• Journal of Forest and Environmental Science
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• v.30 no.3
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• pp.293-300
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• 2014

An explanatory survey was conducted to assess the contribution of palm species in carbon sequestration in the homegarden of the Sylhet Metropolitan City Corporation of Bangladesh. Assessment was done by means of two stage random sampling. A total of 10 housing area were selected randomly for the study and 4 common palm tree species were found abundantly. From the observations abundance of palm trees [Areca catechu (175/housing area), Cocos nucifera (145/housing area), Borassus flabellifer (124/housing area) and Phoenix sylvestris (27/housing area)] were found higher in all homesteads in comparison with other species. Study revealed that total organic carbon (MTOC mt/ha) was highest in Cocos nucifera (12.48 mt/ha), followed by Areca catechu (4.20 mt/ha), Borassus flabellifer (3.02 mt/ha) and Phoenix sylvestris (0.59 mt/ha). Total amount of organic carbon stored by palm trees in homestead areas was found 20.28 metric ton/ hector in the study area. Study revealed that palm trees of homestead forest accumulate a good amount of biomass and is a good sinker of organic carbon from the atmosphere. Proper management of palm trees will help to improve the local, national and international community through carbon sequestration.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.3
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• pp.323-329
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• 2007

There is no certain definition about advanced drinking water treatment but it is generally known as activated carbon process, membrane process or ozone process which can remove non-conventional pollutants such as taste and odor compounds, and micro-pollutants. There are more than 20 processes related to activated carbon as adsorber or biological activated carbon in Korea. The saturated carbon by pollutants can be reused by reactivation. However, the effect of reactivation on activated carbon is not well-understood in terms of changing physical properties of carbon to adsorption capacity of natural organic matter (NOM). In this study, the effects of reactivation on physical properties of activated carbon were investigated by isotherm and breakthrough of NOM. Ash content was increased from 8% to 13.3%. Iodine number is commonly used as an indicator for performance of reactivation. The iodine number was decreased about 20% after reactivating twice. The degree of reactivation can be evaluated by not only iodine number but also apparent density.

• Carbon letters
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• v.11 no.1
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• pp.13-21
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• 2010

Coconut shell activated carbon (CSAC) was investigated for its ability in the removal of two neutral chlorinated organic compounds, namely trichloroethylene (TCE) and dichloromethane (DCM) from aqueous solution using a packed bed column. The efficiency of the prepared activated carbon was also compared with a commercial activated carbon (CAC). The important design parameters such as flow rate and bed height were studied. In all the cases the lowest flow rate (5 mL/min) and the highest bed height (25 cm) resulted in maximum uptake and per cent removal. The experimental data were analysed using bed depth service time model (BDST) and Thomas model. The regeneration experiments including about five adsorption-desorption cycles were conducted. The suitable elutant selected from batch regeneration experiments (25% isopropyl alcohol) was used to desorb the loaded activated carbon in each cycle.

• Journal of environmental and Sanitary engineering
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• v.24 no.2
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• pp.40-48
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• 2009

Unusual bloom of toxic cyanobacteria in water bodies have drawn attention of environmentalists world over. Major bloom of Anabaena, Microcystis in water storage reservoir, rivers and lake leading to adverse health effects have been reported from Australia, England and many part of the world. These cyanobacterial cells can release intercellular matter like toxin in water and these intercellular matter can increase the concentration of organic matter. Cellysis can occur when algal cells meet the disinfectants like chlorine in water treatment plant and the resultant rising up of DOC(Dissolved Organic Carbon) or TOC(Total Organic Carbon) can increase the formation of disinfection by products. Disinfectants that kill microorganisms react with the organic or inorganic matter in raw water. In general disinfectants oxidize the matter in raw water and the resultant products can be harmful to human. There are always conflict about which is more important, disinfection or minimizing disinfection by products. The best treatment process for raw water is the process of the lowest disinfection by products and also the the lowest microorganism. In this study the cultured cells, Microcytis Aeruginosa(MA), Anabaena Flos-aquae(AF), Anabaena Cylindrica(AC), and the cells obtained in Daechung Dam(DC) whose dominant species was Anabaena Cylindrica were subjected to chlorination. Chlorination oxidizes inorganic and organic compounds and destruct live cells in raw water. Chloroform was analyzed for the cultured cells which were treated with $20mg/\ell$ dose of chlorine. In general chloroform is easily formed when dissolved organic matter react with chlorine. The cultured cells contributes the concentration of dissolved organic carbon and also that of total organic carbon which might be potent precusors of chloroform formed. The correlations of the concentration of chloroform, DOC and TOC were investigate in this study.

