• Journal of Korean Society on Water Environment
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• v.22 no.2
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• pp.308-313
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• 2006

Charicteristics of piggery waste and treatment processing sludges for reuse were investigated. If it was thoroughly regulated in disinfectants, antibiotic substances and heavy metals, raw piggery waste can be gratified in criteria for fermentative compost (liquid) for flowers cultivation. Also, Because it is satisfied with various criteria of heavy metals and fertilizer contents for reuse except water content, primary pre-treatment sludge is very good material for composting. If provated goods on heavy metals are used in coagulation & dewatering process, coagulation & dewatering sludges are suitable for criteria of special waste regulation and by-product compost. This study proves that, if they are accomplished with suitable composting and mature process, piggery waste and processing sludges are free from microbiological problems as well as criteria of composting.

• Journal of Korean Society of Water and Wastewater
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• v.13 no.3
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• pp.56-60
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• 1999

In this study the feasibility of usage of raw sludge (sludge from water treatment plant) and chalk from schools and institutes was investigated to remove the phosphorus in water and wastewater. In this study phosphorus removal efficiencies of sludge and chalk were investigated by changing various factors. The time to reach the equilibrium using chalk and raw sludge under different pHs was obtained. Based on this result, Freudlich adsorption isotherm was applied. Results showed that a portion of phosphorus was removed by adsorption to chalk and raw sludge. The phosphorus removal efficiency using calcinated chalk was about three times higher than that of chalk. It means that some portion of $CaCO_3$ contained in chalk was converted to CaO by calcination and this was proved by X-ray diffraction experiment. About 90% phosphorus removal was observed using sludge and calcinated chalk respectively while about 20% phosphorus removal efficiency was achieved using chalk from the water sample in Lake Sihwa.

• Journal of Environmental Science International
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• v.19 no.1
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• pp.9-16
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• 2010

This pilot study evaluated fueling feasibility of sewage sludge, which contains a large amount of water content, by applying melting of thermoplastic polyethylene (PE). This study has identified a simultaneous achievement of drying and heating value improvement of the sewage sludge. The sewage sludge collected from a sewage sludge treatment plant during a winter period had a water content of 83.7 wt%, a combustible volatile content of 12.5 wt%, and an ash content of 3.8 wt%. The higher heating value (HHV) of the dried sewage sludge, before impregnation or coating of PE, was 4,600 kcal/kg. The collected sewage sludge was immersed into the melted PE solution, which had a HHV of 11,070 kcal/kg, and kept immersing with increasing reaction time. As the reaction (immersing or coating or impregnation) time increased, the water content of the sludge decreased. However, the HHV of the sludge increased with increasing the reaction time. The HHVs of the sewage sludge immersed or dipped into the melted PE solution for 15 min ranged from 6,780 to 8,170 kcal/kg with water content less than 7 wt%. This result indicates the melted PE solution can be utilized as an improvement technology for dryness and heating value of the sewage sludge with high water content. The sewage sludge impregnated or coated with melted PE can be utilized as potential fuel or energy resources.

• Applied Biological Chemistry
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• v.41 no.2
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• pp.181-186
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• 1998

The effects of sewage treatment on characteristics of sludge as a composting material were investigated for a year during the initial operation at the full-scale Chunan sewage treatment plant. Due to the shortage of design capacity of belt press, a sludge dewatering unit, non-volatile solids were recirculating and concentrating in the treatment plant, resulting in an increase of MLSS and a decrease in F/M ratio at the activated sludge system. Special attention is required for long term operations since the increase of non-volatile solids in the plant would deteriorates the treatment efficiency. The sewage sludge of the Chunan sewage treatment plant showed 79.5% of water content, 11.6% of organic content, and C/N ratio of 6.1, and contained As 1.8 mg/kg, Cd 27 mg/kg, Hg <0.1 mg/kg, Pb 54 mg/kg, T-Cr 370 mg/kg, and Cu 1,100mg/kg of heavy metals. In order to be used as raw material for optimum composting, the sewage sludge requires bulking agents for moistrure/porosity control and a carbon source for adjusting C/N ratio. However, the sewage sludge is not adequate as a soil conditioner after composing due to a high content of heavy metals. If the sewage sludge has to he used as a soil conditioner after composting, it as required to identify and remove tire industrial wastewater portions in tire influent of the plant since heavy metals in the influent were mostly concentrated in dewatered sludge.

