107 results on '"Sung-Kyu Maeng"'
Search Results
2. Fate of Effluent Organic Matter During Bank Filtration
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Sung Kyu Maeng
- Published
- 2023
3. Introduction
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Sung Kyu Maeng
- Published
- 2023
4. Occurrence and Fate of Bulk Organic Matter and Pharmaceutically Active Compounds in Managed Aquifer Recharge
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Sung Kyu Maeng
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- 2023
5. Framework for Assessment of Organic Micropollutants Removals During Managed Aquifer Recharge
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Sung Kyu Maeng
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- 2023
6. Role of Biodegradation in the Removal of Pharmaceutically Active Compounds During Bank Filtration
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Sung Kyu Maeng
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- 2023
7. Organic Micropolluutant Removal from Wastewater Effluent-Impacted Drinking Water Sources During Bank Filtration and Artificial Recharge
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Sung Kyu Maeng
- Published
- 2023
8. Summary and Conclusions
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Sung Kyu Maeng
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- 2023
9. Multiple Objective Treatment Aspects of Bank Filtration
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Sung Kyu Maeng
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- 2023
10. Impact of Sonication on Algal Organic Matter Characteristics of Anabaena Circinalis, Microcystis Aeruginosa, and Chlorella Vulgaris
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Tien Dang Anh, Huyen Duong Thi, Ji Won Park, Sang Yeob Kim, Jae Woo Lee, and Sung Kyu Maeng
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- 2023
11. Biomass formation and organic carbon migration potential of microplastics from a PET recycling plant: Implication of biostability
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Huyen Duong Thi, Sang Yeob Kim, Sang-Yeop Jung, Heejong Son, Seungdae Oh, and Sung Kyu Maeng
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Environmental Engineering ,Health, Toxicology and Mutagenesis ,Environmental Chemistry ,Pollution ,Waste Management and Disposal - Published
- 2023
12. Impact of sonication on the algal organic matter characteristics of Anabaena circinalis, Microcystis aeruginosa, and Chlorella vulgaris
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Anh Tien Dang, Thi Huyen Duong, Ji-won Park, Sang-Yeob Kim, Jae Woo Lee, and Sung Kyu Maeng
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Process Chemistry and Technology ,Chemical Engineering (miscellaneous) ,Pollution ,Waste Management and Disposal - Published
- 2023
13. Biological detoxification of oxytetracycline using Achromobacter-immobilized bioremediation system
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Hiep T. Nguyen, Sharf Ilahi Siddiqui, Sung Kyu Maeng, and Seungdae Oh
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Process Chemistry and Technology ,Safety, Risk, Reliability and Quality ,Waste Management and Disposal ,Biotechnology - Published
- 2023
14. Occurrences and changes in bacterial growth-promoting nutrients in drinking water from source to tap: a review
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Thi Huyen Duong, Sang-Yeop Chung, Jin Hyung Noh, Ji-Won Park, Seungdae Oh, Sung Kyu Maeng, Heejong Son, and Emmanuelle Prest
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Total organic carbon ,Environmental Engineering ,Nutrient ,Environmental chemistry ,Environmental science ,Water treatment ,Groundwater recharge ,Bacterial growth ,Algal bloom ,Surface water ,Groundwater ,Water Science and Technology - Abstract
Biostable drinking water, which limits bacterial growth and community changes, is obtained by removing bacterial growth-promoting nutrients, such as assimilable organic carbon (AOC), through a range of treatment processes. To date, various controlled laboratory bacterial growth tests have been developed using different inoculum types to study the growth-promoting nutrients in water. However, many countries have not considered limiting bacterial growth by reducing the growth-promoting nutrients in drinking water, because they primarily use chlorine in their distribution systems. This review provides an overview of the available methods to analyze dissolved growth-promoting nutrients in water and summarizes the current knowledge on nutrient characteristics and concentrations in water from source to tap, through various treatment processes. Bacterial growth-promoting nutrients in surface water are affected by seasonal variables, such as water temperature, precipitation, and algal blooms. The use of groundwater, bank filtration, and artificial recharge of water sources provide low bacterial growth-promoting nutrient concentrations in drinking water. The treatment type as well as operational conditions significantly affect biostable drinking water production. To achieve water biostability, it is important to understand not only the water treatment process but also the distribution conditions, including the impact of pipe materials on the nutrient levels in water. The impact of climate change on biostability as well as the role of complex and particle bound nutrients on microbial growth in drinking water distribution systems should be investigated in future studies.
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- 2021
15. Potential organic matter management for industrial wastewater guidelines using advanced dissolved organic matter characterization tools
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Sang Yeob Kim, Ji Won Park, Jin Hyung Noh, Young Ho Bae, and Sung Kyu Maeng
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Industrial wastewater ,Discharge standards ,Process Chemistry and Technology ,Total organic carbon ,Chemical oxygen demand ,Safety, Risk, Reliability and Quality ,Waste Management and Disposal ,Biotechnology - Abstract
Since 2021, national standards of South Korea for industrial wastewater discharge to surface water have changed from chemical oxygen demand to total organic carbon for the organic matter. Conventional organic matter parameters (e.g., biochemical oxygen demand, chemical oxygen demand and total organic carbon) are limited means of understanding the behavior of dissolved organic matter in industrial wastewater treatment processes. Thus, the current study used advanced dissolved organic matter characterization tools (e.g., fluorescence excitation emission matrix and size exclusion chromatography-organic carbon detection) to scrutinize industrial wastewater characteristics from three full-scale industrial wastewater treatment plants (IWTPs). The tools were conducive to tracking industrial wastewater sources of total organic carbon, influencing the overall performance of IWTPs, and proposing alternative processes to lower total organic carbon concentration in the effluent. The results of this study suggest that the diagnosis of IWTPs based on dissolved organic matter characteristics could be a useful tool for providing more insight into total organic carbon management.
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- 2022
16. Effects of N-Acyl Homoserine Lactone on Immobilized Scenedesmus Quadricauda Bead Using Ca-Alginate
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Seon-Won Yoon, Jin Hyung Noh, Ji Won Park, Sang Yeob Kim, Yun Lee, Byeong Gyu Choi, and Sung Kyu Maeng
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- 2022
17. Influence of algal organic matter on the attenuation of selected trace organic contaminants and dissolved organic matter in managed aquifer recharge: column studies
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Soo Hyun So, Ji-Won Park, Sung Kyu Maeng, and Jin Hyung Noh
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chemistry.chemical_classification ,Total organic carbon ,Environmental Engineering ,biology ,0208 environmental biotechnology ,02 engineering and technology ,Groundwater recharge ,010501 environmental sciences ,Biodegradation ,Contamination ,biology.organism_classification ,01 natural sciences ,Algal bloom ,020801 environmental engineering ,chemistry ,Environmental chemistry ,Dissolved organic carbon ,otorhinolaryngologic diseases ,Microcystis aeruginosa ,Organic matter ,0105 earth and related environmental sciences ,Water Science and Technology - Abstract
In this study, the effects of algal organic matter (AOM) from Microcystis aeruginosa on the attenuation of selected trace organic contaminants (TrOCs) were observed in managed aquifer recharge using laboratory scale soil columns. Changes in dissolved organic matter and bacteriological characteristics were also investigated to elucidate the performance of managed aquifer recharge during algal bloom. AOM exhibited a high ratio of biopolymers and low molecular weight neutrals in dissolved organic matter. Dissolved organic matter was effectively removed even after the addition of AOM (4 mg L−1) in the feed water during soil passage; however, the removal rate was significantly reduced under abiotic conditions, confirming that the main removal mechanisms of dissolved organic matter involve biodegradation. AOM exhibited a much higher ratio of assimilable organic carbon/dissolved organic carbon than river water. Attenuation of four hydrophilic acid TrOCs (diclofenac, bezafibrate, ibuprofen, and ketoprofen) was significantly reduced in the presence of AOM during soil passage, but neutral TrOCs were not affected by AOM. It was difficult to remove carbamazepine using managed aquifer recharge. AOM influenced the attenuation of gemfibrozil, diclofenac, bezafibrate, ibuprofen, ketoprofen, carbamazepine, pentoxifylline, and phenacetin even after ozonation, followed by soil passage. Thus, it is important to monitor the removal of some TrOCs in managed aquifer recharge during algal blooms.
