• Horticultural Science & Technology
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• v.30 no.5
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• pp.501-508
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• 2012

Reducing carbon dioxide ($CO_2$) exhaust has become a major issue for society in the last few years, especially since the initial release of the Kyoto Protocol in 1997 that strictly limited the emissions of greenhouse gas for each country. One of the primary sectors affecting the levels of atmospheric greenhouse gases is agriculture where $CO_2$ is not only consumed by plants but also produced from various types of soil and agricultural ecosystems including greenhouses. In greenhouse cultivation, $CO_2$ concentration plays an essential role in the photosynthesis process of crops. Optimum control of greenhouse $CO_2$ enrichment based on accurate monitoring of the added $CO_2$ can improve profitability through efficient crop production and reduce environmental impact, compared to traditional management practices. In this study, a sensor-based control system that could estimate the required $CO_2$ concentration considering emission from soil for cucumber greenhouses was developed and evaluated. The relative profitability index (RPI) was defined by the ratio of growth rate to supplied $CO_2$. RPI for a greenhouse controlled at lower set point of $CO_2$ concentration (500 ${\mu}mol{\cdot}mol^{-1}$) was greater than that of greenhouse at higher set point (800 ${\mu}mol{\cdot}mol^{-1}$). Evaluation tests to optimize $CO_2$ enrichment concluded that the developed control system would be applicable not only to minimize over-exhaust of $CO_2$ but also to maintain the crop profitability.

• Mass Spectrometry Letters
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• v.13 no.4
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• pp.166-176
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• 2022

Banana peels are also widely used as bio-adsorbent in the removal of chemicals contaminants and heavy metals from water and soil. GC-MS plays an essential role in the phytochemical analysis and chemo taxonomic studies of medicinal plants containing biologically active components. Intrinsically, with the use of the flame ionization detector and the electron capture detector which have very high sensitivities, Gas chromatography can quantitatively determine materials present at very low concentrations and most important application is in pollution studies. In the present study banana peels were used as bio-adsorbent to remediate the heavy metal contaminated water taken from three different stations located around the industrial belts of Ranipet, Tamilnadu, India. The AAS analysis of the samples shows a decrement of chromium concentration of 98.93%, 96.16% and 96.5% in Station 1, 2 and 3 respectively which proves the efficiency of the powdered peels of Musa paradisiaca. The GC-MS analysis of the control and treated peels of Musa paradisiaca reveals the presence of phytochemicals like Acetic Acid, 1-Methylethyl Ester, DL-Glyceraldehyde Dimer, N-Hexadecanoic Acid, 3-Decyn-2-Ol, 26-Hydroxy, Cholesterol, Ergost-25-Ene-3,5,6,12-Tetrol, (3.Beta.,5.Alpha.,6.Beta.,12.Beta.)-, 1-Methylene-2b-Hydroxymethyl-3, and 3-Dimethyl-4b-(3-Methylbut-2-Enyl)-Cyclohexane in the control banana peels. The banana peels which were used for the treatment reveals the changes and alteration of the phytochemicals. It is concluded that the alteration in phytochemicals of the experimental banana peels were due to adsorption of chromium heavy metal from the sample.

• Korean Journal of Environmental Agriculture
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• v.42 no.4
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• pp.371-381
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• 2023

The effectiveness of plant-based attractants was studied using large traps, which attracted relatively more snails in agricultural water drainage ditches and rice-cultivating environments, although their effectiveness in rice fields and lakes was limited. The rate began to rise after three hours of observation. Watermelon peel exhibited the highest apple snail attraction rate (13.8%), followed by potatoes (10.0%), and apple peel (8.8%). These values significantly differed from the attraction rate attributed to papaya leaves (F=3.84; P=0.0387). After 24 h, watermelon peel and apple peel indicated a higher rate of attraction (23.4% and 21.7%, respectively), which were significantly different compared with those of papaya leaves and potatoes (F=9.94; P=0.00455). Large bait traps outperformed funnel traps in capturing golden apple snails and trapped a significant number of snails measuring over 1 cm in size. Watermelon peel was the most effective attractant for a large bait trap, followed by apple peel, potatoes, and papaya leaves. On average, 110 snails were captured in the lure net. However, potatoes, apple peels, and papaya leaves caught an average of 93, 80, and 79 snails, respectively. Among the attractants, the lure effect of the snails was not significantly different. The efficiency of large bait traps in capturing snails, regardless of the plant attractant employed, followed the order: apple peel > watermelon peel and potatoes > papaya leaves > melon > Korean melon. Watermelon peel is highly recommended for farmer use, as well as apple peel and potatoes. Utilizing these snail attractants may contribute positively to developing a safe and environment-friendly integrated pest management strategy.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.141-141
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• 2013

