• Nuclear Engineering and Technology
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• v.54 no.12
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• pp.4441-4448
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• 2022

The electrochemical oxidation process has been widely studied in the field of wastewater treatment for the decomposition of organic materials through oxidation using ·OH generated on the anode. Pt anode electrodes with high durability and long-term operability have a low oxygen evolution potential, making them unsuitable for electrochemical oxidation processes. Therefore, to apply Pt electrodes that are suitable for long-term operation and large-scale processes, it is necessary to develop a new method for improving the decomposition rate of organic materials. This study introduces a method to improve the decomposition rate of organic materials when using a Pt anode electrode in the electrochemical oxidation process for the treatment of organic decontamination liquid waste. Electrochemical decomposition tests were performed using sodium dodecylbenzenesulfonate (SDBS) as a representative organic material and a Pt mesh as the anode electrode. Y₂O₃ particles were introduced into the electrolytic cell to improve the decomposition rate. The decomposition rate significantly improved from 21% to 99%, and the current efficiency also improved. These results can be applied to the electrochemical oxidation process without additional system modification to enhance the decomposition rate and current efficiency.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.1
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• pp.109-118
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• 2001

In the stage of aftercare in waste landfill management, it is very difficult to estimate the decomposition of landfill waste by excavation which damages the low permeability layer. This study developed the method to analyze the amount of landfill waste degraded bio-chemically as the types of leachate and gas, and applied the method to Nanjido landfill(NL). Application result showed that 70% of high biodegradable waste in NL was transformed to gas and leachate by 2000. Also this study suggested that the transformed portions of waste name for "Decomposition Index" at that time and the proposed method must be modified according to the biological condition of waste degradation.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.2
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• pp.43-51
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• 2018

The objective of this research was to assess the effect of moisture content and water injection method into the landfill on waste decomposition in an aerobic landfill. Firstly, respirometric experiments were performed in order to assess the effect of initial moisture content (20%, 30%, 40% and 50% respectively) on landfilled waste decomposition. The cumulative oxygen uptake and oxygen uptake rate were highly increased with the increase of initial moisture content. Secondly, lysimeter experiments showed that in comparison with the vertical injection method, dry fog system enhanced decomposition of organic wastes. Also, dry fog system provided uniform moisture distribution more than the vertical injection method within landfill.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.11a
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• pp.404-405
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• 2018

• Journal of Korea Society of Waste Management
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• v.35 no.8
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• pp.744-753
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• 2018

The Stockholm Convention, which was adopted in Sweden in 2001 to protect human health and the environment, includes regulations for Persistent Organic Pollutant Rotors such as toxic and bioaccumulatives. Currently, there are 28 types of materials. This prohibits and limits the production, use, and manufacture of products. Korea is a member of the Convention, and it is necessary to prepare management and treatment plans to address the POP trends. Thus, we experimentally investigate whether the environmentally stable incineration is achieved when the sample is thermally treated using the Lab-scale (1 kg/hr). The target samples is pesticides in liquid phase and solid phase. In this study, organic chlorinated pesticides and their thermal characteristics were analyzed. We calculated the theoretical air volume based on the element analysis results. Because the interior of the reactor is small, more than 10 times of the air ratio was injected. The retention time was set to at least 4 seconds using a margin. The incineration temperature was $850^{\circ}C$ and $1100^{\circ}C$. Thus, we experimentally investigated whether the environmentally stable incineration was achieved when the sample was thermally treated using the Lab-scale (1 kg/hr). We analyzed five types of exhaust gas; the 02 concentration was high, but the CO amount decreased. Complete combustion is difficult because of the small size of the furnace due to the nature of Lab-scale. The organic chlorine-containing pesticide had an average decomposition rate of 99.9935%. Considering the decomposition rates of organic chlorine-containing pesticide in this study, the incineration treatment at over 2 ton/hour, which is typical for a conventional incinerator, is possible. Considering the occurrence of dioxins and unintentional persistent organic pollutants, it can operate at more than $1,100^{\circ}C$.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.526-537
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• 1993

The development of composting techniques is essential to the low input sustainable agriculture. This paper resents an evaluation of composting system, compost materials, aeration & temperature effects, compost maturity , and operational concerns for compost utilization. The composting of organic waste is markedly affected by the nature of the feedstock and the operational temperature employed for the process. These two major parameters are critically examined in this paper, with references to the decomposition of the organic waste. Future research should concentrate on the indications of stability and environmental problems.

