survey of the water dropwort contamination with Fasciola species, very low prevalence of F. hepatica contamination was detected in the samples.

• Journal of Korean Society of Water and Wastewater
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• v.32 no.6
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• pp.559-572
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• 2018

The aim of this study was to evaluate pretreatment methods for 27 pharmaceuticals and personal care products (PPCPs) in various sewage samples using a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) and online solid-phase extraction with LC-MS/MS. Extraction efficiencies of PPCPs in the solid phase under different experimental conditions were evaluated, showing that the highest recoveries were obtained with the addition of sodium sulfate and ethylenediaminetetraacetic acid disodium salt dehydrate in acidified conditions. The recoveries of target compounds ranged from 91 to 117.2% for liquid samples and from 61.3 to 137.2% for solid samples, with a good precision. The methods under development were applied to sewage samples collected in two sewage treatment plants (STPs) to determine PPCPs in liquid and solid phases. Out of 27 PPCPs, more than 19 compounds were detected in liquid samples (i.e., influent and effluent) of two STPs, with concentration ranges of LOQ-33,152 ng/L in influents and LOQ-4,523 ng/L in effluents, respectively. In addition, some PPCPs such as acetylsalicylic acid, ibuprofen, and ofloxacin were detected at high concentrations in activated sludge as well as in excess sludge. This methodology was successfully applied to sewage samples for the determination of the target compounds in STPs.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.2
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• pp.42-51
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• 2010

Herbs and shrubs are employed for environmental restoration purposes. Among common herbs and shrubs, few species with low germination rates were selected and studied for enhanced germination rates and decreased germination times via soaking treatment. Rhus chinensis, incubator grown samples treated with the bacterial solution for 72hrs followed by immediate seeding showed the highest germination rate of 26.7% and germination period of 5.7 days, 3 days decrease from the control. Treatment of distilled water (t=3.79, p<0.01), nutrient broth (t=4.44, p<0.00) and bacterial solution (t=4.42, p<0.00) showed highly significant difference. In the case of soil tests, treating in the nutrient broth for 72 hrs followed by immediate seeding yielded the the highest germination rate of 23.3% with 7.3 days to initial germination, a decrease of 14.7 days with respect to the control. All the samples followed by immediate seeding showed significant difference (t=2.13, p<0.05). Incubator grown samples of Lespedeza cyrtobotrya showed different results. The incubator samples suspended for 48 hrs in distilled water followed by immediate seeding and 1 day drying displayed the highest germination rate of 96.7%, surpassing that of the control by 33.4%. The incubator samples treated with the distilled water and nutrient broth showed enhanced germination. But only the samples treated with distilled water and nutrient broth for 48hrs showed the increased germination in soil tests. All the sample treated for 24 hrs followed by immediate seeding or dried for 1 day showed initial germination as early as 1 day in incubator. The initial germinations were shortened in the samples treated with distilled water and nutrient broth for 48hrs in soil tests. Lespedeza cuneata incubator sample treated with nutrient broth for 24 hrs and dried for 1 day exhibited the highest germination rate of 83.3%, a 31.1% improvement over the control. The incubator samples treated with distilled water for 48 hrs (t=4.20, p<0.01) showed effective increase of germination. The treatment of distilled water (t=2.96, p<0.05) and bacterial solution (t=2.24, p<0.05) showed significant difference. The germination rates in soil were less than those of incubator and the control. The incubator samples treated with distilled water and bacterial solution displayed 1 day germination period, shortened by 1.3 days compared to the control. For soil grown samples, the samples treated with distilled water showed delayed initial germination and those treated with nutrient broth for 48hrs and bacterial solution for 72hrs shortened initial germination.

