• Journal of Ecology and Environment
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• v.29 no.1
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• pp.23-27
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• 2006

This study was conducted to evaluate forest carbon cycling and soil $CO_2$ efflux rates in a 42-year-old pine (Pinus densiflora) stand located in Hamyang-gun, Korea. Aboveground and soil organic carbon storage, litterfall, litter decomposition, and soil $CO_2$ efflux rates were measured for one year. Estimated aboveground biomass carbon storage and increment in this stand were $3,250gC/m^2\;and\;156gC\;m^{-2}yr^{-1}$, respectively. Soil organic carbon storage at the depth of 30 cm was $10,260gC/m^2$ Mean organic carbon inputs by needle and total litterfall were $176gC\;m^{-2}yr^{-1}\;and\;235gC\;m^{-2}yr^{-1}$, respectively. Litter decomposition rates were faster in nne roots less than 2 mm diameter size ($<220\;g\;kg^{-1}yr^{-1}$) than in needle litter ($<120\;g\;kg^{-1}yr^{-1}$). Annual mean and total soil respiration rates were $0.37g\;CO_2m^{-2}h^{-1}$ and $2,732g\;CO_2m^{-2}yr^{-1}$ during the study period. A strong positive relationship existed between soil $CO_2$ efflux and soil temperature (r=0.8149), while soil $CO_2$ efflux responded negatively to soil pH (r=-0.3582).

• Journal of the korean society of oceanography
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• v.34 no.3
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• pp.144-150
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• 1999

Slope sedimentation on the modern west Florida continental margin is controlled by pelagic carbonate accumulation and off-shelf sedimentation of neritic carbonates and terrigenous fines. Production and deposition of pelagic carbonates by planktonic foraminifera and coccoliths have played a significant role in the total slope sedimentation and are mainly promoted by sea-surface productivity. Organic carbon data reflect the relatively high biological productivity in surface waters, indicating high accumulation of biogenic calcareous sediments. The surface-water productivity in the study area is supported by the relation among microfossil assemblages, carbonate mineralogy and sedimentary organic carbon.

• Journal of Environmental Science International
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• v.27 no.6
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• pp.411-423
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• 2018

To investigate the distribution characteristics of grain size and organic matter of surface sediments from the Nakdong-Goryeong Mid-watershed, surface sediments were collected and analyzed. The samples were collected from six sited at four different times between May 2013 and May 2014. The were analyzed for grain size, water content, ignition loss, chemical oxygen demand, total organic carbon and total nitrogen. The surface sediments were mainly composed of medium sand (mean 44.7%) and coarse sand (mean 32.8%) and became coarser in May 2014. Fine sediments at the site NG-2 were poorly sorted and positively skewed, and occur in a tributary environment that is relatively low-energy compared with the other sites. The water content at the studied sites (15.3 ~ 34.9%) averaged 20.25%, and ignition loss (0.4 ~ 5.8%) and total nitrogen (274 ~ 2493 mg/kg) averaged 1.33% and, 696 mg/kg, respectively. These values indicated that the sediments were not seriously contaminated when compared with the sediment pollution evaluation standard of the National Institute of Environmental Research. The chemical oxygen demand (mean 0.17%) was at the non-polluted level compared with United States Environmental Protection Agency sediment quality standards. The total organic carbon (mean 0.18%) at all sites except site NG-2 (lowest effect level) was the no effect level of the Ontario sediment quality guidelines. The COD/IL (0.02 ~ 0.20) and C/N (0.73 ~ 6.76) were less than 1 and 10, respectively. Organic matter in the study area produced naturally from aquatic organisms. Results of principal component analysis showed that fine sediments (very fine sand and silt) were significantly affected by organic matters (ignition loss, chemical oxygen demand, total organic carbon and total nitrogen). In addition, the highest organic matters content in the study area occurred at the site with the finest sediments (NG-2).

