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Kang P.-G.,Han River Environment Research Center | Kang P.-G.,New York University | Mitchell M.J.,New York University
Biogeochemistry | Year: 2013

The heterogeneity of DOM is closely linked with the various sources and the diversity of biogeochemical processes. We studied the spatial and temporal patterns of the quantity (bioavailable [B-] and refractory concentrations by laboratory incubations) and quality (δ13C, aromaticity, and size-fraction by ultrafiltration [low molecular weight (LMW) < 1 kDa and high molecular weight (HMW) > 1 kDa]) of dissolved organic C (DOC), N (DON), and S (DOS) for surface waters (two upland streams, two wetland-affected streams, and lake outlet) over a 14-month period within the Arbutus Lake watershed in the Adirondack Mountains of New York State, USA. The % BDOC and % BDON of this watershed averages ranged from 6 to 18 % and from 12 to 43 %, respectively. The DOC and DON concentrations increased as water was transported through wetland areas of the Arbutus Lake watershed. DOC and DON constituents in the surface waters passing through a wetland were composed mostly of refractory HMW components (% HMWDOC: 55 %, % HMWDON: 60 %) with a higher level of aromaticity compared to upland streams (% HMWDOC: approximately 35 %, % HMWDON: approximately 30 %). DOS was dominated by the refractory (% BDOS range 6-13 %) and LMW (% LMWDOS range 62-96 %) form and we suggest that bacterial dissimilatory sulfate reduction might play an important role in generating this distinct DOS biogeochemistry. The aromaticity was positively related to total DOC concentration, but negatively to % BDOC. Arbutus Lake DOM was dominated by bioavailable and LMW characteristics, compared to wetland-affected streams where refractory and HMW DOM fractions were more prevalent. Our study suggests the different variability of DOM characteristics among elements (C, N, S) using a "bioavailability-molecular size model" showing a diagenetic perspective due to the relative refractoriness of the LMW DOS. This study also highlights the importance of multiple approaches for understanding DOM biogeochemistry with respect to molecular size, bioavailability, aromaticity, stoichiometry, isotopic values, and elemental concentrations. © 2013 Springer Science+Business Media Dordrecht. Source


Kim H.-C.,Sejong University | Shin J.,Korea Institute of Science and Technology | Shin J.,Korea University | Won S.,Han River Environment Research Center | And 3 more authors.
Water Research | Year: 2015

A fermentative strategy with an anaerobic moving bed biofilm reactor (AMBBR) was used for the treatment of domestic wastewater. The feasibility of using a membrane separation technique for post-treatment of anaerobic bio-effluent was evaluated with emphasis on employing a membrane distillation (MD). Three different hydrophobic 0.2μm membranes made of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), and polypropylene (PP) were examined in this study. The initial permeate flux of the membranes ranged from 2.5 to 6.3Lm-2h-1 when treating AMBBR effluent at a temperature difference between the feed and permeate streams of 20°C, with the permeate flux increasing in the order PP98% rejection of dissolved organic carbon was also achieved. The characterization of wastewater effluent organic matter (EfOM) using an innovative suite of analytical tools verified that almost all of the EfOM was rejected via the PVDF MD treatment. © 2015 Elsevier Ltd. Source


Kim J.,Korea Institute of Science and Technology | Shin J.,Korea Institute of Science and Technology | Shin J.,Korea University | Kim H.,Korea Institute of Science and Technology | And 6 more authors.
Bioresource Technology | Year: 2014

Despite significant research efforts over the last few decades, membrane fouling in anaerobic membrane bioreactors (AnMBRs) remains an unsolved problem that increases the overall operational costs and obstructs the industrial applications. Herein, we developed a method for effectively controlling the membrane fouling in a sponge-submerged AnMBRs using an anaerobic rotary disk MBR (ARMBR). The disk rotation led the effective collision between the sponge and membrane surface; thus successfully enhanced the membrane permeability in the ARMBR. The effect of the disk rotational speed and sponge volume fraction on the membrane permeability and the relationship between the water flow direction and membrane permeability were investigated. The long-term feasibility was tested over 100. days of synthetic wastewater treatment. As a result, stable and economical performance was observed without membrane replacement and washing. The proposed integrated rotary disk-supporting media appears to be a feasible and even beneficial option in the AnMBR technology. © 2014 Elsevier Ltd. Source


Kim G.,Hannam University | Lee H.,Daehakro | Lim Y.,Chungbuk Research Institute | Jung M.,Han River Environment Research Center | Kong D.,Han River Environment Research Center
Water Science and Technology | Year: 2010

It is a well-known fact that baseflow discharge of rainfall runoff significantly impacts the quality of surface water. In this paper, the impact of nitrates discharged as baseflow on stream water quality were studied using PULSE, a hydrograph separation software developed by USGS, to calculate the monthly baseflow discharge. We took water quality and flow rate data from a monitoring station site (code: Ghapcehon2) in Daejeon city and acquired 2005 groundwater quality data in the watershed from government agencies. Agricultural and forestry land use are dominant in the area. The baseflow contributes 85%-95% of stream flows during the spring and fall, 25%-38% during the summer and winter. The monthly nitrate loading discharged as baseflow for Ghapcheon2 was estimated by using monitored nitrate concentrations of groundwater in the watershed. Nitrate loading induced by baseflow at Ghapcheon2 was estimated as 5.4 tons of NO3 --N/km2, which is about 60% of nitrate loading of surface water, or 9.2 tons of NO3 --N/km2. This study shows that groundwater quality monitoring is important for proper management of surface water quality. © IWA Publishing 2010. Source


Park M.,Han River Environment Research Center | Park M.-H.,University of Massachusetts Amherst
Journal - American Water Works Association | Year: 2015

Contaminants of emerging concern (CECs) are raising public awareness because of their potential effect on aquatic ecosystems and public health. For this study, the authors applied spatial analyses to four selected US watersheds to identify critical areas susceptible to CECs and used watershed characteristics (i.e., potential source distribution, land use, climatic and hydrologic conditions) to prioritize the types of CECs. The results identified sub-basins where major wastewater treatment plants are located as critical areas for potential CEC point source pollution in general. Sub-basins containing intensive agricultural activities with high precipitation greatly contributed to CEC pollution, especially during wet-weather periods. The rank of prioritized prescribed pharmaceutical groups was similar for most watersheds because of the association between pharmaceutical groups and population demographics. Prioritized pesticide types were dependent on the type and areas of crops and urban yards in each watershed. This study demonstrates the utility of using spatial analysis for effectively assessing CECs in watersheds, which is important for the implementation of monitoring and management strategies. 2015 © American Water Works Association. Source

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