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The production of volatile fatty acids (VFAs) from waste stream has been recently getting attention as a cost-effective and environmentally friendly approach in mechanical–biological treatment plants. This is the first study to explore the use of a functional bacterium, AM5 isolated from forest soil, which is capable of enhancing the production of VFAs in the presence of soil bacteria as a co-digester in non-strict anaerobic fermentation processes of food waste leachates. Batch laboratory-scale trials were conducted under thermophilic conditions at 55 °C and different pH values ranging from approximately 5 to 11, as well as under uncontrolled pH for 15 days. Total solid content (TS) and volatile solid content (VS) were observed with 58.42% and 65.17% removal, respectively. An effluent with a VFA concentration of up to 33,849 mg/L (2365.57 mg/g VS; 2244.45 mg/g chemical oxygen demand (COD)-VFA VS; 1249 mg/g VSremoved) was obtained at pH 10.5 on the second day of the batch culture. The pH resulted in a significant effect on VFA concentration and composition at various values. Additionally, all types of VFAs were produced under pH no-adjustment (approximately 5) and at pH 10.5. This research might lead to interesting questions and ideas for further studies on the complex metabolic pathways of microbial communities in the mixture of a soil solution and food waste leachate.
Van Hong Thi Pham; Jeongyoon Ahn; Jaisoo Kim; Sangbeom Lee; Ingyu Lee; Sungchul Kim; Soonwoong Chang; Woojin Chung. Volatile Fatty Acid Production from Food Waste Leachate Using Enriched Bacterial Culture and Soil Bacteria as Co-Digester. Sustainability 2021, 13, 9606 .
AMA StyleVan Hong Thi Pham, Jeongyoon Ahn, Jaisoo Kim, Sangbeom Lee, Ingyu Lee, Sungchul Kim, Soonwoong Chang, Woojin Chung. Volatile Fatty Acid Production from Food Waste Leachate Using Enriched Bacterial Culture and Soil Bacteria as Co-Digester. Sustainability. 2021; 13 (17):9606.
Chicago/Turabian StyleVan Hong Thi Pham; Jeongyoon Ahn; Jaisoo Kim; Sangbeom Lee; Ingyu Lee; Sungchul Kim; Soonwoong Chang; Woojin Chung. 2021. "Volatile Fatty Acid Production from Food Waste Leachate Using Enriched Bacterial Culture and Soil Bacteria as Co-Digester." Sustainability 13, no. 17: 9606.
In this study, a pilot-scale reactor was designed and compared using computational fluid dynamics (CFD) for a high-efficiency CO2 methanation reaction. The trends of the CO2 methanation catalyst efficiency at a pilot or industrial scale could be lower than those measured at the laboratory scale, owing to the flow of fluid characteristics. Therefore, the CO2 methanation reactor was designed based on the results of the CFD analysis to minimize the above phenomenon. Ni–Ce–Zr was used to manufacture a CO2 methanation catalyst in the form of pellets. The catalyst successfully produced about 43.3 Nm3/d of methane from the reactor. This result shows that CO2 methanation, which is known as an exothermic reaction, was stable at the pilot scale. It is believed that the self-supply of energy will be possible when this CO2 methanation technology is applied to industrial processes generating large amounts of CO2 and H2 from by-product gases.
Jeongyoon Ahn; Heysuk Kim; Yeonhee Ro; Jintae Kim; Woojin Chung; Soonwoong Chang. Development of Pilot-Scale CO2 Methanation Using Pellet-Type Catalysts for CO2 Recycling in Sewage Treatment Plants and Its Validation through Computational Fluid Dynamics (CFD) Modeling. Catalysts 2021, 11, 1005 .
AMA StyleJeongyoon Ahn, Heysuk Kim, Yeonhee Ro, Jintae Kim, Woojin Chung, Soonwoong Chang. Development of Pilot-Scale CO2 Methanation Using Pellet-Type Catalysts for CO2 Recycling in Sewage Treatment Plants and Its Validation through Computational Fluid Dynamics (CFD) Modeling. Catalysts. 2021; 11 (8):1005.