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- 2020
18. Characterization of natural organic matter and assimilable organic carbon from an advanced full-scale drinking water treatment plant to tap
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Sung Kyu Maeng, Woo-hyeun Joe, and Ji-Won Park
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Total organic carbon ,Chemistry ,Environmental chemistry ,Full scale ,Water treatment ,Natural organic matter ,Characterization (materials science) - Published
- 2020
19. Water quality analyses between tap water and treated water by point-of-use water dispenser systems
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Kim, Sungpyo, Yeong Na, Jaehyeok Kim, Keun-Young Park, Ji-Won Park, Sung Kyu Maeng, and Ji Hyang Kweon
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Tap water ,Water cooler ,Treated water ,Environmental engineering ,Environmental science ,Point (geometry) ,Water quality ,Reverse osmosis - Published
- 2019
20. Effects of N-acyl homoserine lactone on immobilized Scenedesmus quadricauda bead using Ca-alginate for wastewater treatment
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Seon-Won Yoon, Jin-Hyung Noh, Ji-Won Park, Sang-Yeob Kim, Yun Lee, Byeong-Gyu Choi, and Sung-Kyu Maeng
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Process Chemistry and Technology ,Safety, Risk, Reliability and Quality ,Waste Management and Disposal ,Biotechnology - Published
- 2022
21. A shift from chemical oxygen demand to total organic carbon for stringent industrial wastewater regulations: Utilization of organic matter characteristics
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Ji Won Park, Sang Yeob Kim, Jin Hyung Noh, Young Ho Bae, Jae Woo Lee, and Sung Kyu Maeng
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Biological Oxygen Demand Analysis ,Environmental Engineering ,Industrial Waste ,General Medicine ,Management, Monitoring, Policy and Law ,Wastewater ,Dissolved Organic Matter ,Waste Management and Disposal ,Waste Disposal, Fluid ,Carbon ,Water Pollutants, Chemical - Abstract
From 2022, industrial wastewater discharge regulations in South Korea will replace chemical oxygen demand (COD
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- 2021
22. Lab experiments on hybridization of managed aquifer recharge with river water via sand column, pre-oxidation, and nanofiltration
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Woo Hyuck Bang, Thi Huyen Duong, Gyoo-Bum Kim, and Sung Kyu Maeng
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Environmental Engineering ,Ozone ,Health, Toxicology and Mutagenesis ,Public Health, Environmental and Occupational Health ,chemistry.chemical_element ,Water ,General Medicine ,General Chemistry ,Groundwater recharge ,Contamination ,Pollution ,River water ,Water Purification ,chemistry.chemical_compound ,Potassium permanganate ,chemistry ,Rivers ,Sand ,Environmental chemistry ,Dissolved organic carbon ,Chlorine ,Environmental Chemistry ,Nanofiltration ,Groundwater ,Water Pollutants, Chemical - Abstract
A hybridization of managed aquifer recharge (MAR) with pre-oxidation processes was conducted in this study to investigate changes in dissolved organic matter characteristics and the attenuation of selected trace organic contaminants (TrOCs). Potassium permanganate, chlorine, and ozone treatments were used for pre-oxidation, which effectively attenuated some TrOCs, particularly the combination of MAR with ozone achieved 84-99% attenuation. The pre-oxidation step using potassium permanganate showed high removal of carbamazepine (96%). Moreover, MAR was also combined with nanofiltration (NF) as a multi-barrier concept for the removal of persistent TrOCs after MAR. A short-chain polyfluoroalkyl substance (PFAS) was effectively removed after combining MAR columns with NF membranes. Thus, pre-oxidation coupled with MAR followed by NF could potentially enhance the removal of selected TrOCs.
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- 2021
23. Intermittent water supply impacts on distribution system biofilms and water quality
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Gonzalo Del Olmo, Stewart Husband, Sung Kyu Maeng, Víctor Soria-Carrasco, Isabel Douterelo, Joby Boxall, and Carolina Calero Preciado
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Environmental Engineering ,Microorganism ,0208 environmental biotechnology ,Water supply ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Distribution system ,Water Supply ,Water Quality ,Ecosystem ,Turbidity ,Waste Management and Disposal ,Biofilm growth ,0105 earth and related environmental sciences ,Water Science and Technology ,Civil and Structural Engineering ,business.industry ,Drinking Water ,Ecological Modeling ,Biofilm ,Pulp and paper industry ,Pollution ,020801 environmental engineering ,Biofilms ,Environmental science ,Water quality ,Water Microbiology ,business - Abstract
Intermittent water supplies (IWS) are routinely experienced by drinking water distribution systems around the world, either due to ongoing operational practices or due to one off interruptions. During IWS events changing conditions may impact the endemic biofilms leading to hydraulic mobilisation of organic and inorganic materials attached to pipes walls with a resulting degradation in water quality. To study the impact of IWS on the microbiological and physico-chemical characteristics of drinking water, an experimental full-scale chlorinated pipe facility was operated over 60 days under realistic hydraulic conditions to allow for biofilm growth and to investigate flow resumption behaviour post-IWS events of 6, 48 and 144 hours.\ud \ud \ud \ud Turbidity and metal concentrations showed significant responses to flow restarting, indicating biofilm changes, with events greater than 6 hours generating more turbidity responses and hence discolouration risk. The increase in pressure when the system was restarted showed a substantial increase in total cell counts, while the subsequent increases in flow led to elevated turbidity and metals concentrations. SUVA254 monitoring indicated that shorter times of non-water supply increased the risk of aromatic organic compounds and hence risk of disinfection-by-products formation. DNA sequencing indicated that increasing IWS times resulted in increased relative abundance of potential pathogenic microorganisms, such as Mycobacterium, Sphingomonas, and the fungi Penicillium and Cladosporium.\ud \ud \ud \ud Overall findings indicate that shorter IWS result in a higher proportion of aromatic organic compounds, which can potentially react with chlorine and increase risk of disinfection-by-products formation. However, by minimising IWS times, biofilm-associated impacts can be reduced, yet these are complex ecosystems and much remains to be understood about how microbial interactions can be managed to best ensure continued water safe supply.
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- 2021
24. Effects of biochar addition on the fate of ciprofloxacin and its associated antibiotic tolerance in an activated sludge microbiome
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Seungdae Oh, Youngjun Kim, Donggeon Choi, Ji Won Park, Jin Hyung Noh, Sang-Yeop Chung, Sung Kyu Maeng, and Chang-Jun Cha
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Sewage ,Ciprofloxacin ,Charcoal ,Microbiota ,RNA, Ribosomal, 16S ,Health, Toxicology and Mutagenesis ,General Medicine ,Toxicology ,Pollution ,Anti-Bacterial Agents - Abstract
This study investigated the effects of adding biochar (BC) on the fate of ciprofloxacin (CIP) and its related antibiotic tolerance (AT) in activated sludge. Three activated sludge reactors were established with different types of BC, derived from apple, pear, and mulberry tree, respectively, and one reactor with no BC. All reactors were exposed to an environmentally relevant level of CIP that acted as a definitive selective pressure significantly promoting AT to four representative antibiotics (CIP, ampicillin, tetracycline, and polymyxin B) by up to two orders of magnitude. While CIP removal was negligible in the reactor without BC, the BC-dosed reactors effectively removed CIP (70-95% removals) through primarily adsorption by BC and biodegradation/biosorption by biomass. The AT in the BC-added reactors was suppressed by 10-99%, compared to that without BC. The BC addition played a key role in sequestering CIP, thereby decreasing the selective pressure that enabled the proactive prevention of AT increase. 16S rRNA gene sequencing analysis showed that the BC addition alleviated the CIP-mediated toxicity to community diversity and organisms related to phosphorous removal. Machine learning modeling with random forest and support vector models using AS microbiome data collectively pinpointed Achromobacter selected by CIP and strongly associated with the AT increase in activated sludge. The identification of Achromobacter as an important AT bacteria revealed by the machine learning modeling with multiple models was also validated with a linear Pearson's correlation analysis. Overall, our study highlighted Achromobacter as a potential useful sentinel for monitoring AT occurring in the environment and suggested BC as a promising additive in wastewater treatment to improve micropollutant removal, mitigate potential AT propagation, and maintain community diversity against toxic antibiotic loadings.
