• Journal of Environmental Health Sciences
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• v.38 no.2
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• pp.151-158
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• 2012

Objectives: Bioaerosols released by treating organic-waste resources cause a variety of environmental and hygiene problems. The objective of this study was to investigate the distribution characteristics of the airborne bacteria emitted from a pig manure composting plant, a principal site for organic-waste resource facilities. Methods: Three types of pig manure composting plant were selected based on fermentation mode: screw type, rotary type and natural-dry type. Each site was visited and investigated on a monthly basis between September 2009 and August 2010. A total of 36 air samplings were obtained from the pig manure composting plants. The air sampling equipment was a six-stage cascade impactor. Quantification and qualification of airborne bacteria in the air samples was performed by agar culture method and identification technique, respectively. Results: The mean concentrations of airborne bacteria in pig manure composting plant were 7,032 (${\pm}1,496$) CFU $m^{-3}$ for screw type, 3,309 (${\pm}1,320$) CFU $m^{-3}$ for rotary type, and 5,580 (${\pm}1,106$) CFU $m^{-3}$ for natural dry type. The screw type pig manure composting plant showed the highest concentration of airborne bacteria, followed by the natural dry type and the rotary type. The ratio of respirable to total airborne bacteria was approximately 40-60%. The predominant genera of airborne bacteria identified were Micrococcus spp., Staphylococcus spp. and Escherichia spp. Conclusion: Monthly levels of airborne bacteria were highest in August and lowest in November regardless of fermentation mode. There was no significant correlation relationship between airborne bacteria and environmental factors such as temperature, relative humidity and particulate matters in pig manure composting plants.

• Journal of environmental and Sanitary engineering
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• v.6 no.1
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• pp.7-25
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• 1991

Until now, pure drinking water grnerally menas the water without taste, odor, general bacteria, coliform, and other exotic substance. Such a definition has been changing recently due to the finding of numerous other inorganic and organic substances unknown to us. 10 years ago, major causes of death were infectious agents and parasites contained in water, but recently, it has become apparent that some substances contained in drinking water cause cancer and heart diseases. We must drink about 2L of water everyday in order to maintain healthy condition. Waters used for drinking include tap water, well water, spring water, filtered water, etc., but the quality of drinking water has more polluted due to the industrial development and population increase. For example, industrial waste waters from industrial plants pollute the water supply sources ; toxic substances contained in the waste waters pollute the ground water sources by penetrating the geological strata, and municipal, livestock, public building waste waters also pollute the water supply sources. Sometimes, the polluted surface waters were announced to be polluted by various kinds of orgainc substance, and it is reported that the pollution of ground water by orga nic substances has few in number but high in its concectration comparing with those of surface water. As the water quality pollution level increases, so the amount of disinfectant also increase. For example, chlorine solution, one of widely used disinfectants, creates trihalomethane(THM), a carcinogen, and halogen compounds. According to Oliver, through chlorine disinfection process, humine substance and chlorine create bolatile organic halide and nonvolatile organic halide by chemical reaction. There are tens or hundreds filtering devices, but filtering principles and maintenance metjhods are different, so their efficiency tests are needed. According to Smith, the effeciency tests aginst over 30 Ameican filtering devices show that 10 devices can remove 85% of volatile organics and further studies on filtered waters are underway. In consideration of important impacts of polluted drinking water on national health, authors studied the state of water quality pollution against tap water used as drinking water, filtration device passed water, ground water, and conserved drinking water ; tested the efficiency of filtration devices for tap water ; tried to sep up the detection method by using ion chromatography based on negative ion and positive ion by using single column, and attemped the simple filtration method for general households.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.4
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• pp.49-57
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• 2016

In this study, a thermal hydrolysis technology was used to treat the poultry carcasses that were killed due to Avian Influenza (AI) occurrence, as well as to determine the possibility of fueling for the resultant products. Experimental results showed that the poultry carcasses were liquefied except for sand, and showed the optimum efficiency at $190^{\circ}C$ and operating time of 60 minutes. It has been shown that liquid products obtained after thermal hydrolysis has good conditions for fuel conversion since it had high carbon contents and calorific value, as well as low ash content. In addition, it was possible to operate the thermal hydrolysis facility by using only the waste heat generated in the combustion without injecting the auxiliary fuel, and the exhaust gas generated in the combustion has a small influence on the atmosphere.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.1
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• pp.1-10
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• 2018

