• Proceedings of the Membrane Society of Korea Conference
• /
• 2005.05a
• /
• pp.108-111
• /
• 2005

• Membrane Journal
• /
• v.13 no.1
• /
• pp.9-19
• /
• 2003

Membrane process was investigated to recover process water and valuable gold from washing water of electroless PCB plating processes. The filtration experiments were carried out using not only a RO membrane test cell to determine suitable membrane for washing water but also spiral wound membrane modules of nanofiltration and reverse osmosis for scale-up. At first, RO-TL(tap water, low pressure), RO-BL(brackish water, low pressure) and RO-normal(for water purifier) sheet membranes made by Saehan Co. were tested, and the performance of RO-TL membrane showed most suitable f3r recovery of soft etching, catalyst and Ni washing waters. As a result of RO test cell, the experiments for scale-up were carried out using RO-TL modules far water purifier at 7bar and $25^{\circ}C $The permeate flux fur Au washing water was about 30 LMH, but Au rejection was less than 80%. The permeate fluxes for Pd, Ni and soft etching washing water were about 22, 17 and 10 LMH, respectively. The Pd, Ni and Cu rejections showed more than 85, 97 and 98% respectively. The nanofiltration module for water purifier was introduced to recover Au selectively from Au, Ni and Cu ions in Au washing water. Most of Ni and Cu ions in the feed washing water were removed, and only Au ion was existed 81.9% in the permeate. Furthermore, Au ion in the permeate was concentrated and recovered by RO-TL membrane module. Finally, Au was also able to recover effectively by using 4 inch diameter spiral wound modules of NF and RO-TL membranes, in series.

• Membrane Journal
• /
• v.29 no.1
• /
• pp.11-17
• /
• 2019

In the field of water treatment membranes, polymers are used together with ceramics as the most important materials. In this review, I tried to analyze the technology trends of polymer membrane materials based on commercial products. For this purpose, according to the types of water treatment membranes such as MF (Microfiltration), UF (Ultrafiltration) and NF (Nanofiltration), the trends of polymer membrane products were investigated by countries, materials, and companies. Through this, we were able to classify the types of materials that are mainly used for each type of membrane, and at the same time, identify the companies that are dominant in the market, and analyze which materials constitute the product portfolio. Based on these results, we have presented the characteristics of the material market according to each type of membrane, and proposed a technology development strategy to enter each market based on these characteristics.

• Korean Membrane Journal
• /
• v.4 no.1
• /
• pp.12-19
• /
• 2002

Nanofiltration of aqueous dye solutions was carried out using polyamide (PA) nanofiltration (NF) composite membranes. The PA composite membranes were prepared by the interfacial polymerization of piperazine (PIP) and trimesoyl chloride (TMC) on the surface of microporous polysulfone (PSf) ultrafi1tration (UF) membranes. After characterization in terms of their permeation performance and surface ionic property, they were used for the separation of dye solutions such as Direct Red 75, 80, 81, and Direct Yellow 8 and 27. The separation conditions were varied to study the factors affecting on the permeation performance of the membranes: different concentrations of dye solutions, operating temperature and time, and flow rate of a feed solution. The surface property of the membrane, especially its ionic property, as a function of operating time was examined with a zeta-potentiometer and the relationship between the surface chemistry of the membrane and its permeation properties was also studied.

• Proceedings of the Membrane Society of Korea Conference
• /
• 1998.10a
• /
• pp.140-142
• /
• 1998

돈사에서 발생하는 폐수는 주로 돈뇨와 음용수의 누수 및 세척수 등으로 구성되어 있는데, 생물학적인 축산폐수처리법과 퇴비화법 등으로 처리를 하고 있다. 그러나 일반적인 돈사폐수에는 분의 함량이 많아 부유물질의 양이 많고 유기물 등 오염성분의 농도가 높은 특성을 가지고 있어서 기존의 생물학적 축산폐수 처리법으로는 과부하 운전으로 인한 어려움이 있고, 퇴비화법으로는 수분조절제의 소요량이 많은 문제점을 가지고 있다. 대부분의 현지 양돈농가에서는 돈뇨 등 폐수처리의 어려움으로 인하여 분뇨 분리 시설이 있어도 분뇨를 혼합한 슬러리 형태로 퇴비화하고 있다. 따라서 퇴비화 공정에서 수분조절제로 쓰이는 톱밥의 소요량이 돈분만 퇴비화할 때보다 훨씬 많고 기존의 퇴비화 시설도 과부화 상태로 운전하고 있는 실정이다.