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- 2022
25. Comparison of pre-oxidation between O3 and O3/H2O2 for subsequent managed aquifer recharge using laboratory-scale columns
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Se Hee Park, Seunghak Lee, Jaewon Choi, Hyun-Chul Kim, Jin Hyung Noh, and Sung Kyu Maeng
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Urban surface ,021110 strategic, defence & security studies ,Environmental Engineering ,Ozone ,Health, Toxicology and Mutagenesis ,0211 other engineering and technologies ,02 engineering and technology ,Groundwater recharge ,010501 environmental sciences ,Laboratory scale ,Contamination ,Pretreatment method ,01 natural sciences ,Pollution ,chemistry.chemical_compound ,Trihalomethane ,chemistry ,Environmental chemistry ,Dissolved organic carbon ,Environmental Chemistry ,Environmental science ,Waste Management and Disposal ,0105 earth and related environmental sciences - Abstract
A hybrid process of managed aquifer recharge with pre-oxidation was investigated as part of a multiple-barrier approach for safe water production. This study evaluated O3 and O3/H2O2 for the pre-oxidation of urban surface water prior to managed aquifer recharge (MAR) and compared their effectiveness with respect to trace organic contaminants (TrOCs), biostability, and trihalomethane formation potential. The combination of pre-oxidation and MAR was performed using long-term column studies, and the results confirmed the removal of 64 and 56% dissolved organic carbon by using O3 and O3/H2O2, respectively. MAR combined with O3 and O3/H2O2 achieved >50% removal of dissolved organic carbon with the first 5 days of residence time. O3 alone showed better performance in alleviating trihalomethane formation potential during chlorination compared to using O3/H2O2. The pre-oxidation of urban surface water was effective in attenuating selected TrOCs (35 - >99% removal), and subsequent MAR achieved >99% removal of selected TrOCs within the first 5 days, regardless of pretreatment methods examined in this study. The results of this study provide an understanding of the effects of O3 and O3/H2O2 as pre-oxidation processes on urban surface water prior to MAR, as well as the resulting impact on MAR.
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- 2019
26. Reducing bacterial aerosol emissions from membrane bioreactors: The impact of SRT and the addition of PAC and calcium
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Sung Kyu Maeng, Soohoon Choi, Han Yong Kim, Jin Hyung Noh, and Hanna Choi
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Powdered activated carbon treatment ,Environmental Engineering ,chemistry.chemical_element ,Calcium ,Membrane bioreactor ,complex mixtures ,Bioreactors ,Bioreactor ,Waste Management and Disposal ,Water Science and Technology ,Civil and Structural Engineering ,Aerosols ,Sewage ,Chemistry ,Ecological Modeling ,Membranes, Artificial ,respiratory system ,Particulates ,Pollution ,Aerosol ,Charcoal ,Environmental chemistry ,Particle size ,Powders ,Aeration - Abstract
Bacterial aerosols resulting from membrane bioreactor (MBR) processes, which require excessive aeration in a confined space, are important to investigate because of their possible adverse effects on human health. This study investigated the influence of solid retention time (SRT) on bacterial aerosols from MBRs. Moreover, powdered activated carbon (PAC) and calcium were used to attenuate bacterial aerosol emissions from MBRs. The particulate matter (PM) emitted from the MBRs was reduced by 30.5 and 25.2% at SRTs of 20 and 80 d, respectively, compared to the level emitted at an SRT of 10 d. Total cell counts were similarly reduced at SRTs of 20 and 80 d. Longer SRTs also led to greater reductions in the particle size distribution of the sludge within 10 μm. Several factors in the MBR influenced the behavior of the bacterial aerosol emissions from the MBRs. This study showed that changes in viscosity and particle size induced by the SRT influenced the bacterial aerosol emissions in MBRs. Therefore, SRT was identified as an important design parameter affecting bacterial aerosol emissions in MBR processes. The amounts of particulate matter and bacterial aerosols were reduced in MBRs using PAC and calcium, both of which exerted an immediate effect on the bacterial aerosol emissions in MBRs by increasing the aerosol-particle size.
- Published
- 2019
27. Effects of hydraulic loading rate and organic load on the performance of a pilot-scale hybrid VF-HF constructed wetland in treating secondary effluent
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Yeonsung Jung, Seunghak Lee, Ji-Won Park, Woo Hyuck Bang, and Sung Kyu Maeng
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Environmental Engineering ,Denitrification ,Health, Toxicology and Mutagenesis ,0208 environmental biotechnology ,chemistry.chemical_element ,Pilot Projects ,02 engineering and technology ,Wastewater ,010501 environmental sciences ,Waste Disposal, Fluid ,01 natural sciences ,Dissolved organic carbon ,Environmental Chemistry ,Organic matter ,Effluent ,Humic Substances ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,Total organic carbon ,Suspended solids ,Public Health, Environmental and Occupational Health ,Proteins ,General Medicine ,General Chemistry ,Pollution ,020801 environmental engineering ,Biodegradation, Environmental ,chemistry ,Wetlands ,Environmental chemistry ,Constructed wetland ,Carbon - Abstract
This study evaluated the performance of a pilot-scale hybrid constructed wetland system for secondary effluent and investigated bulk organic matter characteristics. The hybrid constructed wetland consisted of a vertical-flow (VF) bed followed by a horizontal-flow (HF) bed. We also investigated the effects of hydraulic loading rates and influent organic load on the performance of the pilot-scale VF-HF hybrid constructed wetland. The results showed a high removal efficiency for suspended solids (>95%) and organic matter as determined by total organic carbon (>98.5%) and dissolved organic carbon (>70%), but no significant change in nitrogen removal was observed. The wetland treatment efficiency for suspended solids and organic matter showed a good buffer capacity even when hydraulic loading rates increased from 750 to 1500 L m−2 d−1 and 500–1000 L m−2 d−1 during the VF and HF stages, respectively. Moreover, there was no significant change in the performance when influent organic load increased eight-fold. Fluorescence excitation-emission matrix and liquid chromatography-organic carbon detection (LC-OCD) were used to investigate the dissolved organic matter characteristics in the hybrid VF-HF constructed wetland. Fluorescence excitation-emission matrix spectroscopy showed that both protein- and humic-like substances did not significantly change in the effluent when hydraulic loading rates and organic load increased by two- and eight-fold, respectively. Biopolymers determined using LC-OCD were effectively removed via the VF and HF stage wetlands, indicating the occurrence of biodegradation. Fluorescence excitation-emission matrix spectroscopy and LC-OCD provided the fate of dissolved organic matter characteristics in the hybrid VF-HF constructed wetland.
