• Korean Journal of Ecology and Environment
• /
• v.45 no.1
• /
• pp.42-51
• /
• 2012

This study investigated the characteristics of natural organic matter (NOM) with general water characteristics (pH, DO, electrical conductivity, BOD, COD, TN, TP, Chl-$a$, DOC, $UV_{254}$, SUVA) and the 3D fluorescence excitation-emission matrix (FEEM) in the Yeongsan River basin. FEEM was used to classify protein-like and fulvic & humiclike substances with fluorescence intensity in the matrix of excitation and emission wavelength. The concentration of BOD, COD, TN, electrical conductivity and DOC in the region of Gwangju city (Gwangju sewage treatment plant: GJS, Gwangjucheon: GJC, Gwangju 2: GJ2) was relatively higher than the upper reaches and lower reaches of the Yeongsan River basin. SUVA in most sites was lower than 3 L $mg^{-1}\;m^{-1}$ as the hydrophilic substances, except Damyang (DY) in the upper reaches of Yeongsan river was higher than 3 L $mg^{-1}\;m^{-1}$ as the hydrophobic substances during winter and autumn. In the FEEM investigation the fulvic and humic substances were found in most sites, and in sites regarding Gwangju city (GJS, GJC, GJ2) during winter and GJC in summer, protein-like substances were found. The trend of fluorescence intensities from the upper reaches to the lower reaches in most sites corresponded to that regarding the concentration of water characteristics (BOD, COD, TN, DOC). That is why the region of Gwangju city (GJS, GJC, GJ2) was relatively higher. This results were an equivalent trend to those of fluorescence index (FI) in most sites, and the higher FIs in the sites of Gwangju city indicate more microbial-derived substances due to enormous effluent organic matters (EfOM) from huge Gwangju sewage treatment plants.

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.4
• /
• pp.377-384
• /
• 2005

Algae causes not only the eutrophication of lake, but also the deterioration of drinking water process. Especially, algogenic organic matters(AOM) are assumed as disinfection by-products(DBPs) precursors like humic and fulvic acids. In this study, it was investigated the characteristics changes of algogenic organic matter(AOM) by prechlorination and coagulation treatment. Evaluation of enhanced coagulation and applicability of UV oxidation process were also evaluated as the drinking water treatment system for the eutrophicated water source. prechlorination was effective process for algae removal but caused releasing of dissolved organic matter(DOC) into water due to the destruction of algae's cell. In coagulation treatment with Fe(III) coagulant, reaction pH is an important factor for the removal of AOM and triholomathanes(THMs). At pH 5, removal efficiency of DOC and THMs were dramatically improved by 50% and 28%, respectively, in comparison with the conventional coagulation treatment at about pH 7. Photo-Fenton($UV/H_2O_2/Fe^{3+}$) process among the UV oxidations is the most effective system to remove AOM, but its removal efficiency was lower than that of enhanced coagulation treatment at pH 5.

• Journal of Environmental Science International
• /
• v.15 no.8
• /
• pp.785-797
• /
• 2006

The formation characteristics of trihalomethanes (THMs) and haloacetic acids (HAAs) were investigated in chlorination of raw water of different organic mallet characteristics. The samples used in this study were hydrophobic (N-HPO) and hydrophilic fraction (N-HPI) (which were concentrated and separated from Nakdong river water), and humic acid (HA) (which is known as a strong hydrophobic acid) as a reference organic matter, the specific UV absorbance (SUVA) of which was 2.19, 1.15 and 7.92, respectively. With increasing chlorine contact time, THMFP and HAAFP (the formation potential of THMs and HAAs) increased, but their increase was different depending on the organic mallet characteristics (i.e., for N-HPI, THMFP was higher than HAAFP, but the inverse result was obtained for N-HPO and HA and the ratio between them was greater for HA), and the mainly formed chemical species were CHCI$_3$ in case of THMs and dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) in case of HAAs for N-HPO and HA (and the ratios of CHCI$_3$ to total THMs and DCAA and TCAA to total HAAs for HA were higher than those for N-HPO), but for N-HPI, the ratio of brominated THMs was a little higher than that of CHCI$_3$ and the ratio of DCAA and TCAA to total HAAs was lower than that of N-HPO, although they are main chemical species in case of HAAs. Comparing THMFP and HAAFP with the increase in bromide concentration added with those in not adding it, the former increased greatly and its increase was higher for the organic mallet with stronger hydrophobicity, but the latter was lower for N-HPO and N-HPI and was similar for HA. The main chemical species with increasing bromide concentration were CHBt$_3$ in case of THMs regardless of organic matter characteristics, and dibromoacetic acid (DBAA) for N-HPO and N-HPI, DBAA and tribromoacetic acid (TBAA) for HA in case of HAAs. With increasing reaction temperature and pH, THMFP and HAAFP increased for the former, but for the latter, THMFP increased and HAAFP decreased, although the rate of increase or decrease was different with organic mallet characteristics.

