• Membrane and Water Treatment
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• 제3권4호
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• pp.211-219
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• 2012

To enhance the efficiency of water treatment and reduce the extent of membrane fouling, the membrane separation process is frequently preceded by other physico-chemical processes. One of them might be ion exchange. The aim of this work was to compare the efficiency of natural organic matter removal achieved with various anion-exchange resins, and to verify their potential use in water treatment prior to the ultrafiltration process involving a ceramic membrane. The use of ion exchange prior to ceramic membrane ultrafiltration enhanced final water quality. The most effective was MIEX, which removed significant amounts of the VHA, SHA and CHA fractions. Separation of uncharged fractions was poor with all the resins examined. Water pretreatment involving an ion-exchange resin failed to reduce membrane fouling, which was higher than that observed in unpretreated water. This finding is to be attributed to the uncharged NOM fractions and small resin particles that persisted in the water.

• Journal of Applied Biological Chemistry
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• 제43권1호
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• pp.31-36
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• 2000

Apparent MWDs of DOM in natural waters and swine wastewaters were determined through membrane ultrafiltration. The nominal MWCOs of ultrafiltration membranes by the manufacturer were confirmed to be similar with those obtained from the ultrafiltration procedures employed in this study using six MW standard compounds. Natural waters showed a wide range of MWOs, but 62.4~87.5% were in the range of MW<10K. High MW fractions were preferentially removed through water treatment processes. Swine wastewater showed two major ranges of MWDs, 49.0% in <1K and 36% in >50k while anaerobically treated swine wastewaters showed 17.5~18.0% in <1K and 53.0~58.8% in <50K. The overall DOM was reduced during anaerobic treatment by 76.8~80.0% as COD; however. the percentage of low MW fractions decreased and that of the high MW fractions increased.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2015년도 춘계학술대회
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• pp.177-178
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• 2015

Sediments play a major role in determining pollution pattern in aquatic systems and reflecting the pollutant deposition. In the present study analysis the depth effect of organic pollutants and heavy metals using slow release biostimulant ball (BSB) in coastal sediment. BSB size fixed at 3cm, depth varied from 0cm to 10cm depth and 1 and 3 month interval period was carried out for the study. The organic pollutants of chemical oxygen demand, total solids and volatile solids were significantly changed at the surface sediment (0cm)in 1 month and 3 month interval time using BSB. In contrast, sediment depth increase upto 10cm the reduction percentage decrease like to control. Vertical distribution of heavy metals are not consistent from the surface layer toward the bottom layers. Heavy metals fractions were significantly changes, the exchangeable fraction was reduced and other organic and residual fractions were stabilized percentage are increased. This finding concluded BSB is effective for reduce organic pollutants, heavy metals stabilization from the contaminated sediment.

• 한국환경과학회지
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• 제23권9호
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• pp.1655-1662
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• 2014

A comprehensive fractionation technique was applied to a set of water samples obtained along drinking water treatment process with ozonation and biological activated carbon (BAC) process to obtain detailed profiles of dissolved organic matter (DOM) and to evaluate the haloacetic acid (HAA) formation potentials of these DOM fractions. The results indicated that coagulation-sedimentation-sand filtration treatment showed limited ability to remove hydrophilic fraction (28%), while removal of hydrophobic and transphilic fraction were 57% and 40%, respectively. And ozonation and BAC treatment showed limited ability to remove hydrophobic fractions (6%), while removal of hydrophilic and transphilic fractions were 25% and 18%. The haloacetic acid formation potential (HAAFP)/dissolved organic carbon (DOC) of hydrophilic fraction was the highest along the treatment train and HAAFP/DOC of hydrophilic fraction was higher than hydrophobic and transphilic fraction as 23%~30%, because of better removal for hydrophobic fraction both in concentration and reactivity.

• 한국식품과학회지
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• 제34권2호
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• pp.244-248
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• 2002

용매분획에 의한 콩나물, 미나리, 무의 추출물들이 Saccharomyces cerevisiae의 ADH의 활성에 미치는 영향을 in vitro에서 조사하였다. 이 추출물들은 알코올로 추출한 것을 용매분획에 의해 수용성 분획물과 유기성인 염기성, 산성, 중성, 페놀성 분획물들을 얻었다. 수용성 분획물들은 유기성 분획물들 보다 ADH 활성을 훨씬 높게 촉진시켰다. 수용성 분획물인 콩나물, 미나리, 무의 촉진율은 각각 125.75%, 104.94%, 87.63%를 나타냈다. 염기성, 산성, 중성의 분획물들에서 염기성 분획물이 약 40%로 가장 높았고 다른 분획물들은 25% 이하로 나타났으며 큰 차이를 보이지 않았다. 페놀성 분획물들 역시 ADH 활성에 큰 영향을 나타내지 못했다. 따라서, 이 분획물들을 ADH 활성 촉진에 이용할 때는 무기물, 아미노산 등의 상승효과를 얻을 수 있는 수용성 분획물들을 이용해야 할 것으로 사료된다.

• 한국토양비료학회지
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• 제45권1호
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• pp.30-36
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• 2012

The active fraction of soil organic matter, which includes organic debris and light organic fraction, plays a major role in nutrient cycling. In addition, particulate organic matter is a valuable index of labile soil organic matter and can reflect differences in various soil behaviors. Since soil organic matter bound to soil mineral particles has its density lower than soil minerals, we partitioned soil organic matter into debris ($<1.5g\;cm^{-3}$), light fraction ($1.5-2.0g\;cm^{-3}$), and heavy fraction ($>2.0g\;cm^{-3}$), based on high density $ZnCl_{2-}$ sucrose solutions. Generally, partitioned organic bands were clearly separated, demonstrating that the $ZnCl_{2-}$ sucrose solutions are useful for such a density gradient centrifugation. The available gradient ranges from 1.2 to $2.0g\;cm^{-3}$. Although there was not a statistically meaningful difference in organic debris and organomineral fractions among the examined soils, there was a general trend that a higher content of organic debris resulted in a higher proportion of light organomineral fraction. In addition, high clay content was associated with increased fraction of light organomineals. Partitioning of soil organic carbon revealed that carbon content is reduced in the heavy fraction than in the light fraction, reflecting that the light fraction contains more fresh and abundant carbon than the passive resistant fraction. It was also found that carbon contents in the overall organic matter, debris, light fraction, and heavy fractions may differ considerably in response to different farming practices.