- Published
- 2019
28. A proof of concept study for wastewater reuse using bioelectrochemical processes combined with complementary post-treatment technologies
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Sung Kyu Maeng, Waris Khan, Hyoungmin Woo, Hodon Ryu, Hyun-Chul Kim, Sungpyo Kim, and Joo-Youn Nam
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Environmental Engineering ,Wastewater ,Chemistry ,Advanced oxidation process ,Chemical oxygen demand ,Sewage treatment ,Biodegradation ,Reuse ,Aeration ,Pulp and paper industry ,Effluent ,Article ,Water Science and Technology - Abstract
This article describes a proof-of-concept study designed for the reuse of wastewater using microbial electrochemical cells (MECs) combined with complementary post-treatment technologies. This study mainly focused on how the integrated approach works effectively for wastewater reuse. In this study, microalgae and ultraviolet C (UVC) light were used for advanced wastewater treatment to achieve site-specific treatment goals such as agricultural reuse and aquifer recharge. The bio-electrosynthesis of H(2)O(2) in MECs was carried out based on a novel concept to integrate with UVC, especially for roust removal of trace organic compounds (TOrCs) resistant to biodegradation, and the algal treatment was configured for nutrient removal from MEC effluent. UVC irradiation has also proven to be an effective disinfectant for bacteria, protozoa, and viruses in water. The average energy consumption rate for MECs fed acetate-based synthetic wastewater was 0.28±0.01 kWh per kg of H(2)O(2), which was significantly more efficient than are conventional electrochemical processes. MECs achieved 89±2% removal of carbonaceous organic matter (measured as chemical oxygen demand) in the wastewater (anolyte) and concurrent production of H(2)O(2) up to 222±11 mg L(−1) in the tapwater (catholyte). The nutrients (N and P) remaining after MECs were successfully removed by subsequent phycoremediation with microalgae when aerated (5% CO(2), v/v) in the light. This complied with discharge permits that limit N to 20 mg L(−1) and P to 0.5 mg L(−1) in the effluent. H(2)O(2) produced on site was used to mediate photolytic oxidation with UVC light for degradation of recalcitrant TOrCs in the algal-treated wastewater. Carbamazepine was used as a model compound and was almost completely removed with an added 10 mg L(−1) of H(2)O(2) at a UVC dose of 1000 mJ cm(−2). These results should not be generalized, but critically discussed, because of the limitations of using synthetic wastewater.
- Published
- 2019
29. An Assessment of the Effectiveness of Riverbank Filtration in a Sewage Plant Effluent-Impacted River Using a Full-Scale Horizontal Well
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Jin-Hyung Noh, Soo-Hyun So, Ji-Won Park, Sang-Yeob Kim, Kyung-Guen Song, Jaewon Choi, Gyoo-Bum Kim, Heejong Son, Heeyoung Kim, and Sung-Kyu Maeng
- Subjects
Geography, Planning and Development ,Aquatic Science ,Biochemistry ,riverbank filtration ,dissolved organic matter ,Nakdong river ,trace organic contaminants ,Water Science and Technology - Abstract
From 2014 to 2020, a full-scale horizontal well was operated to investigate the performance of full-scale riverbank filtration (RBF) in the Nakdong River in Korea, which is significantly impacted by the effluents from sewage treatment plants. In this study, an individual lateral full-scale horizontal collector well was investigated for the first time in Korea, and its performance was determined based on the turbidity and levels of iron, total nitrogen, dissolved organic matter, and four selected trace organic contaminants (TrOCs) (tebuconazole, hexaconazole, iprobenfos, and isoprothiolane) in the RBF and Nakdong River. The turbidity of the river was high with an average of 10.8 NTU, while that of the riverbank filtrate was 0.5 NTU or less on average. The average dissolved organic carbon (DOC) concentrations were 2.5 mg/L in the river water and 1.4 mg/L in the riverbank filtrate, which indicated a 44% reduction in DOC content during the RBF. Out of the 10 laterals, 8 laterals exhibited similar levels of iron, manganese, total nitrogen, DOC, and total hardness, electrical conductivity, and turbidity. The characteristics of the remaining two laterals were different. Because the groundwater inflow was relatively low (
- Published
- 2022
30. Chloride-Mediated Enhancement in Heat-Induced Activation of Peroxymonosulfate: New Reaction Pathways for Oxidizing Radical Production
- Author
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Yong Yoon Ahn, Minjeong Kim, Seungkwan Hong, Chang Ha Lee, Sung Kyu Maeng, Jaesang Lee, Hongshin Lee, Donghyun Lee, Woo Hyuck Bang, Min-Sik Kim, Jaemin Choi, Eun Tae Yun, and Jung Hyun Lee
- Subjects
Heat induced ,Hot Temperature ,Chemistry ,General Chemistry ,010501 environmental sciences ,Photochemistry ,01 natural sciences ,Chloride ,Peroxides ,Chlorides ,Oxidizing agent ,medicine ,Environmental Chemistry ,Chlorine ,Oxidation-Reduction ,Water Pollutants, Chemical ,0105 earth and related environmental sciences ,medicine.drug - Abstract
This study is the first to demonstrate the capability of Cl– to markedly accelerate organic oxidation using thermally activated peroxymonosulfate (PMS) under acidic conditions. The treatment effici...
- Published
- 2021
31. Assessment of organic carbon migration and biofilm formation potential on polymeric tubes in contact with water
- Author
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Thi Huyen Duong, Sung Kyu Maeng, and Ji-Won Park
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Environmental Engineering ,Health, Toxicology and Mutagenesis ,0211 other engineering and technologies ,Biomass ,chemistry.chemical_element ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,chemistry.chemical_compound ,Silicone ,Water Supply ,Environmental Chemistry ,Humans ,Tube (fluid conveyance) ,Thermoplastic elastomer ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Polyurethane ,021110 strategic, defence & security studies ,Chemistry ,Drinking Water ,Plasticizer ,Biofilm ,Pollution ,Carbon ,Chemical engineering ,Biofilms ,Water Microbiology - Abstract
Biofilm formation has been frequently identified as a pathway of nosocomial infection in polymeric tubes used for patients of all ages. Biofilm formation on tube surfaces can lead to hygienic failure and cause diarrhea, stomach pain, inflammation, and digestive system disease. This study investigated the influence of polymeric tube materials in contact with water on the biomass formation potential and migration potential of microbially available carbon from plasticizers using a BioMig test. The thermoplastic elastomer tube, which is reusable, leached a relatively low amount of assimilable organic carbon to water. In contrast, the assimilable organic carbon migration potential of polyurethane was the most significant, 6-fold greater than that of the thermoplastic elastomer. Moreover, the same materials (e.g., silicone) produced via different manufacturing processes showed significant differences in migration behaviors. The potential biomass formation observed in polyurethane was approximately 7 × 109 cells cm−2 for both Aeromonas hydrophila and Escherichia coli strains. This study highlights the importance of choosing the correct material characteristics of polymeric tubes in contact with water to protect them from bacterial contamination. Therefore, manufacturers can use the BioMig test to evaluate and produce more hygienic and biostable tubes.
- Published
- 2020
32. Fluorescence descriptors for algal organic matter and microalgae disintegration during ultrasonication
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Waris Khan, Ji Won Park, and Sung Kyu Maeng
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Process Chemistry and Technology ,Safety, Risk, Reliability and Quality ,Waste Management and Disposal ,Biotechnology - Published
- 2022
33. Feasibility of membrane distillation process for potable water reuse: A barrier for dissolved organic matters and pharmaceuticals
- Author
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Junki Kim, Kyung Guen Song, Sung Kyu Maeng, Joonhong Park, Jaewon Shin, and Seongpil Jeong
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Environmental Engineering ,Health, Toxicology and Mutagenesis ,0211 other engineering and technologies ,02 engineering and technology ,010501 environmental sciences ,Wastewater ,Membrane distillation ,01 natural sciences ,law.invention ,Water Purification ,law ,Republic of Korea ,Environmental Chemistry ,Waste Management and Disposal ,Effluent ,Filtration ,0105 earth and related environmental sciences ,Distillation ,021110 strategic, defence & security studies ,Fouling ,Chemistry ,Drinking Water ,Membrane fouling ,Membranes, Artificial ,Pulp and paper industry ,Pollution ,Membrane ,Pharmaceutical Preparations ,Feasibility Studies ,Sewage treatment - Abstract
In this study, the feasibility of the membrane distillation (MD) process as a wastewater reclamation system for portable reuse was investigated. The flux was stably maintained at about 20 L/m2h (LMH) at ΔT 30 °C, compared to higher flux at ΔT 50 °C, which showed a rapid decrease in the flux due to severe fouling. MD produced excellent quality of potable water satisfied the drinking water standards of Korea from effluent of sewage treatment plant (ESTP). The fractions of the hydrophobic OC (HOC) and chromatographic DOC (CDOC) from LC-OCD analysis was firstly suggested to understand different organic transport during the MD process. The transport of organic matters across the MD membrane mitigated at low operation temperature and the transported organics in all the tested waters were mostly volatile low molecular weight organics, aromatic amino acids. All of thirteen selected pharmaceuticals were completely removed by MD, regardless of their properties. In order to retard the membrane fouling of the MD process, coagulation and filtration pre-treatments were applied. The pre-treatment process coupled MD process could successfully remove impurities including NH4-N without severe membrane fouling. Moreover, coagulation pretreatment reduced transport of ammonia due to decrease in pH.