• Animal cells and systems
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• v.10 no.4
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• pp.191-196
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• 2006

This study was carried out to evaluate soil carbon cycling of a 36-year-old larch (Larix leptolepis) stand in Korea. The aboveground and soil organic carbon storage, litterfall, and soil respiration rates were measured over twoyear periods. The estimated aboveground biomass carbon storage and increment were 4220 gC $m^{-2}$ and 150 gC $m^{-2}\;yr^{-1}$, respectively. Mean organic carbon inputs by needle and total litterfall were 118 gC $m^{-2}\;yr^{-1}$ and 168 gC $m^{-2}\;yr^{-1}$, respectively. The aboveground carbon increment of the stand was similar to the annual input of carbon from total litterfall. The soil respiration rates correlated exponentially with the soil temperature at a depth of 20 cm ($R^2$ = 0.86). In addition, the exponential regression equation indicated a relatively strong positive relationship between the soil respiration rates and soil temperature, while there was no significant relationship between the soil respiration rates and the soil moisture content. The annual mean and total soil respiration rates were 0.40 g $CO_2\;m^{-2} h^{-1}$ and 3010 g $CO_2\;m^{-2}\;yr^{-1}$ over the two-year study period, respectively.

• Environmental Engineering Research
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• v.22 no.3
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• pp.237-244
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• 2017

At present, in India, handling of solid waste has become a major challenge for the municipal authorities. Composting of solid waste, especially organic waste, can be one of the solutions to tackle the issue of handling solid waste. The present study is focused on agitated piles composting of flower waste (FW). Five combinations of FW with dry leaves (DL) and cow dung (CD) were prepared to conduct the study. Significant changes were observed due to the addition of bulking agent. The bulking material helps to reduce the production of leachate and also to maintain the aerobic condition within the piles. The reduction of total organic carbon was 21% in FW composting which increased by 36.48% during the composting of FW on addition of DL and CD. On the 120th day of composting, the pH of pile five (70 kg FW + 20 kg CD + 15 kg DL) was 7.33, electrical conductivity 2.77 mS/cm, total organic carbon 26.9%, total nitrogen 2.2%, and C:N ratio was 12. Appropriate proportion of waste mixture played an important role in providing favorable conditions for the microbial transformation of flower waste to stabilized compost. Finally, FW with the combination of CD and DL was found to be successful during pile composting.

• Journal of Ecology and Environment
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• v.30 no.1
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• pp.17-21
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• 2007

The organic carbon (OC) distribution of Pinus densiflora forest in Songgye valley at Mt. Worak National Park were studied as a part of the National Long-Term Ecological Research in Korea. In order to investigate the OC distribution, OC in plant biomass, litterfall, litter layer on forest floor, and soil were estimated. The density of P. densiflora forest was 1,300 trees/ha, average DBH was $15.2{\pm}6.17\;cm$ and average tree height was $10.7{\pm}2.56\;m$. The shrub layer was dominated by shrubby Quercus variabilis, Fraxinus sieboldiana and lndigofera kirilowii with low frequency, and herb layer was dominated by Pteridium aquilinum and Miscanthus sinensis. Total amount of OC stored in this pine forest was 142.78 ton C/ha. Organic carbon stored in soil and plant biomass accounted for 59.2% and 37.8%, respectively. Amount of OC distributed in trees, shrubs, herbs and litter layer in this pine forest was 51.79, 2.03, 0.12 and 4.29 ton C/ha, respectively. Amount of OC returned to forest floor via litterfall was $1.50\;ton\;C\;ha^{-1}\;yr^{-1}$. Soil organic carbon (SOC) decreased along the soil depth. Total amount of SOC within 50cm soil depth was $84.55\;ton\;C\;ha^{-1}\;50\;cm-depth^{-1}$.

• Economic and Environmental Geology
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• v.35 no.5
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• pp.429-436
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• 2002

Core samples, drilled in the middle region of Bavaria, were analyzed to study the characteristics of organic matter in the Upper Jurassic Solnhofen limestone of southern Germany. The core (48$^{\circ}$53'N, 1-1$^{\circ}$19'E) contains Upper Jurassic Solnhofen strata ranging from the upper part of the Geisental Formation throughout the Solnhofen Formation to the lower part of the Mornsheim Formation. In the core, the Upper Jurassic lithologies consist of platy limestone, bedded limestone and massive limestone often interbedded with some chert layers. Geochemical variations (Carbon, Nitrogen and Total Organic Carbon) and Rock-Eval pyrolysis parameters (S$_2$ peak and Hydrogen Index) indicate that the organic matter in the Upper Jurassic limestone is mostly of marine origin. Particularly, the relation-ship of Hydrogen Index and S$_2$ as a function of Total Organic Carbon suggests that the upper formation of the core (Mornsheim Formation) was more influenced by terrigenous influx than the Solnhofen and Geisental Formations.

