• Journal of Animal Environmental Science
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• v.18 no.3
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• pp.235-246
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• 2012

Reusing livestock manure have various advantages in securing soil organic resources. In this study, the N-loading and recycling capacity assessment of animal manure was analyzed by comparing between the cultivated areas of crops and the amount of manure units that are generated from livestock manure. From this assessment, the possibility of recycling resources of livestock manure was evaluated. The amount generated of livestock manure in Gyeonggi-do were evaluated by applying the manure units to the number of livestock manure. The analysis of manure unit per ha shows that the N loading by MU is quite different by region. When it comes to nitrogen loading, the MU per ha of cultivated land in excess of the N-amount was the highest in the Gyeonggi-do province with 2.70 MU/ha, which is higher than the appropriate level. The Chungcheongnam-do province came next with 2.31 MU. So the recycling capacity assessment was carried out mainly based on areas of forage crops, rice that can be provided by recycling livestock manure. The recycling capacity ware highest in Jeollanam-do and Jeollabuk-do. In order to properly apply the livestock manure into organic resources, the seasonal situation that effects the nitrogen demands of crops along with the regional effects crop cultivation should be seriously analyzed. In addition, a system that can effectively produce and manage fertilizer should be established.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.693-698
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• 2002

The production accounts of domestic by-product is increased after 1990's. It is worried about the life reduction of dump land, as dump land's capacity have reached to limitation and the amount of construction industrial wastes is going higher. Recently, recycling aggregates could be gained from the reconstruction works using recycle process. And the study and research of recycle concretes developed concrete application methods. It could put some outcome of studies to practical use for concrete products. The methods of crushing waste concrete are going diverse. In this study, the fundamental experiments and recycling application is investigated and analyzed with use of recycling aggregate which made of mechanical crush and underwater electrical impact crush. and the difference between underwater electrical impact crush, mechanical crush and natural aggregates is studied.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.381-386
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• 2001

The dust generated from the electric arc furnace steel making process is classified as hazardous material by Korean Environmental Protection Acts, mainly because of the existence of water teachable Pb, Zn and Cd. Thus the treatment of EAF dust is being carried out to fulfill both the environmental aspect and recovery of valuable metals. To establish the proper process for recovering the valuable metals (Fe, Zn, Pb and Cd) and producing the non-toxic slag from EAF dust, using RAPID-10 system, feasibility study have been carried out. To find out the scale-up factor for designing the commercial scale EAF dust treatment process(capacity 50,000 ton EAF dust per year) entitled RAPID-50 system. The design and construction of RAPID-50 (RIST Arc Plasma Industrial Device) system for treating 50,000 ton of EAF dust per year is now undergoing. Overall plan for treating EAF dust generated in KOREA will be setup after successful operation (December, 2002) of RAPID-50 system.

• Advances in environmental research
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• v.5 no.1
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• pp.51-59
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• 2016

In this study, nitrate reduction of real groundwater sample by 2.2%Cu-1.6%Pd-hematite catalyst was evaluated at different nitrate concentrations, catalyst concentrations, and recycling. Results show that the nitrate reduction is improved by increasing the catalyst concentration. Specific nitrate removal by 2.2%Cu-1.6%Pd-hematite increased linearly with the increase of nitrate concentration showing that the catalyst possesses significantly higher reduction capacity. More than 95% nitrate reduction was observed over five recycles by 2.2%Cu-1.6%Pd-hematite with ~56% nitrogen selectivity in all recycling batches. The results from this study indicate that stable reduction of nitrate in groundwater can be achieved by 2.2%Cu-1.6%Pd-hematite over the wide range of initial nitrate inputs.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.4
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• pp.153-159
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• 2000

Large-scale simulated lysimeter experiments were conducted for 4 years as a fundamental study to develop enhanced landfill stabilization method, which accelerate stabilization time and make efficient practical use of self-purification capacity of pollutants in semi-aerobic solid waste landfill. The amount of TOC(total organic carbon) decomposition increased as the landfill depth increased. In case of T-N(total nitrogen), the self-purification capacity increased linearly with the landfill thickness until it reached a maximum level of 6 m. Beyond this level, the self-purification capacity was not increased. The results from lysimeter experiments indicate that 6m of landfill thickness is optimum for self-purification capacity of pollutants considering the mass balance of TOC and T-N.

• Resources Recycling
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• v.29 no.6
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• pp.41-47
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• 2020

This study was carried out to utilize the coal bottom ash generated in a circulating fluidized bed combustion boiler as a treatment agent for heavy metal ions, and experiments were conducted to remove heavy metal ions from the acid mine drainage. The batch experiments were conducted to investigate the influence of dosage of ash, initial concentration of solution on the removal capacity of heavy metal ions (Cu, Cd, Cr, Pb). The results of the experiment showed that the total removal capacity of heavy metals was 30.8 mg/L and 46.4 mg/g, respectively, under the condition that the concentration of coal ash was added as 15 g/L of heavy materials and 10 g/L of light materials. After that, a long-term column experiment was performed to determine the maximum removal capacity of heavy metal ions (Cu, Cd, Cr, Pb, As), and the removal capacity for each metal component was investigated. After approximately 60 days of operation, the maximum removal capacity of heavy metals was 23.6 mg/g at pH 9.25.

