• 대기
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• 제29권5호
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• pp.689-698
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• 2019

Air pollution in urban areas has become a serious problem in the recent years. Especially, high concentrations of particulate matter (PM) cause negative effects on human health. Several studies suggest urban forest as a tool for improving air quality because of the capability of forests in reducing PM concentrations through deposition and adsorption using leaf area. For this reason, the National Institute of Forest Science plans to install in-situ observation stations for PM and biogenic volatile organic compounds (BVOCs) on a national scale to verify the net effect of forests on urban air pollution. To measure the quantitative change of PM concentrations due to the urban forest, stations should be located within and outside the forest area with respect to atmospheric circulation. In this study, we analyze the wind direction at the potential measurement sites to assess suitable locations for detecting the effect of urban forests on air quality in five cities (i.e. Gwangju, Daegu, Busan, Incheon, and Ilsan). This technical note suggests effective locations of in-situ measurements by considering main wind direction in the five cities of this study. A measurement station network created in the future based on the selected locations will allow quantitative measurements of PM concentration and BVOCs emitted from the urban forest and help provide a comprehensive understanding of the forest capabilities of reducing air pollution.

• 한국환경과학회지
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• 제8권6호
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• pp.685-690
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• 1999

The pollution characteristics of groundwaters in Taegu City and correlation coefficients(r) between water pollution indicators were investigated for two years from January 1996 to December 1997. Volatile organic compounds such as TCE(tri-chloroethylene), PCE(tetrachloroethylene), l,l,l-trichloroethane, THM(trihalo-methane), dichloromethane, pesticides such as diazinon, parathion, malathion, and toxic inoganic matters such as As, Hg, Se, Pb, Cd, $Cr_6^+,$ CN were not detected in the groundwaters. Mean values of groundwater pollution indicators were below drinking-water standards, but hardness, $KMnO_4-C(potassium$ permanganate consumption), evaporate residues, $SO_4^{-2},\;Fe,\;NO_3^{-}-N,$ color and turbidity exceeded a little in some samples. As groundwater became deeper, hardness and evaporate residues remarkably increased, but $KMnO_4-C,\;NO_3^{-}-N,\;Cl-,$ color, turbity and bacteria decreased. $KMnO_4-C,$ evaporate residues, $Cl^-\;and\;SO_4^{-2}$ were very high at industrial and commercial areas, and $NO_3^--N$ and $NH_4^+-N$ were very high at agricultural and forest areas. It showed high positive significances in the relationships between hardness and each of evaporate residues, $SO_4^{-2}$, Zn and Mn, $KMnO_4-C$ and each of color, turbidity and Zn, color and each of turbidity, Cu, Zn and Mn, turbidity and each of Fe, Cu, Zn and Mn, and evaporate residues and each of $Cl^-,\;SO_4^{-2}$ and Zn.

• 한국지반환경공학회 논문집
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• 제9권2호
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• pp.23-29
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• 2008

고농도 입자성 유기 폐수를 대상으로 기존 혐기성 공정인 CSTR과 UASB공정으로 처리 시 불량한 상징수질, 불안정한 운전 특성과 같은 문제점이 제시되었다. 이에 본 연구는 새로운 개념의 ADEPT(Anaerobic Digestion Elutriated Phased Treatment) 공정을 주정폐수에 적용하여 처리 가능성을 평가하였다. CSTR과 ADEPT의 성능 비교 결과 ADEPT공정에서 gas 발생량은 약 2배였으며, 유기물 제거 효율과 고형물 제거 효율 역시 더 높은 효율을 보여주었다. 또한 ADPET는 비교적 짧은 HRT에서도 휘발성 지방산 생성으로 인한 pH 저하의 영향을 받지 않았으며, 안정적으로 pH를 유지하였다. ADEPT의 recycle ratio를 6Qin과 2Qin으로 변화를 주어 운전 시 6Qin의 운전 기간 동안 높은 처리 효율을 보여주었다. 따라서 ADEPT는 짧은 HRT로 인한 경제성 향상과 메탄 발생을 이용한 에너지 회수, 또한 산 생성조에서 생성되는 유기산을 최대로 생산, BNR 공정의 유기 탄소원으로 활용 가치가 있다고 판단된다.

