• Journal of Korean Society of Environmental Engineers
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• v.35 no.1
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• pp.23-30
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• 2013

The sludge disposal is a major economic factor in the sewage treatment facility operation. Moreover, since the ocean dumping will be prohibited by Korean environmental law from 2013, sludge should be eliminated or sludge volumetric reduction should be performed urgently. In this study, improvement of the sewage sludge dewaterability was investigated by ultrasound and electric field treatment. Sludge was treated by a single or in combination of either the electric field or ultrasound on a pilot pretreatment facility, then it was dewatered by lab-scale filter press. The operating input energy of ultrasound device was varied from 225~1,200 kJ/L and electric field device was varied from 4.5~24 kJ/L. The water contents of dewatered sludge cake treated with ultrasound (1,200 kJ/L) and combination of ultrasound/electric field (1,224 kJ/L) were decreased 10~12% by comparing non-treated sludge. At that time, water contents were 65~66%. The combination treatment of ultrasound/electric field was effective to reduce water content of dewatered sludge cake, however, water content was not changed by a single treatment of electric field because of low energy density.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.1
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• pp.121-128
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• 2009

Objectives of this study were to investigate influencing factors of detention time, particle size distribution, and filter medium characteristics for waterworks sludge dewatering. The stepped pressure filtration was carried out with lab scale apparatus and the filter press pilot test for dewatering was conducted at the water treatment plant. Effects of filter medium and polymer dose were examined through observing water content and dewatering velocity and cyclic dewatering rate with filter press pilot test. Relationships among detention time, particle size distribution and filtration resistance were analyzed. Prolongation of sludge detention time was found to cause blinding phenomenon in cake and filter medium and to decrease dewatering process efficiency. The average specific resistance increased according to detention time. In pilot test of dewatering for thickened sludge with Nylon Multi-NY840D and Nylon Mono-100% filter media, dewatering velocities were 0.92 and $0.93kg\;DS/m^2{\cdot}hr$ according to 0.1% polymer dose of dried solids weight base. And cyclic dewatering rates were 2.45 and $2.50kg\;DS/m^2{\cdot}cycle$ cycle for the Nylon Multi-NY840D and Nylon Mono-100% media. Dewatering velocity of polymer dosed sludge was observed to be higher than that of non-polymer sludge.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.526-531
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• 2000

Application of electrodewatering (EDW) to mechanical dewatering system was studied to decrease water content in the sludge generated from waste water treatment process. Experiments realized the reduction of water content in the sewage sludge. EDW enhancing the conventional filtration by an electric field is an emerging technology with the potential to improve dewatering. In this study, a piston filter press was constructed, the digested sludges were dewatered by EDW under conditions of DC electric field and constant pressure in the piston filter press. Constant electric field from $0{\sim}120\;V/cm$ and constant pressure $98.1{\sim}392.4\;kPa$ were used. The results showed that as electric field was increased the dewatering rates increased and as pressure was increased the dewatering rates decreased. Also as polymer was added the dewatering rates increased. This experiments produced final sludge cake with water content of 60 wt% using EDW, compared with 80 wt% using pressure filtration alone.

• Journal of Korean Society on Water Environment
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• v.32 no.5
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• pp.458-464
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• 2016

This study evaluated the dewatering efficiency of inorganic dehydrating agents that contain oyster shells. A filter press dehydrator was used for this study. The experiments were performed by the single injection of calcium-based chemicals, the single injection of oyster shells, and the mixed injection of oyster shells and calcium-based chemicals. The moisture content of the dewatered cake generated after dehydration confirmed that the best dewatering efficiency was found at the mixing ratios of CaCO₃ to sludge, oyster shell to sludge, and inorganic dehydrating agent to sludge of 3:1, 10:1, and 1.5:2.5:1, respectively. The moisture contents exhibited less than 58% when the injection mixing ratio of inorganic dehydrating agent to sludge was 1.5:2.5:1. From EPS, SEM, and EDX analysis, it was found that the calcium adsorbed on the sludge surface could reduce extracellular polymeric substances (EPSs) and enhanced the dewaterbility. Based on the above results, it is considered possible to apply inorganic dehydrating agents containing recycled oyster shells in sludge dewatering in order to reduce sludge.

• Membrane and Water Treatment
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• v.9 no.5
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• pp.353-361
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• 2018

Fouling characteristics of humic substances on tight ultrafiltration (UF) membrane have been investigated. The tight UF membrane was prepared by blending polysulfone (PSf) in N.N-dimethylacetamide (DMAc) with 25%wt of Polyethylene glycol (PEG400) and 4%wt of acetone. Fouling characteristic of the modified PSf membrane was observed during peat water filtration in different trans-membrane pressure (TMP). It was found that the acetone modified membrane provided 13% increase in TMP during five hours of peat water filtration, where a stable flux was reached within 150 minutes. Meanwhile, the increase of TMP from 10 psig to 30 psig resulted in a fouling resistance enhancement of 60%. Furthermore, based on the fouling analysis, fouling mechanism at the first phase of filtration was attributed to intermediate blocking while the second phase was cake formation.

• Membrane and Water Treatment
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• v.9 no.5
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• pp.343-351
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• 2018

As membrane fouling is based on various factors, it is a complex phenomenon that is hard to estimate. This study investigated membrane fouling in a thermophilic jet loop membrane bioreactor (JLMBR). With this purpose, four different empirical membrane fouling models with different sludge retention times were applied on the flow data obtained in the system. As a result of the model implementation, it was found for all sludge retention times that, standard blocking is effective in the first 1.5 hours of filtration, while cake filtration was dominant in the remaining duration. Additionally, it was observed that as the sludge retention time increases, membrane fouling rate decreases.

