• Journal of Korean Society on Water Environment
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• v.20 no.2
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• pp.110-119
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• 2004

The combination of biological and physical/chemical technologies is a promising technique to reduce highly concentrated pollutants in livestock wastewater. It is suggested to treat livestock wastewater efficiently as follows: firstly, biodegradable organic matters, nitrogen and some of phosphorus should be removed by a biological treatment process and then residual non-biodegradable organic matters, color and phosphorus be eliminated by physicochemical technologies. In this study, therefore, the integrations of chemical coagulation, activated carbon adsorption, Fenton oxidation and ozonation were evaluated to provide appropriate post-treatment processes for biologically pre-treated livestock wastewater. After chemical coagulation followed by ozonation or Fenton oxidation process, the quality of treated wastewater could meet the discharge limit in Korea. However, a yellowish brown color still remained in the treated wastewater after a single method such as coagulation and Fenton oxidation was applied. The ozonation was found to be the most effective technology for the decolorization. Neither simple biological nor physicochemical treatment provides adequate decolorization and sufficient depletion of organics in livestock wastewater so far. Consequently, the integration of Fenton oxidation and ozonation with a biological treatment process is recommended to treat livestock wastewater in terms of removal efficiency.

• Molecular & Cellular Toxicology
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• v.4 no.1
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• pp.45-51
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• 2008

Volatile Organic Compounds (VOCs) have been shown to cause nervous system disorders through skin contact or respiration, and also cause foul odors even at low densities in most cases. Also, as a compound itself, VOCs are directly harmful to the environment and to the human body, and may participate in photochemical reactions in air to create secondary pollutants. In this study, HL-60 cells were treated with volatile organic compounds, including ethylbenzene and trichloroethylene, at a value of $IC_50$. Then, the in house-prepared Human HazChem arrayer was utilized in order to compare the gene expression between the two VOCs. After hybridization, 8 upregulated genes and 8 downregulated genes were discovered in the HazChem array. The upregulated genes were identified as SG15, TNFSF10, PRNP, ME1, NCOA4, SRXN1, TXNRD1, and XBP1. The downregulated genes were identified as MME, NRF1, PRARBP, CALCA, CRP, BAX, C7 or f40, and FGFR1. Such results were highly correlated with the quantitative RT-PCR results. The majority of the 16 genes were related with the characteristics of VOCs, including respiratory mechanism, apoptosis, and carcinogenesis-associated genes. Our data showed that our human HazChem array can be used to monitor hazardous materials via gene expression profiling.

• Journal of environmental and Sanitary engineering
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• v.20 no.3 s.57
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• pp.36-43
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• 2005

Prior to the study of the sewage treatment methods, water quality for Gwangju sewage of fluent was investigated from January to December, 2004 for sewage water reuse. Monthly mean values of BOD, SS, turbidity, total phosphorus and color were 4.1 mg/L, 2.9 mg/L, 0.8 NTU, 1.3 mg/L, and 27 unit, respectively. Jar-test was performed to investigate the removal efficiency of pollutants under the coagulation conditions of fast mixing for 5 min, slow mixing for 15 min and precipitation for 1hr. Here, alum and polyaluminium chloride (PAC) were used as coagulants to reduce color, turbidity, total phosphorus (TP) and total organic carbon (TOC) in sewage effluents. The results showed that PAC gave better efficiency in removing turbidity and dissolved phosphorus than alum. It was also found from the relative molecular weight (RMW) distribution analysis that organic matter over 1,000 Dalton (Da) was easily removed by coagulation and subsequently MF treatment, while it was not effective for less than 500 Da. Based on tis result, Natural organic matter (NOM) with lower molecular weight (< 500 Da) may cause harmful disinfectant by-product (DBP) after chlorine treatment. Thus, activated carbon adsorption seems to be required for the complete removal of DBP in the hybrid system.

• Journal of Environmental Science International
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• v.15 no.11
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• pp.1011-1016
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• 2006

Recently, volatile organic compound(VOC) has been noted as a main cause of air pollution. VOC, with its toxic and offensive odor, is hazardous to health. Furthermore indoor, underground and hish-rise buildings are preferable living spaces. People spend more than 80% of the day indoor, so indoor air pollution is a matter of importance. In Korea, from 2004, 10 types of indoor pollutants in public facilities have been identified. However, there is no standard for individual VOC, so the regulation has not yet effectively been carried out. In this study, we have studied on the diffusion of Benzene in a room using a numerical analysis for various air-controlled conditions consisted of door, window and ventilation system. This study investigates spatial concentration distribution and time-history of room-averaged benzene concentration for several cases. The results of this study show that when the room is ventilated by a small fan only for 30 minutes, the average concentration of benzene is decreased a very little, thus the impact to human body would be serious compared to the case of natural ventilation by window and door, In the case of natural ventilation by window and door, if the wind speed is higher than 0.5m/s, it takes small than 4 minutes for benzene to spread to the target concentration of $1.2mg/m^3$.