• 자원리싸이클링
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• 제3권1호
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• pp.17-24
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• 1994

석유화학산업에서 발생된 폐촉매에는 귀금속계 금속이나 회유금속들이 잔조해 있는데, 이들 유가금속을 회수하는 것은 환경보존과 자원재활용 측면에서 매우 중요하다. 본 연구에서는 백금계 폐촉매로부터 귀금속을 회수하는 연구를 수행하였다. 폐촉매 시료로는 Naphtha로부터 에틸렌을 제조시에 사용했던 알루미나담체 0.3% Pd 폐촉매와, 원유 정제 후 벤젠, 톨루엔, 크실렌 등을 제조시에 사용한 알루미나담체 0.3% Pt/Re 폐촉매를 사용하였다. 시료들은 배소과정을 거쳐서 탄수와 황 등 원유로부터 유입된 가연성 물질들을 제거하고, 분쇄한 다음 6N 염산 및 왕수로 침출하였다. Pd는 Fe분말을 사용한 석출법에 의하여 침출액 중에서 금속 Pd로 회수하였다. Pt/Re 폐촉매 경우에는 염산 및 왕수로 침출 후 Fe 분말을 사용하여 Pt를 먼저 회수한 다음, 여액에 황화나트륨을 첨가하여 Re 황화물로 침전시켜서 Re을 회수하였다. 본 연구에서는 폐촉매 침출시 6N 염산을 침출액으로 사용하여 왕수를 사용한 것과 비슷한 정도의 침출효과를 얻을 수 있었는데, 이것은 침출시 소요비용을 줄이고 폐산처리시에 왕수보다 쉽게 처리할 수 있다는 점에서 공점상 효과적이다.

• 한국물환경학회지
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• 제18권2호
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• pp.151-157
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• 2002

Landfill leachate is one of highly contaminated and heterogeneous wastewater. The leachate from initial landfill can be treated by anaerobic process because it contains biodegradable matters, particularly, volatile fatty acids (VFAs). However, the anaerobic treatment of leachate is generally required longer hydraulic retention time (HRT) than aerobic process and another treatment process to satisfy effluent concentration. Therefore the modification of conventional anaerobic treatment is needed. Two phase anaerobic membrane process (TPAMP) is an integrated membrane process to be able to separate anaerobic metabolism into two phase which are acidogenesis and methanogenesis for improvement of anaerobic treatment efficiency. In this study, the efficiency of TPAMP and conventional anaerobic treatment were compared in terms of HRT, effluent SCOD, VFAs Membrane used in TPAMP was the UF of capillary type with the surface area of $0.048m^2$. The average effluent SCOD of conventional anaerobic treatment was 1352 mg/L and the removal was 96 % at HRT 60 days, while in TPAMP, 927 mg/L and 98% at HRT 30 days.

• 한국기후변화학회지
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• 제6권1호
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• pp.41-47
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• 2015

This study was carried out simulating domestic utilization conditions of a wood pellet stove and a wood pellet boiler in order to determine emission factors (EFs) of macro-pollutants, i.e., carbon monoxide, nitrogen oxides, sulfur oxides, ammonia, particulate matters (total suspended particulate, $PM_{10}$, $PM_{2.5}$, black carbon) and trace pollutants (i.e., ten different volatile organic compounds). The composite pollutants EFs for the pellet stove were: for TSP 4.58 g/kg, for $PM_{10}$ 3.35 g/kg, for $PM_{2.5}$ 2.48 g/kg, CO 119.23 g/kg, NO 14.40 g/kg, $SO_2$ 0.17 g/kg, TVOC 37.73 g/kg, $NH_3$ 0.02 g/kg and emissions were similar to the pellet boiler appliance: for TSP 4.73 g/kg, for $PM_{10}$ 3.41 g/kg, for $PM_{2.5}$ 2.63 g/kg, CO 161.51 g/kg, NO 13.67 g/kg, $SO_2$ 0.19 g/kg, TVOC 45.22 g/kg, $NH_3$ 0.02 g/kg.