- Published
- 2020
34. Biological stability in the ozone and peroxone pretreatment systems in river water
- Author
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Sung Kyu Maeng, Ji-Won Park, Jin-Hyung Noh, and Se-Hee Park
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chemistry.chemical_compound ,Ozone ,chemistry ,Environmental chemistry ,0208 environmental biotechnology ,Environmental science ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,River water ,020801 environmental engineering ,0105 earth and related environmental sciences - Published
- 2018
35. Treatment of highly saline RO concentrate using Scenedesmus quadricauda for enhanced removal of refractory organic matter
- Author
-
Sungpyo Kim, Wook Jin Choi, Sung Kyu Maeng, Waris Khan, Ji-Won Park, Hee Sung Yang, Hyun-Chul Kim, Ihnsup Han, Kyung Guen Song, and Hyoungmin Woo
- Subjects
chemistry.chemical_classification ,Mechanical Engineering ,General Chemical Engineering ,0208 environmental biotechnology ,Aqueous two-phase system ,02 engineering and technology ,General Chemistry ,010501 environmental sciences ,Biodegradation ,01 natural sciences ,Decomposition ,020801 environmental engineering ,chemistry.chemical_compound ,chemistry ,Wastewater ,Environmental chemistry ,Dissolved organic carbon ,General Materials Science ,Organic matter ,Hydrogen peroxide ,Reverse osmosis ,0105 earth and related environmental sciences ,Water Science and Technology - Abstract
This study achieves a better understanding how Scenedesmus quadricauda microalgae participate in the phycoremediation of a reverse osmosis (RO) concentrate at a high salinity (8000 mg Cl− L− 1). Algal treatment of the RO concentrate under continuous illumination resulted in a notable increase in the biodegradability of dissolved organic matter, subsequent removal of biodegradable fractions, and simultaneous removal of nutrients (N and P). This is the first time that S. quadricauda is shown to induce the degradation of polymeric organic matter in the RO concentrate, which is typically refractory to microbial decomposition. In this study, the mechanisms for algae-induced degradation were investigated by measuring the hydrogen peroxide (H2O2) released out of algal cells and dispersed in the aqueous phase. The algae-induced biodegradation process has an advantage over typical electrochemical oxidation technologies in that photo-sensitive living organisms are capable of self-repair, reproduction, and nutrient uptake. Our results indicate that the use of algae-induced oxidation is highly feasible as a safe, inexpensive technology to pre-treat non- or slowly-biodegradable organic matter in wastewater prior to downstream biological processing.
- Published
- 2018
36. Characterization and assessment of organic carbon migration and biomass formation potential of polymeric pipes using modified BioMig
- Author
-
Sung Kyu Maeng, Jin Hyung Noh, Thi Huyen Duong, and Ji-Won Park
- Subjects
Total organic carbon ,Process Chemistry and Technology ,Biomass ,02 engineering and technology ,010501 environmental sciences ,Contamination ,engineering.material ,Polyethylene ,021001 nanoscience & nanotechnology ,Pulp and paper industry ,01 natural sciences ,Pollution ,Characterization (materials science) ,Current (stream) ,chemistry.chemical_compound ,Coating ,chemistry ,engineering ,Chemical Engineering (miscellaneous) ,Environmental science ,Leachate ,0210 nano-technology ,Waste Management and Disposal ,0105 earth and related environmental sciences - Abstract
To evaluate and approve the materials that can be in contact with drinking water with respect to biological contamination, organic carbon migration and biomass formation potential assays are widely employed. In previous studies, to conduct the assays, the entire material was exposed to the test water by submerging the material into glass jars. However, these are not realistic conditions since the water contact only the inner surface of the pipe in the distribution system, which may be different from the outer surface with respect to the coating layers. Furthermore, the extra components such as the glass jar containers and stainless steel holders might be the sources of organic carbon contamination. These two factors may result in imprecise conclusions. Here, we introduced a minor but essential modification to the BioMig test, which is the most current test on the migration potential and biomass formation potential. In this modified BioMig method, the outer surface and cutting edges, which are not in contact with water in practical water distribution systems, would not be exposed to the test water. Moreover, the assimilable organic carbon formation potential via chlorination in the leachates was observed and recommended as an additional test in the migration potential assay. The modified test results demonstrated that polyethylene (PE) material is the most unfavorable material, notably when used in chlorinated drinking water. This proposed test provided an alternative approach to the decision-makers with respect to evaluating the pipe material characteristics.
- Published
- 2021
37. Dissolved organic matter characteristics and removal of trace organic contaminants in a multi-soil-layering system
- Author
-
Jin Hyung Noh, Kyung Guen Song, Se-Yeon Won, Sung Kyu Maeng, and Ji-Won Park
- Subjects
Chemistry ,Process Chemistry and Technology ,Sand filter ,Slag ,02 engineering and technology ,Fractionation ,010501 environmental sciences ,Contamination ,021001 nanoscience & nanotechnology ,01 natural sciences ,Pollution ,Wastewater ,visual_art ,Environmental chemistry ,Dissolved organic carbon ,visual_art.visual_art_medium ,Chemical Engineering (miscellaneous) ,Water treatment ,0210 nano-technology ,Zeolite ,Waste Management and Disposal ,0105 earth and related environmental sciences - Abstract
This study investigated the role of soil mixture blocks (SMBs) in the removal of trace organic contaminants and the changes in dissolved organic matter characteristics in a laboratory-scale multi-soil-layering (MSL) system. The experimental setup included three soil-based water treatment systems, namely MSL, MSL without SMBs (zeolite/slag), and a sand filter. The effect of SMBs in the removal of dissolved organic matter in MSL was not significant, but the use of zeolite/slag in MSL enhanced the removal of humic substances and building blocks. Through membrane fractionation, the size distribution of dissolved organic matter in the MSL system was not changed, and the majority of the dissolved organic matter is below 1 kDa. Ten pharmaceutically active compounds and three endocrine-disrupting compounds were used to investigate the removal of selected trace organic contaminants in the MSL system, zeolite/slag, and sand filter. The attenuation of pentoxifylline, caffeine, 17α-ethinylestradiol, estrone, and 17β-estradiol in the MSL system was similar to that for zeolite/slag, and the removal efficiency was greater than 80%. However, pentoxifylline, caffeine, 17α-ethinylestradiol, estrone, and 17β-estradiol exhibited relatively low removal efficiencies in the sand filter compared to those in the MSL system and zeolite/slag. Results from this study provide insight into the removal of selected trace organic contaminants in MSL system, which could be considered as one of the series of barriers to remove trace organic contaminants in wastewater.