• The KSFM Journal of Fluid Machinery
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• v.17 no.3
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• pp.41-45
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• 2014

The biological aerated filter (BAF) reactor is regarded as an effective biological wastewater treatment method. It can remove pollutants by carrier filtration and biodegradation. Due to its advantages, which include high biomass retention, tolerance to toxicity, excellent removal efficiency, and slurry separation, BAF has been widely used to remove COD, $NH_4{^+}-N$, phosphorus, and other harmful organic substances. In this study, the BAF reactor was used to remove organic contaminants of domestic wastewater of Korea at both the benchand pilot-scale. The main objectives of this study are to: (i) investigate the removal efficiency of organic contaminants (ex. COD, nitrate, phosphorus) in BAF reactors at both scales; (ii) characterize the small-scale wastewater treatment plant using the BAF reactor. The concentration of COD in the influent increased from 69 to 246 mg/L. During the operation period, the final effluent concentration of COD remained maximum 4.0 mg/L, and the average removal efficiency was above 88%. The present study investigated the removal efficiencies of COD, TN, TP and $NH_4{^+}-N$ from smelting wastewater by BAF system. When treating wastewater in both bench and pilot-scale reactors, the BAF worked well.

• Journal of Ecology and Environment
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• v.38 no.3
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• pp.319-326
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• 2015

This study investigates the behavioral characteristics and forms of phosphorus in the sediment according to the oxygen condition (aerobic/anaerobic). In the behavioral characteristics analysis, Al-P and Fe-P concentrations were the highest among the forms of inorganic phosphorus, and therefore had the strongest impact on sorption and release corresponding to environmental condition changes. In the experimental investigation of the inorganic forms of phosphorus in the sediment according to the oxygen condition, we determined that the forms of inorganic phosphorus did not greatly affect the sorption or release reaction because the distribution ratios of the inorganic forms remained constant corresponding to changes of dissolved oxygen (DO) conditions. In contrast, the forms of organic phosphorus in the sediments affected both sorption and release. Furthermore, labile-P and moderately labile-P forms were the major mechanisms of sorption in sediment. Moderately labile-P was the greatest contributor to phosphorus release action in sediment. As environmental changes are important for the behavioral characteristics of phosphorus in sediment, the forms of phosphorus should be considered to have a greater effect, especially in the organic phosphorus case. Therefore, based on the present study results, sediment evaluation aimed at controlling internal pollutants in reservoirs should include an examination of the forms of phosphorus present, as well as the release characteristics of environmental changes, which are influential factors of phosphorus control. Further research in this field is required.

• Environmental Mutagens and Carcinogens
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• v.15 no.2
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• pp.131-139
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• 1995

Air suspedned particulates are the most serious factor among air pollutants in Seoul and their extracts have been revealed to be pulmonary carcinogenes. Air particulates were collected at a site representative of the high traffic area of Seoul from December 1993 to May 1994. Polycyclic aromatic hydrocarbons (PAHs) and nitroarenes in organic extracts of air particulates were determined by gas chromatography and mutagenicity of particle extracts was evaluated by the pre-incubation procedure with Salmonella typhirnurium TA98 and TA 98NR. The average concentration of total suspended particulates and inhalable (less than 10 $\mu$m) particulates were 169.63 $\mu g/m^3$, 141.92 $\mu g/m^3$, respectively. The relative contribution of organic matters was highest in neutral fraction and was lowest in basic fraction. Among identified 20 PAHs, the level of PAHs with 4-benzen ring i.e., pyrene, benzo(a)anthracene and chrysene were much higher than the PAHs with higher ring numbers. The mutagenicity of air particulates was much higher in the presence of rat liver microsomai fraction (S9 mixture) than that observed in its absence, which indicates that air particulates contained both direct and indirect mutagens. Nitroarenes in this study were not almost detected but mutagenicity of their fraction was higher. These results are represent to research for the identification of nitroarenes in the forward study.

