Flotation separation of quartz from apatite and surface forces in bubble–particle interactions: Role of pH and cationic amine collector contents

Han, Yosep,Han, Seongsoo,Kim, Byeongwoo,Yang, Jiwon,Choi, Junhyun,Kim, Kwanho,You, Kwang-Suk,Kim, Hyunjung Elsevier 2019 Journal of industrial and engineering chemistry Vol.70 No.-

<P><B>Abstract</B></P> <P>Dodecylamine hydrochloride (DAHC) surfactant was used as a collector for effective apatite recovery through flotation separation in siliceous phosphate ore, wherein quartz is the main gangue mineral. The roles of pH and collector concentration were investigated, and the adsorption of the collector on the minerals and related properties were systematically studied by measuring zeta potential, contact angle, surface tension, and adsorption density. When the collector concentration was 5×10<SUP>−5</SUP> M, 23.7% P<SUB>2</SUB>O<SUB>5</SUB> grade was achieved for a conditioning time of 10min. However, the separation performance of the flotation was lower at pH 7 regardless of the collector concentration. Thus, more collector molecules are adsorbed on the quartz surface than the apatite surface at pH 3 and 5×10<SUP>−5</SUP> M of collector, resulting in separation of quartz and apatite. The extended Derjaguin–Landau–Verwey–Overbeek (DLVO) theory, which considers the hydrophobic interaction energy, revealed that the improved flotation performance is attributed to a hydrophobic attractive force that is a consequence of the collector adsorption. Therefore, the results of flotation of artificially mixed minerals further revealed that optimization of the amine collector concentration and pH value can selectively separate quartz from apatite.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Selective separation of quartz from apatite can be obtained using the collector at pH 3. </LI> <LI> Adsorption of the collector on the mineral surface occures by electrostatic attraction. </LI> <LI> Higher selective separation obtained due to higher adsorption of collector on quartz surface. </LI> <LI> Hydrophobic interaction energy improved due to the collector adsorbed on the quartz surface. </LI> <LI> Quartz particle can be reversely floated efficiently by high hydrophobicity interaction. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Electrospun hydrogen manganese oxide nanofibers as effective adsorbents for Li+ recovery from seawater

Yosep Han,Seongmin Kim,Sooyoun Yu,Nosang V. Myung,Hyunjung Kim 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.81 No.-

Highly porous hydrogen manganese oxide (HMO) nanofibers were fabricated by combining electrospinning,calcination, and ion exchanges, and their lithium (Li) recovery performance was systematicallycompared to other adsorbent types (i.e., nanoparticles and porous microbeads with equivalentproperties). In seawater, the HMO nanofibers exhibited an excellent Li+ adsorption capacity (18.8 mg/g)with greater Li+ selectivity over other adsorbents. These might be attributed to the high number ofmacropores in the nanofiber, which facilitated the inward diffusion of Li+ and enhanced the accessibilityof activated sites. Moreover, the Li+ recovery efficiency of the nanofibers remained approximately 95%after 20 recovery cycles.

Transport, retention, and long-term release behavior of ZnO nanoparticle aggregates in saturated quartz sand: Role of solution pH and biofilm coating

Han, Yosep,Hwang, Gukhwa,Kim, Donghyun,Bradford, Scott A.,Lee, Byoungcheun,Eom, Igchun,Kim, Pil Je,Choi, Siyoung Q.,Kim, Hyunjung Elsevier 2016 Water research Vol.90 No.-

<P><B>Abstract</B></P> <P>The transport, retention, and long-term release of zinc oxide nanoparticle aggregates (denoted below as ZnO-NPs) were investigated in saturated, bare and biofilm (<I>Pseudomonas putida</I>) coated sand packed columns. Almost complete retention of ZnO-NPs occurred in bare and biofilm coated sand when the influent solution pH was 9 and the ionic strength (IS) was 0.1 or 10 mM NaCl, and the retention profiles were always hyper-exponential. Increasing the solution IS and biofilm coating produced enhanced retention of ZnO-NPs near the column inlet. The enhanced NPs retention at high IS was attributed to more favorable NP-silica and NP-NP interactions; this was consistent with the interaction energy calculations. Meanwhile, the greater NPs retention in the presence of biofilm was attributed to larger roughness heights which alter the mass transfer rate, the interaction energy profile, and lever arms associated with the torque balance; e.g., scanning electron and atomic force microscopy was used to determine roughness heights of 33.4 nm and 97.8 nm for bare sand and biofilm-coated sand, respectively. Interactions between NPs and extracellular polymeric substances may have also contributed to enhanced NP retention in biofilm-coated sand at low IS. The long-term release of retained ZnO-NPs was subsequently investigated by continuously injecting NP-free solution at pH 6, 9, or 10 and keeping the IS constant at 10 mM. The amount and rate of retained ZnO-NP removal was strongly dependent on the solution pH. Specifically, almost complete removal of retained ZnO-NPs was observed after 627 pore volumes when the solution pH was 6, whereas much less Zn was recovered when the eluting solution pH was buffered to pH = 9 and especially 10. This long-term removal was attributed to pH-dependent dissolution of retained ZnO-NPs because: (i) the solubility of ZnO-NPs increases with decreasing pH; and (ii) ZnO-NPs were not detected in the effluent. The presence of biofilm also decreased the initial rate and amount of dissolution and the subsequent transport of Zn<SUP>2+</SUP> due to the strong Zn<SUP>2+</SUP> re-adsorption to the biofilm. Our study indicates that dissolution will eventually lead to the complete removal of retained ZnO-NPs and the transport of toxic Zn<SUP>2+</SUP> ions in groundwater environments with pH ranges of 5–9.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Mobility of ZnO-NPs decreases at high ionic strength and in biofilm-coated sand. </LI> <LI> NPs–NPs interaction leads to the hyper exponential shape of retention profiles. </LI> <LI> Lowering pH highly increases the release rate and amount of retained ZnO-NPs. </LI> <LI> The release of ZnO-NPs at low pH mainly occurs by the dissolution of NPs. </LI> <LI> The presence of biofilm retards the release of retained ZnO-NPs. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Transport, Retention, and Long-term Release Behaviors of Zinc Oxide Nanoparticles in Saturated Quartz Sand

