• 한국조경학회지
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• 제27권5호
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• pp.38-47
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• 2000

Carbon dioxide is a major greenhouse gas causing climate change. This study quantified annual direct and indirect uptake of carbon by urban greenspace, and annual carbon release from vegetation maintenance and fossil fuel consumption. The study area was whole Chuncheon and Kangleung, and also two districts of Kangnam and Junglang in Seoul, cities located in middle Korea. Carbon uptake by urban greenspace played an important role through offsetting carbon release by 6-7% annually in Chuncheon and Kangleung. For Kangnam and Junglang, where the population density was relatively higher, urban greenspace annually offset carbon release by 1-2%. Future possible tree plantings could double annual carbon uptake by existing trees in urban lands (except natural and agricultural lands) of a study city. Based on study results, planning and management guidelines for urban greenspace were suggested to save energy and to reduce atmospheric $CO_2$ concentrations. They included selection of optimum tree species, proper planting location from buildings, design of multilayered planting, amendment of existing regulations for greenspace enlargement, avoidance f intensive vegetation maintenance, and conservation of natural vegetation.

• 미생물학회지
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• 제16권1호
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• pp.21-29
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• 1978

In the fed-batch fermentation of penicillin specific uptake rates of carbon source and ammonia nitrogen, and specific production rate of penicillin as the most important process variables were evaluated over the fermentation course and their effects on the productivity studied. As the results, glucose and lactose each as a major carbon source showed the following values, respectively ; the specific uptake rates of 47-93 mg hexose per gm-DCW per he and 37-44 mg hexose per gm-DCW per hr, the specific uptake rates of 4.6-6.8 mg $NH_3-N$ per gm-DCW per hr, and 1.2 mg $NH_3-N$ per gm-DCW per he and the specific production rates of 32-42 arbitrary unit per gm-DCW per hr and 46-50 arbitrary unit per gm-DCW per hr. The productivity of penicillin could be improved by controlling the feed rates of glucose and ammonia nitrogen to meet the uptake rates.

• 상하수도학회지
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• 제34권6호
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• pp.437-443
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• 2020

Biological phosphorus removal is accomplished by exposing PAO(phosphorus accumulating organisms) to anaerobic-aerobic conversion conditions. In the anaerobic condition, PAO synthesize PHB(polyhydroxybutyrate) and simultaneously hydrolysis of poly-p resulting phosphorus(Pi) release. In aerobic condition, PAO uptake phosphorus(Pi) more than they have released. In this study, cyanobacteria Synechococcus sp., which is known to be able to synthesize PHB like PAO, was exposed to anaerobic-aerobic conversion. If Synechococcus sp. can remove excess phosphorus by the same mechanism as PAO, synergistic effects can occur through photosynthesis. Moreover, Synechococcus sp. is known to be capable of synthesizing PHB using inorganic carbon as well as organic carbon, so even if the available capacity of organic carbon decreases, it was expected to show stable phosphorus removal efficiency. In 6 hours of anaerobic condition, phosphorus release occurred in both inorganic and organic carbon conditions but SPRR(specific phosphorus release rate) of both conditions was 10 mg-P/g-MLSS/day, which was significantly lower than that of PAO. When converting to aerobic conditions, SPUR(specific phosphorus uptake rate) was about 9 mg-P/g-MLSS/day in both conditions, showing a higher uptake rate than the control condition showing SPUR of 6.4 mg-P/g-MLSS/day. But there was no difference in terms of the total amount of removal. According to this study, at least, it seems to be inappropriate to apply Synechococcus sp. to luxury uptake process for phosphorus removal.

• Journal of Forest and Environmental Science
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• 제35권4호
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• pp.240-247
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• 2019

This study quantified carbon reduction services through direct harvesting of Ilex rotunda and Machilus thunbergii, which are the typical urban landscape tree species in southern Korea. A total of 20 open-grown tree specimens (10 specimens for each species) were selected reflecting various sizes of stem diameter at breast height of 1.2 m (DBH) at a regular interval. The study measured biomass for each part of the tree specimens including roots to compute total carbon storage per tree. Annual carbon uptake per tree was also calculated analyzing the DBH growth rate of stem disk specimens. Quantitative models were developed using DBH as an independent variable to easily estimate storage and annual uptake of carbon by tree growth for each species. All the models had a high goodness-of-fit with R²=0.95-0.99. The difference in carbon reduction services between DBH sizes increased with increasing DBH. The storage and annual uptake of carbon from a tree with DBH of 10 cm were 13.5 kg and 2.4 kg/yr for I. rotunda, and 19.1 kg and 3.6 kg/yr for M. thunbergii, respectively. The tree of this size stored the amount of carbon equivalent to that emitted from a gasoline use of approximately 24 L for I. rotunda and 34 L for M. thunbergii, respectively. The study provides actual measurement data to quantify carbon reduction services of urban open-grown landscape trees for the warm-temperate species that have been little known until now.

