• Analytical Science and Technology
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• v.31 no.5
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• pp.185-194
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• 2018

At the end of November 2010, livestock infected with foot and mouth disease (FMD) were buried, increasing concern about secondary pollution of drinking water and groundwater with odor. Hence, measures to reduce pollution of drinking water and groundwater are needed. In this study, based on livestock type and soil texture, five pilot-scale burial sites were monitored for the past three years from Feb 2012 to 2015. Leachate from the site was analyzed for 90 compounds. A detailed investigation has been completed, looking into organic matter decomposition characteristics of the buried bodies, relevant trace elements thereof, and in particular metabolite concentration changes such as the degree of decomposition of a carcass. From the results, no detectable heavy metals, including cadmium and arsenic, were measured. Among animal types, the rate of cattle decomposition is faster than swine decomposition, and the decomposition of the bodies were performed in sequence from sand, clay loam, sandy loam.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.3
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• pp.557-564
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• 2000

This study is aimed to develop the adsorbent which can effectively remove toxic hydrophobic organic compounds from the aqueous phase. The emphasis was made to elucidate the adsolubilization behavior of sparingly soluble organic compounds (SSOCs) into the cetyltrimetylammonium bromide(CTAB) layer formed on anthracite by the partition coefficient. The amount of SSOCs removed from aqueous solution was increased with increase of the amount of CTAB coated on the surface and wich increase of SSOCs's hydrophobicity. With the surface-modified solid shown in above. chloroform and benzene at the initial concentration of $6{\times}10^{-4}M$ were removed over 95%. Experimentally determined partition coefficient($K_d$) values between organo-anthracite and organics were 4~25 times higher than theoretical $K_d$ values of same organics Organo-anthracite formed by the addition of the CTAB can effectively immobilize organic contaminants dissolved in landfill leachate and can also be applicable to wastewater treatment containing toxic hydrophobic organic compounds such as chloroform and benzene.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.3
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• pp.43-53
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• 2023

This batch experiment evaluated the impacts of major plant nutrient releases by applying the modified Hyperbola model on the leachates and N₂O emissions from incorporated rice hull biochar with organic fertilizer materials. The treatments consisted of the control as incorporated with organic fertilizer materials, the incorporated rice hull biochar with organic fertilizer materials, and the incorporated plasma-activated rice hull biochar with organic fertilizer materials under redox conditions. The results indicated that the maximum release amount of NH₄-N was 3486.3 mg L^-1 in the control, and their reduction rates of NH₄-N, NO₃-N, PO₄-P, and K were 8.0%, 17.5% 44.3.0% and 8.7%, respectively, relative to the control. In the control, the highest soluble amount of PO₄-P was 681.0 mg L^-1. The estimations for accumulated NH₄-N, NO₃-N, PO₄-P, and K-releases in all the treatments were significantly (p<0.01) fitted with a modified Hyperbola model. For greenhouse gas emissions, the lowest cumulative N₂O was 340.4 mg kg^-1 in the soil incorporated with plasma-activated rice hull biochar, and the reduction rates were 27.8% and 86.4% in the rice hull biochar and plasma-activated rice hull biochar treatments, respectively, compared to the control. Therefore, it concluded that the incorporated rice hull biochar can be especially useful for controlling PO₄-P release and N₂O emissions for bio-fertilizer applications.

• Journal of Soil and Groundwater Environment
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• v.6 no.4
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• pp.41-50
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• 2001

The use of clay has been the favored method of reducing or eliminating hazardous contaminants in the leachate from landfills. But, neither natural clays nor organoclays modified with surfactants are able to effectively sorb both heavy metals and organic contaminants. Therefore, the objective of this study is to determine the optimal amount of surfactant added on the clay mineral to effectively remove both of them. For this purpose, Na-Bentonite as the natural clay, and hexadecyltrimethylammonium (HDTMA) as the cationic surfactant were used, Chlorobenzene and lead ($Pb^{2-}$) were selected as representative contaminants. Experimental result showed that chlorobenzene sorption increased with increasing HDTMA to bentonite, ratios. On the contrary, the removal rate of lead decreased as the amount of HDTMA increased. The removal of chlorobenzene was influenced by the amount of HDTMA added to the bentonites rather than initial concentration of chlorobenzene, but the removal of lead was much more influenced by the initial concentration of lead. The adsorption of lead was not affected by chlorobenzene, and vice versa. The competitive sorption between the heavy metal and the organic contaminant was not present.