• YAKHAK HOEJI
• /
• v.44 no.5
• /
• pp.406-410
• /
• 2000

The present method is to describe a potentiometric norfloxacin electrode system characterized by a membrane, based on the use of norfloxacin (NF) complex with ion-association reagents. These complexes were dissolved in DMSO, DMF acetonitrile or acetone and dispersed in plasticized poly(vinyl chloride) matrix. The picric acid complex electrode exhibited near-Nernstian response for NF in acetate buffer solution (pH 4.0) with a slope of 53.03 mV/decade. And linear response over the range of 10$^{-5}$ to 10$^{-3}$M solution of NE. The ingredients in tablet, capsule and biological important organic acids were not interfere.

• The Journal of Korean Medicine
• /
• v.24 no.1
• /
• pp.155-168
• /
• 2003

This study was carried out to investigate the effect of Keuibi-tang (KBT) on the injury of gastric mucous membrane by stress and ethanol in mice. The normal group was non-inflammation elicited mice. The two control groups were mice with gastro-inflammation elicited by stress and ethanol. The two sample groups were mice administered KBT before gastro-inflammation elicitation. In the common morphology and histochemical change, the two control groups were observed with various injuries such as hemorrhagic erosion and ulcer, while the sample group was the same as the normal group. In the immunohistochemical change, the distributions of PNA and COX-1 treated with KBT noticeably increased over the control group (P<0.05). The distributions of $NF-{\kappa}B$ p50, COX-2 and TUNEL in the group treated with KBT were noticeably lower than in the control group (P<0.05). The distribution of KBT was the same as the normal group. According to the above results, it is supposed that KBT is applicable to gastritis and gastric ulcer due to stress and alcoholic drinks.

• Advances in environmental research
• /
• v.5 no.2
• /
• pp.141-151
• /
• 2016

Large amounts of aluminum hydroxide ($Al(OH)_3$) exist in water purification sludge (WPS) because of the added aluminum coagulant in water treatment process. Notably, $Al(OH)_3$ is an amphoteric compound, can be dissolved in its basic condition using sodium hydroxide to form aluminate ions ($Al(OH)_4{^-}$). However, in a process in which pH is increasing, the humid acid can be dissolved easily from WPS and will inhibit the recovery and reuse of the dissolved aluminate ions. This study attempts to fix this problem by a novel approach to separate $Al(OH)_4{^-}$ ions using nanofiltration (NF) technology. Sludge impurity in a alkaline solution is retained by the NF membrane, such that the process recovers $Al(OH)_4{^-}$ ions, and significantly decreases the organic matter or heavy metal impurities in the permeate solution. The $Al(OH)_4{^-}$ ion is an alkaline substance. Experimental results confirm that a recovered coagulant of $Al(OH)_4{^-}$ ion can effectively remove kaolin particles from slightly acidic synthetic raw water.

• Proceedings of the Membrane Society of Korea Conference
• /
• 1995.06a
• /
• pp.39-50
• /
• 1995

The membrane processes that are commonly uscd in water and wastewater treatment are reverse osmosis (Ro), ultrafiltration (UF) and microfiltration (MF), which utilize pressure differentials. There is also nano-filtration (NF), or low-pressure reverse osmosis, which is positioned midway between conventional reverse osmosis and ultrafiltration. Reverse osmosis membranes reject dissolved ions, while ultrafiltration can be used to reject relatively larger molecules, such as protein, polysacchalides and so on. Microfiltration is capable of eliminating particles at submicron level. This paper summarizes the characteristics of MSAS process first, as it is the main membrane process applied to wastewater treatment. Two successful examples of the applications, the cases of individual building reuse system and nightsoil treatment, are then shown. The latest trend of new membrane applications, i.e., immersed-type MSAS is also introduced.

• Membrane and Water Treatment
• /
• v.3 no.4
• /
• pp.231-242
• /
• 2012

The performance of a nanofiltration membrane for treatment of a low-level radioactive liquid waste was investigated through static and dynamic tests. The liquid waste ("carbonated water") was obtained during conversion of $UF_6$ to $UO_2$. In the static tests membrane samples were immersed in the waste for 24, 48 or 72 h. The transport properties of the samples (hydraulic permeability, permeate flow, selectivity) were evaluated before and after immersion in the waste. In the dynamic tests the waste was permeated in a permeation flow front system under 0.5 MPa, to determine the selectivity of NF membranes to uranium. The surface layer of the membrane was characterized by zeta potential, field emission microscopy, atomic force spectroscopy and infrared spectroscopy. The static test showed that the pore size distribution of the selective layer was altered, but the membrane surface charge was not significantly changed. 99% of uranium was rejected after the dynamic tests.