We have generated the needle-typed nonthermal plasma jet by using an Ar gas flow at atmospheric pressure. Diagnostics of electron temperature anddensity is critical factors in optimization of the atmospheric plasma jet source in accordance with the gas flow rate. We have investigated the electron temperature and density of plasma jet by selecting the four metastable Ar emission lines based on the atmospheric collisional radiative model and radial profile characteristics of current density, respectively. The averaged electron temperature and electron density for this plasma jet are found to be ~1.6 eV and ~$3.2{\times}10^{12}cm^{-3}$, respectively, in this experiment. The densities of OH radical species inside the various bio-solutions are found to be higher by about 4~9 times than those on the surface when the argon bioplasma jet has been bombarded onto the bio-solution surface. The densities of the OH radicalspecies inside the DI water, DMEM, and PBS are measured to be about $4.3{\times}10^{16}cm^{-3}$, $2.2{\times}10^{16}cm^{-3}$, and $2.1{\times}10^{16}cm^{-3}$, respectively, at 2 mm downstream from the surface under optimized Ar gas flow 250 sccm.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.2
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• pp.57-66
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• 2019

This study carried out on-site investigation and precision monitoring to prepare proper design and operation technical guidelines for the use of bio gas in organic waste resources (fertilizing urine, food waste, food waste, food waste, etc.). According to the government's mid- and long-term policy on bio gasification, the expansion of waste resources is actively being pushed forward. However, facilities that use the biogas produced for urban gas and transportation are still under-efficient. Precision monitoring was carried out for biogasification facilities of organic waste resources in seven locations nationwide. When the results of precision monitoring were summarized with the four-season average, the efficiency analysis of each organic waste resource showed that the organic breakdown rate was 66.3% on average on VS basis. Analysis of biogas characteristics before and after pretreatment revealed that the $H_2S$ average of the entire facility was measured at 949.7 ppm using iron salts and desulfurization (dry, wet) and that the quality refining facility shearing and rear end was 29.0 ppm and 0.3 ppm. The methane content was found to be reduced by 65.6% at the rear of the fire tank, 63.5% at the back and 97.5% at the rear.

• Journal of Climate Change Research
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• v.8 no.3
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• pp.257-264
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• 2017

Carbon capture and storage (CCS) technology has been suggested as an ultimate strategy for mitigating climate change. However, potential leakage of $CO_2$ from the CCS facilities could lead to serious damage to environment. Plants can be a bio-indicator for $CO_2$ leakage as a cost-effective way, although plants' responses vary with plant species. In this study, a greenhouse experiment was conducted to investigate the relation between the $CO_2$ tolerance of corn species and the initial physiological responses to the elevated soil $CO_2$ concentration. Treatment groups included CI (99.99% $CO_2$ gas injection) and BI (no gas injection). Mean soil $CO_2$ concentration for the CI treatment was 19.5~39.4%, and mean $O_2$ concentration was 6.6~18.4%. The soil gas concentrations in the BI treatment were at the ambient levels. In the CI treatment, chlorophyll content was not decreased until the $13^{th}$ day of the $CO_2$ injection. On the $15^{th}$ day, leaf starch content and stomatal conductance were increased by 89% and 25% in the CI treatment compared to the BI treatment, respectively. This might be due to the compensatory reaction of corn to avoid high soil $CO_2$ stress. However, the prolonged $CO_2$ injection decreased chlorophyll content after 13 days. After $CO_2$ injection, plant biomass was reduced by 25% in the CI treatment compared to the BI treatment. Due to the inhibited root growth, leaf phosphorous and potassium contents were decreased by 54% on average in the CI treatment. This study indicates that corn has a high tolerance to soil $CO_2$ concentration of 30% for 2 weeks by its compensatory reactions such as an maintenance of chlorophyll content and an increase in stomatal conductance.

• Membrane Journal
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• v.21 no.2
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• pp.177-192
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• 2011

Hollow fiber membrane using CTA polymers were prepared by the phase separation method for the separation and purification of biogas and the hollow fiber gas separation membrane modules with the effective surface area of 0.17 $m^2$ were prepared. The pure gas permeation properties of membrane modules for methane, oxygen and carbon dioxide were measured. The permeance of $CO_2$ and $CH_4$were 0.46 GPU and 18.52 GPU, respectively, therefore, the high $CO_2$/$CH_4$ selectivity of 40.4 was obtained. The separation and purification test for 4 different simulated mixed gases were carried out after the pure gas test and the gas concentration and flux of the permeate at the various stage-cut were measured from the 1 stage, 2 stage, and 3 stage cascade of membrane modules. In the 1 stage test, the concentration of $CH_4$ increased as the increase of the stage-cut, while the $CH_4$ recovery efficiency ratio decreased. In the 2 stage test, the $CH_4$ recovery efficiency ratio increased compared to the 1 stage. The 3 stage test was employed to reduce the loss of $CH_4$ in biogas and the result showed less than 5% of $CH_4$ recovery loss.

