• Resources Recycling
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• v.25 no.4
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• pp.3-10
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• 2016

A lot of researches have been carried out on the recovery of resources from the seawater all over the world. The boron concentration in seawater is low about at 4.5ppm, but considering the volume of seawater, the total weight of dissolved boron amounts to about 5.4 trillion tons. The boron is an essential resource in about 300 kinds of industries. Korea has imported all of the boron and spent more than 700 billion won each year. In this article, we introduce the domestic and international research trends and technologies for removing or recovering the boron from wastewater and seawater. Most of the researches have been conducted to remove the boron from the desalination process, and to recover the boron mainly from wastewater and brine. The technique for the recovery of the dissolved boron includes the ion exchange, which is the most representative, the adsorption membrane filtration (AMF), solvent extraction, and so on.

• Resources Recycling
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• v.18 no.1
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• pp.58-67
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• 2009

The annual requirement of domestic waste photoresist stripper solution is about 1 trillion won level (50,000 tons) depends entirely on imports for its supplies. Nevertheless, there waste strippers which contain the impurities have been recycled or incinerated to a low level of recycle. These days the recycling technologies of the waste stripper solution has been widely studied from the view points of economy and efficiency. In this paper, the recycling technologies on patent of the waste stripper solution were analyzed. The range of search was limited within the open patents of USA (US), European Union (EP), Japan (JP), and Korea (KR) up to september, 2007. Patents have been collected using key-words searching and filtered by filtering criteria. The trends of the patents was analyzed by the years, countries, companies, and technologies.

• Membrane Journal
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• v.22 no.4
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• pp.235-242
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• 2012

Ammonium perchlorate (AP) is primarily derived from the process of liquid incineration treatment when dismantling a solid rocket propellant. A series of batch dead-end nanofiltration (NF) and reverse osmosis (RO) membrane experiments were conducted to explore the retention mechanisms of AP under various hydrodynamic and solution conditions. Low levels of silicate type of siloxane had been detected through the GC/MS and FTIR analysis of liquid solutions extracted from solid ammonium perchlorate composite propellant (APCP). It is indicated that NF/RO membranes fouling in the presence of APCP was mainly attributed to the AP interactions because the concentration of silicate type of siloxane was negligible compared to that of AP. The osmotic pressure of AP was presumably resulted in the flux declines ranging from 13 to 17% in the case of the application of low-pressure (551 and 896 kPa for NF and RO) compared to those in application of high-pressure. The retention of AP by NF/RO membranes significantly varied from approximately 10 to 70% for NF and 26 to 87% for RO, depending on the operating and solution water chemistry conditions. The results suggested that retention efficiency of AP was fairly increased by reducing concentration polarization (i.e. application of low-pressure and stirring speed of 600 rpm) and increasing the pH of a solution. The result of this study was also consistent with the previous modeling of 'solute mass transfer of NF/RO membranes' and demonstrated that hydrodynamic and solution water chemistry conditions are to be a key factor in the retention of AP by NF/RO membranes.

• Journal of Wetlands Research
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• v.18 no.2
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• pp.183-193
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• 2016

In this study, design and performance of infiltration trench using woodchip as media for treating stormwater from highway were examined through field monitoring. Average reduction efficiency for TSS, COD, BOD, TN, and TP was 88%, 94%, 85%, 80%, and 75% respectively, which is similar to values reported by other studies and design manuals even though direct comparison is not possible due to different monitoring and design conditions. Mean field infiltration rate estimated by measuring the change of water depth inside the observation well was about 40mm/hr, and the time taken for complete infiltration was about 0.83days, which corresponds well with design criteria recommended by MOE guidelines in Korea. In addition, according to analysis of infiltration rate and reduction efficiency, effective rainfall depth applied for determining water quality volume(WQv), 5mm was found to be properly established as design criteria. Woodchip must be considered and included as an alternative media together with crushed rock and gravel into the design guidelines because it has more advantages in terms of weight, porosity, cost, and easiness of management than other media materials.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.25 no.3
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• pp.95-99
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• 2019

In the modified atmosphere packaging of powdered infant formula, the oxygen inside the package may cause its quality deterioration and needs to be minimized for quality preservation. A way of oxygen scavenger inclusion in the single-serve package without contacting the product was devised for removing oxygen residing initially and permeating through the seal layer during the storage. A polyethylene/pulp multi-layer porous filter bag of 5 × 7 cm containing 13 g of powdered infant formula was packaged in an 8 × 9 cm size aluminium laminated film package with a Fe-based oxygen scavenger of 1.8 g. After nitrogen flushed packaging, the active packages were stored at 30℃ for 254 days with periodical quality measurement. The active package could remove the initial residual oxygen of 1.4% completely and maintain absence of oxygen for the whole storage, which contributed to reduced oxidation observed in lower product peroxide value compared to that of the product in the control package. There was no influence of packaging treatment on content of 5-hydroxymethylfurfural, reaction product of initial nonenzymatic browning. The devised oxygen-scavenging single-serve package showed a potential to improve the preservation of infant formula powder and extend the shelf life.