This page has only limited features, please log in for full access.
Tannery wastewater contains a variety of complex organic compounds that is usually refractory for biodegradation. In this study, the research objective was to couple novel beneficial microorganisms to oxic processes to degrade organic pollutants at an industrial-scale tannery wastewater treatment plant. The characteristics of the conversion and biodegradation of organic material are also discussed. Although several negatively influencing factors (e.g., chromium) for the removal of organic material were present in this treatment system, an average chemical oxygen demand (COD) removal efficiency of 95.2% was achieved during the 328-day operation. Moreover, the results of a Fourier transform infrared spectroscopy and three-dimensional excitation and emission matrix fluorescence spectra were consistent, showing that organic pollutants (e.g., protein-like, polysaccharide-like, and humic acid-like materials) showed great conversion and synchronous degradation under biotreatment. Humic acid-like and protein-like organic matter were the main components of the influent and effluent organic material, respectively. This was attributed to inoculation of a special composition of beneficial microorganisms with abundant functional genes related to the degradation of organic material.
Yu Cheng; Kangmin Chon; Xianghao Ren; Yingying Kou; Moon-Hyun Hwang; Kyu-Jung Chae. Bioaugmentation treatment of a novel microbial consortium for degradation of organic pollutants in tannery wastewater under a full-scale oxic process. Biochemical Engineering Journal 2021, 175, 108131 .
AMA StyleYu Cheng, Kangmin Chon, Xianghao Ren, Yingying Kou, Moon-Hyun Hwang, Kyu-Jung Chae. Bioaugmentation treatment of a novel microbial consortium for degradation of organic pollutants in tannery wastewater under a full-scale oxic process. Biochemical Engineering Journal. 2021; 175 ():108131.
Chicago/Turabian StyleYu Cheng; Kangmin Chon; Xianghao Ren; Yingying Kou; Moon-Hyun Hwang; Kyu-Jung Chae. 2021. "Bioaugmentation treatment of a novel microbial consortium for degradation of organic pollutants in tannery wastewater under a full-scale oxic process." Biochemical Engineering Journal 175, no. : 108131.
This study systematically investigated the oxidative treatment of five selected pesticides, alachlor (ALA), carbendazim (CAR), diuron (DIU), pyrimethanil (PYR), and tebuconazole (TEB), by comparing their relative reactivities as a function of three different oxidative treatment processes (i.e., chlorine (HOCl), ozone (O3), and ozone/hydrogen peroxide (O3/H2O2)) under various oxidant dosages, reaction times, and pH conditions. For oxidative treatment, pesticide standards were spiked into rainwater. The removal efficiency of the selected pesticides varied considerably depending on the oxidative treatment processes. HOCl, O3, and O3/H2O2 treatments were highly effective at eliminating CAR (>80%) and PYR (>99%), while they were not significantly effective in removing TEB ( O3 (20%) > HOCl (8.5%). The effect of increasing the solution pH from 5.0 to 9.0 on pesticide degradation varied between the oxidative treatment processes. Additionally, NH4+, NO2−, and humic acid in rainwater significantly inhibited pesticide degradation.
Duuriimaa Ochir; Yonggu Lee; JaeGwan Shin; Sangwon Kim; Jinwoo Kwak; Kangmin Chon. Oxidative Treatments of Pesticides in Rainwater Runoff by HOCl, O3, and O3/H2O2: Effects of pH, Humic Acids and Inorganic Matters. Separations 2021, 8, 101 .
AMA StyleDuuriimaa Ochir, Yonggu Lee, JaeGwan Shin, Sangwon Kim, Jinwoo Kwak, Kangmin Chon. Oxidative Treatments of Pesticides in Rainwater Runoff by HOCl, O3, and O3/H2O2: Effects of pH, Humic Acids and Inorganic Matters. Separations. 2021; 8 (7):101.
Chicago/Turabian StyleDuuriimaa Ochir; Yonggu Lee; JaeGwan Shin; Sangwon Kim; Jinwoo Kwak; Kangmin Chon. 2021. "Oxidative Treatments of Pesticides in Rainwater Runoff by HOCl, O3, and O3/H2O2: Effects of pH, Humic Acids and Inorganic Matters." Separations 8, no. 7: 101.
In-situ sludge reduction plays a significant role in reducing excess sludge production. This study investigated the role of beneficial microorganisms (BM) in the anoxic-oxic-settling-anoxic (A-OSA) process associated with the in-situ sludge reduction efficiency under synthetic landfill leachate treatment. The rates of excess sludge reduction with the inoculation of BM increased up to 53.6% (calculated as total suspended solids) and 38.3% (calculated as total volume), respectively. Side-stream reactors, as important components of the A-OSA process, were further studied to explore change of parameters related to in-situ sludge reduction. With the inoculation of BM, the release and conversion of extracellular polymeric substances and the dehydrogenase activity (increasing rate = 60.9%) were increased. Species richness and microbial diversity, as well as the microbial community composition (e.g., hydrolytic and fermentative bacteria), were improved via bioaugmentation. Moreover, potential gene functions of microorganisms were positively regulated and the abundance of gene expressions (e.g., nirK, norB) for in-situ sludge reduction could be improved.
Yu Cheng; Kangmin Chon; Xianghao Ren; Ying Lee; Yingying Kou; Yan Wu; Mingyu Shen; Moon-Hyun Hwang; Kyu-Jung Chae. Contributions of enhanced endogenous microbial metabolism via inoculation with a novel microbial consortium into an anoxic side-stream reactor to in-situ sludge reduction for landfill leachate treatment. Journal of Environmental Management 2021, 295, 113088 .
AMA StyleYu Cheng, Kangmin Chon, Xianghao Ren, Ying Lee, Yingying Kou, Yan Wu, Mingyu Shen, Moon-Hyun Hwang, Kyu-Jung Chae. Contributions of enhanced endogenous microbial metabolism via inoculation with a novel microbial consortium into an anoxic side-stream reactor to in-situ sludge reduction for landfill leachate treatment. Journal of Environmental Management. 2021; 295 ():113088.