Chicago/Turabian StyleJeongyoon Ahn; Heysuk Kim; Yeonhee Ro; Jintae Kim; Woojin Chung; Soonwoong Chang. 2021. "Development of Pilot-Scale CO2 Methanation Using Pellet-Type Catalysts for CO2 Recycling in Sewage Treatment Plants and Its Validation through Computational Fluid Dynamics (CFD) Modeling." Catalysts 11, no. 8: 1005.
Iron oxide nanoparticles synthesis is an expanding area of research due of their magnetic properties and possible applications in several novel technologies. FeONPs are indispensable in the biomedical field for diagnosis, treatments and drug delivery and in bioremediation applications. The synthesis route of nanoparticles is a major concern because biological methods are eco-friendly, and chemical methods are considered toxic. The objective of this study is to synthesize FeONPs by two different methods and to compare their properties and efficiency in applications. FeONPs were synthesized and characterized by microscopic and various spectroscopic techniques. The synthesized FeONPs were screened for their cytotoxic activity on PBMCs using MTT assay and found to exhibit good biocompatibility. Moreover, the GS FeONPs exhibited potential antibacterial activities and meanwhile showed less toxicity in brine shrimp lethality assay. Hence, these nanoparticles are biocompatible, environmentally safe and can be utilized in many medical applications.
Mohammed Junaid Hussain Dowlath; Shazia Anjum Musthafa; S.B. Mohamed Khalith; Sunita Varjani; Sathish Kumar Karuppannan; Ganesh Munuswamy Ramanujam; Aarrthy M. Arunachalam; Kantha Deivi Arunachalam; Murugesan Chandrasekaran; Soon Woong Chang; Woo Jin Chung; Balasubramani Ravindran. Comparison of characteristics and biocompatibility of green synthesized iron oxide nanoparticles with chemical synthesized nanoparticles. Environmental Research 2021, 201, 111585 .
AMA StyleMohammed Junaid Hussain Dowlath, Shazia Anjum Musthafa, S.B. Mohamed Khalith, Sunita Varjani, Sathish Kumar Karuppannan, Ganesh Munuswamy Ramanujam, Aarrthy M. Arunachalam, Kantha Deivi Arunachalam, Murugesan Chandrasekaran, Soon Woong Chang, Woo Jin Chung, Balasubramani Ravindran. Comparison of characteristics and biocompatibility of green synthesized iron oxide nanoparticles with chemical synthesized nanoparticles. Environmental Research. 2021; 201 ():111585.
Chicago/Turabian StyleMohammed Junaid Hussain Dowlath; Shazia Anjum Musthafa; S.B. Mohamed Khalith; Sunita Varjani; Sathish Kumar Karuppannan; Ganesh Munuswamy Ramanujam; Aarrthy M. Arunachalam; Kantha Deivi Arunachalam; Murugesan Chandrasekaran; Soon Woong Chang; Woo Jin Chung; Balasubramani Ravindran. 2021. "Comparison of characteristics and biocompatibility of green synthesized iron oxide nanoparticles with chemical synthesized nanoparticles." Environmental Research 201, no. : 111585.
Using photocatalysts to harvest photon energy from sunlight (renewable fuel) is a promising pathway for a wide range of applications, especially for the removal of contaminants from water. Porphyrin and its derivatives are analogs of natural chlorophyll; both compounds have similar structures and photochemical properties. Therefore, various porphyrin derivatives have been extensively studied as effective sensitizers for light energy absorption and as nature-inspired photocatalysts for water treatment. In this study, a simple solvophobic self-assembly protocol is employed to obtain nanostructured porphyrin from monomeric tetrakis-triphenylamine porphyrin (TTPAP) in a mixture of THF/H2O. The porphyrin is assembled into various forms such as rod-like and belt-like microstructures, depending on the water fraction in the THF/H2O mixture. The main driving forces for self-assembly of the TTPAP monomers into nanostructured materials are balanced stacking involving hydrophobic interactions of the periphery and π-π interactions of the porphyrin cores. While both porphyrin microstructures (rod-like and belt-like) show reasonable photocatalytic activity toward rhodamine B (RhB) dye in aqueous media under simulated visible irradiation, the belt-like porphyrin aggregates exhibit better performance than the rod-like counterparts under the same reaction conditions. A possible mechanism for the photocatalytic activity of the TTPAP aggregates in RhB degradation is also presented.