• 한국기후변화학회지
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• 제6권1호
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• pp.49-54
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• 2015

Manually fed firewood burning appliances, i.e., stove and boiler, were tested in order to determine emission factors (EFs) of macro-pollutants, i.e., carbon monoxide, nitrogen oxides, sulfur oxides, ammonia, particulate matters (total suspended particulate, $PM_{10}$, $PM_{2.5}$, black carbon) and trace pollutants (i.e., ten different volatile organic compounds). The composite pollutants EFs for the wood stove were: for TSP 15.45 g/kg, for $PM_{10}$ 6.53 g/kg, $PM_{2.5}$ 4.16 g/kg, CO 175.49 g/kg, NO 1.58 g/kg, $SO_2$ 0.15 g/kg, TVOC 48.02 g/kg, $NH_3$ 0.02 g/kg and emissions were similar to the wood boiler appliance: for TSP 12.23 g/kg, for $PM_{10}$ 5.84 g/kg, $PM_{2.5}$ 3.66 g/kg, CO 146.74 g/kg, NO 1.42 g/kg, $SO_2$ 0.15 g/kg, TVOC 47.78 g/kg, $NH_3$ 0.01 g/kg.

• 한국해양환경ㆍ에너지학회지
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• 제9권1호
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• pp.1-13
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• 2006

가막만 표층퇴적물중 유기물량의 시 공간적 분포 특성 및 기원을 파악하고자 2000년 4윌부터 2002년 3월까지월간격으로 현장조사를 실시하였다. 강열감량(IL)은 $4.6{\sim}11.6%(7.1{\pm}1.6%)$, 화학적산소요구량(CODs)은 $2.25{\sim}99.26mgO_2/g-dry(30.98{\pm}19.09mgO_2/g-dry)$, 총 황화물량(AVS)은 $nd{\sim}10.29mgS/g-dry(1.02{\pm}0.58mgS/g-dry)$, 식물색소량은(phaeopigment) $6.84{\sim}116.18{\mu}g/g-dry(23.72{\pm}21.16{\mu}g/g-dry)$, 입자성유기탄소(POC)는 $5.45{\sim}23.24 mgC/g-dty(10.34{\pm}4.40C\;mgC/g-dry)$, 입자성유기질소(PON)는 $0.71{\sim}2.99mgN/g-dry(1.37{\pm}0.58mgN/g-dry)$, 함수율(water content)은 $43.1{\sim}77.6%(55.8{\pm}5.6%)$의 범위를 나타냈으며 펄 함량(mud content)은 모든 정점에서 95% 이상의 값을 나타냈다. 유기물질의 공간적인 분포는 북서 내만역, 만 중앙부와 동쪽해역 그리고 남쪽만 입구역으로 대별되어, 북서 내만역과 남쪽 만 입구역은 만 중앙부와 동쪽해역 및 백야도 인근해역보다 대부분 항목에서 높은 유기물 농도를 나타내었다. 특히 북서 내만역은 과도한 양식활동에 따른 과잉의 유기물 공급, 육상으로부터 생활하수 및 산업폐수 유입, 분지형태의 지형적 특성에 의한 물질의 장기체류로 유기오염이 매우 심각하게 나타났다. 그리고 그로인한 하계 수온약층에 의한 저층의 무산 소 환경이 형성되고 있다. 경시적인 변동양상은 북서 내만역과 남쪽 만 입구역에서 저수온기보다 고수온기에 주로 높은 농도를 보였다. 반면에 만 중앙부와 동쪽해역은 각 항목에서 변동양상의 일정한 규칙성은 보여지지 않으나 황 화물을 제외하면 주로 저수온기에 더 높은 농도를 나타내었다. 황화물 농도는 모든 정점에서 고수온기에 더 높게 나타났으며, 특히 만 중앙부와 동쪽해역은 화학적산소요구량이 $20mgO_2/g-dry$을 넘는 경우 고수온기를 중심으로 일시적인 황화물 증가양상이 나타났다. 가막만 표층퇴적물중 유기물질의 기원은 C/N 비가 평균 8 이하로, 육상기원보다 해양기원 유기물에 의한 것으로 나타났으나, POC/phaeopigment 비로부터 유기물 조성에 있어서 살아있는 식물플랑크톤보다 유기쇄설물이 우점하며, CODs/IL 비로부터 유기쇄설물은 해양자체 순환에 의해 생산되는 것보다 양식활동에서 발생하는 잉여사료와 생물의 배설물 등 인위적 활동에 의한 부분이 높은 것으로 추정되었다.

