• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2004.04a
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• pp.186-190
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• 2004

• Journal of the Korean Applied Science and Technology
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• v.24 no.4
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• pp.332-338
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• 2007

Based on the experiment results of laboratory scale modified anoxic-oxic process for leachate treatment, biological nitrogen removal program was verified in terms of SS, COD, and TN concentration. These measured water qualities concentration could be predicted by biological nitrogen removal program with $R^2$ of 0.994, 0.987, 0.990, respectively. No error was occurred between water qualities concentration and quite wide range of water qualities concentration (i.e., 50-4200 mg/L) during the modelling. Each unit and final effluent of simulated concentration was kept good relationship with that of measured concentration therefore this biological nitrogen removal program for sewage or wastewater treatment plants has good reliance.

• Journal of Korean Society of Rural Planning
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• v.12 no.2 s.31
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• pp.49-56
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• 2006

The application of domestic wastewater on rice paddies results in the accumulation of sodium(Na$^+$) to the soil. Excessive concentration of sodium may cause the deterioration of the physical characteristics of the soil, change in the osmosis of the soil, destruction of soil aggregates as well as ion toxicity due to sodium accumulation. Using domestic wastewater as irrigation water should be preceded by measures to prevent or control the soil salinization caused by sodium. Agricultural reuse of domestic wastewater were found not to cause serious problems with food safety due to heavy metals. However, pre-treatment using ultraviolet or ozone is recommended to reduce the number of bacteria and gem and for public health reasons. Using domestic wastewater has shown that reducing the standard application of chemical fertilizers by as much as 50% reduced the harvesting index by only 10%. This study has shown that it is feasible to reuse domestic wastewater on rice paddies. In order to facilitate the application, it is deemed necessary to establish wastewater treatment technologies in the future, to review criteria for recycling domestic wastewater for agricultural purposes such as conditions of soil and cropping system and to resolve conflicts with farmers and public health issues.

• Journal of the Korea Organic Resources Recycling Association
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• v.4 no.1
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• pp.61-72
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• 1996

Recently, significant attention is given to the wastewater treatment using Constructed wetland. This is because the wetland system is a kind of natural taeatment system, simple to maintain and it has relatively fewer technical difficulty. Thus, it would be a practical method to employ especially in rural area in Korea. In this paper, the authors dscuss the design criteria of construted wetland developed in USA as an initial feasibility study to adopt it in Korea. We discuss about especially types of vegetation, natural succession and management, planting techniques, seeding teckniques and management after censtruction.

• Journal of Environmental Science International
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• v.13 no.2
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• pp.161-165
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• 2004

This study has been conducted to develop a new recycling technology of sewage sludge using a carbonization process. The carbonizing yield, the calorific value and EC(electric conductivity) of carbonized sewage sludge had a tendency to be decreased with increase of the carbonizing temperature and time, but pH and the C/N were increased with increase the carbonizing temperature and time. The whole pore volume of carbonized sludge processed in the carbonizing furnace was /g, which was smaller than that in the electric furnace. But, the rates of mesopore and macropore were found to account for 100% therein. Rate of color and organic materials removal for dyeing wastewater were determined 70~97%, 78~83% on cotton yarn, 88~96%, 69~80% on wool wastewater and 77~89%, 77~87% on towel compared with powder activated carbon. Effect of carbonized sludge on chrysanthemum growth was investigated. Plant height and number of leaves was better mixture of carbonized sludge than comparison.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.2
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• pp.257-264
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• 2011

Recycling of industrial products as the stabilizers can be proper handling of industrial products and has positive side in terms of recycling of wastes. In this study, the final aims were to evaluate the usability as stabilizer of Bio-solids which was generated from contaminated soil with heavy metals after primary process and to compare the treatment efficiency with slag being currently applied in many existing sites. Soluble and exchangeable forms have closely related to pollution of groundwater and plant growth and they can be used to determine the effect of the stabilization efficiency. Slag and Bio-solids were tested to investigate the capacity of stabilizing arsenic. Slag treatment process 4 (PS-ball 5%) showed higher leachate concentration rather to 0.84% compared to treatment 1 (blank) based on an average of 0.63%. The other hand treatment 4 (Bio-solids 5%) showed the lowest soluble and exchangeable forms to 0.57% when Bio-solids was applied to stabilize arsenic. Thus, the leaching of arsenic will be more reduced if the Bio-solids are used as stabilizer in stead of slag which is being currently used in many fields.