D. Duong La; Ratan W. Jadha; Nilesh M. Gosavi; Eldon R. Rene; Tuan Anh Nguyen; Bui Xuan-Thanh; D. Duc Nguyen; W. Jin Chung; S. Woong Chang; X. Hoan Nguyen; Lam Dai Tran; Sheshanath V. Bhosale. Nature-inspired organic semiconductor via solvophobic self-assembly of porphyrin derivative as an effective photocatalyst for degradation of rhodamine B dye. Journal of Water Process Engineering 2021, 40, 101876 .
AMA StyleD. Duong La, Ratan W. Jadha, Nilesh M. Gosavi, Eldon R. Rene, Tuan Anh Nguyen, Bui Xuan-Thanh, D. Duc Nguyen, W. Jin Chung, S. Woong Chang, X. Hoan Nguyen, Lam Dai Tran, Sheshanath V. Bhosale. Nature-inspired organic semiconductor via solvophobic self-assembly of porphyrin derivative as an effective photocatalyst for degradation of rhodamine B dye. Journal of Water Process Engineering. 2021; 40 ():101876.
Chicago/Turabian StyleD. Duong La; Ratan W. Jadha; Nilesh M. Gosavi; Eldon R. Rene; Tuan Anh Nguyen; Bui Xuan-Thanh; D. Duc Nguyen; W. Jin Chung; S. Woong Chang; X. Hoan Nguyen; Lam Dai Tran; Sheshanath V. Bhosale. 2021. "Nature-inspired organic semiconductor via solvophobic self-assembly of porphyrin derivative as an effective photocatalyst for degradation of rhodamine B dye." Journal of Water Process Engineering 40, no. : 101876.
Yeon Hee Ro; Woo Jin Chung; Ravincran Balasubramani; Soon Woong Chang; Hyunook Kim; Joung Du Shin. Effects on Physicochemical Properties of Poultry and Cattle Manure Composts to Different Mixing Ratios of Activated Rice Hull Biochar for Aerboic Digestion Process. Journal of Korea Society of Waste Management 2020, 37, 443 -450.
AMA StyleYeon Hee Ro, Woo Jin Chung, Ravincran Balasubramani, Soon Woong Chang, Hyunook Kim, Joung Du Shin. Effects on Physicochemical Properties of Poultry and Cattle Manure Composts to Different Mixing Ratios of Activated Rice Hull Biochar for Aerboic Digestion Process. Journal of Korea Society of Waste Management. 2020; 37 (07):443-450.
Chicago/Turabian StyleYeon Hee Ro; Woo Jin Chung; Ravincran Balasubramani; Soon Woong Chang; Hyunook Kim; Joung Du Shin. 2020. "Effects on Physicochemical Properties of Poultry and Cattle Manure Composts to Different Mixing Ratios of Activated Rice Hull Biochar for Aerboic Digestion Process." Journal of Korea Society of Waste Management 37, no. 07: 443-450.