The amount of biogas increases as the amount of organic waste increases. Recently, biogas from organic waste have been made much efforts to utilize as a energy. In particular, the concentration of $CH_4$ and $CO_2$ generated from sewage sludge and livestock manure treatment are 60-70% and 30-35%, and $CH_4$ and $CO_2$ generated from food wastes are 60-80% and 20-40%. In case of landfill gas, $CH_4$ and $CO_2$ have a concentration of 40-60% and 40-60% respectively. Therefore, in order to use the biogas more widely, it is necessary to convert the biogas to methanol, LNG or DME. In this study, experiments were conducted to produce hydrogen and carbon monoxide through various biogas reforming reactions on $Ni/Ce-ZrO_2/Al2O3$ catalysts. The experiment of synthetic gas synthesis was carried out on a wide concentrations of methane and carbon dioxide, which were the major constituents of biogas from various organic wastes. The effect of $(O_2+CO_2)/CH_4$ (=R') on the yields of hydrogen and carbon monoxide, the conversion rate of methane and carbon dioxide was investigated. Also simulation for syngas synthesis on the $CO_2$ reforming of $CH_4$ was computed by employing total Gibbs free energy minimization method using PRO/II simulator, and compared with the experimental results on wet and dry reforming reaction of biogas.

• Applied Chemistry for Engineering
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• v.28 no.6
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• pp.649-654
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• 2017

An activated carbon was prepared from waste citrus peel produced in large amounts in Jeju Island, Korea, using KOH activation and its characteristics was examined. Under the condition of the KOH ratio between 100 and 300%, activation temperature from 400 to $900^{\circ}C$ and activation time from 0.5 to 1.5 h, the iodine adsorptivity of the activated carbon prepared increased but the yield decreased with respect to the increase of each conditions. The iodine adsorptivity and yield of the activated carbon prepared at the activation time of more than 1.5 h were similar to those of using 1.5 h. In addition, as the KOH ratio increased, the specific surface area and pore volume of the activated carbon increased, but the pore diameter decreased. The activated carbon has an average pore diameter of $20{\sim}25{\AA}$. Also, the activated carbon prepared at 300% KOH and $900^{\circ}C$ for 1.5 h has the highest specific surface area of $1,527m^2/g$ and iodine adsorptivity of 1,246 mg/g.

• Applied Chemistry for Engineering
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• v.28 no.6
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• pp.663-669
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• 2017

Activated carbons were prepared from waste citrus peels using KOH, NaOH, and $ZnCl_2$ as activating chemicals. They were prepared at optimal conditions including the chemical ratio of 300%, activation time of 1.5h, and activation temperature of $900^{\circ}C$ for KOH, $700^{\circ}C$ for NaOH, and $600^{\circ}C$ for $ZnCl_2$, which were named as ACK, ACN, and ACZ, respectively. Using the activated carbons, their adsorption characteristics for three target gases such as acetone, benzene, and methylmercaptan (MM) were carried out in a batch reactor. The adsorption behavior of activated carbons for three target gases followed the Freundlich model better than the Langmuir. And the experimental kinetic data followed a pseudo-second-order kinetic model more than pseudo-first-order one. Following the intraparticle diffusion model suggested that the external mass transfer and particle diffusion were occurred simultaneously during the adsorption process.