• Journal of Environmental Impact Assessment
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• v.32 no.5
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• pp.353-362
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• 2023

TOC, which can measure more than 90% of organic substances, can be measured quickly and easily,replacing BOD and COD, which were indicators of organic pollutants. According to water quality pollution control standards, when measuring TOC, if the inorganic carbon ratio in the sample is over 50%, the NPOC (Non-Purgeable Organic Carbon) method should be used. If volatile organic compounds (VOCs) are present at a certain concentration, the TC-IC (subtracting inorganic carbon from total carbon) method should be used. To validate the limitations of these analytical conditions, experiments were conducted by varying the ratio of TOC to IC in purified water and measuring the concentration of TOC in test solutions. The results showed no significant difference between the TC-IC method and the NPOC method. When measuring samples with added VOC standard solutions, it was observed that the carbon loss due to purging was not significant when using the NPOC method. Therefore, it is concluded that the choice of analytical method does not lead to significant differences when VOCs are present in the sample. To account for potential variations in results based on water quality pollution control standards and regulations regarding the approval and testing of environmental measurement devices, a comparison of field sample concentration values was made using two widely used types of TOC analyzers in Korea. The results showed variations of 0.02 to 0.83 mg/L between methods depending on the manufacturer, highlighting the need for caution when selecting an instrument.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.486-490
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• 2014

This study was conducted to investigate the effect of carbonized biomass from crop residues on soil carbon storage during soybean cultivation. The carbonized biomass was made by field scale mobile pyrolyzer. The treatments consisted of control without input and three levels of carbonized biomass inputs as $59.5kg10a^{-1}$, C-1 ; $119kg10a^{-1}$, C-2 ; $238kg10a^{-1}$, C-3. Soil samples were collected during the 113 days of experimental periods, and analyzed soil pH and moisture contents. Soil carbon contents and soybean yield were measured at harvesting period. For the experimental results, soil pH ranged from 6.8 to 7.5, and then increased with increasing carbonized material input. Soil moisture contents were slightly higher by 0.1~1.5% than the control, but consistent pattern was not observed among the treatments. Soil carbon and organic carbon contents in the treatments increased at 24 and 15% relative to the control at 15 days after sowing, respectively. Loss rate of SOC (soil organic carbon) relative to its initial content was 7.2% in control followed by C-1, 6.8%> C-2, 3.5%>C-3, 1.1% during the experimental periods. The SOC change rate decreased with increasing carbonized biomass rate. It was appeared that soybean yields were $476.9kg10a^{-1}$ in the control, and ranged from 453.6 to $527.3kg10a^{-1}$ in the treatments. However, significant difference was not found among the treatments. It might be considered that the experimental results will be applied to soil carbon sequestration for future study.

• Ocean and Polar Research
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• v.27 no.1
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• pp.1-13
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• 2005

The samples for organic carbon analysis were collected between $5^{\circ}\;and\;17^{\circ}N$ along $131.5^{\circ}W$ in the northeast Pacific KODOS (Korea Deep Ocean Study) area. The mean concentration of total organic carbon (TOC) in the surface mixed layer $({\sim}50 m)$ was $100.13{\pm}2.05{\mu}M-C$, while the mean concentration of TOC in the lower 500m of the water column was $50.19{\pm}4.23{\mu}M-C$. A strong linear regression between TOC and temperature $(r^2=0.70)$ showed that TOC distribution was controlled by physical process. Results from the linear regression between chlorophyll-a and TOC, and between chlorophyll-a and particulate organic carbon (POC), decreasing of dissolved organic carbon (DOC) in the surface layer caused by non-biological photo-oxidation process. Below the surface layer, biological production and consumption occurred. DOC accumulation dominated in the depth range of $30{\sim}50m$ and DOC consumption occurred in the depth range of $50{\sim}200m$. TOC was inversely correlated with apparent oxygen utilization (AOU) and TOC/AOU molar ratios ranged from -0.077 to -0.21. These ratios indicated that TOC oxidation was responsible fur $10.9{\sim}30.1%$ (mean 20.2%) of oxygen consumption in the NE Pacific KODOS area. In the euphotic zone, distributions of dissolved and particulate organic matter were controlled by photo-chemical, chemical, biological and physical processes.

