• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.2
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• pp.77-86
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• 2001

As construction and expansion of wastewater treatment works is continuing, generation of sludge is increasing. Bur most sludge is not used appropriately but disposed by landfill dumping to sea. Furthermore direct landfilling of sludge cake containing moisture content over 75% has been legally prohibited since 2001 that's enforcement will be more strict in 2003. Such a situation means nowadays recycling of organic waste such as sludge and food waste is necessary. Composting is one of recycling methods commonly and used as an effective means of stabilizing organic waste and then compost can be used as fertilizer. However fertilizer law management which include standard of compost products and other fertilizers applied all sludge products indiscriminiately and was not flexible. So MOE has graded organic composts according to land applications to improve recycle of organic wastes. The classified organic compost which contains low contaminants has been possible to use as various purpose. This study enalyzed 30 samples which were raw materials for compost and compost products management well and to estimate the quality of compost products. Heavy metals were measured in Raw materials and OM/N, NaCl and VS were tested in compost products as well as heavy metals. As a result, approximate 10% of raw materials was not suitable to the grade A and 6.7% over the grade B of the regulation on raw materials for compost. In the case of 30 produced compost propducts approximate, 57% of composts was not compatible with the grade A and B of the regulation on composting product. The qualities of compost products were worse than raw materials, because the compost products have more regulation item raw materials have.

• Journal of the Korean Wood Science and Technology
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• v.18 no.1
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• pp.3-9
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• 1990

Expression is on operation of separating liquid from solid liquid mixtures which has long been used on a universal scale in widely divergent fields. In fruit pulps processing and fermentation industries. removal of a portion of the liquid in filler cake is essential to the maximum yields of products. In sewage sludge treatments, dewatering of filter cakes is important to disposal by incineration. transportation. and landfill. In the chemical process industries, drying of wet cakes increases cost, and it is desirable to eliminate as much liquor as possible by non-thermal methods. This paper is mainly concerned with the development of a simplified equation for constant-pressure expression.

• 연구논문집
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• s.30
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• pp.67-77
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• 2000

This study was performed to investigate the characteristics and performance of model Decanter for separating swine wastewater to solid and liquid which is slurry state with 12.6% TS. Swine wastewater of the slurry tank was pumped into model Decanter which capacity was $2m^3$/hr in 10% TS Slurry inside of bowl was separated to solid-liquid by centrifugal acceleration. Sampling was done in the section of slurry feed pipe, supernatant outflow pipe, cake discharge pipe. After solid-liquid separation TS, $COD_cr$ and slurry volume reduction effect represented 38%, 40%, 19.6% respectively. Relation factor of model Decanter operation slurry concentration, optimum retention time of slurry, overflow velocity of supernatant, supernatant concentration, sludge removal rate etc. Optimal operation conditions can be set and evaluated efficiency based on the experimental results in the case of Decanter adopted for solid-liquid separation in highly concentrated swine wastewater.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.3
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• pp.523-533
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• 2000

A two-phase anaerobic reactor with submerged membrane system was developed for increasing acidogen concentration and methane recovery. The membrane used was mixed esters of cellulose of $0.5{\mu}m$ pore size and $0.8m^2$ of effective surface area. The methanogenic reactor comprised of UASB (Upflow Anaerobic Sludge Blanket) and AF (Anaerobic Filter). COD removal efficiency was 70~80% and the methane content in the biogas increased up to 90% for the submerged membrane system in the anaerobic reactor. As the cake resistance of membrane caused a serious problem, stainless steal prefilters (40, 53, $63{\mu}m$) and air backwashing methods were applied to minimize the cake resistance effectively. Among the tested prefilters. the $63{\mu}m$ prefilter showed the best performance for reduction of cake resistance and a successful long-tern operation. By cleaning with alkali first and acidic solution later. the permeate flux decreased by long term operation was recovered to 89% of that with a new membrane.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.2
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• pp.19-30
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• 2019

