• Journal of Korean Society of Water and Wastewater
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• v.18 no.3
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• pp.279-290
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• 2004

Sludge quantity has increased at "A"water treatment plant due to deterioration of raw water quality and GAC installation. Increased sludge resulted in overloading on sludge handling facilities. The object of this study is to survey sludge quantity and capacity of sludge handling facilities at "A"water treatment plant. Measured quantity of sedimentation sludge considerably exceeded the design capacity of sludge holding basin. Sludge holding basin was properly designed, but low concentration of sludge discharged from sedimentation basin caused production of large volume of the sludge. Timer operated control system for sludge withdrawal unit and leakage through a control valve were suspected to cause the low concentration. Augmentation of the control system by a turbidity meter and addition of a new control valve successfully reduced the sludge volume enough to satisfy the design capacity of sludge holding basin. Unlike sedimentation sludge, measured quantity of washwater was considerably less than the design capacity of washwater basin because it was over-designed.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.3
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• pp.451-460
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• 2006

While sludge settles down in a batch column, sludge concentration becomes high. Sludge concentration change is one of the most critical causes of the sludge settling velocity variation. Therefore, sludge concentration change causes sludge index to change. SVI is more sensitive than other sludge indexes to the change of sludge concentration. And if sludge-water interface has reached final height within 30minutes, SVI is not suitable for prediction of sludge settling characteristic, Therefore, SVIs of each sludge are, in some cases, different although each sludge has the same settling velocity. But SVI has been widely used to interpret sludge settling characteristic by a simple testing method. This work has two purposes. The first purpose is to predict sludge settling velocity by using sludge-water interface settling velocity. And the second purpose is to develop new sludge settling characteristic index to exactly interpret sludge settling characteristic by overcoming the limit of SVI.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.555-559
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• 2001

A by-product, waste sludge water produced from ready mixed concrete(remicon) factories may affect our environmental contamination if it is discharged without proper waste disposal. In Korea, all waste sludge water has been recycled in the way of mixing water of remicon, but the quality of the concrete then produced can be deteriorated, so it might cause slump loss or irregular compressive strength. In this study, waste sludge water is divided into two parts, remicon sludge and residual water in order to make it's property more stable. Then, the remicon sludge and high-alkaline residual water were used as admixture and alkali activator respectively. In this paper we research about quality of with remicon sludge and residual water and performed the fundamental properties of cement matrix mixed with remicon sludge and residual water.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.1
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• pp.147-155
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• 2006

For the further study of the solids flux theory, several researchers have proposed models to predict sludge settling velocity for each different concentration by using sludge indexes, SVI, SSVI and $SSVI_{3.5}$. It is difficult to apply the above models to predict sludge-water interface height in a batch column because sludge settling velocity changes while sludge settle down. While sludge settle down in a batch column, sludge concentration becomes high. The sludge concentration change is one of the most critical causes of the change of sludge settling velocity. Also, sludge concentration change causes of sludge index to change. SVI is more sensitive than SSVI or $SSVI_{3.5}$ to the change of sludge concentration. Each sludge has physical characteristics of its own which makes the settling velocity for each sludge different. The purpose of this study is to establish the correction factors that are able to compensate the errors derived from each different sludge settling characteristic by using sludge indexes, therefore the correction factors are applicable to the model for the change of sludge-water interface height.

• Journal of the Korean Geotechnical Society
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• v.29 no.2
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• pp.57-64
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• 2013

In this paper, in order to solve high water content of water sludge and promote its recycle, sludge mixtures with various mixing ratios were produced. Sludge mixture consisted of water sludge and weathered granite soil. Their physical properties and unsaturated characteristics (soil-water characteristic curve, and unsaturated permeability function) were investigated by laboratory tests. Experimental test results indicated that at a given matric suction volumetric water content of sludge mixture increased as water sludge content increased. Air entry values of sludge mixture increased from 0.9 kPa to 2.4 kPa with an increase in water sludge content or fine content. In addition, unsaturated permeability function, which is an important factor for performing infiltration analysis, was predicted using saturated permeability and soil-water characteristic curve of sludge mixture.

• The KSFM Journal of Fluid Machinery
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• v.8 no.1 s.28
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• pp.30-36
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• 2005

A sludge treatment system for introducing the waste water mixture with paint sludge from the water bath of paint booth and for recycling cleaned water to paint booth after sludge separation is developed. Floated sludge is introduced from the water surface in the bath by using floating-skimmer, and is conveyed by pump to the centrifugal separator where sludge and cleaned water are separated. From the operation results of the present sludge treatment systems applied in actual paint booths, paint sludge can be separated automatically and effectively from water bath with its water content of $60-70\%$, and sludge-free clean water is returned to paint booth.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.259-266
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• 2004

Developed is a sludge treatment system for introducing the waste water mixture with paint sludge from the water bath of paint booth and for recycling cleaned water to paint booth after sludge separation. Floated sludge is introduced from the water surface in the bath by using floating skimmer, and is conveyed by pump to the centrifugal separator where sludge and cleaned water are separated. From the operation results of the present sludge treatment systems applied in actual paint booths, paint sludge can be separated automatically and effectively from water bath with its water content of $60-70\%$, and sludge-free clean water is returned to paint booth.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.1
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• pp.156-163
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• 2006

While sludge is settling in batch column, sludge concentration becomes high. Because the characteristic of sludge settling changes in function of time due to the sludge concentration change, the sludge settling velocity changes too. Also, because the sludge settling characteristic is influenced by a physical characteristic of sludge and a column height etc, it is difficult to exactly measure the sludge settling characteristic. Although the sludge volume indexes, SVI, SSVI and $SSVI_{3.5}$, are used to predict sludge settling characteristic, these indexes are not reliable values. Because the previously established models for sludge settling velocity predict the sludge settling velocity only, it is difficult to predict sluge-water interface height by using those models. The purpose of this experiment is to establish the empirical model which predicts the sludge interface height change with respect to the sludge physical characteristic and the settling condition.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.2
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• pp.249-255
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• 2014

So many drinking water treatment plants are under various difficulties by new reinforced effluent standards. Since the target turbidity, much higher than annual average, for designing sludge thickener have to be set to confront high turbidity season, the sludge at thickener should be put up for a long time during usual days. So the soluble manganese and chloroform may be formed under the anaerobic environment in the sludge thickener when the sludge retention time is longer with low turbidity. This phenomenon results in difficulties to keep regulatory level of the discharged effluent. For an effort to overcome the problems, a sludge aeration was successfully implemented into the thickening process. As a result, the final effluent quality and sludge volume were much improved; 41 % of manganese, 62 % of chloroform and 35 % of sludge volume. Additionally, effluent quality was improved ; 61 % of Manganese on aeration with pH control and we could make sure of stability effluent quality despite a long sludge retention time. We recommended the standard of installation sludge aeration equipment to nationally supply water treatment plant under effluent water quality problem ; Manganese, Chloroform, etc.

• 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.