• Journal of Korean Society of Water and Wastewater
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• v.30 no.6
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• pp.673-682
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• 2016

In this study, we investigated influent and effluent water pollutants in 53 Public Sewage Treatment Works (PSTWs) where industrial wastewater or landfill leachate is combined four times for two years from 2014 to 2015. Also, we analyzed the characteristics of heavy metals and volatile organic carbons at influent and effluent of these PSTWs caused by sewage treatment combined with industrial wastewater or landfill leachate. As a result, six heavy metals such as barium, copper, iron, manganese, nickel and zinc, and four volatile organic carbons (VOCs) including phenols, di(2-)ethylhexyl phthalate (DEHP), formaldehyde and toluene were observed above detection limits in most of PSTWs. Also, it was revealed that six heavy metals such as hexavalent chromium, mercury, cadmium, chromium, nickel and selenium, and four VOCs including 1,1-dichloroethylene, vinyl chloride, naphthalene, and epichlorohydrin were observed more frequently according to precipitation. As a result of reviewing the monitoring data on "Water Quality Monitoring Networks" in lower watersheds of PSTWs, both heavy metals and VOCs were below detection limits, indicating that the effluent water had little influence on the watershed. Nevertheless for the better management of influent and effluent pollutants in PSTWs, it is necessary to establish the advanced management plans for water pollutants in PSTWs, which include a list of priority substances management, monitoring plans, and guidelines for industrial wastewater and landfill leachate combined in PSTWs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3806-3813
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• 2012

The coastal environment is affected by Cu and Zn contamination through diverse routes, including antifouling agents, industrial wastewater, and domestic activities. In this study, Crassostrea gigas and Littorina brevicula were used to examine the distributions of Cu and Zn, which are related to the increase in the use of new antifouling agents that have been used for ships since the TBT ban in 2003. The average Cu and Zn concentrations in the samples were 231.8 ${\mu}g/g$ and 492.6 ${\mu}g/g$, respectively. Both the Cu and Zn concentrations were highest in the shipyard samples, followed by the harbor sample for Cu and the industrial area sample for Zn. The results indicated that the Cu concentration was affected by the antifouling agents, and the Zn concentration was affected by both the antifouling agents and industrial wastewater. The areas that need intensive control to address the Cu and Zn contamination in major Korean coasts were identified.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.491-491
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• 2018

본 연구는 포장모형(APEX, Agricultural Policy Environmental eXtender)과 유역모형(SWAT, Soil and Water Assessment Tool)을 연계하여 새만금 유역의 미래 수문 수질영향과 용수생산성을 분석하기 위한 기초연구이다. APEX 모형을 연계하기에 앞서 SWAT 모형을 이용하여 만경강 유역의 유출량, T-N, T-P를 모의하고 그 적용성을 평가하였다. 모의 기간은 2004년부터 2017년까지 총 14년이며, 기상, 유출량 그리고 월단위 수질 자료를 모형의 입력자료 및 보정을 위해 사용하였다. 매개변수 보정은 객관적 보정이 가능한 SWAT-CUP을 이용하여 최적화 하였으며, 매개변수 보정의 목적함수는 NSE(Nash-Sutcliffe Efficiency)로 평가하였다. 모형의 적용성 평가 결과, 보정기간의 연평균 유출량은 실측치 835mm, 모의치 677mm로 나타났고, R2는 0.64, RMSE는 3.87mm/day, NSE는 0.61, RMAE는 0.99로 나타났다. 검정기간의 연평균 유출량은 실측치 884mm, 모의치 702mm로 나타났고, R2는 0.67, RMSE는 2.92mm/day, NSE는 0.7, RMAE는 0.94로 나타났다. 유출량의 결과를 살펴보면 검정기간이 보정기간보다 모의결과가 더 나은 것으로 나타나며, 이는 실측자료의 일관성 차이로 판단된다. T-N과 T-P의 경우 매개변수만으론 보정의 한계가 있으며, 실측치와 근접하게 모의하기 위해서 만경강 본류에 영향을 끼칠 수 있는 외부유입량을 고려할 필요가 있다. 따라서 본 연구에서는 만경강 상류의 경천댐, 대아댐 그리고 용담댐으로 부터 유입되는 외부유입량 자료를 수집하여 SWAT의 입력자료로 구축하였으며, 대상유역 내 익산, 완주, 전주, 김제에 위치하고 있는 하수처리장, 축산폐수처리장, 분뇨처리시설, 산업폐수처리시설 그리고 농공단지처리시설 등 총 12곳에 대한 점오염원 데이터를 입력자료로 구축하여 만경강 상류 농업소유역의 수질영향을 평가하였다. 본 연구결과는 향후 미래 수문 수질 모의에 대한 기초자료로 제공될 것이며, 외부유입량을 고려한 만경강 유역의 용수생산성 분석을 통해 미래 농업수자원 관리계획 수립에 활용할 수 있을 것이다.

