• Title, Summary, Keyword: Dissolved organic matter

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Distributions and Sources of Dissolved Organic Matter in Seawaters Surrounding Aqua Farms on the Haengwon-ri in Jeju-Island in Summer 2015 (2015년 하계 제주 행원리 일대 양식장주변 해수 중 용존유기물 분포와 기원)

  • Kim, Jeonghyun;Kim, Tae-Hoon
    • Ocean and Polar Research
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    • v.39 no.1
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    • pp.35-43
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    • 2017
  • Concentrations of dissolved organic carbon (DOC), dissolved organic nitrogen (DON), dissolved organic phosphate (DOP), and colored dissolved organic matter (CDOM) were measured in the coastal sea off inland aqua farms in northeastern Jeju Island in summer 2015. The highest concentrations of DOC, DON, and DOP were revealed in the surface water off Hado-ri where the lowest salinity conditions prevailed (31.6). The concentrations of DOC, DON, and DOP in the surface water were lower in the inner stations (SH1-1, 1-2, and 1-3) near the aqua farms of the Haengwon-ri than in the outer stations. The concentrations of DOC, DON, and DOP negatively correlated with salinity. These results indicate that the contribution of dissolved organic matter (DOM) from the aqua farms seems to be not significant. On the other hand, the higher concentrations of DON and DOP in the inner stations of Hado-ri (HD 1-1) seem to be attributed to excrement of migrating birds. The three components of CDOM (T, M, and C peaks) showed no relationship with salinity, perhaps due to various in situ productions by marine organisms and decomposition by ultraviolet radiation. The observed lower C:M ratio, an indicator of terrestrial source, and the higher biological index (BIX) of CDOM in the station off Hado-ri indicate that DOM is produced mainly by biological activity. Based on the higher humification index (HIX) of CDOM and the higher DOC:DON ratio off Haengwon-ri, refractory DOM in the inland aqua farms is likely transported to the coastal sea.

Characterization of Natural Organic matter by Rapid Mixing Condition (급속교반조건에서 Alum 응집제의 가수분해종 분포특성과 유기물특성변화)

  • Song, Yu-Kyung;Jung, Chul-Woo;Son, Hee-Jong;Sohn, In-Shik
    • Journal of Korean Society of Water and Wastewater
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    • v.20 no.4
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    • pp.559-571
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    • 2006
  • The overall objective of this research was to find out the interrelation of coagulant and organic matter during rapid mixing process and to identify the change of organic matter by mixing condition and to evaluate the effect of coagulation pH. During the coagulation, substantial changes in dissolved organics must be occurred by coagulation due to the simultaneous formation of microflocs and NOM precipitates. Increase in the organic removal efficiency should be mainly caused by the removal of microflocs formed during coagulant injection. That is, during the mixing period, substantial amount of dissolved organics were transformed into microflocs due to the simultaneous formation of microflocs and NOM precipitates. The results also showed that 40 to 80% of dissolved organic matter was converted into particulate material after rapid mixing process of coagulation. During the rapid mixing period, for purewater, formation of dissolved Al(III) (monomer and polymer) constant by rapid mixing condition, but for raw water, the species of Al hydrolysis showed different result. During the rapid mixing period, for high coagulant dose, Al-ferron reaction increases rapidly. At A/D(Adsorption and Destabilization) and sweep condition, both $Al(OH)_3(s)$ and dissolved Al(III) (monomer and polymer) exist, concurrent reactions by both mechanism appear to cause simultaneous precipitation.

Biological stability in the ozone and peroxone pretreatment systems in river water (하천수 내 생물학적 안정성에 따른 유기물 특성변화와 오존산화기반 전처리 연구)

  • Park, Se-Hee;Noh, Jin-Hyung;Park, Ji-Won;Maeng, Sung-Kyu
    • Journal of Korean Society of Water and Wastewater
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    • v.32 no.2
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    • pp.159-168
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    • 2018
  • Climate change is believed to increase the amount of dissolved organic matter in surface water, as a result of the release of bulk organic matter, which make difficult to achieve a high quality of drinking water via conventional water treatment techniques. Therefore, the natural water treatment techniques, such as managed aquifer recharge (MAR), can be proposed as a alternative method to improve water quality greatly. Removal of bulk organic matter using managed aquifer recharge system is mainly achieved by biodegradation. Biodegradable dissolved organic carbon (BDOC) and assimilable organic carbon (AOC) can be used as water quality indicators for biological stability of drinking water. In this study, we compared the change of BDOC and AOC with respect to pretreatment methods (i.e., ozone or peroxone). The oxidative pretreatment can transform the recalcitrant organic matter into readily biodegradable one (i.e., BDOC and AOC). We also investigated the differences of organic matter characteristics between BDOC and AOC. We observed the decreases in dissolved organic carbon (DOC) and the tryptophan-like fluorescence intensities. Liquid chromatographic - organic carbon detection (LC-OCD) analysis also showed the reduction of the low molecular weight (LMW) fraction (15% removed, less than 500 Da), which is known to be easily biodegradable, and the biopolymers, high molecular weight fractions (66%). Therefore, BDOC consists of a broad range of organic matter characteristics with respect to molecular weight. In AOC, low molecular weight organic matter and biopolymers fraction was reduced by 11 and 6%, respectively. It confirmed that biodegradation by microorganisms as the main removal mechanism in AOC, while BDOC has biodegradation by microorganism as well as the sorption effects from the sand. $O_3$ and $O_3+H_2O_2$ were compared with respect to biological stability and dissolved organic matter characteristics. BDOC and AOC were determined to be about 1.9 times for $O_3$ and about 1.4 times for $O_3+H_2O_2$. It was confirmed that $O_3$ enhanced the biodegradability by increasing LMW dissolved organic matter.

