• Journal of Wetlands Research
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• v.18 no.1
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• pp.39-44
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• 2016

The reuse of spent coffee powder has been researched for environmental engineering applications such as adsorbents of organic/inorganic pollutants. In this study adsorption equilibrium tests and adsorption kinetics tests for the removal of aqueous organic pollutant (methylene blue) were conducted using spent coffee powder, granular activated carbon, and powdered activated carbon. It was found that the maximum adsorption capacity of three adsorbents followed the order of powdered activated carbon (178.6 mg/g) > spent coffee powder (60.6 mg/g) > granular activated carbon (15.6 mg/g). The results of adsorption kinetics tests also indicated that spent coffee powder had higher kinetic parameters than granular activated carbon for pseudo 1st and 2nd order kinetics. The high performance of spent coffee powder might be due to its porous surface like those of granular and powdered activated carbons and smaller particle size comparing with granular activated carbon.

• Molecular & Cellular Toxicology
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• v.5 no.3
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• pp.179-186
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• 2009

Hexachlorobenzene (HCB) is a bioaccumulative, persistent, and toxic pollutant. HCB is one of the 12 priority of Persistent Organic Pollutants (POPs) intended for global action by the United Nations Environment Program (UNEP) Governing Council. POPs are organic compounds that are resistant to environmental degradation through chemical, biological, and photolytic processes. Some of HCB is ubiquitous in air, water, soil, and biological matrices, as well as in major environmental compartments. HCB has effects on various organs such as thyroid, bone, skin, kidneys and blood cells and especially, revealed strong toxicity to liver. In this study, we identified genes related to hepatotoxiciy induced by HCB in human hepatocellular carcinoma (HepG2) cells using microarray and gene ontology (GO) analysis. Through microarray analysis, we identified 96 up- and 617 down-regulated genes changed by more than 1.5-fold by HCB. And after GO analysis, we determined several key pathways which known as related to hepatotoxicity such as metabolism of xenobiotics by cytochrome P450, complement and coagulation cascades, and tight junction. Thus, our present study suggests that genes expressed by HCB may provide a clue for hepatotoxic mechanism of HCB and gene expression profiling by toxicogenomic analysis also affords promising opportunities to reveal potential new mechanistic markers of toxicity.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.3
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• pp.119-128
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• 1988

The purpose of this research is to quantify the effects of water content(0.3~1.255%) and temperature ($4{\sim}40^{\circ}C$) on the equilibrium distribution of toxic organic pollutant in unsaturated soil. The priority pollutants, Dichloromethane and 1, 1, 1-Trichloroethane were selected as toxic organic pollutants and the Korean decomposed granite soil as the experimental soil media. Two models were developed on the basis of shapes of soil water distribution in unsaturated soil and compared; complete surface coating(model I) vs. spot clustering (model II). From the experiment, a large decrease in the values of effective partition coefficient ($K_{eff}$) was observed as the water content increased. As the temperature increased, the $K_{eff}$ values decreased, and this effect was magnified at lower water contents. The values of $K_{eff}$ were correlated better with the estimated values using model II. Thus it was experimentally proved that the soil water tends to enclose the soil grain partly at lower water contents.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.4
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• pp.153-159
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• 2000

Large-scale simulated lysimeter experiments were conducted for 4 years as a fundamental study to develop enhanced landfill stabilization method, which accelerate stabilization time and make efficient practical use of self-purification capacity of pollutants in semi-aerobic solid waste landfill. The amount of TOC(total organic carbon) decomposition increased as the landfill depth increased. In case of T-N(total nitrogen), the self-purification capacity increased linearly with the landfill thickness until it reached a maximum level of 6 m. Beyond this level, the self-purification capacity was not increased. The results from lysimeter experiments indicate that 6m of landfill thickness is optimum for self-purification capacity of pollutants considering the mass balance of TOC and T-N.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.4
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• pp.151-160
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• 2006

Anaerobic treatment of landfill leachate was studied to investigate the behaviors of pollutant and the characteristics of microorganism for 10 months. The upflow anaerobic sludge blanket (UASB) reactor achieved about 90% chemical oxygen demand (COD) removal at organic loading rates(OLR) up to $20kgCOD/m^3.d$. At higher OLR ($8-20kgCOD/m^3.d$), the propionate concentration increased, indicating that converting propionate to acetate was the rate-limiting step. Nevertheless, increase in the precipitate inside and on the surface of granules as well as on the wall of the reactor resulted in operational problems. The main inorganic precipitate in the granule was calcium compound. Although specific methanogenic activity (SMA) was not affected seriously in this study, metals had to be removed prior to anaerobic treatment so as to be free from the excessive inorganic accumulation that resulted in operational problems.