• Environmental Analysis Health and Toxicology
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• 제30권
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• pp.1.1-1.8
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• 2015

Objectives In this study, the effect of tube length and outer diameter (OD) size of hydroxylated-multi walled carbon nanotubes (OH-MWCNTs) on their uptake and toxicity was investigated in the nematode Caenorhabditis elegans using a functional mutant analysis. Methods The physicochemical properties of three different OH-MWCNTs were characterized. Uptake and toxicity were subsequently investigated on C. elegans exposed to MWCNTs with different ODs and tube lengths. Results The results of mutant analysis suggest that ingestion is the main route of MWCNTs uptake. We found that OH-MWCNTs with smaller ODs were more toxic than those with larger ODs, and OH-MWCNTs with shorter tube lengths were more toxic than longer counterparts to C. elegans. Conclusions Overall the results suggest the aspect ratio affects the toxicity of MWCNTs in C. elegans. Further thorough study on the relationship between physicochemical properties and toxicity needs to be conducted for more comprehensive understanding of the uptake and toxicity of MWCNTs.

• 한국기후변화학회지
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• 제7권4호
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• pp.499-506
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• 2016

This study was conducted to estimate carbon stock and uptake for Larix kaempferi Lamb., the single species, which is the most widely distributed one following Pinus densiflora, using data from 6th national forest inventory and forest type map of 1:5,000. Overall distribution area of Larix kaempferi in South Korea was shown as 272,800ha, in detail, Gangwon-do was the most widely distributed region with 39.6% (108,141 ha) of the whole forest area, and Gyeongsangbuk-do was 18.6%(50,839 ha), Chungcheongbuk-do was 15.1%(41,205ha) in order. As the results of analysis in carbon stock and uptake for each province, the values were high with Gyeonggi-do 109.0 tC/ha, $10.3tCO_2/ha/yr$, Gangwon-do 349.1 tC/ha, $9.7tCO_2/ha/yr$ in order, and Jeollabuk-do was the lowest with 78.3 tC/ha, $7.6tCO_2/ha/yr$. Also, the results of estimation in total carbon stocks and uptakes by year (1989~2015) were turned out that total carbon stocks and uptakes were 24,891 thousand tC, $2,428thousand\;tCO_2$ in 2015, increasing about 4.8 times and 3.8 times each compared with 5,238 thousand C/ha, $640thousand\;CO_2$ in 1989. Although forest area was decreased 26.6% with 371,884 ha in 1989 to 272,800 ha in 2015, carbon stocks and uptakes were increased in 2015 in that forest stock was increased 126% compared to 1989.

• 한국조경학회지
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• 제42권5호
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• pp.64-72
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• 2014

본 연구는 생산형 녹지로서의 과수원을 대상으로 사과나무에 의한 탄소의 저장 및 연간 흡수를 산정하고, 재배과정에서 관리에 기인하여 발생하는 연간 탄소배출량을 파악하여 탄소저감 효과를 계량화하였다. 연구대상 과수원에서 유목에서 성목에 이르는 일정 간격의 근원직경 크기를 고려한 수목을 구입하여, 근굴취를 포함하는 직접수확법에 의해 개체당 부위별 및 전체 생체량을 산정하고 탄소저장량을 산출하였다. 근원부의 줄기 원판을 채취하여 직경생장을 분석하고 연간 탄소흡수량을 산정하였다. 관리에 따른 연간 탄소배출은 전정, 제초, 관수, 시비, 병충해 방제 등을 포함하는 관리자료의 구득, 관리자 면담 및 부분 실측을 바탕으로 계량화하였다. 근원직경을 독립변수로 생장에 따른 사과나무 단목의 탄소저장과 연간 탄소흡수를 계량화하는 활용 용이한 계량모델을 개발하였다. 사과나무의 탄소저장량과 연간 탄소흡수량은 모두 직경생장과 더불어 증가하였고, 직경급 간 그 차이도 직경이 커질수록 증가하는 경향이었다. 근원직경 10 및 15cm인 사과나무 단목은 각각 9.1 및 21.0kg의 탄소를 저장하고, 연간 1.0 및 1.6kg의 탄소를 흡수하는 것으로 나타났다. 연구대상 과수원의 단위면적당 탄소저장량과 연간 탄소흡수량은 각각 3.81t/ha, 0.42t/ha/년이었고, 연간 탄소배출량은 1.30t/ha/년이었다. 즉, 관리 관련 연간 탄소배출량은 연간 탄소흡수량보다 약 3배 더 많았다. 연구결과를 토대로, 생산형 녹지에 적용 가능한 관수, 농약 및 비료의 효율적 적용을 포함하는 저탄소형 관리방안을 모색하였다. 본 연구는 아직 부진했던 뿌리 생체량의 실측과 탄소배출의 구체적 인벤토리를 통해 탄소계량 관련 정보를 구축하는 새로운 초석을 제공한다.