• Journal of the korean society of oceanography
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• 제36권1호
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• pp.9-18
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• 2001

Chemical speciation of five heavy metals (Cr, Cu, Ni, Pb, Zn) has been analyzed from 37 surface and 2 core sediments of Kyeonggi Bay, using the modified sequential extraction method based on Tessier et at. (1979). The results show that heavy metals in the Kyeonggi Bay surface sediments are associated dominantly with the crystal lattice fraction. But in the polluted sediments of the Incheon North Harbor, the importance of the labile fractions increased while that of the lattice fraction decreased. In particular, the adsorbed and the easily reducible fractions showed a noticeable increase. In the core samples emerged a speciation pattern which differed significantly from that of the surface sediments. A sharp increase in the percentage of the reducible and organic/sulfide fractions and a decrease in the lattice fraction were observed. Throughout the vertical column, however, the metal contents in the lattice fraction showed stability while those of the labile fractions showed an upward increase. The strong association of heavy metals with the organic/sulfide fraction could be attributed in part to the sulfate reduction prevailing in the polluted harbor sediments.

• 한국환경보건학회지
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• 제34권6호
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• pp.446-451
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• 2008

In this study, the removal characteristics of organic components and nutrients of sewage taken from the Suwon area were investigated in a lab-scale modified DNR (Daewoo Nutrient Removal) process. The modified DNR process consisted of a sludge denitrification tank, an anaerobic tank, an anoxic tank, an aerobic tank, a secondary anoxic tank and a secondary aerobic tank. The proposed process with the average C/N ratio of 3.5 was performed for the sewage treatment. The results were compared with other existing DNR processes. The organic fractions in sewage were analyzed by measuring the oxygen uptake rate. The resulting removal efficiencies of SS, BOD, COD, TN and TP were 93.1%, 95.5%, 86.1%, 67.8% and 80.6%, respectively.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 추계학술대회
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• pp.107-118
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• 2000

For the last several decades, the fate of organic pollutants has been extensively studied in natural environments with emphasis on sorption and desorption phenomena. Although the mechanisms involved are not clear yet there is a consensus about the existence of hysteresis in the sorption and desorption of organic pollutants. Furthermore, it is found that hysteresis is the outcome of slow nonequilibrium sorption of organic pollutants, which results in the formation of desorption-resistant fractions of the pollutants. Desorption-resistant fractions may increase as a function of the residence time of the pollutants in the environments. Field monitoring data show a slow but continuous decline of chemicals applied to soil, followed by little or no subsequent disappearance. One plausible explanation for such resistance to biodegradation, desorption, or extraction can be attributed the gradual movement of organic pollutants to less accessible remote sites inside the matrix with time. This phenomenon has been termed sequestration or aging. The fact that some pollutants are sequestered in soil with time may have a great impact on bioremediation and risk assessment, Some portion of the resistant pollutants may still be present in the environments after bioremediation. It requires vigorous means to completely remove the aged portion that may not be further bioavailable. However, precaution should be taken since aging is not always evident. Aging seems to be soil and chemical specific.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1263-1263
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• 2001

The amounts of organic matter present in soil and the rate of soil organic matter (SOM) turnover are influenced by agricultural management practice, such as rotation, tillage, forage plow down direct seeding and manure application. The amount of nutrients released from SOM is highly dependent upon the state of the organic matter. If it contains a large proportion of light fractions (low-density) more nutrients will be available to the glowing crops. However, if it contains mostly heavy fractions (high-density) that are difficult to breakdown, then lesser amounts of nutrients will be available. The state of the SOM and subsequent release of nutrients into the soil can be predicted by NIRS as long as a robust regression equation is developed. The NIRS method is known for its rapidity, convenience, simplicity, accuracy and ability to analyze many constituents at the same time. Our hypothesis is that the NIRS technique allows researchers to investigate fully and in more detail each field for the status of SOM, available moisture and other soil properties in Alberta soils for precision farming in the near future. One hundred thirty one (131) Alberta soils with various levels (low 2-6%, medium 6-10%, and high >10%) of organic matter content and most of dry land soils, including some irrigated soils from Southern Alberta, under various management practices were collected throughout Northern, Central and Southern Alberta. Two depths (0- 15 cm and 15-30 cm) of soils from Northern Alberta were also collected. These air-dried soil samples were ground through 2 mm sieve and scanned using Foss NIR System 6500 with transport module and natural product cell. With particle size above 150 microns only, the “Ludox” method (Meijboom, Hassink and van Noorwijk, Soil Biol. Biochem.27: 1109-1111, 1995) which uses stable silica, was used to fractionate SOM into light, medium and heavy fractions with densities of <1.13, 1.13-1.37 and >1.37 respectively, The SOM fraction with the particle size below 150 microns was discarded because practically, this fraction with very fine particles can't be further separated by wet sieving based on density. Total organic matter content, mechanical texture, ash after 375$^{\circ}C$, and dry matter (DM) were also determined by “standard” soil analysis methods. The NIRS regression equations were developed using Infra-Soft-International (ISI) software, version 3.11.