• Fire Science and Engineering
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• v.33 no.2
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• pp.107-113
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• 2019

Recently, due to global warming, the trend shows an increase in number of lightning strikes which increase risk regarding industry infrastructures. Especially in case where the lightning strikes infrastructures including refinery, petorchemical plant facilities or storage tanks, it can cause power failures, electrical machine malfunction and damage which can lead to fire explosion and multiple calamities. Therefore, detailed case studies must be conducted through a systematic research regarding lightning strike accidents in order to understand its mechanism and devise preventive measures. This paper aims to study cases of explosion regarding waste water storage tanks in refineries and petrochemical plants in order to analyze its root cause and provide preventive measures for avoiding lightning related incidents.

• Korean Journal of Environmental Agriculture
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• v.17 no.2
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• pp.145-149
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• 1998

To find out the effect of water hyacinth(Eichhornia crassipes Solms-Laub) on the control of eutrofication and plant damage with irrigation water contamination, its ability to remove the nutrients such as nitrogen and phosphrus was studied. The overall results are summarized as follow. 1. It was possible to cultivate water hyacinth for 4 month from June to the middle of October in Suwon. 2. The number of plant was increased from 1,320 to 50,600 for 4 months, and total amounts of N, P, K removed from Seo-Ho by water hyacinth were 78.3, 64.2 and 152.4 kg/10a, respectively. 3. EC and $NH_4-N$ contents were lower at water hyacinth treatment than non-treatment and monthly variation of those contents were decreased until August. 4. With the cultivation of water hyacinth in animal waste water in vinyl plastic house, pH, EC, COD and concentrations of $NH_4-N$ and $PO_4-P$ in the water were drastically decreased. 5. Nitrogen contents absorbed from waste water existed in the order of leaf > stem > root but those of phosphorus root > stem > leaf.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1733-1738
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• 2008

The treatment efficiency of rotating biological contactors (RBCs) for the high strength of dairy wastewater was investigated. Two different systems were conducted composing of a single RBC with tapered aeration reactors for the system A and a sequential RBCs following tapered aeration reactors for the system B. Experiments using dairy wastewater were conducted for 50 days period of time, in which hydraulic rates were maintained at the constant ratios of 346L per day and variable BOD concentrations were at the range from 1,358mg/L to 829mg/L, the $COD_{cr}$, concentration of the range were from 2,384mg/L to 1,329mg/L, the range of T-N concentrations was from 66mg/L to 38mg/L, and 50% of internal recycle and 50% of sludge return were performed. Results indicated that the removal efficiencies of the system B were higher than those of the system A. The removal efficiencies of system A for the BOD, $COD_{cr}$, T-N and T-P were 97.8%, 96.7%, 87.2% and 82%, respectively. The removal efficiencies of system B for the BOD, $COD_{cr}$, T-N and T-P were as of 98.5%, 98.5%, 91.3% and 89%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.558-566
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• 2017

In this study, we developed an electron-emission OH radical generator for waste water treatment. The stability of the circuitry was ensured by implementing stable pulse waves with a MOSFET and reducing the momentary current rise. The OH radical generator uses a high-voltage and low-current discharger. The performance of the device was evaluated experimentally, which showed that it is possible to produce a stable and uniform pulse waveform for the drain current of the power MOSFET, which is connected to the input side of an AC multiplying converter through negative feedback circuitry with CR-snubber architecture. It was also possible to reduce the excitation current of the converter and improve the stability of the oscillation circuit. In addition, the generator can generate hydroxyl radicals stably. The bactericidal activities were also evaluated, and the germicidal power for E. coli, S. aureus, and S. flexneriwas improved by 99.9% or more after 60 minutes.