• Solar Energy
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• v.18 no.3
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• pp.197-203
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• 1998

A 5 ton/day pilot scale two-phase anaerobic digester was constructed and tasted to treat Korean food wastes in Anyang city. The process was developed based on 3 years of lab-scale experimental results on am optimim treatment method for the recovery of biogas and humus. Problems related to food waste are ever Increasing quantity among municipal solid wastes(MSW) and high moisture and salt contents. Thus our food waste produces large amounts of leachate and bed odor in landfill sites which are being exhausted. The easily degradable presorted food waste was efficiently treated in the two-phase anaerobic digestion process. The waste contained in plastic bags was shredded and then screened for the removal of inert material such as fabrics and plastics, and subsequently put into the two-stage reactors. Heavy and light inerts such as bones, shells, spoons and plastic pieces were again removed by gravity differences. The residual organic component was effectively hydrolyzed and acidified in the first reactor with 5 days space time at pH of about 6.5. The second, methanization reactor part of which is filled with anaerobic fillters, converted the acids into methane with pH between 7.4 to 7.8. The space time for the second reactor was 15 days. The effluent from the second reactor was recycled to the first reactor to provide alkalinities. The process showed stable steady state operation with the maximum organic rate of 7.9 $kgVS/m^3day$ and the volatile solid reduction efficiency of about 70%. The total of 3.6 tons presorted MSW containing 2.9 tons of food organic was treated to produce about $230m^3$ of biogas with 70% of methane and 80kg humus. This process is extended to full scale treating 15 tons of food waste a day in Euiwang city and the produced biogas is utilized for the heating/cooling of adjacent buildings.

• Journal of Apiculture
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• v.34 no.4
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• pp.315-323
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• 2019

Large amounts of sludge produced by paper mill industries represent one of the most serious environmental problems in the world. Recently, beekeepers living in the neighborhood of the paper mill in Hwasan County, Youngcheon city, GB, Korea, became alarmed that honey bee colonies were dying off suddenly across the neighborhood. A preliminary study was conducted to evaluate the toxicity (oral, fumigation, repellent) of recycled solid paper mill sludge (SPMS) and leachate paper mill sludge (LPMS) to honey bee workers under laboratory conditions, and to analyze the volatile organic compounds(VOC). The SPMS and LPMS were separately subjected to a liquid-liquid extraction (LLE) at three temperatures to extract VOC(highest VOC yields: 1.52% SPMS and 0.34% LPMS). A total of 70 chemicals were detected in the VOC of paper mill sludges, of which 49 and 21 volatile organic compounds from SPMS and LPMS, respectively. The SPMS was dominated by high degree presence of stanols (saturated sterols), such as cholestanol, cholestan-3-ol and also saturated hydrocarbons. However, LPMS was characterized by the absence of sterols. Both SPMS and LPMS showed an influence on the olfactory behavior of honey bee on Y-tube assay, with repulsion rates of 72 and 68%, respectively. Both SPMS and LPMS at concentration of 100mg/mL caused higher honey bee oral mortality than the untreated controls at 48, 72, 96 and 120 hours after treatment(highest oral mortality at 120 hr: 85.74%(SPMS); 93.51 % (LPMS)). A similar pattern was observed when honey bees were tested to fumigant toxicity. Both SPMS and LPMS caused significant higher mortality than the untreated control 24 hour after the exposure (highest fumigation mortality at 120 hr: 69.4% (SPMS); 56.8% (LPMS)). These preliminary results indicated that paper mill sludge could be partly responsible for sudden death and disappearance of honey bees, especially in hot humid summer days. With climate change, the risk of environmental chemical exposure to honey bee would pose greater attention.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.588-597
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• 2016

In this study, we attempted to improve the biogas production efficiency by varying the mixing ratio of the mixed sludge of organic wastes in the improved single-phase anaerobic digestion process. The types of organic waste used in this study were raw sewage sludge, food wastewater leachate and livestock excretions. The biomethane potential was determined through the BMP test. The results showed that the biomethane potential of the livestock excretions was the highest at $1.55m^3CN4/kgVS$, and that the highest value of the composite sample, containing primary sludge, food waste leachate and livestock excretions at proportions of 50%, 30% and 20% respectively) was $0.43m^3CN4/kgVS$. On the other hand, the optimal mixture ratio of composite sludge in the demonstration plant was 68.5 (raw sludge) : 18.0 (food waste leachate) : 13.5 (livestock excretions), which was a somewhat different result from that obtained in the BMP test. This difference was attributed to the changes in the composite sludge properties and digester operating conditions, such as the retention time. The amount of biogas produced in the single-phase anaerobic digestion process was $2,514m^3/d$ with a methane content of 62.8%. Considering the value of $2,319m^3/d$ of biogas produced as its design capacity, it was considered that this process demonstrated the maximum capacity. Also, through this study, it was shown that, in the case of the anaerobic digestion process, the two-phase digestion process is better in terms of its stable tank operation and high efficiency, whereas the existing single-phase digestion process allows for the improvement of the digestion efficiency and performance.