Abundantly available biomass wastes from agriculture can serve as effective environmental remediation materials. In this study, activated biochar was fabricated from macadamia nutshell (MCN) through carbonization and chemical modification. The resultant biochars were used as adsorbents to remove toxic metal ions such as Cu2+ and Zn2+ from aqueous solutions. The results showed that the activated MCN biochar has a high adsorption capacity for toxic metal ions. When MCN biochar was activated with K2CO3, the adsorption efficiencies for Cu2+ and Zn2+ were 84.02% and 53.42%, respectively. With H3PO4 activation, the Cu2+- and Zn2+-adsorption performances were 95.92% and 67.41%, respectively. H2O2-modified MCN biochar had reasonable Cu2+- and Zn2+-adsorption efficiencies of 79.33% and 64.52%, respectively. The effects of pH, adsorbent concentration and adsorption time on the removal performances of Cu2+ and Zn2+ in aqueous solution were evaluated. The results exhibited that the activated MCN biochar showed quick adsorption ability with an optimal pH of 4 and 4.5 for both Cu2+ and Zn2+, respectively.
Minh Dao; T. Nguyen; X. Nguyen; D. La; D. Nguyen; S. Chang; W. Chung; Van Nguyen. Toxic Metal Adsorption from Aqueous Solution by Activated Biochars Produced from Macadamia Nutshell Waste. Sustainability 2020, 12, 7909 .
AMA StyleMinh Dao, T. Nguyen, X. Nguyen, D. La, D. Nguyen, S. Chang, W. Chung, Van Nguyen. Toxic Metal Adsorption from Aqueous Solution by Activated Biochars Produced from Macadamia Nutshell Waste. Sustainability. 2020; 12 (19):7909.
Chicago/Turabian StyleMinh Dao; T. Nguyen; X. Nguyen; D. La; D. Nguyen; S. Chang; W. Chung; Van Nguyen. 2020. "Toxic Metal Adsorption from Aqueous Solution by Activated Biochars Produced from Macadamia Nutshell Waste." Sustainability 12, no. 19: 7909.
The use of nano-additives is widely recognized as a cheap and effective pathway to improve the performance of lubrication by minimizing the energy loss from friction and wear, especially in diesel engines. In this work, a simple and scalable protocol was proposed to fabricate a graphene additive to improve the engine lubricant oil. Graphene nanoplates (GNPs) were obtained by a one-step chemical exfoliation of natural graphite and were successfully modified with a surfactant and an organic compound to obtain a modified GNP additive, that can be facilely dispersed in lubricant oil. The GNPs and modified GNP additive were characterized using scanning electron microscopy, X-ray diffraction, atomic force microscopy, Raman spectroscopy, and Fourier-transform infrared spectroscopy. The prepared GNPs had wrinkled and crumpled structures with a diameter of 10–30 µm and a thickness of less than 15 nm. After modification, the GNP surfaces were uniformly covered with the organic compound. The addition of the modified GNP additive to the engine lubricant oil significantly enhanced the friction and antiwear performance. The highest reduction of 35% was determined for the wear scar diameter with a GNP additive concentration of approximately 0.05%. The mechanism for lubrication enhancement by graphene additives was also briefly discussed.
Duong Duc La; Tuan Ngoc Truong; Thuan Q. Pham; Hoang Tung Vo; Nam The Tran; Tuan Anh Nguyen; Ashok Kumar Nadda; Thanh Tung Nguyen; S. Woong Chang; W. Jin Chung; D. Duc Nguyen. Scalable Fabrication of Modified Graphene Nanoplatelets as an Effective Additive for Engine Lubricant Oil. Nanomaterials 2020, 10, 877 .
AMA StyleDuong Duc La, Tuan Ngoc Truong, Thuan Q. Pham, Hoang Tung Vo, Nam The Tran, Tuan Anh Nguyen, Ashok Kumar Nadda, Thanh Tung Nguyen, S. Woong Chang, W. Jin Chung, D. Duc Nguyen. Scalable Fabrication of Modified Graphene Nanoplatelets as an Effective Additive for Engine Lubricant Oil. Nanomaterials. 2020; 10 (5):877.
Chicago/Turabian StyleDuong Duc La; Tuan Ngoc Truong; Thuan Q. Pham; Hoang Tung Vo; Nam The Tran; Tuan Anh Nguyen; Ashok Kumar Nadda; Thanh Tung Nguyen; S. Woong Chang; W. Jin Chung; D. Duc Nguyen. 2020. "Scalable Fabrication of Modified Graphene Nanoplatelets as an Effective Additive for Engine Lubricant Oil." Nanomaterials 10, no. 5: 877.