- Published
- 2021
38. Effects of powdered activated carbon and calcium on trihalomethane toxicity of zebrafish embryos and larvae in hybrid membrane bioreactors
- Author
-
Jin Hyung Noh, Sungpyo Kim, Sung Kyu Maeng, Ji-Won Park, and Soohoon Choi
- Subjects
Powdered activated carbon treatment ,animal structures ,Environmental Engineering ,Health, Toxicology and Mutagenesis ,0211 other engineering and technologies ,chemistry.chemical_element ,02 engineering and technology ,010501 environmental sciences ,Calcium ,Membrane bioreactor ,01 natural sciences ,chemistry.chemical_compound ,Bioreactors ,Bioreactor ,Animals ,Environmental Chemistry ,Waste Management and Disposal ,Zebrafish ,0105 earth and related environmental sciences ,021110 strategic, defence & security studies ,biology ,fungi ,biology.organism_classification ,Pollution ,Trihalomethane ,Membrane ,chemistry ,Charcoal ,Larva ,embryonic structures ,Toxicity ,Biophysics ,Powders ,Trihalomethanes - Abstract
This study investigated the effect of powdered activated carbon and calcium on trihalomethane toxicity in zebrafish embryos and larvae in hybrid membrane bioreactors. Two hybrid membrane bioreactors were configured with the addition of powdered activated carbon or calcium to reduce the trihalomethane formation potential. Trihalomethane formation decreased by approximately 37.2% and 30.3% in membrane bioreactor-powdered activated carbon and membrane bioreactor-calcium, respectively. Additionally, the toxic effect of trihalomethane formation was examined on zebrafish embryos and larvae. About 35% of the embryos exposed to trihalomethanes (800 ppb) showed signs of deformation, with the majority displaying coagulation within 24 h after exposure. Color preference tests, which were conducted to identify any abnormal activities of the embryos, showed an increase in preference from short to longer wavelengths upon exposure to high levels of trihalomethanes. This may indicate damage to the optical organs in zebrafish when exposed to trihalomethanes. Behavioral analysis showed reduced mobility of zebrafish larvae under different trihalomethane concentrations, indicating a decrease in the average activity time with an increasing trihalomethane concentration. The membrane bioreactor effluents were toxic to zebrafish embryos and larvae in the presence of high trihalomethane concentrations. To understand the mechanism behind trihalomethane toxicity, further studies are needed.
- Published
- 2021
39. Seasonally related effects on natural organic matter characteristics from source to tap in Korea
- Author
-
Hyun-Chul Kim, Sung Kyu Maeng, Ilhwan Choi, and S.H. So
- Subjects
Environmental Engineering ,0208 environmental biotechnology ,chemistry.chemical_element ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Natural organic matter ,Water Purification ,law.invention ,law ,Republic of Korea ,Dissolved organic carbon ,Chlorine ,Environmental Chemistry ,Biological activated carbon ,Waste Management and Disposal ,Filtration ,0105 earth and related environmental sciences ,Total organic carbon ,Chemistry ,Drinking Water ,Sedimentation ,Pollution ,Carbon ,020801 environmental engineering ,Charcoal ,Environmental chemistry ,Water treatment ,Seasons - Abstract
In this study, natural organic matter (NOM) characteristics were investigated over three years of monthly monitoring to determine the effect of seasonal variations on NOM levels from source to tap. Liquid chromatography with organic carbon detection (LC-OCD) was used to determine NOM characteristics and the level of reduction of biodegradable dissolved organic carbon (BDOC). The average dissolved organic matter concentration in the source water (Lake Paldang, Korea) was not significantly different between summer and winter. However, the distribution of NOM components, such as biopolymers, building blocks, low molecular weight (MW) neutrals and acids, identified by LC-OCD, varied seasonally. While high MW NOM was preferentially removed by coagulation/sedimentation/rapid sand filtration (CSR), no seasonal effects were observed on the removal of high MW NOM. CSR and biological activated carbon (BAC) filtration showed a better efficiency of BDOC removal in winter and summer, respectively. High concentrations of chlorine used in the treatment plants in summer resulted in 10% higher DOC concentrations during disinfection. Overall NOM removal efficiencies from source to tap were 45% and 35% for summer and winter, respectively. Principal component analysis also indicated that seasonal variations (principal component 1) showed the strongest positive correlation with the overall performance of water treatment. The long-term monitoring of drinking water treatment processes showed that seasonal variations were important factors affecting NOM characteristics during water treatment.
- Published
- 2017
40. Effect of coagulation conditions on ultrafiltration for wastewater effluent
- Author
-
Thomas C. Timmes, Sung Kyu Maeng, and Hyun-Chul Kim
- Subjects
chemistry.chemical_classification ,Fouling ,Organic base ,General Chemical Engineering ,Ultrafiltration ,02 engineering and technology ,010501 environmental sciences ,Pulp and paper industry ,01 natural sciences ,law.invention ,020401 chemical engineering ,Wastewater ,chemistry ,law ,Coagulation (water treatment) ,Organic matter ,0204 chemical engineering ,Effluent ,Filtration ,0105 earth and related environmental sciences ,Water Science and Technology - Abstract
Low-pressure membrane filtration is increasingly used for tertiary treatment of wastewater effluent organic matter (EfOM), mainly comprising organic base/neutral compounds. In-line coagulation with underdosing, charge neutralization, and sweep floc conditions prior to ultrafiltration (UF) was studied to determine removals of the EfOM components and consequent reduction of fouling using polyethersulfone membranes. Coagulation and UF substantially reduced fouling for all coagulation conditions while removing from 7 to 38% of EfOM organic acids. From 7 to 16% of EfOM organic base/neutrals were removed at neutral pH but there was no significant removal for slightly acid coagulation conditions even though fouling was substantially reduced. Sweep floc produced the lowest resistance to filtration but may be inappropriate for in-line use due to the large added volume of solids. Charge-neutralization resulted in poor recovery of the initial flux with hydraulic cleaning. Under-dosing paralleled sweep floc in reducing hydraulic resistance to filtration (for sub-critical flux) and the initial flux was also easily recovered with hydraulic cleaning. Hydrophobic and hydrophilic base/neutrals were identified on the fouled membranes but as previously reported the extent of fouling was not correlated with accumulation of organic base/neutrals.
- Published
- 2017
41. Influences of NOM composition and bacteriological characteristics on biological stability in a full-scale drinking water treatment plant
- Author
-
Sungpyo Kim, Anne S. Meyer, Ji-Won Park, Sung Kyu Maeng, and Hyun-Chul Kim
- Subjects
Environmental Engineering ,Ozone ,Halogenation ,Health, Toxicology and Mutagenesis ,0208 environmental biotechnology ,02 engineering and technology ,010501 environmental sciences ,engineering.material ,Bacterial growth ,01 natural sciences ,Water Purification ,chemistry.chemical_compound ,Biopolymers ,Dissolved organic carbon ,Escherichia coli ,Environmental Chemistry ,Organic matter ,Organic Chemicals ,Humic Substances ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,Total organic carbon ,biology ,Drinking Water ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,biology.organism_classification ,Pollution ,Carbon ,020801 environmental engineering ,chemistry ,Environmental chemistry ,engineering ,Water treatment ,Biopolymer ,Hydrophobic and Hydrophilic Interactions ,Filtration ,Bacteria - Abstract
The influences of natural organic matter (NOM) and bacteriological characteristics on the biological stability of water were investigated in a full-scale drinking water treatment plant. We found that prechlorination decreased the hydrophobicity of the organic matter and significantly increased the high-molecular-weight (MW) dissolved organic matter, such as biopolymers and humic substances. High-MW organic matter and structurally complex compounds are known to be relatively slowly biodegradable; however, because of the prechlorination step, the indigenous bacteria could readily utilise these fractions as assimilable organic carbon. Sequential coagulation and sedimentation resulted in the substantial removal of biopolymer (74%), humic substance (33%), bacterial cells (79%), and assimilable organic carbon (67%). Rapid sand and granular activated carbon filtration induced an increase in the low-nucleic-acid content bacteria; however, these bacteria were biologically less active in relation to enzymatic activity and ATP. The granular activated carbon step was essential to securing biological stability (the ability to prevent bacterial growth) by removing the residual assimilable organic carbon that had formed during the ozone treatment. The growth potential of Escherichia coli and indigenous bacteria were found to differ in respect to NOM characteristics. In comparison with E. coli, the indigenous bacteria utilised a broader range of NOM as a carbon source. Principal component analysis demonstrated that the measured biological stability of water could differ, depending on the NOM characteristics, as well as on the bacterial inoculum selected for the analysis.