Objective of this study was to develop an organic fertilizer utilizing domestic livestock horn meal and to investigate the application effect of rice and eggplant. The possibility of utilization of livestock horn meal as an organic resource to replace imported expeller cake fertilizer was examined. In order to select domestic organic resources with high nitrogen content, 8 kinds of organic matter such as chicken manure, fish meal, soybean meal, sesame meal, perilla meal, blood meal, livestock horn meal, and beer sludge were analyzed and organic resources with high nitrogen content were selected. In addition, the conditions for the production of organic fertilizers that can be used in organic agriculture were established by mixing of the rice husk biochar and the rice bran as the supplements with the raw materials for mixing ratios. The content of total nitrogen (T-N) in the livestock horn meal was 12.0 %, which was the next low in 13.5 % blood meal. The content of total nitrogen was 5.9 ~ 7.9 % in fish meal and oil cakes. Total nitrogen content of non-antibiotic chicken manure for organic farming was 3 % and nitrogen content in beer sludge was 3.5 %. Organic fertilizer was produced by using biochar, rice bran as a main ingredient of non-antibiotic chicken manure, livestock horn meal and beer sludge. Compared to nitrogen content (4.0 to 4.2 %) of imported expeller cake fertilizer (ECF), the nitrogen content of organic fertilizer utilizing domestic livestock horn meal is as high as 7.5 %. The developed organic fertilizer is met as Zn 400 mg/kg, Cu 120 mg/kg the quality of organic agricultural materials such as or less. To investigate the effect of fertilizer application on the crops, prototypes of developed organic fertilizer were used for the experiment under selected conditions. As a result of application the developed organic livestock horn meal fertilizer (LHMF) for cultivation of the rice and eggplant, the application quantity of the developed organic LHMF 100 % was decreased by 40 % compared to that of the mixed expeller cake fertilizer (MECF). The application of LHMF, which refers to the application rate corresponding to the nitrogen fertilization recommended by the soil test, was reduced by 40% compared to the application rate of MECF, but the same results were obtained in crop growth and yield. The selection of a new high concentration nitrogen source utilizing domestic organic resources and the development of organic fertilizer is the starting point of the research for substitution of imported ECF using domestic local resources at the present time that the spread of eco-friendly agriculture is becoming increasingly important. If it is expanded in the future, it is expected to contribute to the stable production of eco-friendly agricultural products.

• Journal of Korea Soil Environment Society
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• v.2 no.1
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• pp.45-50
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• 1997

The change of industrial structure has brought the sharp declination of mine products, and has made many mines closed, which results in environmental pollution by untreated acid mine drainage(AMD). AMD with low pH and high concentration of heavy metals could severely destroy the ecosystem. Many researches have been carried out for the treatment of AMD. In this study, we have treated AMD with oak compost, mushroom compost, sludge cake and cow manure which usually used in AMD treatment systems, and compared the capability of each organic matter. Cow manure and oak compost have been most effective among 4 organic materials. Oak compost removed the heavy metals by ion exchange between Ca-rich particles and soluble heavy metal ions. It also captured the heavy metals using bound functional groups like -OH and -COO-. Sulfate reducing bacteria existing in the cow manure removed effectively heavy metals by producing metal sulfide compound. Therefore, it is effective to use both organic materials in mixture on the treatment of AMD.

• Membrane Journal
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• v.13 no.2
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• pp.65-72
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• 2003

This study was focused on the investigation of filtration characteristics of membrane-coupled fermentor system for dissolved organics recovery from liquid organic sludge. On the filterability of MF over the range of $0.1{\sim}5 {\mu}m,$ the magnitude of total membrane resistance ($R_t$) is ranged as follows in the order; $0.1 {\mu}m>0.2{\mu}m>0.5 >1{\mu}m>2{\mu}m>5{\mu}m$. The cake layer resistance ($R_c$) occupied about 68~88% of total resistance with fermented sludge. Permeation flux decline was mainly attributed to the $R_c$, which was formed by a strong deposition from physico-chemical interactions of solids on membrane surface. Higher suspended solids (SS) concentration of suspension caused lower permeation flux. However, there was not a proportion relation beyond a certain SS concentration. The cross-flow velocity on the membrane surface was faster, which resulted in the higher permeation flux and also more efficient with low trans membrane pressure (TMP) in viewpoint of energy efficiency. The appropriate pH of suspension was over the range of 5.0~6.0 for dissolved organics recovery as well as the permeation flux. It is possible f3r bacteria to be separated perfectly with $0.1{\mu}m\; and \;0.2{\mu}m$ membrane pore size. Based on experimental results, most appropriate membrane pore size for the recovery is believed to around $1{\mu}m$.