Chicago/Turabian StyleYu Cheng; Kangmin Chon; Xianghao Ren; Ying Lee; Yingying Kou; Yan Wu; Mingyu Shen; Moon-Hyun Hwang; Kyu-Jung Chae. 2021. "Contributions of enhanced endogenous microbial metabolism via inoculation with a novel microbial consortium into an anoxic side-stream reactor to in-situ sludge reduction for landfill leachate treatment." Journal of Environmental Management 295, no. : 113088.
This study examined differences in the adsorption kinetics, isotherms, and thermodynamics of the dyes (methyl orange and fast green FCF) by pristine (M–biochar) and chemical activated mandarin peel biochars (MN–biochar and MZ–biochar). The specific surface area (1085.0 m2/g) and pore volume (0.194 cm3/g) of MZ-biochar much higher than those of the M–biochar (specific surface area = 8.5 m2/g, pore volume = 0.016 cm3/g) and MN–biochar (specific surface area = 181.1 m2/g, pore volume = 0.031 cm3/g). The equilibrium adsorption capacities (mg/g) of MO and FG using M–biochar (MO = 0.95, FG = 0.78) MN–biochar (MO = 2.52, FG = 2.13), and MZ–biochar (MO = 16.27, FG = 12.44) have well-matched the pseudo-second-order model (R2 ≥ 0.952) compared with the pseudo-first-order model (R2 ≥ 0.008). Furthermore, the better explanation of the adsorption behavior of dyes by the Freundlich isotherm model (R2 ≥ 0.978) than the Langmuir isotherm model (R2 ≥ 0.881) supports the assumption that the multilayer adsorption governed the adsorption of dyes using mandarin peel biochars. The adsorptions of dyes were significantly dependent on the solution pH and temperature since the electrostatic and spontaneous endothermic reactions governed their removal using the pristine and chemical activated mandarin peel biochars.
Hyunjun Park; Jiseok Kim; Yong-Gu Lee; Kangmin Chon. Enhanced Adsorptive Removal of Dyes Using Mandarin Peel Biochars via Chemical Activation with NH4Cl and ZnCl2. Water 2021, 13, 1495 .
AMA StyleHyunjun Park, Jiseok Kim, Yong-Gu Lee, Kangmin Chon. Enhanced Adsorptive Removal of Dyes Using Mandarin Peel Biochars via Chemical Activation with NH4Cl and ZnCl2. Water. 2021; 13 (11):1495.
Chicago/Turabian StyleHyunjun Park; Jiseok Kim; Yong-Gu Lee; Kangmin Chon. 2021. "Enhanced Adsorptive Removal of Dyes Using Mandarin Peel Biochars via Chemical Activation with NH4Cl and ZnCl2." Water 13, no. 11: 1495.
The single adsorption of radioactive barium (Ba(II)), cobalt (Co(II)), and strontium (Sr(II)) ions using pristine (SCWB–P) and chemically activated spent coffee waste biochars with NaOH (SCWB-A) were thoroughly explored in order to provide deeper insights into the changes in their adsorption mechanisms through alkaline chemical activation. The greater removal efficiencies of SCWB-A (76.6–97.3%) than SCWB-P (45.6–75.2%) and the consistency between the adsorptive removal patterns (Ba(II) > Sr(II) > Co(II)) and oxygen bond dissociation enthalpies (BaO (562 kJ/mol) > SrO (426 kJ/mol) > CoO (397 kJ/mol)) of radioactive species supported the assumption that the adsorption removal of radioactive species with spent coffee waste biochars highly depended on the abundances of O-containing functional groups. The calculated R2 values of the pseudo-first-order (SCWB–P = 0.998–0.999; SCWB-A = 0.850–0.921) and pseudo-second-order kinetic models (SCWB–P = 0.988–0.998; SCWB-A = 0.935–0.966) are evident that the physisorption mainly controlled the adsorption of radioactive species toward SCWB-P and the chemisorption played a crucial role in their adsorptive removal with SCWB-A. From the calculated intra-particle diffusion, isotherm, thermodynamic parameters, it can be concluded that the intra-particle diffusion and monolayer adsorption primarily governed the adsorption of radioactive species using SCWB-P and SCWB-A, and their adsorption processes occurred spontaneously and endothermically. The dominant adsorption mechanism of spent coffee waste biochars was changed from physisorption (ΔH° of SCWB-P = 21.6–29.8 kJ/mol) to chemisorption (ΔH° of SCWB-A = 42.4–81.3 kJ/mol) through alkaline chemical activation. The distinctive M-OH peak in the O1s XPS spectra of SCWB-A directly corresponding to the decrease in the abundances of O-containing functional groups confirms again that the enrichment of O-containing functional groups markedly facilitated the adsorption removal of radioactive species by chemisorption occurred at the inner and outer surfaces of spent coffee waste biochars.
JaeGwan Shin; Jinwoo Kwak; Yong-Gu Lee; Sangwon Kim; Changgil Son; Kyung Hwa Cho; Sang-Ho Lee; Yongeun Park; Xianghao Ren; Kangmin Chon. Changes in adsorption mechanisms of radioactive barium, cobalt, and strontium ions using spent coffee waste biochars via alkaline chemical activation: Enrichment effects of O-containing functional groups. Environmental Research 2021, 199, 111346 .
AMA StyleJaeGwan Shin, Jinwoo Kwak, Yong-Gu Lee, Sangwon Kim, Changgil Son, Kyung Hwa Cho, Sang-Ho Lee, Yongeun Park, Xianghao Ren, Kangmin Chon. Changes in adsorption mechanisms of radioactive barium, cobalt, and strontium ions using spent coffee waste biochars via alkaline chemical activation: Enrichment effects of O-containing functional groups. Environmental Research. 2021; 199 ():111346.
Chicago/Turabian StyleJaeGwan Shin; Jinwoo Kwak; Yong-Gu Lee; Sangwon Kim; Changgil Son; Kyung Hwa Cho; Sang-Ho Lee; Yongeun Park; Xianghao Ren; Kangmin Chon. 2021. "Changes in adsorption mechanisms of radioactive barium, cobalt, and strontium ions using spent coffee waste biochars via alkaline chemical activation: Enrichment effects of O-containing functional groups." Environmental Research 199, no. : 111346.