• Resources Recycling
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• v.10 no.4
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• pp.24-33
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• 2001

For making a high degree of efficiency, this study attempts to gather each arisen-sludge from experiments and examine into its characteristics, in order to compare the biological reason of removing phosphorus with sintered body using calcite and the artificial reason of removing with a chemical reagent. First, it can be seen that sludge, which is identified CaCO$_3$, of 0.1∼0.2$\mu$m is regularly formed when using sintered body, calcite. And it is one of the results of the chemical methods in order to remove phosphorus that can be seen that sludges of 100∼50 $\mu$m are formed and that the forms of Ca$_2$P$_2$O$\_$7/, Ca$_3$(PO$_4$)$_2$$.$nH$_2$O, $\beta$-Ca$_2$P$_2$O$\_$7/ are shown when using a reagent, CaO dissolved water. The other of the results of the chemical methods can be seen that a lumpof sludge is formed when using wastewater and a reagent Ca$^2$$\^$+/ are used, and that the lump consists of Ca$_3$(PO$_4$)$_2$$.$nH$_2$O와 Ca$_2$H$_2$P$_4$O$\_$14/.

• Resources Recycling
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• v.9 no.4
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• pp.56-62
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• 2000

This study was introduced an amalgamated septic tank system using mineral sintered body was made from non-metallic minerals with a ability being attached or accelerating a vitality of soil microorganism for the effective wastewater treatment. Experimentally, we made an amalgamated septic tank appling anaerobic-aerobic process experimental facilities to two personal houses for handling a residental sewage directly on a small scale from the place of origin. The results are shown as follows; The COD\ulcorner and BOD of effluent were about 10 mg/l after the treatments and T-N removal efficiency was 60-70%. Moreover these results suggested the possibility of denitrification without adding organics and more than 80% of T-P removal also showed the possibility of wastewater treatment biologically.

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.1
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• pp.89-97
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• 2010

In this study, to investigate the effect of chemical pretreatment for livestock wastewater, laboratory scale test for ozonation and linked treatment of sewage were conducted. and the results were obtained as follows. The ozonation of livestock wastewater showed the COD removal rate per hour to be 17%, 78% and 62% at each pH 4, 7 and 10, respectively. With transformation of NBDCOD to biodegradable BDCOD by ozonation, the ratio of SCODcr/TCODcr was increased from 26% to 38%. Accordingly, pretreatment of livestock wastewater affected to the biological post treatment process to elevate removal efficiency by transformation of nonbiodegradable mass to biodegradable mass. As the results of linked treatment of pre-ozonated livestock wastewater and sewage in the MLE process, the treatment efficiencies of TCODcr 93.8%, T-N 74.3%, T-P 89.7%, SS 97.5% were earned at 100% of internal recycle rate. When the internal recycle rate was increased to 150%, the treatment efficiencies of TCODcr 94.5%, T-N 54.5%, T-P 70.8%, SS 98.5% were earned. Also the removal efficiencies of TCODcr 92.6%, T-N 83.1%, T-P 81.9%, SS 98.5% were earned as the internal recycle rate was increased to 200%. Especially, nitrogen removal efficiency in the linked treatment showed 74.3%, 54.5%, 83.1% at 100%, 150% and 200% of internal recycle ratio, respectively, which revealed the tendency of higher removal efficiency than that of sewage treatment.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.3
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• pp.273-278
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• 2007

Modern society has moved from a phosphorus recycling loop, where animal manure and human wastes were spread on farming land to recycle nutrients, to a once-through system, where phosphates are extracted from mined, non-renewable phosphate rock and end up either in landfill(sewage sludge, incinerator ash) or in surface waters. In this research, crystallization of nitrogen and phosphate with natural sources of $Mg^{2+}$ in synthetic water was tested. The operational parameters of pH, mixing time, and the magnesium molar ratio were investigated to find optimal conditions of the MAP precipitation using synthetic wastewater. The removal efficiency of phosphate increased with pH up to 11. By MAP precipitaiton of the synthetic waste water, 94% of the phosphate were eliminated at pH 11. It was found that at least 10 minutes mixing time was required and 20 minutes mixing time was recommended for efficient phosphate removal. High efficiency removal of phosphate was possible when the magnesium molar ratio was 1.0~2.0. The comparative study of different magnesium sources showed that coagulants (PAC) was the more efficient sources than only magnesium. The result showed that 97% of phosphate removal. In conclusion, coagulants (PAC) induced crystallization of struvite and hydroxyapatite was shown to be a technically viable process that could prove cost effective for removing phosphate in wastewater.