• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.8 no.1
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• pp.115-123
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• 1998

Vinyl chloride monomer exists as gas phase at normal temperature and reacts with oxygen and strong oxidant in the air to form oxidized materials. Because of being easily synthesized, it is used as a main source at the synthetic reaction process of PVC synthesis factories. Ministry of Labor regulates its usage as a carcinogen and its exposure level as 1 ppm. But the amount of VCM production in PVC and VCM production process hasn't been exactly estimated. In addition, facilities of this factory are located in outdoor. Therefore, this study was designed to investigate effects of temperature on breakthrough of charcoal tube at a fixed concentration and temperature during VCM sampling based on NIOSH and OSHA methods which were used as methods of occupational environment measuring and analysis. During the sampling of VCM, methods of OSHA and NIOSH require flow rate of 0.05 lpm and sampling volume of $3{\ell}$, $5{\ell}$ respectively, at this time carbon molecular sieve tube and coconut shell charcoal tube are used to observe the breakthrough along with concentration and temperature. As a result, significant difference between average adsorbed amounts of OSHA methods but that of NIOSH methods cannot be found. NIOSH method is likely to be effected by high temperature and normal temperature in high concentration. Breakthrough is not found in the method of OSHA at different conditions of temperature and concentration. As the result of this study we could verify that breakthrough occurred in the process of sampling VCM with NIOSH methods. Therefor in summer time, breakthrough should be considered and research on the breakthrough volume should be done. It is considered the research about the specificity of the coconut shell charcoal and carbon molecular sieve sorbent should be done when sampling VCM in comming days.

• Journal of the Korean Wood Science and Technology
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• v.51 no.3
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• pp.207-221
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• 2023

The increasing demand for clean energy requires considerable effort to find alternative energy sources, such as briquettes. This research aims to develop a charcoal briquette with added pine resin (API) that has excellent combustion speed and distinctive aroma. Briquettes are composed of charcoal, pine resin (concentration: 0%-30%), and starch (up to 7%). They are produced in several stages, including coconut shell pyrolysis in conventional combustion, to obtain charcoal for the briquette precursor. Briquette compaction is conducted by mixing and densifying the charcoal, pine resin, and starch using a hydraulic press for 3 min. The hydraulic press has a total surface area and diameter of 57.7 cm² and 3.5 cm, respectively. The briquettes are dried at different temperatures, reaching 70℃ for 24 h. The study results show that the briquettes have a thickness and diameter of up to 2 and 3.5 cm, respectively; moisture of 2.18%-2.62%; ash of 11.61%-13.98%; volatile matter of 27.15%-51.74%; and fixed carbon content of 40.24%-59.46%. The compressive strength of the briquettes is 186-540 kg/cm². Their calorific value is 5,338-6,120 kcal/kg, combusting at a high speed of 0.15-0.40 s. The methoxy naphthalene, phenol, benzopyrrole, and lauryl alcohol; ocimene, valencene, and cembrene are found in the API. The API briquette has several chemical compounds, such as musk ambrette, ocimene, sabinene, limonene, 1-(p-cumenyl) adamantane, butane, and propanal, which improve aroma, drug application, and fuel production. Accordingly, API briquettes have considerable potential as an alternative energy source and a health improvement product.

• Journal of environmental and Sanitary engineering
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• v.14 no.2
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• pp.18-24
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• 1999

The purpose of this study was carried out to estimate removal possibility of IBMP and IPMP causing odor in raw water. As a result of Freundlich isotherm. IBMP was superior to IPMP in adsorptive capacity. Adsorptive capacities of activated carbon were found to be in order of Lignite, Coconut shell, and Charcoal. These were well fitted with Freundlich isotherm. According to adsorption breakthrough tests for Lignite GAC, breakthrough time of IPMP and IBMP were 5.7hr and 5.5hr, respectively. Because adsorptive capacities of target material were very different with pore size distribution, it seemed that Lignite and Coconut shell based activated carbons were recommended in order to remove door compounds.