• Journal of Korean Society on Water Environment
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• v.26 no.6
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• pp.969-975
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• 2010

Estimating the organic matter loadings from individual treated sewage has become important for establishment of effective management strategies to control refractory organic matter (R-OM) in watersheds. For this study, regression equations were constructed using treated sewage data to convert the chemical oxygen demand (COD) concentrations, which are mostly available from open database, into total organic carbon (TOC) and R-OM concentrations. Effluent samples were collected from five major sewage treatment plants (STPs) located upstream of the lake Paldang. Variations in the OM concentrations were not associated with either the location of the STP or the sampling season. The effluent investigated were characterized by higher ratio of R-OM with respect to biodegradable organic matter (B-OM) and higher presence of dissolved organic matters (DOM) versus particulate organic matter (POM). Compared to $COD_{Mn}$, $COD_{Cr}$ exhibited higher oxidation efficiencies and greater variations in the concentrations. The concentrations of $COD_{Mn}$ were positively correlated with dissolved organic carbon (DOC), total organic carbon (TOC), and R-OM concentrations. There was nearly no seasonal and annual variation in the regression equations between $COD_{Mn}$ and TOC or R-OM concentrations. The constructed regression equations for TOC and R-OM were $0.650({\pm}0.071){\times}COD_{Mn}+1.426({\pm}0.575)$ and $0.340({\pm}0.083){\times}COD_{Mn}+2.054({\pm}0.670)$, respectively. The established equations are expected to contribute to estimating OM loadings from the STPs into the lake Paldang and also to compensating for the deficiency of the data for effluent OM concentrations in STP.

• Current Optics and Photonics
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• v.3 no.4
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• pp.336-341
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• 2019

This paper proposes an optical system where the organic compound content in water is determined by using an ultraviolet (UV) LED (280 nm) and photodetector. The results obtained by the proposed prototype LED spectroscopy system, which includes a single photodetector and two parallel sample holders, are calculated by applying partial least square regression; the values are highly correlated with the actual concentrations of potassium hydrogen phthalate solutions, with an adjusted coefficient of determination about 0.996. Moreover, the total organic carbon values derived from the UV-Vis spectrometer of real samples (lake, river and sea water) differed little from those obtained by the LED spectroscopy. We confirm that the fast, sensitive, and compact LED sensor system can be readily configured for real-time monitoring of organic compounds in water.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.6 no.1
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• pp.55-66
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• 1996

This study was conducted to evaluate breakthrough characteristics of respirator cartridge using multi-organic vapors, including carbon tetrachloride, trichloroethylene, and toluene. The organic vapors were used as single phase, binary system, and ternary system. The results are summarized as follows. 1. Organic vapors studied were 1,000 ppm, 750 ppm, 500 ppm and 250 ppm in single phase. Carbon tetrachloride having the highest molecular weight showed the breakthrough first, and breakthrough sequency by organic vapor was dependent on its molecular weight. The 10% breakthrough times at 1,000 ppm of organic vapor were 97 minutes for carbon tetrachloride, 129 minutes for trichloroethylene and 135 minutes for toluene. 2. When concentrations of organic vapors were at levels of the Threshold Limit Values, the lives of the respirator cartridges were 122 hours in carbon tetrachloride, 18 hours in trichloroethylene and 28 hours in toluene. 3. In the binary system at a total concentration of 1,000 ppm with carbon tetrachloride and trichloroethylene, breakthrough times ranged from 104 minutes to 125 minutes, which were longer than 97 minutes in a single phase (1,000 ppm) for carbon tetrachloride, but shorter than breakthrough times for TCE and Toluene. 4. Breakthrough times in the binary system with carbon tetrachloride and toluene were 131~132 minutes. 5. Breakthrough times in the ternary system with carbon tetrachloride, toluene, and trichloroethyl ene were $120{\pm}8$ minutes, which were longer than 97 minutes in the single phase (1,000 ppm) for carbon tetrachloride, equal to 129 minutes for trichloroethylene, and shorter than 135 minutes for toluene. Those were almost similar to $124{\pm}9$ minutes of breakthrough times in the binary systems.