• Korean Journal of Microbiology
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• v.55 no.3
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• pp.242-247
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• 2019

Biological factors (e.g. microorganism activity) in wastewater treatment plant (WWTP) play essential roles for degradation and/or removal of organic matters. In this study, to understand the microbial functional roles in WWTP, we tried to isolate and characterize a bacterial strain from activated sludge sample. Strain S16 was isolated from the activated sludge of a municipal WWTP in Daejeon metropolitan city, the Republic of Korea. The cells were a Gram-stain-positive, non-motile, facultative anaerobe, and rod-shaped. Strain S16 grew at a temperature of $15{\sim}40^{\circ}C$ (optimum, $30^{\circ}C$), with 0~9.0% (w/v) NaCl (optimum, 1.0~2.0%), and at pH 5.5~9.0 (optimum, pH 7.0~7.5). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain S16 was most closely related to the unique species Miniimonas arenae NBRC $106267^T$ (99.79%, 16S rRNA gene sequence similarity) of the genus Miniimonas. The cell wall contained alanine, glutamic acid, serine, and ornithine. Although the isolation source of the type strain NBRC $106267^T$ which considered as a marine microorganism is sea sand, that of strain S16 is terrestrial environment. It might raise an ecological question for habitat transition. Therefore, comparative genome analysis will be valuable investigation for shedding light on their potential metabolic traits and genomic streamlining.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.2029-2035
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• 2014

In this study, we conducted the adsorption equilibrium and batch experiments of dissolved organic carbon (DOC) in the wastewater by granular activated carbon (GAC). The components of organic compound were Beef extract (1.8 mg/L), Peptone (2.7 mg/L), Humic acid (4.2 mg/L), Tannic acid (4.2 mg/L), Sodium lignin sulfonate (2.4 mg/L), Sodium lauryle sulfate (0.94 mg/L), Arabic gum powder (4.7 mg/L), Arabic acid (polysaccharide) (5.0 mg/L), $(NH_4)_2SO_4$ (7.1 mg/L), $K_2HPO_4$ (7.0 mg/L), $NH_4HCO_3$ (19.8 mg/L), $MgSO_4{\cdot}7H_2O$ (0.71 mg/L), The adsorption characteristics of DOC in synthetic wastewater was described using the mathematical model through a series of isotherm and batch experiments. It showed that there was linear adsorption region in the low DOC concentration (0~2.5 mg/L) and favorable adsorption region in high concentration (2.5~6 mg/L). The synthetic wastewater used was prepared using known quantities of organic and/or inorganic compounds. Adsorption modelling isotherms were predicted by the Freundlich, Langmuir, Sips and hybrid isotherm equations. Especially, hybrid isotherm of Linear and Sips equation was a good adsorption equilibrium in the region of the both the low concentration and high concentration. In applying carbon adsorption for treating water and wastewater, hybrid adsorption equation plus linear equation with Sips equation will be a good new adsorption equilibrium model. Linear driving force approximation (LDFA) kinetic equation with Hybrid (linear+Sips) adsorption isotherm model was successfully applied to predict the adsorption kinetics data in various GAC adsorbent amounts.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.2
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• pp.268-277
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• 2013

This study investigates the effects of accumulated levels of heavy metals and nutrients of cultivated soybean plant tissues, after the continuous application of sewage sludge (SS) and industrial sludge (IS). SS and IS were applied to soybean plants at loading of 0, 11.25, 22.50, and 45.00 Mg/ha, and the contents of heavy metals (Cd, Pb, Ni, Cu, and Zn), proteins, and amino acids in the cultivated soybean plants were measured. The Cd content in the soybean was 0.02~0.05 mg/kg, which is within the safety level set in the standard, and that of Pb was 0.02~0.15 mg/kg, which is also within the safety level except for IS 45 Mg/ha. The soybean harvest quantity was higher in the treatment groups than the control group in the first year. However, in the second year, SS had lower harvest and IS had the same level or a decreasing tendency, compared with the control group. In the first year, the content of amino acid which followed handling of SS was increased in the sludge groups more than in the control group in the case of glutamate. However, the influence of continuous application was increased in the sludge groups in the case of amino acids of 12 types. In conclusions, the accumulation in soybean of heavy metals by sludge treatment is not a problem, but the decreased yields needs to be considered. In addition, the most appropriate level of sludge treatment was 11.25 Mg/ha.