This study explored the effects of peanut shell biochar (PSB) on the adsorption capacities of fungicides with and without successive chemical modifications, using KMnO4 and KOH (PSBOX-A), in order to provide a valuable understanding of their adsorption mechanisms and behaviors. To this end, the physicochemical properties of PSB and PSBOX-A were examined by using the Brunauer–Emmett–Teller method, Fourier transform infrared spectroscopy, and scanning electron microscopy with an energy dispersive X-ray spectrometer. The effects of temperature, ionic strength, and humic acids on the adsorption of fungicides, using PSB and PSBOX-A, were estimated through batch experiments. Furthermore, adsorption kinetics, isotherms, and thermodynamics were studied. The maximum adsorption capacities of fungicides by PSBOX-A were estimated to be more notable (Qmax of carbendazim = 531.2 μmol g−1, Qmax of pyrimethanil = 467.7 μmol g−1, and Qmax of tebuconazole = 495.1 μmol g−1) than PSB (Qmax of carbendazim = 92.6 μmol g−1, Qmax of pyrimethanil = 61.7 μmol g−1, and Qmax of tebuconazole = 66.7 μmol g−1). These findings suggest that successive chemical modification using KMnO4 and KOH could potentially be used to effectively fabricate PSB to remove fungicides in water-treatment processes.
Yong-Gu Lee; JaeGwan Shin; Jinwoo Kwak; Sangwon Kim; Changgil Son; Geon-Youb Kim; Chang-Ha Lee; Kangmin Chon. Enhanced Adsorption Capacities of Fungicides Using Peanut Shell Biochar via Successive Chemical Modification with KMnO4 and KOH. Separations 2021, 8, 52 .
AMA StyleYong-Gu Lee, JaeGwan Shin, Jinwoo Kwak, Sangwon Kim, Changgil Son, Geon-Youb Kim, Chang-Ha Lee, Kangmin Chon. Enhanced Adsorption Capacities of Fungicides Using Peanut Shell Biochar via Successive Chemical Modification with KMnO4 and KOH. Separations. 2021; 8 (4):52.
Chicago/Turabian StyleYong-Gu Lee; JaeGwan Shin; Jinwoo Kwak; Sangwon Kim; Changgil Son; Geon-Youb Kim; Chang-Ha Lee; Kangmin Chon. 2021. "Enhanced Adsorption Capacities of Fungicides Using Peanut Shell Biochar via Successive Chemical Modification with KMnO4 and KOH." Separations 8, no. 4: 52.
This study has evaluated the removal efficiencies of phosphate ions (PO4 3−) using pristine (TB) and chemical-activated tangerine peel biochars. The adsorption kinetics and isotherm presented that the enhanced physicochemical properties of TB surface through the chemical activation with CaCl2 (CTB) and FeCl3 (FTB) were helpful in the adsorption capacities of PO4 3− (equilibrium adsorption capacity: FTB (1.655 mg g−1) > CTB (0.354 mg g−1) > TB (0.104 mg g−1)). The adsorption kinetics results revealed that PO4 3− removal by TB, CTB, and FTB was well fitted with the pseudo-second-order model (R2 = 0.999) than the pseudo-first-order model (R2 ≥ 0.929). The adsorption isotherm models showed that the Freundlich equation was suitable for PO4 3− removal by TB (R2 = 0.975) and CTB (R2 = 0.955). In contrast, the Langmuir equation was proper for PO4 3− removal by FTB (R2 = 0.987). The PO4 3− removal efficiency of CTB and FTB decreased with the ionic strength increased due to the compression of the electrical double layer on the CTB and FTB surfaces. Besides, the PO4 3− adsorptions by TB, CTB, and FTB were spontaneous endothermic reactions. These findings demonstrated FTB was the most promising method for removing PO4 3− in waters.
Changgil Son; Wonyeol An; GeonHee Lee; Inho Jeong; Yong-Gu Lee; Kangmin Chon. Adsorption Characteristics of Phosphate Ions by Pristine, CaCl2 and FeCl3-Activated Biochars Originated from Tangerine Peels. Separations 2021, 8, 32 .
AMA StyleChanggil Son, Wonyeol An, GeonHee Lee, Inho Jeong, Yong-Gu Lee, Kangmin Chon. Adsorption Characteristics of Phosphate Ions by Pristine, CaCl2 and FeCl3-Activated Biochars Originated from Tangerine Peels. Separations. 2021; 8 (3):32.
Chicago/Turabian StyleChanggil Son; Wonyeol An; GeonHee Lee; Inho Jeong; Yong-Gu Lee; Kangmin Chon. 2021. "Adsorption Characteristics of Phosphate Ions by Pristine, CaCl2 and FeCl3-Activated Biochars Originated from Tangerine Peels." Separations 8, no. 3: 32.
In this study, the adsorption of herbicides using ground coffee residue biochars without (GCRB) and with NaOH activation (GCRB-N) was compared to provide deeper insights into their adsorption behaviors and mechanisms. The physicochemical characteristics of GCRB and GCRB-N were analyzed using Brunauer–Emmett–Teller surface area, Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction and the effects of pH, temperature, ionic strength, and humic acids on the adsorption of herbicides were identified. Moreover, the adsorption kinetics and isotherms were studied. The specific surface area and total pore volume of GCRB-N (405.33 m2/g and 0.293 cm3/g) were greater than those of GCRB (3.83 m2/g and 0.014 cm3/g). The GCBR-N could more effectively remove the herbicides (Qe,exp of Alachlor = 122.71 μmol/g, Qe,exp of Diuron = 166.42 μmol/g, and Qe,exp of Simazine = 99.16 μmol/g) than GCRB (Qe,exp of Alachlor = 11.74 μmol/g, Qe,exp of Diuron = 9.95 μmol/g, and Qe,exp of Simazine = 6.53 μmol/g). These results suggested that chemical activation with NaOH might be a promising option to make the GCRB more practical and effective for removing herbicides in the aqueous solutions.
Yong-Gu Lee; JaeGwan Shin; Jinwoo Kwak; Sangwon Kim; Changgil Son; Kyung Cho; Kangmin Chon. Effects of NaOH Activation on Adsorptive Removal of Herbicides by Biochars Prepared from Ground Coffee Residues. Energies 2021, 14, 1297 .