• Journal of Wetlands Research
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• v.16 no.3
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• pp.347-353
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• 2014

This work was performed to find the effect of operation parameters on the permeate flux through the activated sludge dynamic layer, and to indicate the relationship between the water quality of supernatant and flux based on the results. Since the effluent can be obtained through steady and stable formation of cake layer in the bio-filter media system, it is an important subject to keep and control microbes with activated state in the bio-reactor. Filtration resistance was drastically increased at more than 18000mg/L of MLSS. With filtration time continued, the flux was gradually decreased and the water qualities of supernatant monitored by turbidity and TOC were also deteriorated. This phenomenon indicated that the organic materials generated by microbes and accumulated in the reactor might affect the flux in the system. In addition, the decrease of flux was simultaneously observed in the sludge volume index. When SVI was controlled from 150 to 250, the flux was also decreased. The proper aeration time was recommended to 30 to 60 seconds in this system. In order to operate this system steadily, therefore, the control of water quality of supernatant and SVI should be proceeded.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.5
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• pp.304-314
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• 2004

The objective of this study was to investigate the effect of organic materials (compost, straw, green manure, pig manure, seed production oil cake, and industrial by products including municipal sewage sludge, industrial sewage sludge, leather processing sludge, and alcohol fermentation processing sludge) on physical properties of soils in seven paddy and four upland fields with differential soil textures, sandy loam, loam, or clay loam, etc. The investigated physical parameters were bulk density (BD), air permeability (AP), macroporosity, hardness, shear resistance, frictional resistance, water stability aggregate (WSA), and Middleton's dispersion ratio. Except for coarse sandy loam field with weak structure, a decrease in BD and shear resistance, and an increase in macroporosity and AP in plots with applying organic materials compared to plots without applying organic materials appeared. In upland fields, the positive effect of organic materials on WSA, BD, and air permeability was higher than in paddy fields. The combined plot of NPK and compost had lower BD, hardness, and shear resistance, and higher macroporosity and WSA than plot with compost. Green manure had higher positive effect on physical properties of soils compared to other organic materials and the extent of positive effect had no significant correlation with soil organic matter content. Of industrial byproducts applied in coarse sandy loam soil under upland condition, municipal sewage sludge and pig manure compost had higher effect on increase of WSA than leather processing sludge and alcohol fermentation processing sludge. Unlike WSA, there were no significant differences between industrial byproduct types in other physical properties. in silty clay loam soil under the upland condition, straw had more positive effect on soil physical parameters than hairy vetch and pig manure. Therefore, different organic materials had differently active effect on physical parameters depending on types of soil and land use. Especially, it could be thought that well-decomposed organic materials have the advantage of an increase in organic matter content, while coarse organic materials of an increase in WSA.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.8
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• pp.598-606
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• 2013

This study was performed to determine whether biomineralization microbes were actively present underneath landfill cover soil producing biocalcification. From this, various types of microbes were observed. Among them, two species were dominantly found; Bacillus megaterium and Alkaliphilus metalliredigens that were known as biominerlization bacteria. With those microbes, $CO_2$ was more highly consumed than without bacteria. In response, the calcium carbonate mineral was produced at 30% (wt) greater than that of the control. At the same time, TG-DTA was successfully used for quantification of $CO_2$ consumed forming calcium carbonate minerals resulting from biocalcification. It was decided that the presence of solidified sewage sludge cake utilized as a cover soil in the landfill could efficiently contribute to possible media adaptably and naturally sequestering $CO_2$ producing from the landfill.