• Korean Journal of Soil Science and Fertilizer
• /
• v.7 no.1
• /
• pp.17-21
• /
• 1974

This study was performed to find out the organic matter content, and what is more, the relation between its content and major morphological properties of cultivated upland soils in Korea. The results were as follows. 1. The average organic matter content of cultivated upland soils was 1.73 percent, mostly ranging from 0.6 to 2.5 percent. 2. Examining the organic matter content by subgroup of cultivated upland soils. It was found 13 percent in volcanic ash yellowish brown Cambisols and 6.3 percent in Humic yellowish brown Entisols, Fluventic yellowish brown Entisols was found 1.0 percent, lowest one. The average organic matter content of Entisols, Cambisols, and Argillisols was 1.1, 2.1, and 1.8 percent respectively. 3. According to organic matter content by texture of profile, the average content of sandy soils was 1.0 percent; 1.5 percent in coarse loamy soils; and 1.8 percent in fine loamy soils. The organic matter content increased with an increased clay content in coarse texture group, but there was no significant difference between fine loamy and clayey soil group. This tendency was also observed in surface soil texture. 4. In the relation between slope and organic matter content, its content in flat area was 1.3 percent that is rather low compared to 1.6 percent of sloping area. Especially, cultivated upland soils ranging brown 15 to 30 percent in slope were 1.8 percent which is relatively high. 5. The organic matter content have nothing to do with suitability groups. Itss ontent of I, II, III, IV and V class was 1.3, 1.6, 1.7, 1.2 and 2.0 percent respectively.

• Journal of Korean Society for Atmospheric Environment
• /
• v.31 no.3
• /
• pp.239-254
• /
• 2015

Little information on HUmic-Like Substances (HULIS) in ambient particulate matter has been reported yet in Korea. HULIS makes up a significant fraction of the water-soluble organic mass in the atmospheric aerosols and influence their water uptake properties. In this study 24-hr $PM_{2.5}$ samples were collected between December 2013 and October 2014 at an urban site in Gwangju and analyzed for organic carbon (OC), elemental carbon (EC), water-soluble OC (WSOC), HULIS, and ionic species, to investigate possible sources and formation processes of HULIS. HULIS was separated using solid phase extraction method and quantified by total organic carbon analyzer. During the study period, HULIS concentration ranged from 0.19 to $5.65{\mu}gC/m^3$ with an average of $1.83{\pm}1.22{\mu}gC/m^3$, accounting for on average 45% of the WSOC (12~ 73%), with higher in cold season than in warm season. Strong correlation of WSOC with HULIS ($R^2=0.91$) indicates their similar chemical characteristics. On the basis of the relationships between HULIS and a variety of chemical species (EC, $K^+$, $NO_3{^-}$, $SO_4{^{2-}}$, and oxalate), it was postulated that HULIS observed during summer and winter were likely attributed to secondary formation and primary emissions from biomass burning (BB) and traffics. Stronger correlation of HULIS with $K^+$, which is a BB tracer, in winter ($R^2=0.81$) than in summer ($R^2=0.66$), suggests more significant contribution of BB emissions in winter to the observed HULIS. It is interesting to note that BB emissions may also have an influence on the HULIS in summer, but further study using levoglucosan that is a unique organic marker of BB emissions is required during summer. Higher correlation between HULIS and oxalate, which is mainly formed through cloud processing and/or photochemical oxidation processes, was found in the summer ($R^2=0.76$) than in the winter ($R^2=0.63$), reflecting a high fraction of secondary organic aerosol in the summer.