AMA StyleYong-Gu Lee, JaeGwan Shin, Jinwoo Kwak, Sangwon Kim, Changgil Son, Kyung Cho, Kangmin Chon. Effects of NaOH Activation on Adsorptive Removal of Herbicides by Biochars Prepared from Ground Coffee Residues. Energies. 2021; 14 (5):1297.
Chicago/Turabian StyleYong-Gu Lee; JaeGwan Shin; Jinwoo Kwak; Sangwon Kim; Changgil Son; Kyung Cho; Kangmin Chon. 2021. "Effects of NaOH Activation on Adsorptive Removal of Herbicides by Biochars Prepared from Ground Coffee Residues." Energies 14, no. 5: 1297.
This study comprehensively investigated the performances of the anoxic-oxic processes with (AO-M) and without the beneficial microorganisms (AO-N) for the treatment of the ammonium-rich landfill leachates. Although the AO-M had the lower concentrations of the mixed liquor suspended solids (MLSS, 3230 mg L-1) and mixed liquor volatile suspended solids (MLVSS, 2480 mg L-1) compared to the AO-N process (MLSS = 7790 mg L-1; MLVSS = 5260 mg L-1), dissolved organic compounds and nitrogen species could be more effectively removed using the AO-M process (removal efficiency of dissolved organic carbon (DOC) = 99.0%; removal efficiency of total nitrogen (TN) = 79.2%) than the AO-N process (removal efficiency of DOC = 98.6%; removal efficiency of TN = 75.1%). Moreover, the excess sludge production was also less pronounced for the AO-M process than the AO-N process since the enhanced endogenous respiration and relative enzyme activity of microorganisms in the oxic bioreactor of the AO-M process via the inoculation of the beneficial microorganisms reduced the excess sludge production significantly. These observations suggest that the variations in the relative abundances of microorganisms through the inoculation of the beneficial microorganisms into the sludge digestion tank might enhance the removal of nitrogen species and the reduction of the excess sludge production during the during the treatment of the ammonium-rich landfill leachates.
Yu Cheng; Kangmin Chon; Xianghao Ren; Yingying Kou; Yan Wu; Qian Zhao; Moon-Hyun Hwang; Kyu-Jung Chae. The role of beneficial microorganisms in an anoxic-oxic (AO) process for treatment of ammonium-rich landfill leachates: Nitrogen removal and excess sludge reduction. Journal of Environmental Chemical Engineering 2021, 9, 105188 .
AMA StyleYu Cheng, Kangmin Chon, Xianghao Ren, Yingying Kou, Yan Wu, Qian Zhao, Moon-Hyun Hwang, Kyu-Jung Chae. The role of beneficial microorganisms in an anoxic-oxic (AO) process for treatment of ammonium-rich landfill leachates: Nitrogen removal and excess sludge reduction. Journal of Environmental Chemical Engineering. 2021; 9 (4):105188.
Chicago/Turabian StyleYu Cheng; Kangmin Chon; Xianghao Ren; Yingying Kou; Yan Wu; Qian Zhao; Moon-Hyun Hwang; Kyu-Jung Chae. 2021. "The role of beneficial microorganisms in an anoxic-oxic (AO) process for treatment of ammonium-rich landfill leachates: Nitrogen removal and excess sludge reduction." Journal of Environmental Chemical Engineering 9, no. 4: 105188.
This study rigorously investigated the adsorption behaviors and mechanisms of strontium ions (Sr2+) by the pristine and magnetic biochars prepared via the pyrolysis of pristine and FeCl3-pretreated spent coffee grounds (SCG). The FeCl3-pretreatment could magnetize successfully the pristine SCG biochars (magnetization value of pristine SCG biochars = 0.19 emu/g; magnetization value of magnetic SCG biochars = 8.99 emu/g) and improved substantially their specific surface area (pristine SCG biochars = 5.3 m2/g; magnetic SCG biochars = 431.7 m2/g) and total pore volume (pristine SCG biochars = 0.002 cm3/g; magnetic SCG biochars = 0.186 cm3/g). However, the removal efficiency of Sr2+ with the pristine SCG biochars (33.4–34.1%) was not significantly different from that with the magnetic SCG biochars (33.1–33.9%). The calculated kinetic parameters indicate that the adsorption of Sr2+ by the pristine and magnetic SCG biochars was governed by the chemisorption (R2 of the pseudo-first-order kinetic equation ≤ 0.602; R2 of the pseudo-second-order kinetic equation = 1.000). The higher R2 values of the Langmuir isotherm (R2 = 0.999) model compared to the Freundlich isotherm model (R2 ≤ 0.950) are evident that the monolayer adsorption mainly determined the adsorptive removal of Sr2+ with the pristine and magnetic SCG biochars. Moreover, the adsorption of Sr2+ using the pristine and magnetic SCG biochars was the spontaneous and endothermic process. These observations indicate that the FeCl3-pretreatment might offer a viable way to effectively recover the residual SCG biochars after the Sr2+ adsorption through the magnetic separation (recovery rate = 90%).
JaeGwan Shin; Yong-Gu Lee; Jinwoo Kwak; Sangwon Kim; Sang-Ho Lee; Yongeun Park; Kangmin Chon. Adsorption of radioactive strontium by pristine and magnetic biochars derived from spent coffee grounds. Journal of Environmental Chemical Engineering 2021, 9, 105119 .
AMA StyleJaeGwan Shin, Yong-Gu Lee, Jinwoo Kwak, Sangwon Kim, Sang-Ho Lee, Yongeun Park, Kangmin Chon. Adsorption of radioactive strontium by pristine and magnetic biochars derived from spent coffee grounds. Journal of Environmental Chemical Engineering. 2021; 9 (2):105119.
Chicago/Turabian StyleJaeGwan Shin; Yong-Gu Lee; Jinwoo Kwak; Sangwon Kim; Sang-Ho Lee; Yongeun Park; Kangmin Chon. 2021. "Adsorption of radioactive strontium by pristine and magnetic biochars derived from spent coffee grounds." Journal of Environmental Chemical Engineering 9, no. 2: 105119.