• Journal of environmental and Sanitary engineering
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• v.22 no.2
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• pp.9-20
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• 2007

The incineration process has commonly used for wastes amount reduction and thermal treatments of pollutants as the technologies accumulated. However, the process is getting negative public images owing to matter of hazardous pollutants emission. Specially dioxins became a main issue and were mostly emitted from municipal solid wastes incineration. In this reason, pyrolysis/gasification/melting process is presented as an alternative of incineration process. The pyrolysis/gasification/melting process, a novel technology, is middle of verification of commercial plant and development of technologies in Korea. But the survey about the pollutant emission from the process, and background data in these facilities is necessary. So in this survey, t is investigated that the behavior of chlorobenzenes and chlorophenols in plasma type pyrolysis/gasification/melting plant of pilot scale. We investigated discharging behavior of each phase of chlorobenzene through each process in the plsasma type pyrolysis/gasification/melting process. From this result, it was found that about 99 percent of particle-phase chlorobenzene was removed, but on the other hand gas-phase chlorobenzene was increased by about 600 percent through heat exchanger, flue gas cooling, system and semi dry absorption bag filter(SDA/BF). Also, this investigation presented that di-chlorobenzene(DCB) tri-chlorobenzene(TCB), tetra-chlorobenzene(TeCB), penta-chlorobenzene (PCB), except mono-chlorobenzene(MCB) and hexa-chlorobenzene(HCB) were increased through the flue gas cooling system and the semi dry absorption bag filter(SDA/BF). It was investigated that concentration of particle-phase chlorophenol was decreased by about 66 percent, but on the other hand, concentration of gas-phase chlorophenol was increased by about 170 percent through heat exchanger, flue gas cooling system, and semi dry absorption bag filter(SDA/BF). Also, it was found that di-chlorophenol(DCP), tri-chlorophenol(TCP), and penta-chlorophenol(PCP) were increased through the flue gas cooling system, and the semi dry absorption bag filter(SDA/BF). It can be considered that small-scale pilot facility and short investigation period might cause the concentration increase through the flue gas cooling system and the semi dry absorption bag filter(SDA/BF). A further study on real-scale pilot facility and accurate investigation may be required.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.6
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• pp.789-800
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• 2013

$N_2O$ and $CH_4$, Greenhouse gas emission, Forest soil, Closed chamber technique, Soil uptake $N_2O$ and $CH_4$ are important greenhouse gases (GHG) along with $CO_2$ influencing greatly on climate change. Their soil emission rates are highly affected by bio-geo-chemical processes in C and N through the land-atmosphere interface. The forest ecosystems are generally considered to be net emission for $N_2O$; however, net sinks for $CH_4$ by soil uptake. Soil $N_2O$ and $CH_4$ emissions were measured at Mt. Taewha in Gwangju, Kyeonggi, Korea. Closed chamber technique was used for surface gas emissions from forest soil during period from May to October 2012. Gas emission measurement was conducted mostly on daytime (from 09:00 to 18:00 LST) during field experiment period (total 25 days). The gas samples collected from chamber for $N_2O$ and $CH_4$ were analyzed by gas chromatography. Soil parameters were also measured at the sampling plot. GHG averages emissions during the experimental period were $3.11{\pm}16.26{\mu}g m^{-2}hr^{-1}$ for $N_2O$, $-1.36{\pm}11.3{\mu}gm^{-2}hr^{-1}$ for $CH_4$, respectively. The results indicated that forest soil acted as a source of $N_2O$, while it acted like a sink of $CH_4$ on average. On monthly base, means of $N_2O$ and $CH_4$ flux during May (spring) were $8.38{\pm}48.7{\mu}gm^{-2}hr^{-1}$, and $-3.21{\pm}31.39{\mu}gm^{-2}hr^{-1}$, respectively. During August (summer) both GHG emissions were found to be positive (averages of $2.45{\pm}20.11{\mu}gm^{-2}hr^{-1}$ for $N_2O$ and $1.36{\pm}9.09{\mu}gm^{-2}hr^{-1}$ for $CH_4$); which they were generally released from soil. During September (fall) $N_2O$ and $CH_4$ soil uptakes were observed and their means were $-1.35{\pm}12.78{\mu}gm^{-2}hr^{-1}$ and $-2.56{\pm}11.73{\mu}gm^{-2}hr^{-1}$, respectively. $N_2O$ emission was relatively higher in spring rather than other seasons. This could be due to dry soil condition during spring experimental period. It seems that soil moisture and temperature mostly influence gas production and consumption, and then emission rate in subsoil environment. Other soil parameters like soil pH and chemical composition were also discussed with respect to GHG emissions.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.199.2-199.2
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• 2010

Biodiesels are well-known as alternative fuels. also we know that biodiesels increase NOx and reduce PM(Particulate Matter) by previous many studies. But PM in most these studies was considered about the mass. In this study, We have performed experimental test for PM and exhaust emission by mixed ratio of biodiesel in heavy duty diesel engine. PM was investigated by The nano particle number and the mass. The mass of PM was evaluated by using the standard gravimetric method, The number of PM was evaluated by using the EEPS(Engine Exhaust Particle Sizer), on the ESC(European Steady Cycle) mode. Sampled gas through dilutor was directly extracted from tail pipe and EEPS measured diluted exhaust gas. Biodiesel is made up of used cooking oil. Diesel as base fuel was sold on market and contains 2% biodiesel. The mass of PM was reduced 10% and the nano particle number was increased 5%. The particle number less than 40nm was increased, but the particle number more than 40nm is decreased.