• Ocean Science Journal
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• v.40 no.2
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• pp.91-100
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• 2005

Bioassay using the marine bacteria, Vibrio fischeri and rotifer, Brachionus plicatilis, and chemical analyses were conducted to assess the toxicity of the various sewage sludges, one of the major ocean dumped materials in the Yellow Sea of Korea. Sludge elutriates extracted by filtered seawater were used to estimate the ecotoxicity of the sludge. Chemical characterization included the analyses of organic contents, heavy metals, and persistent organic pollutants in sludge. Bacterial bioluminescent inhibition (15 min), rotifer mortality (24 hr) and rotifer population growth inhibition (48 hr) assay were conducted to estimate the sludge toxicity. EC50 15 min (inhibition concentration of bioluminescence after 15 minutes exposed) values by Microtox(R) bioassay clearly revealed different toxicity levels depending on the sludge sources. Highest toxicity for the bacteria was found with the sludge extract from dyeing waste and followed by industrial waste, livestock waste, and leather processing waste. Clear toxic effects on the bacteria were not found in the sludge extract from filtration bed sludge and rural sewage sludge. Consistent with Microtox(R) results, rotifer neonate mortality and population growth inhibition test also showed highest toxicity in dyeing waste and low in filtration bed and rural sewage sludge. High concentrations of persistent organic pollutants (POPs) and heavy metals were measured in the samples from the industrial wastes, leather processing plant waste sludge, and urban sewage sludge. However, there was no significant correlation between pollutant concentration levels and the toxicity values of the sludge. This suggests that the ecotoxicity in addition to the chemical analyses of various sludge samples must be estimated before release of potential harmful waste in the natural environment as part of an ecological risk assessment.

• Korean Journal of Ecology and Environment
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• v.35 no.2 s.98
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• pp.133-140
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• 2002

This study was performed in lab scaled oxidation pond. The removal efficiency of pollutant on the influence of changes of hydraulic retention time and pond style was investigated. The correlation between organic removal efficiency and dissolved oxygen concentration on algal photosynthesis showed the light time revealed a higher relationship more than the dark time, and the squares of the correlation coefficient of 15 days retention time were higher than that of 5 days in single pond. The variation of dissolved oxygen concentration of a series pond was from 4.2 to 19.8 mg/l under 5 days retention time, the concentration of dissolved oxygen increased with increasing step of series pond. Between the single pond and a series of pond system, a series of pond system showed better organic removal efficiency. Average removal efficiency range of $TBOD_5$ and $SBOD_5$ was $49{\sim}83%$ and $87{\sim}92%$, respectively. Algae should be removed appropriately to increase the removal efficiency of organic matter.

• Journal of Environmental Science International
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• v.12 no.9
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• pp.967-976
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• 2003

Volatile organic compounds (VOCs) are present in essentially all natural and synthetic materials from petrol to flowers. In this study, indoor and outdoor VOCs concentrations of houses, offices and internet-cafes were measured and compared simultaneously with personal exposures of each 50 participants in Asan and Seoul, respectively. Also, factors that influence personal VOCs exposure were statistically analyzed using questionnaires in relation to house characteristics, time activities, and health effects. All VOCs concentrations were measured by OVM passive samplers (3M) and analyzed with GC/MS. Target pollutants among VOCs were Toluene, o-Xylene, m/p-Xylene, Ethylbenzene, MIBK, n-Octane, Styrene, Trichloroethylene, and 1,2-Dichlorobenzene. Indoor and outdoor VOCs concentrations measured in Seoul were significantly higher than those in Asan except Ethylbenzene. Residential indoor/outdoor (I/O) ratios for all target compounds ranged from 0.94 to 1.51 and I/O ratios of Asan were a little higher than those of Seoul. Relationship between personal VOCs exposure, and indoor and outdoor VOCs concentrations suggested that time-activity pattern could affect the high exposure to air pollutant. Factors that influence indoor VOCs level and personal exposure with regard to house characteristics in houses were building age, inside smoking and house type. In addition insecticide and cosmetics interestingly affected the VOCs personal exposure. Higher exposure to VOCs might be caused to be exciting increase and memory reduction, considering the relationship between measured VOCs concentrations and questionnaire (p<0.05).

• Journal of the Korean Society for Marine Environment & Energy
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• v.8 no.4
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• pp.213-219
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• 2005

In this study, we try to Quantitatively assess the micropollutants in Gwangyang bay, Gamag bay and Yeoa bay, using simultaneous analytical method fir 310 chemicals. In the results, several dozen organic pollutants were detected in sampling sites, and the major chemicals detected were CH type chemicals, such as aliphatic and polycyclic compounds, and CHN(O) type chemicals, such as aromatic ammines and nitro compounds. The concentration of organic pollutants was higher in summer than in winter. However, there was no association of species of organic pollutants with season. The total concentration of pesticides at each sampling site was measured within the range of $ND{\sim}9.11{\mu}g/L$. Insecticides and fungicides of pesticide type were detected in Gwangyang bay and Gamag bay, while six kinds of endocrine disrupter were detected in southern coastal waters. From the results of this study, we should estimated that the insecticides, the fungicides, and a few of the endocrine disrupters are major pollutant factors in southern coastal waters.

• Journal of the Korean Geosynthetics Society
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• v.22 no.4
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• pp.35-42
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• 2023

This paper described the strength variation characteristics to evaluate the applicability of a reactive material that can absorb organic pollutants as an underground barrier. The Strength was evaluated by unconfined compression test. The test results showed that the strength of the reactive material according to the absorption of each pollutant was in the order of water > TCE > TPH. However, the strength of the reactive material absorbing TPH was greater than that of the case absorbing TCE, when the composition ratio of polynorbornene was 12% or less. The strength of the reaction material in contact with water continued to decrease as the polynorbornene composition ratio decreased. The strength of the reaction material in contact with TCE and TPH increased as the polynorbornene composition ratio decreased from 30% to 21%, and then decreased. In other words, the optimal composition ratio of the reactive material should be applied considering the strength due to contact with pollutants according to the stress conditions occurring in the ground.