In this paper, the anaerobic co-digestion of three different organic wastes, including livestock manure, slaughterhouse waste, and agricultural by-products (ABs), was carried out to enhance the efficiency of mono-digestion of livestock manure. The characteristics of co-digestion were evaluated at different mixing ratios. The experiment was performed using the Batch test and was divided into two parts. The first experimental section (EXP. 1) was designed to evaluate the seasonal characteristics of ABs, which are the different ratios of fruits and vegetables, where the mixing ratio of spring (fruits:vegetables = 3:7) showed the highest biogas yield (0.24 m3/kg volatile solids). The second experiment (EXP. 2) was conducted by using ABs in the ratio that gave the highest biogas yield in EXP. 1 in combinations of three wastes livestock manure, slaughterhouse waste, and ABs. The highest CH4 yield was 0.84 m3/kg volatile solids (VS), which was obtained with a mixing ratio that had even amounts of the three feedstocks. In addition, the results of the second biochemical methane potential test, which assessed the digestive efficiency according to the mixing ratio of the three types of organic waste, showed that the CH4 production rate of the merged digestion was approximately 1.03–1.29 times higher than that of the mono-digestion of livestock manure. The results of our experiment were verified using the modified Gompertz model, the results of which were relatively similar to the experimental results.
Jae Hoon Jeung; Woo Jin Chung; Soon Woong Chang. Evaluation of Anaerobic Co-Digestion to Enhance the Efficiency of Livestock Manure Anaerobic Digestion. Sustainability 2019, 11, 7170 .
AMA StyleJae Hoon Jeung, Woo Jin Chung, Soon Woong Chang. Evaluation of Anaerobic Co-Digestion to Enhance the Efficiency of Livestock Manure Anaerobic Digestion. Sustainability. 2019; 11 (24):7170.
Chicago/Turabian StyleJae Hoon Jeung; Woo Jin Chung; Soon Woong Chang. 2019. "Evaluation of Anaerobic Co-Digestion to Enhance the Efficiency of Livestock Manure Anaerobic Digestion." Sustainability 11, no. 24: 7170.
The Sudokwon landfill site in Korea, is one of the largest landfill sites in the world, and consists of a first landfill site and second landfill site. The second landfill site generates 3–30 times more H2S than that of the first landfill site. However, the cause of the increase in H2S has not been identified. In this study, the main causes of H2S concentration increase were investigated in the second landfill site in the Sudokwon landfill site. We classified wastes at the Sudokwon landfill site into seven types including Construction and demolition (C&D) debris waste. A lysimeter reactor was designed as a similar environment to the Sudokwon landfill site for simulation. In addition, the experiment was conducted under the same conditions. Three components and elements were analyzed to identify the composition of waste in the landfill site. Leachate was analyzed through a chemical oxygen demand and SO42− standard method. For landfill gas, a gas analyzer was used. The trend in the generation of leachate and landfill gas depending on waste composition at the landfill site was observed and the cause of the increase in H2S was examined. As a result, landfilling of C&D debris waste is recommended as a single landfill.
Woojin Chung; Sukyoung Jung; Soonwoong Chang. The Influence of Waste Composition on Landfill Gas Generation in a Pilot-Scale Lysimeter. Applied Sciences 2019, 9, 4677 .
AMA StyleWoojin Chung, Sukyoung Jung, Soonwoong Chang. The Influence of Waste Composition on Landfill Gas Generation in a Pilot-Scale Lysimeter. Applied Sciences. 2019; 9 (21):4677.
Chicago/Turabian StyleWoojin Chung; Sukyoung Jung; Soonwoong Chang. 2019. "The Influence of Waste Composition on Landfill Gas Generation in a Pilot-Scale Lysimeter." Applied Sciences 9, no. 21: 4677.