Source Tracking Of Dissolved Organic Nitrogen At Molecular Level During Storm Events In An Agricultural Watershed

Most Shirina Begum(Begum Most Shirina),Jin Hur(허진),Seung Yoon Lee(이승윤) 대한환경공학회 2021 대한환경공학회 학술발표논문집 Vol.2021 No.11

Synergistic effects of urban tributary mixing on dissolved organic matter biodegradation in an impounded river system

Begum, Most Shirina,Jang, Inae,Lee, Jung-Min,Oh, Han Bin,Jin, Hyojin,Park, Ji-Hyung Elsevier 2019 The Science of the total environment Vol.676 No.-

<P><B>Abstract</B></P> <P>Dams and wastewater may greatly perturb riverine fluxes of dissolved organic matter (DOM) and CO<SUB>2</SUB>, yet little is known about the relationships between altered DOM quality and CO<SUB>2</SUB> emission in eutrophic impounded river systems. A basin-wide field survey of surface water CO<SUB>2</SUB> and dissolved organic carbon (DOC) was combined with laboratory incubations to examine how dams and urban tributaries delivering treated wastewater influence longitudinal patterns in DOM properties and CO<SUB>2</SUB> along the impounded Han River traversing Seoul metropolitan area. Fluorescent DOM indices including parallel factor analysis (PARAFAC) components were used to characterize DOM in relation to biodegradable DOC (BDOC). Compared with distinct downstream increases in DOC and CO<SUB>2</SUB>, BDOC concentration and its proportion in DOC (%BDOC) were highly variable along the mainstem and peaked at urban tributaries. Longitudinal increases in fluorescence index (FI), biological index (BIX), and two PARAFAC components (C2 and C3) contrasted with general decreases in humification index (HIX) and C1, reflecting increasing downstream inputs of anthropogenic DOM. During a 5-day incubation employing continuous CO<SUB>2</SUB> measurements, the cumulative production of CO<SUB>2</SUB> in the mainstem water mixed with urban tributary water was significantly higher than the level expected for conservative mixing of the two samples, indicating a synergistic enhancement of DOM biodegradation. Molecular formulas identified by Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR-MS) revealed more consumed molecules in the mainstem water and more newly produced molecules in the tributary water over the 5-day incubation, implying abundant labile components in the mainstem water discharged from the upstream dam and highly processed tributary DOM limited in immediately biodegradable organic materials. Downstream increases in CO<SUB>2</SUB> and DOC along the Han River, combined with the synergistic effect observed in the mixed water, suggest that mixing wastewater-derived DOM with labile autochthonous DOM can enhance CO<SUB>2</SUB> production in the river system perturbed by impoundment and wastewater.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Field survey was combined with lab incubations to study human impact on river carbon. </LI> <LI> Dissolved organic matter and CO<SUB>2</SUB> vary along impounded river with wastewater influence. </LI> <LI> Urban tributary mixing enhances organic matter degradation and CO<SUB>2</SUB> in impounded river. </LI> <LI> FT-ICR-MS detects organic matter degradation in impounded river and urban tributary. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

CO₂ Outgassing from an Urbanized River System Fueled by Wastewater Treatment Plant Effluents

Yoon, Tae Kyung,Jin, Hyojin,Begum, Most Shirina,Kang, Namgoo,Park, Ji-Hyung American Chemical Society 2017 Environmental science & technology Vol.51 No.18

<P>Continuous underway measurements were combined with a basin-scale survey to examine human impacts on CO2 outgassing in a highly urbanized river system in Korea. While the partial pressure of CO2 (pCO(2)) was measured at 15 sites using syringe equilibration, 3 cruises employing an equilibrator were done along a 30 km transect in the Seoul metropolitan area. The basin-scale survey revealed longitudinal increases in surface water pCO(2) and dissolved organic carbon (DOC) in the downstream reach. Downstream increases in pCO(2), DOC, fluorescence index, and inorganic N and P reflected disproportionately large contributions from wastewater treatment plant (WWTP) effluents carried by major urban tributaries. Cruise transects exhibited strong localized peaks of pCO(2) up to 13 000 mu atm and (CO2)-C-13 enrichment along the confluences of tributaries at an average flow, whereas CO2 pulses were dampened by increased flow during the monsoon period. Fluctuations in pCO(2) along the eutrophic reach downstream of the confluences reflected environmental controls on the balance between photosynthesis, biodegradation, and outgassing. The results underscore WWTP effluents as an anthropogenic source of nutrients, DOC, and CO2 and their influences on algal blooms and associated C dynamics in eutrophic urbanized river systems, warranting further research on urbanization induced perturbations to riverine metabolic processes and carbon fluxes.</P>