• Korean Journal of Environmental Agriculture
• /
• v.30 no.1
• /
• pp.16-23
• /
• 2011

BACKGROUND: This study was conducted to investigate the effects of different organic treatments and a chemical fertilizer on the soil chemical, physical, and microbial properties in an organic pear orchard. METHODS AND RESULTS: Control was referred as a NPK chemical fertilizer (15N-9P-10K) and organic treatments included compost containing with oil cake, compost containing with humic acid, and compost containing with chitin substance. All treatments applied at rates equivalent to 200 g N per tree per year under the tree canopy in March 30 of 2008 and 2009. Soil bulk density, solid phase, liquid phase, and penetration resistance were not significantly different among the treatments. Organic treatment plots had greater organic matter, total nitrogen, potassium, and magnesium concentrations compared to control, and the nutrient concentrations were not consistently affected by the organic treatments. Microbial biomass nitrogen and carbon, dehydrogenase, acid-phosphatase, and chitinase activities overall increased from March to August. Organic treatments, especially compost containing with oil cake or chitin aicd, increased the microbial variables compared to control. CONCLUSION(s): All the organic treatments consistently stimulated soil biological activity. The consistent treatment effect, however, did not occur on the soil mineral nutrition as the trees actively taken up the nutrients during a growing season, which would have diminished treatment effects. Long-term study required for evaluating soil physical properties in a pear orchard.

• Asian Journal of Atmospheric Environment
• /
• v.11 no.2
• /
• pp.96-106
• /
• 2017

In this study, measurements of size-segregated particulate matter (PM) emitted from the combustion of rice straw, pine needles, and sesame stem were conducted in a laboratory chamber. The collected samples were used to analyze amounts of organic and elemental carbon (OC and EC), water-soluble organic carbon (WSOC), humic-like substances (HULIS), and ionic species. The light absorption properties of size-resolved water extracts were measured using ultraviolet-visible spectroscopy. A solid-phase extraction method was first used to separate the size-resolved HULIS fraction, which was then quantified by a total organic carbon analyzer. The results show that regardless of particle cut sizes, the contributions of size-resolved HULIS ($=1.94{\times}HULIS-C$) to PM size fractions ($PM_{0.32}$, $PM_{0.55}$, $PM_{1.0}$, and $PM_{1.8}$) were similar, accounting for 25.2-27.6, 15.2-22.4 and 28.2-28.7% for rice straw, pine needle, and sesame stem smoke samples, respectively. The $PM_{1.8}$ fraction revealed WSOC/OC and HULIS-C/WSOC ratios of 0.51 and 0.60, 0.44 and 0.40, and 0.50 and 0.60 for the rice straw, pine needle, and sesame stem burning emissions, respectively. Strong absorption with decreasing wavelength was found by the water extracts from size-resolved biomass burning aerosols. The absorption ${\AA}ngstr{\ddot{o}}m $ exponent values of the size-resolved water extracts fitted between 300 and 400 nm wavelengths for particle sizes of $0.32-1.0{\mu}m$ were 6.6-7.7 for the rice straw burning samples, and 7.5-8.0 for the sesame stem burning samples. The average mass absorption efficiencies of size-resolved WSOC and HULIS-C at 365 nm were 1.09 (range: 0.89-1.61) and 1.82 (range: 1.33-2.06) $m^2/g{\cdot}C$ for rice straw smoke aerosols, and 1.13 (range: 0.85-1.52) and 1.83 (range: 1.44-2.05) $m^2/g{\cdot}C$ for sesame stem smoke aerosols, respectively. The light absorption of size-resolved water extracts measured at 365 nm showed strong correlations with WSOC and HULIS-C concentrations ($R^2=0.89-0.93$), indicating significant contribution of HULIS component from biomass burning emissions to the light absorption of ambient aerosols.

• Journal of Korean Society of Environmental Engineers
• /
• v.30 no.9
• /
• pp.893-899
• /
• 2008

Changes in spectroscopic characteristics and pyrene binding coefficients of terrestrial dissolved organic matters(DOM) were investigated during microbial incubation. The incubation studies were conducted for 21 days using a leaf litter DOM and a soilderived DOM with an inoculum from a river. The dissolved organic carbon(DOC), the specific UV absorbance(SUVA), the synchronous fluorescence spectra, and the pyrene organic carbon-normalized binding coefficient(K$_{oc}$) of the DOM were measured at the incubation days of 0, 3, 7, 14 and 21. After the 21-day incubation, DOC were reduced to 61% and 51% of the original concentrations of the litter DOM and the soil-derived DOM, respectively. Comparison of the spectroscopic characteristics before and after the incubation revealed that the SUVA, the fulvic-like fluorescence(FLF), the humic-like fluorescence(HLF) of the different DOM were enhanced by the incubation whereas the protein-like fluorescence(PLF) was reduced. This indicates that more aromatic and humic-like compounds were enriched during the biodegradation process while biodegradable and weak carbon structures were depleted. Irrespective of the DOM sources, SUVA values showed a positive relationship with pyrene K$_{oc}$ with a correlation coefficient of 0.97. The FLF and HLF also exhibited good correlations with K$_{oc}$ values although different regression equations were obtained from the different DOM. Our results suggest that the selected spectroscopic characteristics could be good estimation indices for the changes of the binding reactivity of DOM for hydrophobic organic contaminants during biodegradation process.