Effect of Dissolved Organic Matter and Cationic Surfactant on the Distribution of HOC in soil/water system (토양/수체 내 양이온 계면활성제와 용존유기물이 소수성유기화합물의 분포에 미치는 영향 연구)

  • 문정원;박재우
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • pp.281-285
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    • 2000
  • The effect of the presence of dissolved organic matters(DOM) on the binding of phenanthrene to cetylpyridinium chloride(CPC) coated sand was investigated. The distribution coefficient of phenanthrene increased with increase of sufactant coverage, and decreased with the presence of dissolved organic matters except for the 1.600mg/g coverage case. Both Aldrich humic acid and extracted dissolved organic matter showed the similar tendency. For the quantification of the overall distribution coefficient, this study presented mass distribution model and estimated the sorption equilibrium coefficients of hydrophobic organic compounds(HOCs) in multi system. The suggested model combined a series of sorption equilibrium relationships including the adsorption of DOMs on sorbents, the binding between HOCs and DOMs, and the sorption of HOCs on sorbents with or without DOMs.

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Verification of Silt Density Index (SDI) as a fouling index for reverse osmosis (RO) feed water (역삼투 공정 파울링 지표로서 SDI(Silt Density Index)의 적합성 검증)

  • Kim, Su-Han;Kim, Chung-H.;Kang, Suk-H.;Lee, Won-T.;Lim, Jae-L.
    • Journal of Korean Society of Water and Wastewater
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    • v.25 no.4
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    • pp.489-495
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    • 2011
  • Silt Density Index (SDI) has been used as a fouling index for reverse osmosis (RO) processes for decades. In order to decrease RO fouling, feed water should meet SDI standard, which was used to select a proper pretreatment system for RO processes. However, SDI is supposed to be sensitive only to particles larger than 0.45 ${\mu}m$ in terms of diameters while nanoparticles and dissolved organic matter can be potent foulants for RO processes. Our study started from the suspected performance of SDI as a RO fouling index. SDI data from pilot plants located world wide including South Korea were collected and analyzed. Suspended partcle concentration (i.e., turbidity and particle counts), and dissolved organic matter concentration (i.e., dissolved orgnaic carbon (DOC) concentration) data were also collected and compared to SDI values of same water samples. We found that SDI values were not only affected by suspended particle concentration but also by dissolved organic matter concentration. Therefore SDI can be used as a reasonable fouling index for RO feed water because the main foulants for RO processes are suspended particle and dissolved organic matter.

Dissolved Organic Matters Characteristics in Freshwater

  • Park, Je-Chul;Oh, Young-Taek;Bae, Sang-Deuk;Ryu, Dong-Kyeong
    • Proceedings of the Korea Society of Environmental Biology Conference
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    • pp.26-26
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    • 2004
  • This study was conducted to evaluate the characteristics of dissolved orgamc matters based on their origins. The dissolved organic carbon(DOC) represents an index for dissolved organic matter and basically regarded as a source of organic pollution. The monthly variations and vertical profiles of dissolved organic carbon(DOC) in Kumoh reservoir were surveyed from May 2001 to April 2002. In addition, other areas such as river, reservoir, sewage and industrial wastewater were also surveyed in summer 2001. Kumoh reservoir was divided with depth into three layers .: epilimnion, metalimnion and hypolimnion. The proportion of total DOC(T-DOC) was classified by labile DOC(L-DOC) and refractory DOC(R-DOC) on the basis of long-term incubation. DOC of freshwater and Kumoh reservoir was ranged to be 1.6~4.1 mgC/L and 2.1~4.0 mgC/L, respectively. L-DOC accounted for 3~30% of DOC from watershed. Therefore, refractory dissolved organic carbon(R-DOC) was major component of DOC in the watershed. The decomposition rate(k) ranged from 0.008 $d^{-1}$ to 0.083 $d^{-1}$ in Kumoh reservoir. The highest decomposition rate(k) was observed at River Hoein III freshwater. Therefore, modified total organic carbon analyzer is needed to be applied for effective management of dissolved organic matter.