• Journal of environmental and Sanitary engineering
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• v.15 no.2
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• pp.49-57
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• 2000

The objective of this study is to find solid waste decomposition in landfill without leachate discharge. This study was observed variation of landfill gas production rate and leachate for stabilization assessment, and using four sets of lysimeter as experimental apparatus. Soild waste decomposition was accelerated in without leachate discharge system by sufficient moisture for methane bacteria. And gas production rate was between 54.2ℓ/kg VS∼335.9ℓ/kg VS in each lysimeter. Generation time of methane gas was showed different in each lysimeter, but it was much faster than literature research. The time of stabilization phase were began as follows : L-1 400 day, L-2 350 day, L-3 170 day and L-4 70 day respectively. Decreasing times of BOD/COD ratio and C/N ratio were necessary more than literature research because organic matter was not discharge such as wash out.

• Environmental Engineering Research
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• v.22 no.2
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• pp.157-161
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• 2017

Simultaneous treatment of food waste leachate and power generation was investigated in an air-cathode microbial fuel cell. A TCOD removal efficiency of $95.4{\pm}0.3%$ was achieved for an initial COD concentration of 2,860 mg/L. Maximum power density ranged was maximized at $1.86W/m^3$, when COD concentration varied between 60 mg/L and 2,860 mg/L. Meanwhile, columbic efficiency was determined between 1.76% and 11.07% for different COD concentrations. Cyclic voltammetric data revealed that the oxidation peak voltage occurred at -0.20 V, shifted to about -0.25 V. Moreover, a reduction peak voltage at -0.45 V appeared when organic matters were exhausted, indicating that reducible matters were produced during the decomposition of organic matters. The results showed that it was feasible to use food waste leachate as a fuel for power generation in a microbial fuel cell, and the treatment efficiency of the wastewater was satisfied.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.78-82
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• 2003

For the decomposition of laundry wastewater containing Fe-EDTA produced from the steam generators in nuclear power plants, Supercritical Water Oxidation (SCWO) Process, Photocatalytic Oxidation (PO) Process, and Dielectric Barrier Discharge (DBD) Atmospheric Pressure Plasma Process were evaluated. Even though EDTA was converted over 99.98 % by the SCWO process, it was estimated that the countermeasure against corrosion of the equipment should be reinforced for the process stability. It was considered that the PO process is not appropriate for the decomposition of high concentrated laundry wastewater since the conversion ratio of EDTA was around 10 %. Finally, High efficiency of the decomposition of organic matter (methylene blue) was obtained using DBD process even low energy was supplied. However there is still room for the evaluation of EDTA decomposition in order that the DBD process should be applied for the field samples.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.2
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• pp.65-73
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• 2018

This study was carried out for 20 days in a bio-drying batch reactor under the blowing conditions of 0.75, 1.00, 1.25, and $1.50L/min{\cdot}kg$ in order to optimize the operating conditions for the bio-drying of food wastes. The decomposition rate of organic matter during the bio-drying operation period was analyzed using modified Gompertz model. The maximum organic degradation (P) was 2.31, 2.52, 2.27 and 1.88 kg at air flow rates of 0.75, 1.00, 1.25 and $1.50L/min{\cdot}kg$, and the maximum organic degradation rate was 0.33, 0.45, 0.28, and 0.18 kg/day at 1.00, 1.25 and $1.50L/min{\cdot}kg$, respectively, showing excellent organic decomposition efficiency at a air flow rate of $1.00L/min{\cdot}kg$. The lag growth phase time (${\lambda}$) of the bio-drying reactor was 2.10, 1.48, 1.15, and 1.06 days at 0.75, 1.00, 1.25 and $1.50L/min{\cdot}kg$, respectively. The water removal rate in the operation of bio-drying reactor of food waste increased with the increase of air flow rate from the early stage of bio-drying to the middle stage, and the highest water removal rate was observed at the air flow rate of $1.00L/min{\cdot}kg$ at the end of bio-drying. The optimum air flow rate condition of bio-drying reactor was $1.00L/min{\cdot}kg$.