• Applied Chemistry for Engineering
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• v.9 no.3
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• pp.330-335
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• 1998

The objectives of this study are summarized with two. The one is to remove of $COD_{Cr}$, color and turbidity with coagulation and ozonation in nonbiodegradable landfill leachate, the other is to compare of water qualities with pre-ozonation and post-ozonation. The results are summarized as follows ; 1) 90 minutes ozonation with $75mgO_3/min$($4.5gO_3/hr$) was conducted at pH 4,7, 10 to remove $COD_{Cr}$. Removal efficiencies were investigated with 48.2%, 52.6%, and 62.3% respectively. As increasing pH, $COD_{Cr}$ removal efficiencies were increased, it was considered that hydroxyl radical($OH{\cdot}$) which strongly oxdize and nonselectively react with organic compounds, was rapidly produced by ozone self-decomposition at high pH. 2) Alum, ferric chloride and ferrous sulfate were used for coagulation as inorganic coagulant. Ferric chloride was investigated with optimal coagulant, and it removed $COD_{Cr}$ about 12.0% at pH5 and dosage of $2,000m{\ell}/{\ell}$. Cation(C-101P), anion(A-601P) and nonion(SC-050) were tested to remove organic pollutants in landfill leachate. Cation(C-101P) was investigated with the most effective organic coagulant, and removal efficiency of $COD_{Cr}$ was 19.8% at pH5 and dosage of $100m{\ell}/{\ell}$. 3) Color and turbidity were removed up to 88.6%, 97.0% at pH10, when contacted 90 minutes with ozone, respectively. These removal efficiencies were much higher than those of $COD_{Cr}$ and $COD_{Mn}$. It was considered that ozone could oxdize the triggering materials of color and turbidity selectively and preferentially. 4) $COD_{Cr}$, color and turbidity were more effectively removed with pre-ozonation than post-ozonation about 8%, 3.5% and 1% respectively. These results were well corresponed with other's studies that pre-ozonation will increase the effect of coagulation.

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.1
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• pp.47-56
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• 2010

At present, 265 national food waste recycling facilities have been operated by public facilities 95 and private facilities 160. it has continuously installed a food waste treatment facility from 1997. The government set up and implemented guidelines and inspection standards for the installation and operation of the facilities. However, unclear detailed examination items, designs and process standards for the installation procedures of the facilities are causing problems due to the unskilled operation management system, decrease in efficiency and defects of a facility. This study conducted mail and site surveys on 95 public food waste recycling facilities that it suggest the ways to operate facilities which minimize problems. At the result of investigation, a pre-treatment facility was not installed 2 systems(2 inputting facilities) and hopper covers and food was overloaded. also the transportation amount was excessive. In case of a main treatment facility, the secondary environmental pollution was caused by inexperienced operation and the efficiency of the facility was reduced due to excessive input of food. also the operation management standards of the facilities were inappropriate. The odor and food waste leachate treatment facility is investigated as problems that are unskilled operation, lack of regular inspection and inappropriate capacity of the treatment facility. Based on the problems found through the investigation, it suggested some ways of efficient operation. this study might contribute to minimize mistakes and defects and improve the efficiency of install and operation course of food waste recycling facilities through finding.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.1
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• pp.53-61
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• 2013

The characteristics of methane production from pig manure slurry was investigated using anaerobic digestor combined with compost filtration bed. In this study, raw pig manure slurry was digested in mesophilic rectangular digester (effective volume $250m^3$) for 25 days and anaerobic digestion wastewater was filtered through compost filtration bed, which is composed of double layer, sawdust and chaff. The characteristics of anaerobic digestion wastewater were BOD 1,800 mg/L, COD 3,500 mg/L, SS 11,800 mg/L, T-N 1,200 mg/L and T-P 350 mg/L. After the filtration process, the contents of BOD, COD, SS, T-N and T-P of the anaerobic digestion wastewater were reduced by 97%, 62%, 89%, 39% and 57%, respectively. The concentrations of N, $P_2O_5$, and $K_2O$ of the leachate were 1,024, 111 and 407 mg/L, respectively. However, there was no odor emitted from the leachate.