• Economic and Environmental Geology
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• v.27 no.5
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• pp.469-477
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• 1994

Many researchers have investigated most representative sequential extraction method using various reagents for determining the chemical forms of metals in soils and sediments. In this paper, a newly modified method for sequential extraction scheme based on Tessier's method by Environmental Geochemistry Research, Centre for Environmental Technology, Imperial College, was introduced and examined. In comparison with Tessier's method, originally designed for sediment analysis by Atomic Absorption Spectrophotometry (AAS), the sequential extraction scheme has been developed for the multi-element analysis by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The partitioning of particulate trace elements was classified into five fractions: (i) exchangeable, (ii) bound to carbonates or specially adsorbed, (iii) bound to Fe and Mn oxides, (iv) bound to organic matter and sulphides and (v) residuals. The experimental results of the pilot study for in-house reference material (HRM2) and certified international standard reference material (SRM2711) using the modified method showed not only reasonable precision and accuracy but also acceptable overall recovery rates. In addition, mine dump soils sampled in the Dalsung Cu-W mine, Korea were prepared and sequentially extracted using the method. Most of Cu was bound to organic matter/sulphides and residual fractions. The dominant fraction of soil Pb and Zn in the study area was found in the residuals. The fraction of Cd showed a wide variation between samples and could be found bound to the carbonates or specially adsorbed, oxides, organic fraction and residuals. The recovery rates of Cd, however, were poor due to relatively low Cd concentrations in soils. The heavy metals in these mine dumps appear to be in the more inert forms and should not be readily bioavailable. The soils, however, had very low pH values (average 4.1) and had sandy textures; consequently, rapid infiltration of rainfall may increase leaching of Zn and Cd which were found to be around 5 to 10% of the exchangeable fraction. As a result of the investigation of this study, it has been strongly recommended that these mine waste materials should still be considered a significant contaminant source and will need environmental remediation to prevent pollutants from being released into the environment.

• Journal of Korean Society on Water Environment
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• v.25 no.6
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• pp.902-909
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• 2009

With various reservoirs, dams and reduction of water velocity in downstream, rivers in Korea often have characteristics of accumulation of pollutants. Therefore, the main focus of water quality modeling in Korea needs to be shifted from DO to algae and organic matter. Moreover the structures of water quality models should be modified to have capability of simulating BOD which is a key factor of total water pollution load management in Korea as laboratory experiment BOD (Bottle $BOD_5$). In the SWAT model which is one of the widely used water quality models in Korea, the channel water quality module is using main algorithm of the QUAL2E model which has limitations in simulating algae, organic matter and Bottle BOD5 etc. To overcome this hindrance, in this study, the improved channel water quality module of the SWAT model (Q-SWAT) was proposed by linking the algorithms of the QUAL-NIER model which was developed based on the QUAL2E model to the SWAT model. The algorithms estimating the increase of internal organic matter by fractionization algal metabolism process and calculating Bottle $BOD_5$ were added and the results of proposed model were compared to those of the original SWAT model. The results of comparison test are showing that more accurate BOD values can be obtained with the Q-SWAT model and it is anticipated that the Q-SWAT model can be used as an effective tool of decision support through the water quality simulation and long term pollution source analysis.

• Journal of Korean Society on Water Environment
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• v.33 no.6
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• pp.722-727
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• 2017

Livestock manure is known to be the main cause of non-point pollution in agricultural areas. The pollutant reduction ratio of livestock manure recycling to fertilizers was measured in order to analyze the effect on the water quality of the Total Maximum Daily Load (TMDL) system in Korea. The reduction ratio has been applied by theoretical consideration without a survey, and there is no value for Total Organic Carbon (TOC) newly introducing any organic items. The reduction ratio of each pollutant from this study was revealed as follows: TOC, BOD, T-N and T-P were 0.34, 0.60, 0.37, and 0.42 for individual farm and 0.38, 0.61, 0.45 and 0.44 for entrustment facilities, respectively. The reduction ratio of individual farm was surveyed as TOC 0.63, BOD 0.62, T-N 0.42 and T-P 0.32 for liquid fertilizer, and TOC 0.30, BOD 0.64, T-N 0.40 and T-P 0.48 for compost. The total reduction ratio was derived by multiplying the ratio for liquid fertilizer and compost by the respective load. Compared to the pollutant reduction ratio of the individual farm with entrustment facilities marking the higher in liquid fertilizer and the lower in compost. Through this study, we found the difference of pollutant reduction ratio between a livestock manure recycling process and facilities. Although phosphorus is known as a preservative matter, the treatment efficiency of T-P is analyzed to decrease by chemical precipitation.