• Journal of Korean Society on Water Environment
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• v.22 no.4
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• pp.599-604
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• 2006

Nitrogen removal with the combined SHARON (Single reactor system for high ammonium removal over nitrite)ANAMMOX (Anaerobic ammonium oxidation) process using the effluent of ADEPT (Anaerobic digestion elutriated phased treatment) slurry reactor with very low C/N ratio for piggery waste treatment was investigated. For the preceding SHARON reactor, ammonium nitrogen loading and removal rate were $0.97kg\;NH_4-N/m^3_{reactor}/day$ and $0.68kg\;NH_4-N/m^3_{reactor}/day$ respectively. In steady state, bicarbonate alkalinity consumption for ammonium nitrogen converted to $NO_2-N$ or $NO_3-N$ was 8.4 gram per gram ammonium nitrogen. The successive ANAMMOX reactor was fed with the effluent from SHARON reactor. The loading and removal rate of the soluble nitrogen defined as the sum total of $NH_4-N$, $NO_2-N$ and $NO_3-N$ in ANAMMOX reactor were $1.36kg\;soluble\;N/m^3_{reactor}/day$ and $0.7kg\;soluble\;N/m^3_{reactor}/day$, respectively. The average $NO_2-N/NH_4-N$ removal ratio by ANAMMOX was 2.41. Fluorescence in situ hybridization (FISH) analysis verified that Candidatus Kuenenia stuttgartiensis were dominate, which means that they played an important role of nitrogen removal in ANAMMOX reactor.

• Journal of the Korean GEO-environmental Society
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• v.11 no.11
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• pp.27-36
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• 2010

This study was conducted to evaluate physicochemical parameters; temperature, pH, C/N ratio, water content, organic contents and volume in a pilot-scale(capacity : $100m^3$) ultra thermophilic aerobic composting. There were three types input: municipal wasted sludge, livestock manure and slurry, and food waste produced in Jung-Eb city. Each target material was carried out by the first fermentation(organic waste + seed culture) and the second one(organic waste + seed culture + recycle compost), respectively. During composting, only with supply of air and mixing, the temperature increased $90{\sim}105^{\circ}C$ after every mixing in both periods. The changes of pH, $O_2$, $CO_2$ and $NH_3$ represented typical organic decomposition pattern by microorganisms. Also, all other physicochemical parameters of ultra thermophilic aerobic composting process showed similar or better performance than these of general aerobic composting. Heavy metal concentration of fermented compost adapted to compost fertilizer regulation standard in the heavy metal and hazardous analysis.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.903-915
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• 2011

Recently, anaerobic methane production of agricultural waste biomass has received increasing attention. Until now domestic BMP (Biochemical methane potential) studies concerned with agricultural waste biomass have concentrated on the several waste biomass such as livestock manure, food waste, and sewage sludge from WWTP (Waste water treatment plant). Especially, the lack of standardization study of BMP assay method has caused the confused comprehension and interpretation in the comparison of BMP results from various researchers. Germany and USA had established the standard methods, VDI 4630 and ASTM E2170-01, for the analysis of BMP and anaerobic organic degradation, respectively. In this review, BMP was defined in the aspect of organic material represented as COD (Chemical oxygen demand) and VS (Volatile solid), and the influence of several parameters on the methane potential of the feedstock was presented. In the investigation of domestic BMP case studies, BMP results of 18 biomass species generating from agriculture and agro-industry were presented. And BMP results of crop species reported from foreign case studies were presented according to the classification system of crops such as food crop, vegetables, oil seed and specialty crop, orchards, and fodder and energy crop. This review emphasizes the urgent need for characterizing the innumerable kind of biomass by their capability on methane production.

• Clean Technology
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• v.9 no.2
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• pp.49-55
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• 2003

The generation of livestock wastewater in Korea amounts to $130,000m^3/day$, 0.43% of the total waste water volume, but which corresponds to 8.6% of total BOD loading. Furthermore this wastewater contains a large amount of nitrogen and phosphorus that are major causes of eutrophication in rivers and lakes. The average volume of livestock wastewater in a Korea's single farm is only $2.5m^3/day$, which necessitates development of a simple and economical process for the removal of nitrogen and phosphorus. Introduction of filtration method removes more than 90% of suspended solids. Subsequent application of reverse osmosis removes more then 95% of total nitrogen and phosphorus in the wastewater. The effluent of this treatment will yield less than 200 mg/L of total nitrogen and 1 mg/L of total phosphorous, which are lower than 260 mg/L of total N and 50 mg/L of total P, the regulation values of Ministry of Environment, Korea. Treating $2m^3/day$ of livestock wastewater was found to be feasible with the application of filtration and reverse osmosis and the electricity requirement was estimated to be about 30 Kwh/month.