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A Study on the Removal Characteristics of Dissolved Organic and Ammonia Compounds in PFR of Aerated Submerged Bio-film (ASBF) Reactor (PFR 공정의 ASBF 구조에 의한 유기물제거와 질산화의 영향에 대한 연구)

  • Choi, Young-Ik
    • Journal of Environmental Science International
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    • v.17 no.11
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    • pp.1265-1271
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    • 2008
  • Aerated submerged bio-film (ASBF) pilot plant has been developed. The presented studies optimized an inexpensive method of enhanced wastewater treatment. The objectives of this research were to describe pilot scale experiments for efficient removal of dissolved organic and nitrogen compounds by using ASBF reactor in plug-flow reactor (PFR) and improve understanding of dissolved organic matter and nitrogen compounds removal rates with dynamic relationships between heterotrophs and autotrophs in the fixed-film reactor. This research explores the possibility of enhancing the performance of shallow wastewater treatment lagoons through the addition of specially designed structures. This direct gas-phase contact should increase the oxygen transfer rate into the bio-film, as well as increase the micro-climate mixing of water, nutrients, and waste products into and out of the bio-film. This research also investigated the efficiency of dissolved organic matter and ammonia nitrogen removals in the ASBF. As it was anticipated, nitrification activity was highest during periods when the flow rate was lower, but it seemed to decline during times when the flow rate was highest. And ammonia nitrogen removal rates were more sensitive than dissolved organic matter removal rates when flow rates exceeded 2.2 L/min.

Study on the characterization of dissolved organic matters by XAD resin fractionation (XAD 수지분획에 의한 용존유기물질 특성 연구)

  • Park, Jeong-Min;Heo, Seong-Nam;Im, Tae-Hyo;Shin, Chan-Ki
    • Journal of environmental and Sanitary engineering
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    • v.22 no.4
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    • pp.23-32
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    • 2007
  • Changes in the characteristics of dissolved organic matter was studied at selected stations in the Nakdong river basin using physical and chemical methods. Characteristics of dissolved organic matters were analysed and assessed. Production of disinfection byproducts were also investigated. Distribution of the organic compounds according to the Molecular weight(MW) indicate that MWs higher than 100K were highest with cattle excrement wastewater and MW between 100-10K were highest with waters from forest streams. Low MW compounds (Jess than 1K) were highest with the effluents from environmental facilities. Results of resin fractionation study show that acidic hydrophobic substances(AHS) were dominant in many stations. The values were higher in the samples from mainstreams and sidestreams where the influence of organic matter is higher than the water from environmental facilities. Hydrophilic neutral substances(HoN) such as hydrocarbon, pesticides and detergents were higher in the wastewater treatment facilities. HoN values of water from the forest streams were 4.7% indicating there is no synthetic pollutant.

Effect of Operating Conditions on the Fouling of UF Membrane in Treatment of Dissolved Organic Matter (UF를 이용한 용존성 유기물질 제거시 운전조건이 파울링에 미치는 영향)

  • Kwon, Eun-Mi;Yu, Myong-Jin
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.7
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    • pp.1183-1191
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    • 2000
  • Operating conditions for reduction of membrane fouling in treatment of dissolved organic matter by UF membrane process were investigated by pilot-scale plant using various operating conditions. As inlet pressure increased, increament of transmembrane pressure and flux decline were faster. The reason was due to the increase in adsorption of dissolved organic matter and the development of cake layer compression on the membrane surface. When efficient pressure (the difference of pressure between backwash and transmembrane pressures) was high, small amount of pollutant was retained on the membrane surface. When backwash was frequently conducted, low concentration of pollutant was maintained in recycling water. Therefore, backwash could be efficiently conducted with high efficient pressure and high frequency. Fouling rate was correlated with backwash and inlet pressures, recovery rate and cumulative permeated volume. Among the operating parameters backwash pressure was most closely related to fouling rate and inlet pressure was next to backwash pressure. It seems that the fouling was strongly related to pressure which leads to the cake layer compression and adsorption of dissolved organic matter.

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C:N:P stoichiometry of particulate and dissolved organic matter in river waters and changes during decomposition

  • Islam, Mohammad Jahidul;Jang, Changwon;Eum, Jaesung;Jung, Sung-min;Shin, Myoung-Sun;Lee, Yunkyoung;Choi, Youngsoon;Kim, Bomchul
    • Journal of Ecology and Environment
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    • v.43 no.1
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    • pp.14-21
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    • 2019
  • Background: Stoichiometry plays an important role in understanding nutrient composition and cycling processes in aquatic ecosystems. Previous studies have considered C:N:P ratios constant for both DOM (dissolved organic matter) and POM (particulate organic matter). In this study, water samples were collected in the six major rivers in Korea and were incubated for 20 days. C:N:P ratios were determined during the time course of the incubations. This allowed us to examine the changes in N and P contents of organic matter during decomposition. Results: POM and DOM showed significant differences in N and P content and the elemental ratios changed during the course of decomposition; DOM showed higher C:N and C:P ratios than POM, and the C:N and C:P ratios increased during decomposition, indicating the preferential mineralization of P over N and N over C. Conclusions: The N and P contents of organic matter in aquatic ecosystem are far from constant and vary significantly during decomposition. More detailed information on the changes in C:N:P ratios will provide improved understanding of decomposition processes and improved modeling of aquatic ecosystems.