• Analytical Science and Technology
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• v.30 no.4
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• pp.194-204
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• 2017

Direct injection (DI) and solid phase extraction (SPE) methods for the simultaneous determination of pendimethalin (PDM) and dinoseb (DNS) in environmental water have been optimized using the ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method. The limits of quantification (LOQs) of PDM and DNS were $0.01{\mu}g/L$ using the DI method and $0.0001-0.0002{\mu}g/L$ using the SPE method. The precision by SPE UPLC-MS/MS was less than 11 % for intra-day and inter-day analyses. When the proposed SPE method was used to analyze two analytes in environmental water, PDM was detected in a concentration range of $0.0002-0.011{\mu}g/L$ in 31 samples of the 114 surface water samples, and DNS was detected in a concentration range of $0.0005-0.045{\mu}g/L$ in 17 samples of the 114 surface water samples analyzed. When the DI method was used to analyze target compounds in the same samples, the detected concentrations of the two analytes were within 21% in samples with concentrations above $0.01{\mu}g/L$. The DI UPLC-MS/MS method can thus be used for the routine monitoring of PDM and DNS in environmental water, and the SPE LC-MS/MS method can be used for the determination of the ultra-trace PDM and DNS residues in environmental water.

• Journal of Environmental Science International
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• v.9 no.3
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• pp.241-252
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• 2000

Twenty-two water samples(fifteen groundwater and seven geothermal water samples) were collected to elucidate chemical characteristics of the ground and geothermal waters in the Haeundae hot spring area and its vicinity. Major and honor elements were analyzed for ground and geothermal water samples. The concentrations of $K^+$, Na+$, $Ca^{2+}$, $SO_4^{2-}$, $Cl^-$, ^F^-$ and $SiO_2$ were higher in the geothermal water samples than the groundwater samples except $HCO_3^- and Mg^{2+}$ ions. Based on the contents of Fe, Zn, Cu, Al, Mn and Pb, some of the ground and geothermal water samples are contaminated by anthropogenic sources. The ground waters shown on the Piper diagram belong to $Ca-HCO_3$ type, while the geothermal waters Na-Cl type. The graphs of $Cl^-$ versus $Na^+$, $Ca^{2+}, Mg^{2+}, K^+, SO_4^{2-} and HCO_3^-$ indicate that the groundwater is related partly with mineral-water reaction and partly with anthropogenic contamination, while the geothermal water is related with saline water. On the phase stability diagram, groundwater and thermal water mostly fall in the field of stability of kaolinite. This indicates that the ground and geothermal waters proceed with forming kaolinite. Factor and correlation analyses were carried out to simplify the physicochemical data into grouping some factors and to find interaction between them. Based on the Na-K, Na-K-Ca and Na-K-Ca-Mg geothermometers and silica geothermometers, the geothermal reservoir is estimated to have equilibrium temperature between 125${$\mid$circ}C$ and 160${$\mid$circ}C$.

• Journal of Environmental Health Sciences
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• v.29 no.2
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• pp.38-44
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• 2003

This study was performed to investigate the levels of fluoride (F), calcium (Ca), and magnesium (Mg) in water samples taken from five reservoirs or direct sources on a stream used for agricultural or domestic water in the Iksan and Wanjoo areas, Jeon-buk, Korea, and to find a possible link between Ca or Mg and fluoride in water sources in theses areas. The samples were collected by the recommendation methods of the World Health Organization and analyzed by the recommendations of the Japanese Standard Methods. Statistical analyses were performed by the analysis of variance and correlation analysis. The F levels in water samples wire 0.80~2.53 ppm. In four sampling sites the water fluoride levels exceeded 1 ppm. which if the recommended level for fluorosis/caries control. The Ca levels in water samples were 6.82~12.98 ppm, and the Mg levels were 0.30~1.97 ppm, which are lower compared with the natural levels of water sources previously reported by other investigators. This study showed a positive correlation between Ca and Mg (r= 0.8779. p<0.01) and a negative correlation between F and Ca (r=-0.6974, p<0.05) and also between F and Mg (r=-0.5581) in the water samples. However, the study did not find remarkable relationships in fluoride levels between sampling sites. These results support the fact that there were epidemics of dental fluorosis in this area. The lack of significant positive correlations in fluoride levels between sampling sites suggests that there may be some pathways for the transfer of the metal to the water through other environmental media besides the water course. Long-term epidemiological studies are needed on the relationship between high F together with low Ca and Mg levels in the water, and total human health in this community. There should alto be a long-term monitoring of the water quality in this area.