• Journal of Korean Society on Water Environment
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• v.33 no.4
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• pp.409-415
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• 2017

This study aims to evaluate the effect of capping materials on blocking pollutant elution from contaminated sediment to water body. Experiments were carried out under conditions in which the elution rate was intensified artificially using compost with high concentration of organic compound and nutrient salts instead of sediments. Activated carbon (AC), modified activated carbon (MAC), P. putida immobilized activated carbon (PBAC) and effective microorganisms immobilized activated carbon (EBAC) were used as capping materials. Zeolite (ZT) and two kinds of commercially available microorganisms immobilized zeolite products (ZC, ZN) were used for comparison experiment. The elution rate of organic compound, nitrogen and phosphorus were compared with that of control experiment. The experiments were conducted for 56 days. Concentrations of chemical oxygen demand, total nitrogen, and total phosphorus were measured to use the comparison of release rate of organic compound, nitrogen and phosphorus. From the experimental results, AC based materials showed better performance to block the elution of organic compound and nitrogen than ZT based materials. Although ZT based materials were more effective than AC and PBAC to block phosphorus, MAC and EBAC showed the best performance of phosphorus elution blocking among the all candidate materials. In conclusion, EBAC is considered as the most effective capping materials, because organic compound, nitrogen and phosphorus will be degraded continuously by EM in the long term.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.3
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• pp.272-279
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• 2016

Understanding sources and contributions of $PM_{2.5}$ mass and particulate PAHs from traffic-related pollution can provide valuable information for alleviating air contamination from car emissions in urban areas. Two sampling sites at the Gwangju Institute of Science and Technology (GIST, $35.228^{\circ}N$, $126.843^{\circ}E$) and National institute of environmental research NamBu Supersite (NNBS, $35.226^{\circ}N$, $126.848^{\circ}E$) were selected for comprehensive road-oriented-PM investigations. Continuous measurements from optical particle sizer (OPS) and optical particle counter (OPC) with 24 hr integrated filter based samplers for organic carbon, water soluble organic carbon, and Poly Aromatic Hydrocarbons (PAHs) were conducted during Nov. 3 through 22 in 2014. As a result, $PM_{2.5}$ mass concentrations using OPC and OPS in NNBS presented about twice higher than in GIST due to road dust impacts based on wind direction analysis. In addition, ratios of elemental carbon (EC) to organic carbon (OC) and water insoluble organic carbon (WIOC) to organic carbon (OC) supported an additional evidence of the primary pollutant contributions oriented from road dust. PAHs related to 5 rings such as benzo(e&a)pyrene indicates higher associations.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.3
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• pp.131-140
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• 2006

Suspended particulate matter and organic carbon were measured in the Mankyoung river estuary in February, May, July and August 2003. There was a large variance in river discharge between the dry season of February and May and the wet season of July and August. The influx of dissolved organic carbon into the estuary was $8.16{\times}10^2tonC\;month^{-1}$ in the dry season and $5.77{\times}10^3tonC\;month^{-1}$ in the wet season. The influx of particulate organic carbon was $9.37{\times}10^2tonC\;month^{-1}$ and $3.14{\times}10^4tonC\;month^{-1}$ in the dry and wet seasons, respectively. Especially, dissolved organic carbon in the northern part of the site inside the dike was increased in July when torrential rainfall was high. In the research, the distribution of dissolved organic carbon showed conservative behavior with the salinity gradient in the estuary, suggesting that physical mixing between seawater and freshwater dominates the distribution pattern of the dissolved organic carbon in the system. However 60 to 90% of the particulate organic carbon introduced into the estuary was removed from the surface water at the upper estuarine mixing zone of low salinities, showing non-conservative behavior similar with suspended particulate matte r. The completion of the Saemangum Dike is likely to inhibit the exchange of materials between open sea and the Mankyoung estuary. This suggests that the oxidation of organic carbon in the bottom of the estuary may exhaust dissolved oxygen in the confined environment.