Longitudinal discontinuities in riverine greenhouse gas dynamics generated by dams and urban wastewater

Jin, Hyojin,Yoon, Tae Kyung,Begum, Most Shirina,Lee, Eun-Ju,Oh, Neung-Hwan,Kang, Namgoo,Park, Ji-Hyung Copernicus GmbH 2018 Biogeosciences Vol.15 No.20

<P><p><strong>Abstract.</strong> Surface water concentrations of <span class='inline-formula'>CO₂</span>, <span class='inline-formula'>CH₄</span>, and <span class='inline-formula'>N₂O</span> have rarely been measured simultaneously in river systems modified by human activities, contributing to large uncertainties in estimating global riverine emissions of greenhouse gases (GHGs). Basin-wide surveys of the three GHGs were combined with a small number of measurements of C isotope ratios in dissolved organic matter (DOM), <span class='inline-formula'>CO₂</span>, and <span class='inline-formula'>CH₄</span> in the Han River basin, South Korea, to examine how longitudinal patterns of the three gases and DOM are affected by four cascade dams along a middle section of the North Han River (hereafter termed “middle reach”) and treated wastewater discharged to the lower Han River (“lower reach”) traversing the Seoul metropolitan area. Monthly monitoring and two-season comparison were conducted at 6 and 15 sites, respectively, to measure surface water gas concentrations and ancillary water quality parameters including concentrations of dissolved organic carbon (DOC) and optical properties of DOM. The basin-wide surveys were complemented with a sampling cruise along the lower reach and synoptic samplings along an urban tributary delivering effluents from a large wastewater treatment plant (WWTP) to the lower reach. The levels of <span class='inline-formula'><i>p</i>CO₂</span> were relatively low in the middle reach (51-2465<span class='thinspace'></span><span class='inline-formula'>µ</span>atm), particularly at the four dam sites (51-761<span class='thinspace'></span><span class='inline-formula'>µ</span>atm), compared with those found in the largely forested upper basin with scattered patches of croplands (163-2539<span class='thinspace'></span><span class='inline-formula'>µ</span>atm), the lower reach (78-11298<span class='thinspace'></span><span class='inline-formula'>µ</span>atm), and three urban tributaries (2120-11970<span class='thinspace'></span><span class='inline-formula'>µ</span>atm). The upper and middle reaches displayed generally low concentration ranges of <span class='inline-formula'>CH₄</span> and <span class='inline-formula'>N₂O</span>, with some local peaks influenced by agricultural runoff and impoundments. By comparison, the lower reach exhibited exceptionally high concentrations of <span class='inline-formula'>CH₄</span> (1.2-15766<span class='thinspace'></span>nmol<span class='thinspace'></span>L<span class='inline-formula'>⁻¹)</span> and <span class='inline-formula'>N₂O</span> (7.5-1396<span class='thinspace'></span>nmol<span class='thinspace'></span>L<span class='inline-formula'>⁻¹)</span>, which were significantly correlated with different sets of variables such as DO and <span class='inline-formula'><math xmlns='http://www.w3.org/1998/Math/MathML' id='M18' display='inline' overflow='scroll' dspmath='mathml'><mrow class='chem'><msubsup><mi mathvariant='normal'>PO</mi><mn mathvariant='normal'>4</mn><mrow><mn mathvariant='normal'>3</mn><mo>-</mo></mrow></msubsup></mrow></math><span><svg:svg xmlns:svg='http://www.w3.org/2000/svg' width='29pt' height='17pt' class='svg-formula' dspmath='mathimg' md5hash='be398bd0f0b069243c3f6f0b1b183fcd'><svg:image xmlns:xlink='http://www.w3.org/1999/xlink' xlink:href='bg-15-6349-2018-ie00001.svg' width='29pt' height='17pt' src='bg-15-6349-2018-ie00001.png'/></svg:svg></span></span> for <span class='inline-formula'>CH₄</span> and <span class='inline-formula'><math xmlns='http://www.w3.org/1998/Math/MathML' id='M20' display='inline' overflow='scroll' dspmath='mathml'><mrow class='chem'><msubsup><mi mathvariant='normal'>NH</mi><mn mathvariant='normal'>4</mn><mo>+</mo></msubsup></mrow></math><span>

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허진(Jin Hur),박호연(Hoyeon Park),배경록(Kyungrok Bae),Shirina(Most Shirina Begum),신현상(Hyunsang Shin),이병준(Byungjoon Lee),전강민(Kangmin Chon) 대한환경공학회 2022 대한환경공학회 학술발표논문집 Vol.2022 No.11