- Published
- 2016
42. Comparison of pre-oxidation between O
- Author
-
Hyun-Chul, Kim, Se Hee, Park, Jin Hyung, Noh, Jaewon, Choi, Seunghak, Lee, and Sung Kyu, Maeng
- Abstract
A hybrid process of managed aquifer recharge with pre-oxidation was investigated as part of a multiple-barrier approach for safe water production. This study evaluated O
- Published
- 2019
43. Evaluation of organic migration and biomass formation on polymeric components in a point-of-use water dispenser
- Author
-
Keun-Yeong Park, Sungpyo Kim, Ji Hyang Kweon, Sangjung Park, Yeong Na, Ji-Won Park, and Sung Kyu Maeng
- Subjects
Environmental Engineering ,Polymers ,0208 environmental biotechnology ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Water Purification ,chemistry.chemical_compound ,Silicone ,Tap water ,Water Supply ,Biomass ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Water Science and Technology ,Civil and Structural Engineering ,Total organic carbon ,Suspended solids ,Chemistry ,Ecological Modeling ,Drinking Water ,Biofilm ,Pulp and paper industry ,Pollution ,020801 environmental engineering ,Polyvinyl chloride ,Water cooler ,Biofilms ,Water quality ,Water Microbiology - Abstract
To minimize the aesthetic and hygienic concerns regarding tap water (e.g., odor, taste, suspended solids, and microorganisms), point-of-use (POU) water dispensers and filters are used in households worldwide. However, the POU water dispenser itself can adversely impact water quality. This study investigated the bacterial growth through a POU water dispenser fed with chlorinated tap water; specifically, the heterotrophic plate count increased from 0.01 to 20.01 × 103 of colony-forming units per ml. The BioMig test, which evaluates the biostability of polymeric materials based on the migration potential and the biofilm formation potential, was firstly applied for the water dispenser system. Organic migration and biofilm formation varied by the polymer type used in the water dispenser components (e.g., tubing, fittings, and reservoir). Assimilable organic carbon migration in cold water (23 ± 2 °C) was better correlated with the biofilm formation potential (R = 0.93) than that of warm water (60 ± 2 °C) migration (R = 0.62). The most problematic test material was silicone based on assimilable organic carbon migration and biofilm formation, whereas approved materials such as polyethylene and polyvinyl chloride were relatively stable. Polymeric component examination of an actual POU water dispenser revealed highly accumulated biofilms on the silicone tube used in the device (118 × 103 CFU cm−2). The use of polymers with high biofilm formation should be minimized in water dispensers, whereas approved polymeric components contribute to biological stability in the dispensed drinking water.
- Published
- 2019
44. Organic micropollutant removal from groundwater: comparison of pellet softening and nanofiltration
- Author
-
Carlos N. A. Salinas Rodriguez, Youngbeom Yu, Byoung-Soo Kim, Jaewon Choi, Sung-Han Kim, Sung Kyu Maeng, and Seok Won Hong
- Subjects
chemistry.chemical_classification ,Environmental Engineering ,Chromatography ,Health, Toxicology and Mutagenesis ,0208 environmental biotechnology ,chemistry.chemical_element ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,020801 environmental engineering ,law.invention ,chemistry.chemical_compound ,Calcium carbonate ,chemistry ,Chemical engineering ,law ,Pellet ,Dissolved organic carbon ,Organic matter ,Nanofiltration ,Crystallization ,Softening ,Carbon ,0105 earth and related environmental sciences ,Water Science and Technology - Abstract
This study investigated the fate of selected pharmaceuticals and estrogens and the characteristics of bulk organic matter during pellet softening and proposed a possible hybridization with nanofiltration (NF) treatment. A groundwater softening system called pellet softening was used to remove calcium ions from groundwater by crystallizing calcium carbonate on the surface of sand grains that were used as seeding material. This crystallization was confirmed by X-ray powder diffraction, and X-ray fluorescence and scanning electron micrographs were used to characterize the surface of the sand grains during pellet softening. The fluorescence excitation–emission matrix showed that humic-like substances were slightly removed and that specific UV absorbance values decreased after pellet softening. The humic fraction determined by liquid chromatography-organic carbon detection was slightly more attenuated than the fractions of biopolymers, building blocks, low molecular weight acids, and low molecular weight neutrals. Therefore, the aromatic content per unit of dissolved organic carbon was preferentially attenuated during pellet softening. The average removal efficiencies of the three estrogens and 12 selected pharmaceuticals during the softening process were 59 and 5.7%, respectively. However, there was a greater reduction of pharmaceuticals during NF.
- Published
- 2016
45. Forward osmosis membrane fouling and cleaning for wastewater reuse
- Author
-
Youngbeom Yu, Sung Kyu Maeng, and Seockheon Lee
- Subjects
Forward osmosis ,Backwashing ,Filtration and Separation ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Biofouling ,lcsh:Water supply for domestic and industrial purposes ,020401 chemical engineering ,spacer ,0204 chemical engineering ,Reverse osmosis ,0105 earth and related environmental sciences ,Water Science and Technology ,lcsh:TD201-500 ,Fouling ,membrane fouling ,Chemistry ,forward osmosis ,Membrane fouling ,Environmental engineering ,Pulp and paper industry ,Membrane ,Activated sludge ,cross-flow velocity ,air-scouring ,osmotic backwashing - Abstract
Membrane fouling properties and different physical cleaning methods for forward osmosis (FO) and reverse osmosis (RO) laboratory-scale filtration systems were investigated. The membrane fouling, with respect to flux reduction, was lower in FO than in RO when testing an activated sludge effluent. Cross-flow velocity, air-scouring, osmotic backwashing and effect of a spacer were compared to determine the most effective cleaning method for FO. After a long period of fouling with activated sludge, the flux was fully recovered in a short period of osmotic backwashing compared with cleaning by changing cross-flow velocity and air-scouring. In this study, the osmotic backwashing was found to be the most efficient way to clean the FO membrane. The amount of RNA recovered from FO membranes was about twice that for RO membranes; biofouling could be more significant in FO than in RO. However, the membrane fouling in FO was lower than that in RO. The spacer increased the flux in FO with activated sludge liquor suspended solids of 2,500 mg/L, and there were effects of spacer on performance of FO–MBR membrane fouling. However, further studies are required to determine how the spacer geometry influences on the performance of the FO membrane.
- Published
- 2016
46. Effects of phosphate and hydrogen peroxide on the performance of a biological activated carbon filter for enhanced biofiltration
- Author
-
Jin Hyung Noh, Song Hee Yoo, Heejong Son, Katherine E. Fish, Sung Kyu Maeng, and Isabel Douterelo
- Subjects
Environmental Engineering ,Health, Toxicology and Mutagenesis ,0211 other engineering and technologies ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Phosphates ,chemistry.chemical_compound ,Biopolymers ,Dissolved organic carbon ,Environmental Chemistry ,Polyvinyl Chloride ,Hydrogen peroxide ,Waste Management and Disposal ,Effluent ,0105 earth and related environmental sciences ,021110 strategic, defence & security studies ,Biofilm ,Hydrogen Peroxide ,Stainless Steel ,Phosphate ,Pulp and paper industry ,Pollution ,Filter (aquarium) ,Trihalomethane ,chemistry ,Biofilms ,Charcoal ,Biofilter ,Filtration ,Water Pollutants, Chemical ,Trihalomethanes - Abstract
Biofilm formation on biofilters can influence their hydraulic performance, thereby leading to head loss and an increase in energy use and costs for water utilities. The effects of a range of factors, including hydrogen peroxide and phosphate, on the performance of biological activated carbon (BAC) and biofilm formation were investigated using laboratory-scale columns. Head loss, total carbohydrates, and proteins were reduced in the nutrient-enhanced, oxidant-enhanced, and nutrient + oxidant-enhanced BAC filters. However, there were no changes in the removal of dissolved organic matter, trihalomethane formation potential, or selected trace organic contaminants. The biofilm formation on polyvinyl chloride and stainless steel coupons using the laboratory biofilm reactor system was lower when the effluent from a nutrient-enhanced column was used, which indicated that there was less biofilm formation in the distribution systems. This may have been because the effluent from the nutrient-enhanced column was more biologically stable. Therefore, enhanced biofiltration could be used not only to reduce head loss in biofilters, but also to delay biofilm formation in distribution systems.