• 펄프종이기술
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• 제46권1호
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• pp.18-28
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• 2014

Renewable Portfolio Standards(RPS) is a regulation that requires a renewable energy generated from eco-friendly energy sources such as biomass, wind, solar, and geothermal. The RPS mechanism generally is an obligatory policy that places on electricity supply companies to produce a designated fraction of their electricity from renewable energies. The domestic companies to supply electricity largely rely on wood pellets in order to implement the RPS in spite of undesirable situation of lack of wood resources in Korea. This means that the electricity supply companies in Korea must explore new biomass as an alternative to wood. Palm kernel shell (PKS) and empty fruit bunch (EFB) as oil palm wastes can be used as raw materials used for making pellets after their thermochemical treatment like torrefaction. Torrefaction is a pretreatment process which serves to improve the properties including heating value and energy densification of these oil palm wastes through a mild pyrolysis at temperature typically ranging between 200 and $300^{\circ}C$ in the absence of oxygen under atmospheric pressure. Torrefaction of oil palms wastes at above $200^{\circ}C$ contributed to the increase of fixed carbon with the decrease of volatile matters, leading to the improvement of their calorific values over 20.9 MJ/kg (=5,000 kcal/kg) up to 25.1 MJ/kg (=6,000 kcal/kg). In particular, EFB sensitively responded to torrefaction because of its physical properties like fiber bundles, compared to PKS and hardwood chips. In conclusion, torrefaction treatment of PKS and EFB can greatly contribute to the implement of RPS of the electricity supply companies in Korea through the increased co-firing biomass with coal.

• 한국환경과학회지
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• 제17권7호
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• pp.755-765
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• 2008

To investigate correlation between the distribution of marine bacteria and environmental characteristics in the surface sediments of Kamak Bay, chemical oxygen demand(COD), acid volatile sulfide(AVS), ignition loss(IL), total organic carbon(TOC), and total organic nitrogen(TON) were measured and analyzed at 7 stations in winter and summer. In winter, COD and AVS ranged from 13.45 mg/g to 30.06 mg/g(average: 23.58 mg/g) and from 0.03 mg/g to 1.04 mg/g(average: 0.63 mg/g), respectively. IL, TOC, and TON ranged from 8.03% to 11.41%(average: 9.41%), from 1.17% to 2.10%(average: 1.62%), and from 0.09% to 0.18%(average 0.15%), respectively. In summer, COD, AVS, IL, TOC, and TON ranged from 14.06 mg/g to 32.19 mg/g(average: 24.71 mg/g), from 0.03 mg/g to 1.11 mg/g(average: 0.66 mg/g), from 9.00% to 12.15%(average: 10.96%), from 1.27% to 2.12%(average 1.77%), and from 0.12% to 0.19%(average: 0.16%), respectively. These values were relatively higher than those in winter. Kamak Bay had high C/N ratio that might be resulted from the input of terrestrial sewage and industrial wastewater. The number of marine viable bacteria was $8.9{\times}10^4\;cfu/g$ in winter and $9.7{\times}10^5\;cfu/g$ in summer. The most abundant species were Pseudomonas spp., Flavobacterium spp., and Vibrio spp, in the surface sediments of Kamak Bay. It was found that the concentration of organic matters and viable bacterial cells in the inner part were relatively higher than those in the outer of Kamak Bay. The distribution of viable bacterial cells was closely influenced by environmental factors.