• Korean Journal of Poultry Science
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• v.29 no.1
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• pp.13-18
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• 2002

This study was conducted to investigate the effects of dietary activated coconut charcoal (ACC) on Performance, e99 quality and Plasma cholesterol level of Plasma in laying hens. One hundred forty four, 47-wk-old, ISA Brown commercial layers were used in a 28-d feeding trial after a 7-d adjustment Period. Four dietary treatments were 0, 0.5, 1.0 and 1.5e% levees of ACC supplemented to a corn-soybean meal basal diet. Egg Production was significantly increased as the levels of ACC increased. However, egg weight was significantly decreased by the addition of ACC in diets. Egg shell breaking strength tended to decrease as the level of ACC increased, however, no significance was found in this respect. As the levels of ACC increased, egg shell thickness decreased significantly. Although not significant, yolk color tended to increase by the addition of ACC. Egg folk index were significantly increased by the addition of ACC In diet. No significant difference was found among four treatments in total cholesterol, HDL cholesterol, and LDL+VLDL cholesterol concentrations in plasma. In conclusion, dietary supplementation of ACC to layer diets could be used to increase egg Production, and yolk index.

• Food Science of Animal Resources
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• v.43 no.5
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• pp.826-839
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• 2023

This study investigated the effects of different charcoals on the occurrence of 16 polycyclic aromatic hydrocarbons (PAHs) in grilled beef steaks and beef patties. Seven different charcoals were used as follows: from oak wood (C1), from orange wood (C2), from Valonia oak wood (C3), from Marabu wood (C4), extruded charcoal from beech wood (C5), from coconut shells (C6), and from hazelnut shells (C7). The grilling times for each charcoal type were 6 min for the beef patties and 7 min for the beef steaks, until the internal temperature reached at least 74℃. The total concentration of 16 PAHs (PAH16) in beef steaks grilled with C1 (35.75 ㎍/kg) and C7 (36.39 ㎍/kg) was higher than that of C3 (23.80 ㎍/kg) and C6 (24.48 ㎍/kg; p<0.05). The highest amounts of PAH16 (216.40 ㎍/kg) were determined in the beef patty samples grilled using C5 (p<0.05). The summation of benzo[a]anthracene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene, referred to as PAH4, was not detected in any of the beef steaks, whereas it was determined in the beef patties grilled with C2 (7.72 ㎍/kg) and C5 (22.95 ㎍/kg; p<0.05). The PAH16 concentrations of the beef patty samples in each charcoal group were significantly higher compared to the beef steaks (p<0.05). To avoid the formation of high PAH levels, the use of extruded charcoal and hazelnut shell charcoal should therefore be avoided when charcoal grilling beef steaks and beef patties, and low-fat meat products should be preferred.

• Journal of the Korean Applied Science and Technology
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• v.32 no.3
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• pp.480-487
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• 2015

In this study, several kinds of active carbons with high specific surface area and micro pore structure were prepared from the coconut shell charcoal using chemical activation method. The physical property of prepared active carbon was investigated by experimental variables such as activating chemical agents to char coal ratio, flow rate of inert gas and temperature. It was shown that chemical activation with KOH and NaOH was successfully able to make active carbons with high surface area of $1900{\sim}2500m^2/g$ and mean pore size of 1.85~2.32 nm. The coin cell using water-based binder in the electrolyte of LiPF6 dissolved in mixed organic solvents (EC:DMC:EMC=1:1:1 vol%) showed better capacity than that of oil-based binder. Also, it was found that the coin cell of water-based binder shows an improved cycling performance and coulombic efficiency.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.4
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• pp.455-463
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• 2023

Objectives: The aim of this study was to develop an air sampling and analytical method for estimating worker exposure to linear carbonate solvents and to evaluate the method. Methods: The target substances were three linear carbonates: DMC, DEC, EMC. GC/FID was used for sample analysis. Laboratory experiments were conducted to determine desorption solvents and sample capacity, and to evaluate storage stability, accuracy, and precision. Results: Coconut Shell Charcoal (CSC, 100/50 mg) was used as the air sampling media, and a desorption solvent of 5% methanol/95% dichloromethane was selected. Recommended sampling capacities were 1~11 ℓ for DMC, 1~18 ℓ for DEC, and 1~24 ℓ for EMC. The stability of three linear carbonates was demonstrated over 30 days in a refrigerator (4℃). Detection limits were determined as follows: DMC 0.26 ㎍/sample, DEC 0.24 ㎍/sample, and EMC 0.25 ㎍/sample. The total coefficient of variation was calculated as DMC 0.064, DEC 0.079, and EMC 0.07. Conclusions: This sampling and analysis method is suitable for estimating personal exposure to linear carbonates in the workplace.