• Journal of the Korea Organic Resources Recycling Association
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• v.3 no.1
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• pp.73-83
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• 1995

Effect of water treatment sludge(alum sludge) application on the growth of Korea local corn(Zeas Mays L.) was evaluated and phytotoxicity of alum sludge on the growth of corn roots and plant height was tested. Alum sludge itself and composted alum sludge compost were applicated by 1500kg/ha in the plot respectively. For the fertility test, yield, chlorophyll content, plant height of corn treated by alum sludge and composted alum sludge were better than that of control. No clear toxixity of alum sludge was found. At the food chemical analyses of seed corn, no obvious component variation were evaluated either. Test of pH effect on phytotoxicity of alum sludge on corns showed that plant height and root growth of corns were inhibited at low pH 4 solution. Phytotoxicity test of alum sludge extract which was extracted at various pH solutions, showed that growth and cations uptake inhibition were found the more serious the lower the pH. Plant height and root growth injury were serious at higher than 100ppm Al content solution.

• The KSFM Journal of Fluid Machinery
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• v.8 no.2 s.29
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• pp.16-22
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• 2005

This research inspects the discharge state for inside of sedimentation basin, and, through the aboard literature and data, examine sedimentation sludge about discharge plan of effective sedimentation sludge that can discharge in state of high concentration. In this study, we are going to attempt an economy with improvement efficiency for discharge of sedimentation sludge in a water treatment plant.

• Journal of Korean Society of Water and Wastewater
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• v.32 no.3
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• pp.261-268
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• 2018

Sludge transporting pipes in wastewater treatment plant are easy to be clogged with struvite when the digested sludge and dehydrated filtrate are transported through the pipes, which lowers the efficiency of sludge treatment system in a WWTP. pH is one of the most important factors in struvite formation, and carbon dioxide separated from biogas can be used to control pH and struvite formation. By controlling pH, the amount of dehydrating agent can be reduced by about 10%, which saves the budget for facility maintenance. As $CO_2$ is reused and dehydrating chemicals are saved, the approach can contribute to global warming gas reduction.

• Journal of Korean Society on Water Environment
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• v.22 no.4
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• pp.687-694
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• 2006

Dewatering sludge using inorganic chemicals with polymer has been evaded for reuse on account of the risks of high heavy metals contained and soil acidification. Composting feasibility of coagulation & dewatering sludges produced from livestock waste treatment plant was investigated. The results of analysis prove that dewatering sludge is valuable matter with suitable elements for composting if high quality ferric chloride ($FeCl_3$) is used for coagulation & dewatering process. In pot-cultivation of harvestes, using effects of dewatering sludge improved with lime treatment was very effective. The results of pot-cultivation proved that harms of crops according to different acid tolerances were not detected. But it was not applied to crops with weak acid tolerance or greenhouse for free from gas damage. Also, Further studies and monitorings are necessary to use sludges because results of pot-cultivation were generated differently by characteristics of soil, nutrient demand of plants, mature degree of sludge, consecutive cultivation and etc.

• Journal of Korean Society on Water Environment
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• v.22 no.1
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• pp.97-103
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• 2006

Excess sludge treatment and disposal currently represent a rising challenge for domestic or wastewater treatment plants due to economic, environmental and regulation factors. Conventional gravity sedimentation process has been widely used in sludge thickening. The operation method of the process is very simple, but the process requires long detention time for sludge thickening, uses polymers, and shows low sludge thickening efficiency. To solve the problems, we studied on DAF (Dissolved Air Flotation) system. We use bulking sludge of a paper manufacturing plant. The effects of parameters such as SVI (Sludge Volume Index), storage time, initial concentration and wet density of excess sludge were examined. The results showed that the more SVI was low, the more sludge was thickened. As storage time goes by, SVI was increased and thickening performance was deteriorated. In order to improve flotation performance at high concentration, high recycling ratio and pressure did not increase the concentration due to thickening limitation. The addition of 0.8 g/L of loess was increased flotation efficiency of 1.41 times.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.490-499
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• 1998

This study was initiated to investigate the applicability of sludge from water or waste water treatment on the crop cultivation. Sludge is generated in the process of water and wastewater treatment process in large quantity. The sludge can cause many environmental problems. we have a many available treatment methods of sludge However, these methods still shortcomings and are not. The composition of typical municipal sludge contains organics and inorganics. The organics components are normally burnt in high temperature and mainly inorganics components are left after thermal treatment process. For the production of artificial media, chabazite was used as additive, and the mixed material was thermally treated in the firing kiln at 800~1,10$0^{\circ}C$ for about 10 minutes. The physical and chemical characteristics of artificial media were analyzed and it showed that the artificial media could be used as a media for plants and soil conditioner for farmland. The concentrations of the toxic heavy metals in the media were lower then those in the soil quality standard for farmland. This study illustrated that the artificial media production process, and introduced how to produce it's possible application as a media for Plant growth.