• Journal of Ocean Engineering and Technology
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• v.29 no.1
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• pp.78-84
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• 2015

Geosynthetics such as geogrids or geotextiles have been widely used to improve the bearing capacity of soft ground. This study investigated the California bearing ratio (CBR) of waste fishing net (WFN)-reinforced sand. CBR tests were carried out to evaluate the improvement in the bearing capacity of WFN-reinforced sand with different embedded depths. The experimental results indicated that the CBR increased as the embedded depth of the WFN decreased. The bearing capacity ratio (BCR) is the ratio of the bearing capacity of reinforced ground to that of unreinforced ground. The BCR at the penetration depths of 2.5 mm, 5 mm, and the peak point decreased with an increase in the embedded depth.

• Resources Recycling
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• v.18 no.5
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• pp.63-71
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• 2009

Recyclable wastes coming into material recovery facilities(MRFs) is mostly packed by plastic bag or sack bag. Bag rupturing device is essential to improve capacity and efficiency of MRFs. Bag opening works of MRFs is mostly done by numerous workers and shredder-type bag rupturing device. It often makes a problems; decreased capacity, shredded recyclables, worker safety by explosion and broken glasses, etc. In the present work, bag rupturing device with octagonal rotating blade drums has been developed to solve the existing problems and environment assessment is also performed during operation of the device. Capacity of the device was about 5.6 ton/hr at 8.2 rpm of drum revolution speed and 1.25 m/min of belt conveyor speed. It satisfied initial designed capacity(5.0 ton/hr) and max. capacity 8.8 ton/hr was achieved at 12.5 rpm of drum revolution speed and 1.50m/min of belt conveyor speed. Bag rupturing efficiencies on outer and inner bag were obtained at 100% and about 95.6% as average, respectively and original form of glass bottles in the bag was maintained without broken by about 96.5%. This result shows that the safety in hand sorting by the workers could be improved. As result of environmental assessment on the noise, vibration and particulates, the measured levels on noise, vibration and particulates show the below standard regulatory limits. It could be concluded that the problems of existing devices in MRFs could be solved by adopting the bag rupturing device with octagonal rotating blade drums in on-site operation.

• Parasites, Hosts and Diseases
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• v.29 no.3
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• pp.267-278
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• 1991

The natural killer (NK) cell activity of splenocytes and recycling capacity of NK cells were observed by combining the $^{51}Cr-release$ cytotoxicity assay and single cell cytotoxicity assay against YAC-1. The ICR mice were infected intranasally with Naegleria fewleri, that is a pathogenic free-living amoeba. The mice infected with $1{\times}10^5$ trophosoites showed mortality rate of 76.7% and mean survival time of 12. 9 days. The cytotoxic activity of NK cells in infected mice was significantly higher than that of non-infected mice during the period between 12 hours and day 3 after infection, and highest on day 1. The target-binding capacity of NK cells in infected mice was not different from that of non-infected ones. Maximal killing potential and maximal recycling capacity were remarkably increased in infected mice as compared with the control. The results obtained in this observation indicated that elevated NK cell activity in mice infected with N. fowieri was not due to target-binding capacity of NK cells but due to the increased activity of NK cells and increased recycling capacity of individual NK cells.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.240-244
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• 2001

Recycling process involving mechanical, thermal, hydrometallurgical, and sol-gel step has been applied to recover cobalt and lithium from spent lithium ion batteries and to synthesize LiCoO$_2$from leach liquor as cathodic active materials. Electrode materials containing lithium and cobalt could be concentrated with 2-step thermal and mechanical treatment. Leaching behaviors of the lithium and cobalt in nitric acid media was investigated in terms of reaction variables. Hydrogen peroxide in 1 M HNO$_3$solution turned out to be an effective reducing agent by enhancing the leaching efficiency. O f many possible processes to produce LiCoO$_2$, the amorphous citrate precursor process (ACP) has been applied to synthesize powders with a large specific surface area and an exact stoichiometry. After leaching used LiCoO$_2$with nitric acid, the molar ratio of Li/Co in the leach liquor was adjusted at 1.1 by adding a fresh LiNO$_3$solution. Then, 1 M citric acid solution at a 100% stoichiometry was also added to prepare a gelatinous precursor. When the precursor was calcined at 95$0^{\circ}C$ for 24 hr, purely crystalline LiCoO$_2$was successfully obtained. The particle size and specific surface area of the resulting crystalline powders were 20 пm and 30 $\textrm{cm}^2$/g, respectively The LiCoO$_2$powder was proved to have good characteristics as cathode active materials in charge/discharge capacity and cyclic performance.