• Journal of Korean Society on Water Environment
• /
• v.24 no.1
• /
• pp.123-128
• /
• 2008

The Dissolved Organic Carbon (DOC) existing in a water includes both hydrophobic and hydrophilic substances however, most of the discussion focuses on hydrophobic substances. The hydrophobic fraction was easily removed by absorption or coagulation more than hydrophilic fraction. Therefore, control of the hydrophilic fraction is very important in water treatment process. This study is to determine the variation of DOC, the removal efficiency of DOC, and Trihalomethane formation potential (THMFP) after each stage of water treatment process by fractionating Natural Organic Matters (NOM) into hydrophobic and hydrophilic substance. DOC from raw water was fractionated at acidic pH (pH<2) using XAD 8 resin column, into two fraction : hydrophobic substance (i.e. humic substance) adsorbed on XAD 8 and hydrophilic substance which represent the organics contained in the final effluent. THMFP was carried out according to the following set condition: Cl2/DOC=4 mg/mg, incubation at $25^{\circ}C$ in darkness, pH 7 adjust with HCl or NaOH as necessary, and 72hour-contact time. THMs analyzed in this study were chloroform, bromodichloromethane, dibromochloromethan, and bromoform. Sewage was almost evenly split between the hydrophobic (56%) and hydrophilic fraction (44%). But, Aldrich humic substance (AHS) was found to contain less hydrophilics (14%) than hydrophobics (86%). The formation of THMs may depend on the source which is characterized by the composition of organic matters such as AHS and sewage. The THMFP yield of sewage and AHS were assessed as follows. The value of the THMFP reaction yield, AHS $172.65{\mu}g/mg$, is much higher than that of sewage $41.68{\mu}g/mg$. This illustrates possible significant difference in THMFP according to the component type and the proportion of organic matter existing in water source. Apparently AHS react with chlorine to produce more THMFP than do the smaller molecules found in sewage. Water treatment process may reduce THMFP, nevertheless residual DOC (the more hydrophilic substance) has significant THMFP. Further reduction in organic halide precursors requires application of alternative treatment techniques.

• Korean Journal of Environmental Agriculture
• /
• v.6 no.1
• /
• pp.7-16
• /
• 1987

A study was undertaken to investigate the absorption, translocation and metabolism of carbofuran in rice paddies. Ring-3-$^{14}C-carbofuran$ applied onto the paddy soil surface was rapidly absorbed and translocated into rice plants. Within 2 days after treatment, it was observed that carbofuran reached shoot tips and accumulated. More than 15% of total radioactivity was recovered in rice plant from 3 to 20 days after treatment. In organic soluble fraction of rice plant extract, 3-hydroxycarbofuran was the major metabolite recording 43% and 4% of total organic soluble radioactivity in shoot and root at 20 days respectively. 3-Ketocarbofuran and phenolic metabolites including carbofuran phenol, 3-hydroxycarbofuran phenol and 3-ketocarbofuran phenol were also detected in the organic soluble fractions. Some glycosidic conjugates of carbofuran metabolites were found in water soluble fraction of rice plant extract and 3-hydroxycarbofuran was the most abundant aglycone. Radioactivity in paddy soil was rapidly decreased until 3 days after treatment and then maintained almost constant level. A significant portion (42∼56 %) of the total radioactivity remained in soil as nonextractable residue from 5 to 20 days after treatment. The nonextractable radioactivity was mainly located in soil organic matter distributing in humin, fulvic acid and humic acid fractions with the decreasing order. Evolution of $^{14}CO_2$ from ring cleavage of $3-^{14}C-carbofuran$ was negligible recording only 1.8% of total radioactivity during 20 days after treatment.