• Textile Coloration and Finishing
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• v.7 no.2
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• pp.9-16
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• 1995

When alkaline waste water of PET fabric is treated with sulfuric acid, undegradable material, crude TPA sludge is generated, so that treatment has a serious problem. The result of DMT synthesis using crude TPA sludge generated from PET alkaline waste water were as follows: 1. When crude TPA generated from alkaline waste water is reactioned with methanol under catalyst of sulfuric acid, pure DMT can be obtained. 2. In DMT synthesis from crude TPA, addition of copper sulfate can increase yield, and increasing the amount of sulfuric acid can shorten reaction time.

• Journal of Korean Society of Water and Wastewater
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• v.14 no.1
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• pp.117-126
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• 2000

Solubilization pretreatments were conducted to enhance the anaerobic digestion of the waste activated sludge. Four pretreatment techniques including heating, sonication freezing and thawing, and enzyme addition were employed to solubilize the waste activated sludge under various conditions. Thermal pretreatment by heating showed the highest efficiency compared with other methods, and freezing and thawing was confirmed as a feasible alternative of solubilization as well as the pretreatment of dewatering. There is a clear correlation between the solubilization efficiency of the waste activated sludge and the gas production. Batch digestion results showed the cumulative gas production as much as four times after thermal pretreatment as compared with that by the control sludge without pretreatment. As a result, hydrolysis or solubilization pretreatment might play a significant role in the high rate digestion of the waste activated sludge.

• Proceedings of the Membrane Society of Korea Conference
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• 1999.10a
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• pp.39-39
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• 1999

Membrane separation technology has become a more attractive technology on waste water treatment and water recycle in recent years. On this application, membrane does not take main part of treatment, such as decomposition or handling of organic matter in the waste water, but it is very important supporting method in the total system. Activated sludge is most popular method as main part. In the system , membrane works as a separator to obtain clear water after biological treatment, by which the permeate could be released, recycled or applied to further additional treatment, instead of conventional sedimentation, coagulation and sand filtration. We would like to introduce our system cases for waste water treatment and water recycle, in which membrane separation technology works. In most of cases, membranes are applied to solid- liquid separation of activated sludge. Our experiences will be introduced as following items.

• Journal of the Korean GEO-environmental Society
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• v.13 no.8
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• pp.75-84
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• 2012

In this paper, strength and leaching characteristics of water sludge-added lightweight soils(WALS) considering reinforcing materials(waste fishing net, glue treated waste fishing net and geogrid) and layer(1 or 2 layer) were investigated using unconfined compression test and leaching test. Several specimens of water sludge-added lightweight soil consisted of water sludge, cement, and bottom ash were prepared according to flowability. Reinforcing material added into these specimens were waste fishing net and geogrid. A glue treated waste fishing net was also added in order to increase interlocking between soil mixture and waste fishing net. Strength increased in the order of WALS reinforced by waste fishing net, glue treated waste fishing net, and geogrid. Strength of specimen with double layer-reinforcing material was greater than that of specimen with single layer reinforcing material. Leaching result of WALS was also satisfied with standard of ministry of environment.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.1
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• pp.64-69
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• 2013

The various promotion countermeasures such as solidification, carbonization, and the creation of cement materials have been considered to existing treatment methods such as incineration and the creation of composts, since direct landfill was prohibited for encouraging the recycling based on the sludge treatment on land. The Main objective of this study is to investigate the feasibility of co-incineration for MSW (municipal solid waste) and SS (sewage sludge) through the quantitative supply of sewage sludge. In this study, optimum water content to operate normally incinerator is 85%. In order to increase the workability of sewage sludge, it is necessary to supply properly water. In the case study of sites, optimum water content is 87% due to the water evaporation. Therefore, it was found that the water content up to 87% would be reached the stable operation of co-incinerator on the mixture of municipal waste solid and sewage sludge.

• Journal of Environmental Science International
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• v.15 no.11
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• pp.1053-1059
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• 2006

This study was performed to investigate the possible uses of waste sludge for the removal of heavy metal ions. The adsorption experiments were conducted with wastes such as sewage treatment sludge, water treatment sludge and oyster shell to evaluate their sorption characteristics. Heavy metals selected were cadmium, copper and lead. in the sorption experiments on the sewage treatment sludge, water treatment sludge, oyster shell and soil, sorption occurred in the beginning and it reached equilibrium after 40 minutes on the oyster shell and 4 hour on the sewage treatment sludge and water treatment sludge. Results of Freundlich isotherms indicated that sewage treatment sludge could be properly used as an adsorbent for heavy metals and sorption strength of heavy metals was in the order of Pb > Cu > Cd. In the influence of pH on the adsorbents, sorption rate was more than 80% in pH 4 and most of heavy metals were adsorbed in pH 9. Adsorption rate of Cd decreased with decreasing pH and then adsorption rate of Cu was lower in soil.

• Journal of Korean Society on Water Environment
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• v.37 no.5
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• pp.363-368
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• 2021

On the assessment results of the non-point source pollutant removability of bio-block using waste sewage sludge, at the reactor's initial operation stage, the removal efficiency of COD was slightly unstable. However, after the reactor was stabilized, the COD removal efficiency was higher in the reactor filled with bio-blocks compared to the reactor filled with broken stones. In terms of nitrogen and phosphorus, their removal efficiency was unstable at the initial stage of the reactor operation. This phenomenon was investigated through the bio-block elution experiments. Results indicated that nitrogen and phosphorus were eluted from the bio-blocks affecting their removal at the initial operation. Furthermore, based on elution tests conducted after the dry ashing of the waste sewage sludge, part of the nitrogen and phosphorus was eluted similar to the bio-block elution test results, although considerable amounts of nitrogen and phosphorus were reduced compared to the sludge cake. Prior to the use of the waste sewage sludge bio-blocks as a filter medium to remove non-point source pollutants, a stabilization period of 10 days was required. After the stabilization process, results showed similar characteristics as general aggregates. Moreover, to use the bio-block as a filter medium for the non-point pollutant removal, the filling ratio of 75% was the most suitable as it resulted in the highest nitrogen removal efficiency after the stabilization. The results of this study suggested that waste sewage sludge can be suitably recycled as a mixed raw material for the bio-blocks, with satisfactory application as a filter medium in artificial wetlands, stormwater runoff problems, stream water pollutants to eliminate non-point source pollutants.

• Journal of Environmental Health Sciences
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• v.37 no.6
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• pp.467-473
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• 2011

Objectives: Wastewater treatment plants typically produce a large volume of waste sludge. In this study, the conditioning and dewatering properties of a digested and thickened sludge from an industrial wastewater treatment plant were investigated in order to improve the dewaterbility of the sludge. Methods: Jar-tests and Buchner funnel tests were carried out to assess the conditioning and dewatering properties of a waste sludge. TTF (Time to Filter Test) and SRF (Specific Resistance to Filtration) were adopted as the indices of sludge dewaterbility. Results: The valuation indices influencing the dewaterbility of the waste sludge, including TTF, SRF, water contents, VS/TS ratio and turbidity, were measured. The TTF and SRF of the digested and thickened sludge were decreased to 40 sec, $3.43{\times}10^{12}$ m/kg, and 39 sec, $1.09{\times}10^{12}$ m/kg, respectively. Conclusions: The conditioner composed of natural inorganic materials turned out to be effective in the reduction of sludge water contents.

• 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.