This study investigated the competitive adsorption mechanisms of pharmaceuticals (i.e., naproxen, diclofenac, and ibuprofen) toward the pristine and NaOH-activated biochars from spent coffee wastes (SCW) in lake water and wastewater effluent. The kinetic and isotherm studies revealed that the improved physicochemical characteristics and physically homogenized surfaces of the pristine SCW biochar through the chemical activation with NaOH were beneficial to the adsorption of pharmaceuticals (competitive equilibrium adsorption capacity (Qe, exp): NaOH-activated SCW biochar (61.25–192.07 μmol/g) > pristine SCW biochar (14.81–20.65 μmol/g)). The adsorptive removal of naproxen (Qe, exp = 14.81–18.81 μmol/g), diclofenac (Qe, exp = 15.73–20.00 μmol/g), and ibuprofen (Qe, exp = 16.20–20.65 μmol/g) for the pristine SCW biochar showed linear correlations with their hydrophobicity (log D at pH 7.0: ibuprofen (1.71) > diclofenac (1.37) > naproxen (0.25)). However, their Qe, exp values for the NaOH-activated SCW biochar (naproxen (176.39–192.07 μmol/g) > diclofenac (78.44–98.74 μmol/g) > ibuprofen (61.25–80.02 μmol/g)) were inversely correlated to the order of their log D values. These results suggest that the reinforced aromatic structure of the NaOH-activated SCW biochar facilitated the π-π interaction. The calculated thermodynamic parameters demonstrated that the competitive adsorption of pharmaceuticals on the NaOH-activated SCW biochar compared to pristine SCW biochar occurred more spontaneously over the entire pH (5.0–11.0) and ionic strength (NaCl: 0–0.125 M) ranges. These observations imply that the NaOH-activated SCW biochar might be potentially applicable for the removal of pharmaceuticals in lake water and wastewater effluent.
JaeGwan Shin; Jinwoo Kwak; Yong-Gu Lee; Sangwon Kim; Minhee Choi; Sungjun Bae; Sang-Ho Lee; Yongeun Park; Kangmin Chon. Competitive adsorption of pharmaceuticals in lake water and wastewater effluent by pristine and NaOH-activated biochars from spent coffee wastes: Contribution of hydrophobic and π-π interactions. Environmental Pollution 2020, 270, 116244 .
AMA StyleJaeGwan Shin, Jinwoo Kwak, Yong-Gu Lee, Sangwon Kim, Minhee Choi, Sungjun Bae, Sang-Ho Lee, Yongeun Park, Kangmin Chon. Competitive adsorption of pharmaceuticals in lake water and wastewater effluent by pristine and NaOH-activated biochars from spent coffee wastes: Contribution of hydrophobic and π-π interactions. Environmental Pollution. 2020; 270 ():116244.
Chicago/Turabian StyleJaeGwan Shin; Jinwoo Kwak; Yong-Gu Lee; Sangwon Kim; Minhee Choi; Sungjun Bae; Sang-Ho Lee; Yongeun Park; Kangmin Chon. 2020. "Competitive adsorption of pharmaceuticals in lake water and wastewater effluent by pristine and NaOH-activated biochars from spent coffee wastes: Contribution of hydrophobic and π-π interactions." Environmental Pollution 270, no. : 116244.
The sequential effects of the cleaning protocols on the desorption of the reverse osmosis (RO) membrane foulants related to the recovery of the membrane surface characteristics were examined through the autopsies of the fouled RO membrane module from the full-scale seawater desalination plant in the Gijang province (Pusan, Republic of Korea). Although the types of cleaning agents were found to be a key factor affecting the desorption of the RO membrane foulants, the sequential cleaning protocol I (SCP I; 0.1 N NaOH → 0.1 N HCl → deionized (DI) water) more effectively desorbed both the organic and inorganic foulants from the RO membrane surfaces compared to the sequential cleaning protocol II (SCP II: 0.1 N HCl → 0.1 N NaOH → DI water). Moreover, the contact angle and the negative surface zeta potential of the cleaned RO membrane with SCP I were higher than those of the cleaned RO membrane with SCP II. These results demonstrated that the strategic pairing of three different cleaning agents governed the desorption efficiencies of the organic and inorganic foulants and the restoration of the membrane surface features in association with the performances of the RO membranes (i.e., permeate flux and salt rejection).
Yong-Gu Lee; Sangwon Kim; JaeGwan Shin; Hojung Rho; Young Mi Kim; Kyung Hwa Cho; Heonseop Eom; Sang-Eun Oh; Jaeweon Cho; Kangmin Chon. Sequential effects of cleaning protocols on desorption of reverse osmosis membrane foulants: Autopsy results from a full-scale desalination plant. Desalination 2020, 500, 114830 .
AMA StyleYong-Gu Lee, Sangwon Kim, JaeGwan Shin, Hojung Rho, Young Mi Kim, Kyung Hwa Cho, Heonseop Eom, Sang-Eun Oh, Jaeweon Cho, Kangmin Chon. Sequential effects of cleaning protocols on desorption of reverse osmosis membrane foulants: Autopsy results from a full-scale desalination plant. Desalination. 2020; 500 ():114830.
Chicago/Turabian StyleYong-Gu Lee; Sangwon Kim; JaeGwan Shin; Hojung Rho; Young Mi Kim; Kyung Hwa Cho; Heonseop Eom; Sang-Eun Oh; Jaeweon Cho; Kangmin Chon. 2020. "Sequential effects of cleaning protocols on desorption of reverse osmosis membrane foulants: Autopsy results from a full-scale desalination plant." Desalination 500, no. : 114830.