• Journal of Soil and Groundwater Environment
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• v.15 no.6
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• pp.91-98
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• 2010

The effective thermal conductivity of porous materials is usually determined by porosity, water content, and the conductivity of the matrix. In addition, it is also affected by the internal structure of the materials such as the size, arrangement, and connectivity of the matrix-forming grains. Based on the structural models for multi-phase materials, thermal conductivities of soils and sands measured with varying the water content were analyzed. Thermal conductivities of dry samples were likely to fall in the region between the Maxwell-Eucken model with air as the continuous phase and the matrix as the dispersed phase ($ME_{air}$) and the co-continuous (CC) model. However, water-saturated samples moved down to the region between the $ME_{wat}$ model and the series model. The predictive inconsistency of the structural models for dry and water-saturated samples may be caused by the increase of porosity for water-saturated samples, which leads to decrease of connectivity among the grains of matrix. In cases of variably saturated samples with a uniform grain size, the thermal conductivity showed progressive changes of the structural models from the $ME_{air}$ model to the $ME_{wat}$ model depending on the water content. Especially, an abrupt increase found in 0-20% of the water content, showing transition from the $ME_{air}$ model to the CC model, can be attributed to change of water from the dispersed to continuous phase. On the contrary, the undisturbed soil samples with various sizes of grains showed a gradual increase of conductivity during the transition from the $ME_{air}$ model to the CC model.

• Journal of Korean Society on Water Environment
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• v.33 no.2
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• pp.197-202
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• 2017

This paper aimed to evaluate the test results of acute toxicity on effluent samples which were exempted from applying of ecotoxicity criteria. Total 316 effluent samples which were free from controlling of ecotoxicity regulation, were tested. Ratio of effluent samples which were exceeded the ecotoxicity criteria (TU > 1) indicated 23.7%. This ratio was a little bit higher than previous study (22.7%) on effluent samples which were controlled under ecotoxicity criteria. These results mean that our ecotoxicity management system is not appropriate and applying of ecotoxicity criteria to all effluent samples (82 industry categories) were needed in order to improve our ecotoxicity system. In addition, the same numeric criteria (TU 1 or 2) for all industry categories were proposed in consideration of these results. Ratio of effluent samples which exceeded the ecotoxicity criteria (TU > 1) with D. magna indicated 23.7%. However V. fischeri showed 14.6%. As a acute toxicity test organism, D. magna seemed to be more sensitive than V. fischeri. Ratio of samples which were exceeded TU 1 with D. magna by 24 h exposure period test indicated 35 %, whereas 48 h showed 41%.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.E1
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• pp.12-23
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• 2008

Relationship between the optimum soil water content and clay content on soil samples from mid-latitude European forest was tested. Soil samples from 4 different experimental sites (two forest sites in the Netherlands and a Danish forest) were collected, and analyzed for the soil physical and chemical characteristics. Water retention curves for the soil samples were determined according to the standard procedure ISO 11274, and pF decreased with increase in soil water contents. NO is simultaneously produced and consumed by microbiological processes, which comprise of nitrification and denitrification. NO consumption and production rates were determined from the soil samples and compared to their corresponding water retention curves in order to find the optimum soil water content and matric potential for maximum NO release from mid-latitude soils. NO consumption rate coefficient (k) in Hollandse Hout was significantly lower than those in other soil sites. Maximum NO production was observed at an intermediate soil moisture ($0.2{\sim}0.3kg/kg$) in all the soil samples. Resulting from the NO consumption and production rates for the soils, the empirical NO fluxes of the different soils were calculated in the laboratory.