• Membrane and Water Treatment
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• v.7 no.4
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• pp.327-339
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• 2016

Nanofiltration is useful to concentrate propolis extract. During the selection of membrane, both compound rejection and permeate flux are important indicators of process economy. Brazilian green propolis extract was studied to evaluate the separation performance of Startmen 122 and NF270 membranes. Compared to Starmen 122, NF270 membrane showed better rejection of bioactive compounds. The flux decline patterns were further studied using Hermia's model. Cake formation is the major fouling mechanism on the hydrophobic surface of Starmen 122. While the fouling mechanism for NF270 is pore blocking. The fouled membranes were further characterized using SEM and FT-IR to confirm on the predicted fouling mechanisms.

• Membrane and Water Treatment
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• v.9 no.5
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• pp.373-383
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• 2018

Fouling by solids and microorganisms is the major obstacle limiting the efficient use of membrane wastewater treatment. In our previous study, two stages microalgae/membrane filtration system was proposed to treat anaerobic digested palm oil mill effluent (AnPOME). This two stages microalgae/membrane filtration system had showed great potential for the treatment of AnPOME with high removal of COD, $NH_3-N$, $PO_4{^{3-}}$, TSS, turbidity, and colour. However, fouling behavior of the membrane in this two stages microalgae/membrane filtration system was still unknown. In this study, empirical models that describe permeate flux decline for dead-end filtration (pore blocking - complete, intermediate, and standard; and cake layer formation) presented by Hermia were used to fit the experimental results in identifying the fouling mechanism under different experimental conditions. Both centrifuged and non-centrifuged samples were taken from the medium with 3 days RT intervals, from day 0 to day 12 to study their influence on fouling mechanisms described by Hermia for ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) filtration mode. Besides, a more detailed study on the use of resistance-in-series model for deadend filtration was done to investigate the fouling mechanisms involved in membrane filtration of AnPOME collected after microalgae treatment. The results showed that fouling of UF and NF membrane was mainly caused by cake layer formation and it was also supported by the analysis for resistance-in-series model. Whereas, fouling of RO membrane was dominated by concentration polarization.

• Journal of the East Asian Society of Dietary Life
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• v.15 no.2
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• pp.137-151
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• 2005

It is estimated that sesame spread to Korea about B.C.1000 years and people cultivated sesame and ate sesame-oil age of three-nations. In the Koryo dynasty, sesame was cultivated as the major crop and there were specialists for making sesame oil. The sesame oil was enough for the both upper and lower classes. In the Chosun dynasty, it was introduced widely the method of sesame and deul-sesame (Perilla japonica) cultivation, the way of keeping sesame oil, and how to make sesame oil. Also, there were several ways of making sesame oil; press oil from raw sesame, or from roasting, boiling, and steaming sesame and etc. Even though sesame-oil and sesames were consumed in large quantities to cook Chan (찬 side dishes) and Byung-gwa (병과 Korean traditional dessert), most of common people could not use freely because it was expensive. You-mil-gwa (유밀과) took always a major dishes in the ceremony or party of the royal classes to the ordinary classes in the Chosun dynasty. Sesames and Sesame-oil made a major role in adding flavor to Chan-mul and Coookies in the Korean traditional cuisine. Especially, sesame-oil was consumed a lot to cook You-mil-gwa, You-kwa (유과), You-jeon-byung (유전병 fried rice cake) and Yak-bab (약밥). Roasted sesame and black sesame were used to cook Da-sik (다식), Gang-jung, and rice cake. Sesame oil and sesame was the major part of vegetable dishes such as Na-mul and it was used to add flavor to steamed, roasted and, pan-fried dishes and to roast, fry, and stew food. Heuk-im-ja-jook(black sesame porridge) and Im-ja-su-soup(임자수탕).

• Proceedings of the EASDL Conference
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• 2004.10a
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• pp.145-174
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• 2004

It is estimated that sesame spread to Korea about BC 1000 years and people cultivated sesame and ate sesame-oil e age of three-nations. In the Koryo dynasty, sesame was cultivated as the major crop and there were specialists for making sesame oil. The sesame oil was enough for the both upper and lower classes. In the Chosun dynasty, it was introduced widely the method of sesame and deul-sesame (Perilla japonica) cultivation, the way of keeping sesame oil, and how to make sesame oil. Also, there were several ways of making sesame oil; press oil from raw sesame, or from roasting, boiling, and steaming sesame and etc. Even though sesame-oil and sesames were consumed in large quantities to cook Chan(饌, side dishes) and Byung-gwa(餠菓, Korean traditional dessert), most of common people could not use freely because it was expensive. You-mil-gwa(油蜜菓) took always a major dishes in the ceremony or party of the royal classes to the ordinary classes in the Chosun dynasty. Sesames and Sesame-oil made a major role in adding flavor to Chan-mul and Coookies in the Korean traditional cuisine. Especially, sesame-oil was consumed a lot to cook You-mil-gwa, You-kwa(油菓), You-jeon-byung(油煎餠 fried rice cake) and Yak-bab(藥飯). Roasted sesame and black sesame were used to cook Da-sik(茶食), Gang-jung, and rice cake. Sesame oil and sesame was the major part of vegetable dishes such as Na-mul and it was used to add flavor to steamed, roasted and, pan-fried dishes and to roast, fry, and stew food. Heuk-im-ja-jook(black sesame porridge) and Im-ja-su-soup (荏子水湯).