This study has investigated the selective immobilization of antimony using the brucite (magnesium hydroxide)-rich precipitate (BP) collected from a hypochlorous storage tank in a nuclear power plant of South Korea. The energy dispersive X-ray and X-ray diffraction analyses revealed that the BP mainly consisted of magnesium (72.5%) and its dominant mineral phase was brucite (Mg(OH)2). Therefore, brandholzite (Mg[Sb(OH)6]2·6H2O) was newly formed through the surface-induced precipitation during the adsorption of antimony using the BP. The adsorbed amount of antimony increased with decreasing pH values because of the increased positive surface charge of the BP (pHpzc = 9.6). The maximum adsorption capacity (Qmax) of BP, calculated by Langmuir adsorption isotherm, was 11.02 mg/g. The presence of competitive anions did not significantly affect the adsorption of antimony toward the BP due to its high selectivity. These results suggest that the facile utilization of the BP as a low-cost adsorbent seems to be a practical option for the selective removal of antimony from wastewater.
Kyung-Hee Lee; Yong-Gu Lee; JaeGwan Shin; Kangmin Chon; Sang-Ho Lee. Selective Immobilization of Antimony Using Brucite-rich Precipitate Produced during In Situ Hypochlorous Acid Formation through Seawater Electrolysis in a Nuclear Power Plant. Energies 2020, 13, 4493 .
AMA StyleKyung-Hee Lee, Yong-Gu Lee, JaeGwan Shin, Kangmin Chon, Sang-Ho Lee. Selective Immobilization of Antimony Using Brucite-rich Precipitate Produced during In Situ Hypochlorous Acid Formation through Seawater Electrolysis in a Nuclear Power Plant. Energies. 2020; 13 (17):4493.
Chicago/Turabian StyleKyung-Hee Lee; Yong-Gu Lee; JaeGwan Shin; Kangmin Chon; Sang-Ho Lee. 2020. "Selective Immobilization of Antimony Using Brucite-rich Precipitate Produced during In Situ Hypochlorous Acid Formation through Seawater Electrolysis in a Nuclear Power Plant." Energies 13, no. 17: 4493.
This study examined differences in the adsorption isotherms, kinetic equations, and thermodynamics of Sr2+ by biochar from spent coffee grounds (SCG) and powdered activated carbon (PAC). The specific surface area (957.6 m2/g) and pore volume (0.676 cm3/g) of PAC were much greater than those of SCG biochar (specific surface area = 11.0 m2/g, pore volume = 0.009 cm3/g). However, SCG biochar showed a higher maximum adsorption capacity of Sr2+ (Qmax = 51.81 mg/g) compared with PAC (Qmax = 32.79 mg/g) due to its abundance of O-containing functional groups. The negligible removal efficiencies of Sr2+ by SCG biochar and PAC under acidic conditions (pH = 1.0–3.0) are evidence that the electrostatic repulsion might hinder severely the adsorption of Sr2+ by the carbonaceous adsorbents. The higher R2 values of the pseudo-second-order model (R2 ≥ 0.999) compared with the pseudo-first-order model (R2 ≥ 0.815) suggest that chemisorption governed the removal of Sr2+ using SCG biochar and PAC. Furthermore, the better description of the adsorption behavior of Sr2+ by the Langmuir isotherm model (R2 ≥ 0.994) than the Freundlich isotherm model (R2 ≥ 0.982) supports the assumption that the monolayer adsorption played critical roles in the removal of Sr2+ using SCG biochar and PAC. The thermodynamic studies revealed that adsorption of Sr2+ onto SCG biochar and PAC was endothermic and happened spontaneously. Despite the significant inhibitory effects of DOM, SCG biochar exhibited the higher removal efficiencies of Sr2+ compared with PAC. Hence, SCG biochar could be considered as an alternative to PAC for the removal of Sr2+ from aqueous solutions.
JaeGwan Shin; Sang-Ho Lee; Sangwon Kim; Duuriimaa Ochir; Yongeun Park; Jihye Kim; Yong-Gu Lee; Kangmin Chon. Effects of physicochemical properties of biochar derived from spent coffee grounds and commercial activated carbon on adsorption behavior and mechanisms of strontium ions (Sr2+). Environmental Science and Pollution Research 2020, 28, 40623 -40632.
AMA StyleJaeGwan Shin, Sang-Ho Lee, Sangwon Kim, Duuriimaa Ochir, Yongeun Park, Jihye Kim, Yong-Gu Lee, Kangmin Chon. Effects of physicochemical properties of biochar derived from spent coffee grounds and commercial activated carbon on adsorption behavior and mechanisms of strontium ions (Sr2+). Environmental Science and Pollution Research. 2020; 28 (30):40623-40632.
Chicago/Turabian StyleJaeGwan Shin; Sang-Ho Lee; Sangwon Kim; Duuriimaa Ochir; Yongeun Park; Jihye Kim; Yong-Gu Lee; Kangmin Chon. 2020. "Effects of physicochemical properties of biochar derived from spent coffee grounds and commercial activated carbon on adsorption behavior and mechanisms of strontium ions (Sr2+)." Environmental Science and Pollution Research 28, no. 30: 40623-40632.
The fouling characteristics of dissolved organic matter (DOM) in the fresh water and seawater compartments of the reverse electrodialysis (RED) system were investigated under natural water conditions. The salinity gradient power generation was governed monovalent ions whereas multivalent ions strongly contributed to the fouling formation of the ion-exchange membranes (IEMs). The partial deposition of DOM within the membrane pores during its passage from the fresh water compartment to the seawater compartment facilitated the fouling formation of the IEMs. Despite of the similar DOC losses in fresh water (DOC loss = 20%) and seawater (DOC loss = 22%) through the RED system, the colour variations of the anion-exchange membranes (AEMs) and spacers in contact with fresh water were more noticeable than those in contact with seawater. These results indicate that the deposition of hydrophobic DOM components onto the AEM surfaces water may lead to the increases in the pressure drop of the fresh water compartment and the decreases in the power density of the RED system. Therefore, an appropriate pre-treatment strategy capable of mitigating membrane fouling by hydrophobic DOM components seemed to be indispensable to maintain constantly the performance of the RED system under natural water conditions.
Kangmin Chon; Namjo Jeong; Hojung Rho; Joo-Youn Nam; Eunjin Jwa; Jaeweon Cho. Fouling characteristics of dissolved organic matter in fresh water and seawater compartments of reverse electrodialysis under natural water conditions. Desalination 2020, 496, 114478 .