• 한국환경생태학회지
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• 제27권5호
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• pp.571-578
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• 2013

본 연구는 도시의 주요 상록 조경수종인 소나무와 잣나무를 대상으로, 직접수확법을 통해 탄소저장 및 흡수를 용이하게 추정하는 회귀모델을 제시하고 도시수목의 탄소저감 효과를 계량화하는데 필요한 기반정보를 구축하였다. 수종별로 유목에서 성목에 이르는 일정 간격의 흉고직경 크기를 고려하여 개방 생장하는 조경수목을 구입한 후, 근굴취를 포함하는 직접수확법에 의해 개체당 부위별 및 전체 생체량을 측정하고 탄소저장량을 산출하였다. 또한, 흉고 부위의 수간원판을 채취하여 직경생장을 분석하고 탄소흡수량을 산정하였다. 흉고직경을 독립변수로 생장에 따른 수종별 단목의 탄소저장 및 흡수를 계량화하는 활용 용이한 회귀모델을 유도하였다. 이들 회귀식의 $r^2$는 0.98 이상으로서 적합도가 상당히 높았다. 동일 직경의 탄소저장 및 흡수량은 유목의 경우 소나무가 잣나무보다 더 많았으나, 20cm 이상 성목의 경우 생장량 차이에 기인하여 그 반대인 경향을 보였다. 흉고직경 25cm인 소나무와 잣나무는 각각 115.6kg, 130.0kg의 탄소를 저장하고, 연간 9.4kg, 14.6kg의 탄소를 흡수하는 것으로 나타났다. 본 연구는 조경수목의 직접 벌목 및 근굴취의 난이성에 기인하여, 생체량 확장계수, 지하부/지상부 비율, 직경생장 등 산림수목의 계수를 대용하여 대상수종의 탄소저감을 계량화한 기존 연구의 한계성을 극복할 새로운 초석을 마련하였다.

• 대한환경공학회지
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• 제28권5호
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• pp.480-486
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• 2006

B시 S하수처리장에서 화학침전 공정에서 MLE 공정으로 공법을 변경하였으며, 생물학적으로 탈질시 부족한 탄소원을 보충하기 위해 외부탄소원이 요구되었다. 본 연구에서는 약 4.7%의 아세트산을 포함하는 TPA(Terephthalic Acid) 생산부산물의 대체탄소원으로 적용 가능성을 평가하기 위해 NUR(Nitrate Uptake Rate) 및 OUR(Oxygen Uptake Rate) 실험과 현장 적용실험을 수행하였다. 실험 결과 TPA 생산 부산물은 일반 상용 외부탄소원으로 널리 쓰이는 메탄올보다 빠른 순응특성을 나타내었고 비탈질율이 $8.24mg{NO_3}^--N/gVSS/hr$, 단위 질산성 질소 제거당 COD 소모비는 $3.70COD_{Cr}/g\;NO_3$, RBDCOD 함량 99.4%로 나타났다. S하수처리장에 대한 TPA 생산부산물 현장 적용 실험을 통해 안정적인 영양염류 제거효율을 나타내었으며 방류수 T-N 농도가 8.2 mg/L로 생물학적 탈질에 요구되는 탄소원을 보충할 수 있는 대체탄소원으로 적합하다고 판단되었다.

• 한국환경복원기술학회지
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• 제25권3호
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• pp.17-28
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• 2022

We evaluated the effect of CO₂ offsetting by estimating changes in carbon uptake under various forest management scenarios and proposed forest management strategies to achieve carbon neutrality. Paju and Goseong, which have relatively large forest areas but different industrial characteristics, were selected for the study sites. The current state of forest distribution was analyzed using forest type maps and aerial photographs, and the amount of carbon uptake was calculated using the equation presented by the IPCC Guidelines for National Greenhouse Gas Inventories and the national emission/absorption coefficients from the Korea National Greenhouse Gas Inventory Report. As of 2015, the forest carbon absorption in Paju and Goseong was 49,931 t/yr and 94,225 t/yr, respectively, and the annual carbon absorption per unit area was 2.28 t/ha/yr and 2.16 t/ha/yr. Under the forest management scenarios, the annual maximum carbon absorption per unit area is estimated to increase to 5.68 t/ha/yr in Paju and 4.22 t/ha/yr in Goseong, and this absorption would increase further if urban forests were additionally created. Even if the current forests of Paju and Goseong are maintained as they are, emissions from electricity use can be sufficiently offset. However, by applying appropriate forest management strategies, emissions from sectors other than electricity use could be offset. This study can be applied to the establishment of carbon absorption strategies in the forest sector to achieve carbon neutrality.