- Published
- 2020
47. Bacterial growth through microfiltration membranes and NOM characteristics in an MF-RO integrated membrane system: Lab-scale and full-scale studies
- Author
-
Anne S. Meyer, Isabel Douterelo, Young-Joo Lee, Ji-Won Park, and Sung Kyu Maeng
- Subjects
0301 basic medicine ,Osmosis ,Environmental Engineering ,Biofouling ,Microorganism ,Microfiltration ,030106 microbiology ,Microbial Consortia ,Fresh Water ,Bacterial growth ,Water Purification ,03 medical and health sciences ,Adenosine Triphosphate ,RNA, Ribosomal, 16S ,Food science ,Reverse osmosis ,Waste Management and Disposal ,Water Science and Technology ,Civil and Structural Engineering ,Bacteria ,Chemistry ,Bacteroidetes ,Ecological Modeling ,Biofilm ,Membranes, Artificial ,Flow Cytometry ,Pollution ,Membrane ,Biofilms ,Filtration - Abstract
Biofilm formation on membrane surfaces causes many operational problems such as a decrease in permeate flux and an increase in hydraulic resistance. In this study, the ability of bacteria to pass through microfiltration (MF) membranes and the growth potential of microfilterable bacteria were investigated in order to understand biofouling in MF-reverse osmosis (RO) integrated membrane systems. Growth of microfilterable bacteria in MF permeate was observed, indicating that not all MF membranes can guarantee the total rejection of bacteria. Changes in natural organic matter (NOM) characteristics and growth potential of bacteria during the treatment process are important factors in the occurrence of biofilm development in water treatment systems. Analysis of protein-like and humic-like substances in NOM of two successive RO stages revealed an increase in the concentrations of both biopolymers and humic substances of RO concentrates. Unexpectedly, the use of antiscalants was seen to enhance the growth of bacteria in the RO feed water in this study. Bacterial 16s rRNA pyrosequencing revealed that passing source water through the MF membranes dramatically changed bacterial community structure. The bacterial communities that passed through the MF steps primarily belonged to the family Comamonadaceae. However, several bacteria groups including Flavobacteriaceae, Sphingobacteriaceae and Sphingomonadaceae selectively composed the biofilm community formed on the RO membranes. Thus, understanding the selectivity and filterability of MF towards microorganisms involved in biofouling on RO membrane surfaces is crucial for the improvement of membrane-related operational processes.
- Published
- 2018
48. The growth of Scenedesmus quadricauda in RO concentrate and the impacts on refractory organic matter, Escherichia coli, and trace organic compounds
- Author
-
Hyun-Chul Kim, Song Hee You, Joo-Youn Nam, Hodon Ryu, Thomas C. Timmes, and Sung Kyu Maeng
- Subjects
Osmosis ,Environmental Engineering ,Environmental remediation ,0208 environmental biotechnology ,02 engineering and technology ,010501 environmental sciences ,Wastewater ,01 natural sciences ,Waste Disposal, Fluid ,Article ,Phosphates ,Nutrient ,Enterobacteriaceae ,Polysaccharides ,Escherichia coli ,Microalgae ,Organic matter ,Water Pollutants ,Organic Chemicals ,Reverse osmosis ,Waste Management and Disposal ,Humic Substances ,0105 earth and related environmental sciences ,Water Science and Technology ,Civil and Structural Engineering ,chemistry.chemical_classification ,Nitrates ,Chemistry ,Ecological Modeling ,Pollution ,Decomposition ,020801 environmental engineering ,Environmental chemistry ,Degradation (geology) ,Aeration ,Filtration ,Scenedesmus - Abstract
This study achieves a better operational simplicity for the phycoremediation of reverse osmosis (RO) concentrate using Scenedesmus quadricauda microalgae. Under continuous illumination with CO2 supplementation, algal growth in the RO concentrate resulted in a conversion of polymeric organic matter (a mixture of humic substances and polysaccharides) to biodegradable fractions and their prompt removal along with inorganic nutrients (NO3- and PO43-). The algal-induced degradation of humic-like substances which are typically refractory to microbial decomposition was demonstrated in an indirect manner. In this study, we also investigated the effects of algal treatment on the growth of Escherichia coli and removal of trace organic compounds (TOrCs) from the RO concentrate. Our results indicate that algal treatment of the RO concentrate using aeration with 10% (v/v) CO2 under continuous illumination is highly feasible as a safe and inexpensive technology to remove non- or slowly-biodegradable organic matter, reduce enteric bacteria, and attenuate TOrCs in wastewater. However, the results should not be generalized, but critically discussed, due to limitations of using the synthetic RO concentrate in evaluating the performance of wastewater remediation with microalgae.
- Published
- 2018
49. Multi-barrier approach for removing organic micropollutants using mobile water treatment systems
- Author
-
Youngbeom Yu, Yang Hun Choi, Soohoon Choi, Jaewon Choi, and Sung Kyu Maeng
- Subjects
Pollution ,Flocculation ,Environmental Engineering ,Dissolved air flotation ,media_common.quotation_subject ,02 engineering and technology ,010501 environmental sciences ,complex mixtures ,01 natural sciences ,law.invention ,Water Purification ,law ,Republic of Korea ,medicine ,Environmental Chemistry ,Waste Management and Disposal ,Filtration ,0105 earth and related environmental sciences ,media_common ,Pollutant ,Contamination ,bacterial infections and mycoses ,021001 nanoscience & nanotechnology ,Pulp and paper industry ,Charcoal ,bacteria ,Environmental science ,Water treatment ,0210 nano-technology ,Water Pollutants, Chemical ,Activated carbon ,medicine.drug - Abstract
The diversity of organic micropollutants (OMPs) in aquatic environments has been increasing rapidly during the last decade. Therefore, it is important to monitor and attenuate emerging contaminants before they can negatively affect the aquatic environment. However, due to the diversity and complexity of OMPs, there are limitations to using a single method for treating a combination of these pollutants. To address this issue, a mobile water treatment system (MWTS) equipped with different treatment units was designed to remove OMPs under field conditions. The MWTS was configured with various modular units including coagulation, flocculation, dissolved air flotation, membrane filtration, ozone oxidation, granular activated carbon, and UV disinfection. Each treatment unit could be operated either individually or in different combinations to identify the optimal configuration of treatment units for the removal of OMPs. To investigate the effectiveness of the MWTS, twelve OMPs were selected and introduced simultaneously into the feed water samples collected from different rivers throughout Korea. The current study proved that the MTWS is an effective solution to treat OMPs and is a time saving treatment system. The combined effects of the different treatment units removed over 99% of the selected OMPs, regardless of their physicochemical properties. Moreover, since the system is mobile, on-site analyses can be conducted to identify the most effective treatment method and configuration for each OMP.
- Published
- 2018
50. Removal of Organic Matter and Pharmaceuticals in Wastewater Effluent through Managed Aquifer Recharge
- Author
-
Sung Kyu Maeng, Heechul Choi, Huncheol Im, and Inseol Yeo
- Subjects
chemistry.chemical_classification ,Waste management ,Wastewater ,chemistry ,Environmental engineering ,Environmental science ,Organic matter ,Groundwater recharge ,Effluent - Published
- 2015
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