AMA StyleKangmin Chon, Namjo Jeong, Hojung Rho, Joo-Youn Nam, Eunjin Jwa, Jaeweon Cho. Fouling characteristics of dissolved organic matter in fresh water and seawater compartments of reverse electrodialysis under natural water conditions. Desalination. 2020; 496 ():114478.
Chicago/Turabian StyleKangmin Chon; Namjo Jeong; Hojung Rho; Joo-Youn Nam; Eunjin Jwa; Jaeweon Cho. 2020. "Fouling characteristics of dissolved organic matter in fresh water and seawater compartments of reverse electrodialysis under natural water conditions." Desalination 496, no. : 114478.
The objective of this study was development of a simple and reliable microbial toxicity test based on fermentative bacteria to assess heavy metal (Hg2+, Cu2+, Cr6+, Ni2+, As5+, or Pb2+)-contaminated water. The dominant species of test organisms used in this study was a spore-forming fermentative bacterium, Clostridium guangxiense. Toxicity of water was assessed based on inhibition of fermentative gas production of the test organisms, which was analyzed via a syringe method. Overall, the fermentative bacteria-based test kits satisfactorily identified increased toxicity of water as water was contaminated with high amounts of heavy metals; however, levels of inhibition were dissimilar depending on the species of metals. Inhibitory effects of Hg2+, Cu2+, Cr6+, and Ni2+ were considerably greater than those of As5+ and Pb2+. The 24 h half-maximum effective concentrations (EC50) for Hg2+, Cu2+, Cr6+, Ni2+, As5+, and Pb2+ were analyzed to be 0.10, 0.51, 1.09, 3.61, 101.33, and 243.45 mg/L, respectively, confirming that Hg2+, Cu2+, Cr6+, and Ni2+ are more toxic to fermentative gas production than As5+ and Pb2+. The fermentative bacteria-based toxicity test represents an improvement over other existing toxicity tests because of ease of end-point measurement, high reproducibility, and favorable on-site field applicability. These advantages make the fermentative bacteria-based test suitable for simple and reliable toxicity screening for heavy metal-contaminated water.
Heonseop Eom; Woochang Kang; Seunggyu Kim; Kangmin Chon; Yong-Gu Lee; Sang-Eun Oh. Improved toxicity analysis of heavy metal-contaminated water via a novel fermentative bacteria-based test kit. Chemosphere 2020, 258, 127412 .
AMA StyleHeonseop Eom, Woochang Kang, Seunggyu Kim, Kangmin Chon, Yong-Gu Lee, Sang-Eun Oh. Improved toxicity analysis of heavy metal-contaminated water via a novel fermentative bacteria-based test kit. Chemosphere. 2020; 258 ():127412.
Chicago/Turabian StyleHeonseop Eom; Woochang Kang; Seunggyu Kim; Kangmin Chon; Yong-Gu Lee; Sang-Eun Oh. 2020. "Improved toxicity analysis of heavy metal-contaminated water via a novel fermentative bacteria-based test kit." Chemosphere 258, no. : 127412.
This study investigated effects of the thermal hydrolysis pre-treatment on mechanical deep dewaterability of dewatered sludge to extend understanding of dewatering characteristics of thermally hydrolyzed sludge. Floc sizes of dewatered sludge were gradually reduced during the thermal hydrolysis pre-treatment at 170 °C and 185 °C with increasing retention time whereas longer retention time (>60 min) increased floc sizes of thermally hydrolyzed sludges at 200 °C due to formation of undesired refractory organic materials (ROMs), which might hinder the disintegration of dewatered sludge flocs. Similar trends were found for thermal hydrolytic solubilization of dewatered sludge. This demonstrated that the efficiency of the thermal hydrolysis pre-treatment at a higher temperature (200 °C) with longer retention time (≥60 min) could be strongly influenced by the formation of ROMs associated with changes of solid fractions and some free amino acids (i.e., β-aminobutyric acid, 4-hydroxyproline, and cysteine). Since the trade-off between the degradation of dewatered sludge and the formation of ROMs determined mechanical deep dewaterability of thermally hydrolyzed sludge, the lowest residual weight and moisture content were observed for thermally hydrolyzed sludges at 200 °C with retention time range of 60 min (residual weight = 0.165; moisture content = 55.38%) to 90 min (residual weight = 0.160; moisture content = 59.87%). These observations were intimately correlated to variations of extracellular polymeric substances during the thermal hydrolysis pre-treatment, but not in accordance with the change pattern of capillary suction time (CST) values. This is evident that the CST value was inadequate to estimate mechanical deep dewaterability of thermally hydrolyzed sludge.
Hee-Joong Kim; Kangmin Chon; Yong-Gu Lee; Youn-Kwon Kim; Am Jang. Enhanced mechanical deep dewatering of dewatered sludge by a thermal hydrolysis pre-treatment: Effects of temperature and retention time. Environmental Research 2020, 188, 109746 .
AMA StyleHee-Joong Kim, Kangmin Chon, Yong-Gu Lee, Youn-Kwon Kim, Am Jang. Enhanced mechanical deep dewatering of dewatered sludge by a thermal hydrolysis pre-treatment: Effects of temperature and retention time. Environmental Research. 2020; 188 ():109746.
Chicago/Turabian StyleHee-Joong Kim; Kangmin Chon; Yong-Gu Lee; Youn-Kwon Kim; Am Jang. 2020. "Enhanced mechanical deep dewatering of dewatered sludge by a thermal hydrolysis pre-treatment: Effects of temperature and retention time." Environmental Research 188, no. : 109746.
This study investigated the single and competitive adsorption characteristics of micropollutants using the pristine and alkali-modified spent coffee grounds (SCG) biochars. The alkali modification substantially improved the physicochemical characteristics of the SCG biochars (specific surface area and pore volume), which may have led to differences in the adsorption behaviors of the micropollutants. The pseudo second order model (R2 ≥ 0.990) better described the single and competitive adsorption kinetics than the pseudo first order model (R2 ≥ 0.664). It is evident that chemisorption played a key role in the removal of the micropollutants by the pristine and alkali-modified SCG biochars. The single and competitive adsorptions of the micropollutants were highly dependent on the solution pH and ionic strength since the pore-filling effects, electrostatic and hydrophobic interactions governed their removal by the pristine and alkali-modified SCG biochars. The higher removal efficiencies of the micropollutants by the alkali-modified SCG biochars (≥ 44.5%) in the presence of dissolved organic matter compared to the pristine SCG biochars (≤ 18.5%) support the assumption that alkali modification could markedly reinforce the surface structural properties of the SCG biochars related to the adsorption capacities.