• Journal of Environmental Health Sciences
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• v.35 no.6
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• pp.500-509
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• 2009

Passive samplers have been used for many years for the sampling of organic vapors in work environment atmospheres. Currently, all passive samplers used in domestic occupational monitoring are foreign products. This study was performed to evaluate variable parameters for the development of passive organic samplers, which include the geometry of the device and diffusive length for the sampler design. Four prototype diffusive lengths; A-1(4.5 mm), A-2(7.0 mm), A-3(9.5 mm), A-4(12.0 mm) were tested for adsorption performances to a chemical mixture (benzene, toluene, trichloroethylene, and n-hexane) according to the US-OSHA's evaluation protocol. A dynamic vapor exposure chamber developed and verified by related research was used for this study. The results of study are as follows. The results in terms of sampling rate and recommended sampling time test indicate that the most suitable model was A-3 (9.5 mm diffusive lengths on both sides) for passive sampler design in time weighted average (TWA) assessment. Sampling rates of this A-3 model were 45.8, 41.5, 41.4, and 40.3 ml/min for benzene, toluene, trichloroethylene, and n-hexane, respectively. The A-3 models were tested on reverse diffusion and conditions of low humidity air (35% RH) and low concentrations (0.2 times of TLV). These conditions had no affect on the diffusion capacity of samplers. In conclusion, the most suitable design parameters of passive sampler are: 1) Geometry and structure - 25 mm diameter and 490 $mm^2$ cross sectional area of diffusion face with cylindrical form of two-sided opposite diffusion direction; 2) Diffusive length - 9.5 mm in both faces; 3) Amount of adsorbent - 300 mg of coconut shell charcoal; 4) Wind screen - using nylon net filters (11 ${\mu}m$ pore size).

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.6 no.2
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• pp.187-201
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• 1996

This study was to evaluate the efficiency of diffusive monitor using activated carbon fiber(ACF, KF-1500) in measuring airborne organic solvents. The following characteristics were identified and studied as critical to the performance of diffusive monitor; recovery, sampling rate, face velocity, reverse diffusion and storage stability. For the evaluation of the performance of this monitor, MIBK, PCE, toluene were used as organic solvents. In the sampling rate experiments, eight kinds of solvents (n-hexane, MEK, DIBK, MCF, TCE, CB, xylene, cumene) as well as the above solvents were used. The results were as follows: 1. The desorption efficiencies(DE's) of ACF diffusive monitor ranged from 83 % to 101 %. In contrast, those of coconut shell charcoal ranged from 78 % to 102 %. Especially, the DE's of ACF for the polar solvents such as MEK were superior to those of charcoal. 2. Experimental sampling rates on ACF were average 42ml/min(37-46ml/min) for 11 organic solvents at $24{\pm}2^{\circ}C$, $50{\pm}5%RH$. However ideal sampling rates(DA/L) were 33 % higher than experimental sampling rates. 3. The initial response(15~16 min) of the testing monitor was 2 times higher than the actual concentration determined by the reference methods at $24{\pm}2^{\circ}C$, $8{\pm}5%RH$ and $80{\pm}5%RH$. Within 1 hours, the curve reached a linear horizontal line at low humidity condition. But sampling efficiencies decreased with respect to time at high humidity condition. And sampling efficiencies were higher at high humidity condition than low humidity condition for MIBK. 4. At very low velocity (less than 0.02 m/sec), the concentration of ACF diffusive monitor were poorly estimated. But ACF diffusive monitor were not affected at higher velocity(0.2 m/sec-0.6 m/sec). 5. There was no significant reverse diffusion when the ACF monitors were exposed to clean air for 2 hours after being exposed for 2 hours at the level of 1 TLV. 6. There was no significant sample loss during 3 weeks of storage at room temperature and 5 weeks of storage at refrigeration.