JaeGwan Shin; Yong-Gu Lee; Sang-Ho Lee; Sangwon Kim; Duuriimaa Ochir; Yongeun Park; Jihye Kim; Kangmin Chon. Single and competitive adsorptions of micropollutants using pristine and alkali-modified biochars from spent coffee grounds. Journal of Hazardous Materials 2020, 400, 123102 .
AMA StyleJaeGwan Shin, Yong-Gu Lee, Sang-Ho Lee, Sangwon Kim, Duuriimaa Ochir, Yongeun Park, Jihye Kim, Kangmin Chon. Single and competitive adsorptions of micropollutants using pristine and alkali-modified biochars from spent coffee grounds. Journal of Hazardous Materials. 2020; 400 ():123102.
Chicago/Turabian StyleJaeGwan Shin; Yong-Gu Lee; Sang-Ho Lee; Sangwon Kim; Duuriimaa Ochir; Yongeun Park; Jihye Kim; Kangmin Chon. 2020. "Single and competitive adsorptions of micropollutants using pristine and alkali-modified biochars from spent coffee grounds." Journal of Hazardous Materials 400, no. : 123102.
The fouling and cleaning behaviors of m-phenylenediamine (MPD), coumarin-3-carboxylic acid (CCA), and d-(+)-glucose (DG) on polyamide nanofiltration (NF) membrane surfaces were investigated with a focus on the two intrinsic equilibrium constants (pKa,intr.) of carboxylic and amine functional groups determined using potentiometric titration. The charged foulants (MPD and CCA) strongly influenced the pKa,intr. of the membrane surface after the fouling layer formed via electrostatic interactions (Virgin = 3.4 and 9.2; MPD-fouled = 4.1 and 8.1; CCA-fouled = 1.5 and 12.4). Moreover, the pKa,intr. of electrostatically fouled membranes substantially recovered when using cleaning agents that released electrostatic interactions (cleaned MPD-fouled = 3.5 and 9.0; cleaned CCA-fouled = 3.3 and 9.6). In contrast, the neutral foulant (DG) did not affect the pKa,intr. (DG-fouled = 3.5 and 9.2); however, the ζ-potential of DG-fouled membrane was closer to zero than the virgin membrane (Virgin = -28.1 mV and DG-fouled = -7.2 mV at pH 7). The pKa,intr. value accurately represented the electrostatic interactions between organic foulants and membrane surfaces. Potentiometric titration is a facile method of determining the pKa,intr. that gives an in-depth understanding of the electrostatic interactions at the membrane surface associated with the membrane fouling and cleaning mechanism.
Hojung Rho; Jaeweon Cho; Paul Westerhoff; Kangmin Chon. Intrinsic pKa of Nanofiltration Membrane Surfaces to Assess Fouling and Cleaning Behaviors Induced by Foulant–Membrane Electrostatic Interactions. Environmental Science & Technology 2020, 54, 7706 -7714.
AMA StyleHojung Rho, Jaeweon Cho, Paul Westerhoff, Kangmin Chon. Intrinsic pKa of Nanofiltration Membrane Surfaces to Assess Fouling and Cleaning Behaviors Induced by Foulant–Membrane Electrostatic Interactions. Environmental Science & Technology. 2020; 54 (12):7706-7714.
Chicago/Turabian StyleHojung Rho; Jaeweon Cho; Paul Westerhoff; Kangmin Chon. 2020. "Intrinsic pKa of Nanofiltration Membrane Surfaces to Assess Fouling and Cleaning Behaviors Induced by Foulant–Membrane Electrostatic Interactions." Environmental Science & Technology 54, no. 12: 7706-7714.
The charge characteristics (i.e., surface charge and zeta potential) of two different nanofiltration (NF) membranes were characterized by the potentiometric titration and electrophoresis methods under various experimental conditions, i.e., pH, ionic strength, ionic species, and organic fouled membranes to clarify the salt rejection mechanism of the NF membranes. The both charge characteristics of the NF membranes clearly represented the variation in the salt rejection behavior at different ionic strengths and for electrostatically fouled membranes. However, the surface charge of the NF membranes was independent of the ionic species and with the neutrally fouled membrane, whereas the zeta potential changed substantially with changes in the ionic species and the neutrally fouled membrane. Therefore, the variation in salt rejection behavior for different ionic species and with a neutrally fouled membrane was better described by the zeta potential values, which reflected the ion transport properties (i.e., ion valency and diffusivity) affecting the electrophoretic and electroosmotic flows at the shear plane of the membranes. These results indicate the electrophoresis method is considered as a promising tool for predicting the electrostatic transport of various ions at the shear plane of the membrane surfaces, intimately associated with the salt rejection behavior in the NF membrane processes.
Byung-Moon Jun; Jaeweon Cho; Am Jang; Kangmin Chon; Paul Westerhoff; Yeomin Yoon; Hojung Rho. Charge characteristics (surface charge vs. zeta potential) of membrane surfaces to assess the salt rejection behavior of nanofiltration membranes. Separation and Purification Technology 2020, 247, 117026 .
AMA StyleByung-Moon Jun, Jaeweon Cho, Am Jang, Kangmin Chon, Paul Westerhoff, Yeomin Yoon, Hojung Rho. Charge characteristics (surface charge vs. zeta potential) of membrane surfaces to assess the salt rejection behavior of nanofiltration membranes. Separation and Purification Technology. 2020; 247 ():117026.
Chicago/Turabian StyleByung-Moon Jun; Jaeweon Cho; Am Jang; Kangmin Chon; Paul Westerhoff; Yeomin Yoon; Hojung Rho. 2020. "Charge characteristics (surface charge vs. zeta potential) of membrane surfaces to assess the salt rejection behavior of nanofiltration membranes." Separation and Purification Technology 247, no. : 117026.