Yosep Han(한요셉) 환경독성보건학회 2017 한국독성학회 심포지움 및 학술발표회 Vol.2017 No.2

Diminazene aceturate exacerbates renal fibrosis after unilateral ureteral obstruction in female mice

( Yosep Kim ),( Jongwan Kim ),( Sang Jun Han ) 대한신장학회 2023 Kidney Research and Clinical Practice Vol.42 No.2

Background: Diminazene aceturate (DIZE), an angiotensin-converting enzyme 2 (ACE2) activator, exerts anti-inflammatory and antifibrotic effects in a variety of human chronic diseases. However, the role of DIZE in kidney fibrosis and the underlying mechanism remain unclear. Therefore, we investigated the effects of DIZE on the progression of renal fibrosis after unilateral ureteral obstruction (UUO), a well-established model of chronic kidney disease. Methods: C57BL/6 female or male mice were subjected to right UUO. Mice received 15 mg/kg DIZE or vehicle (saline) daily. On the 7th day after UUO, kidneys were collected for analysis of renal fibrosis (α-smooth muscle actin, phosphorylated SMAD3, transforming growth factor (TGF)-β, Masson’s trichrome, and Sirius red staining), inflammation (macrophage infiltration, proinflammatory cytokines/ chemokines), apoptosis/necrotic cell death (TUNEL and periodic acid-Schiff staining), and ACE2 activity and messenger RNA (mRNA) expression. Results: Treatment with DIZE exacerbated renal fibrosis by upregulating the profibrotic TGF-β/SMAD3 pathway, proinflammatory cytokine/chemokines (interleukin [IL]-1β, monocyte chemoattractant protein-1, IL-6, and macrophage inflammatory protein-2) levels, M2 macrophage accumulation (CD206, IL-4, IL-10, and CX3CL1), and apoptotic/necrotic cell death in the obstructed kidneys of female mice but not male mice. However, DIZE treatment had no effect on ACE2 activity or mRNA expression. Conclusion: DIZE exacerbates UUO-induced renal fibrosis by aggravating tubular damage, apoptosis, and inflammation through independent of angiotensin (1-7), angiotensin II levels, and ACE2 expression/activity, rather than protecting against renal fibrosis after UUO. DIZE also has powerful effects on recruiting macrophages, including the M2-polarized subtype, in female UUO mice.

과학 기술 정보 수용에 대한 영향 요인의 탐색

송요셉(Yosep Song),한동섭(Dong-sub Han) 부산울산경남언론학회 2011 지역과 커뮤니케이션 Vol.15 No.2

이 연구는 과학 기술과 관련된 정보들의 효과적인 수용 방안을 과학 교육과의 연계를 통해 살펴본 것이며, 특히 원자력 관련 정보의 수용에 많은 관심을 두고 있다. 한국에서 원자력 관련 정책들은 실패하는 경우가 많았는데, 이러한 사례들은 주로 정보의 전달이 곧 태도의 변화를 유도할 것이라는 인식에 기반하고 있다. 그러나 원자력과 관련된 태도는 관련된 정보보다도 기존에 형성되어 있던 부정적인 인식에 더욱 많은 영향을 받고 있으며 쉽게 변화하지도 않고 있다. 이 연구는 과학 교육과 원자력 관련 정보 제공과의 연계를 통해 이러한 상황의 개선을 모색하고 있다. 연구는 자기 확신, 관련성 인식, 유용성 인식, 미디어 내용 판단, 미디어 내용 흥미, 태도의 여섯 변인들이 맺는 관계를 9개의 가설을 통해 검증하는 과정이었으며, 가설들은 두 가지를 제외하고 모두 채택되었다. 연구 결과에 의하면, 원자력 관련 정보의 제공보다도 원자력을 위시한 과학 기술 영역에 대한 내적인 학습 유지 요인을 더욱 중요시할 필요가 있다. 또한 교육자는 관련성과 유용성을 강조하는 목표 설정을 통해 학습을 촉진하는 역할을 수행할 수 있다. 그리고 이러한 부분이 충족될 때 미디어가 취급하는 원자력 관련 정보들의 다양화도 효과를 발휘할 수 있다. 이상의 유기적인 연계를 통해 원자력에 대한 수용성이 높아질 수 있다. This research examines effective ways to accept the information related to scientific technology in connection with science education, and particularly it has great interest in the information related to nuclear energy. Many policies related to nuclear energy in Korea have failed, and these cases are based mainly on the recognition that the conveyance of information will induce changes in attitude. However, attitude toward nuclear energy is more affected by the negative recognition that has been previously formed than by the information related to nuclear energy. This research attempts to improve such circumstances through connecting science education with providing the information related to nuclear energy. This research was a process in which connections formed by 6 variables, namely, self-assurance, relevance recognition, utility recognition, media content judgment, media content interest, and attitude were tested through 9 hypotheses, and all the hypotheses except two hypotheses were adopted. According to the results of this research, more emphasis needs to be placed on internal learning maintenance factors for scientific technology realms including nuclear energy rather than providing the information related to nuclear energy. And educators can play the role of promoting learning through establishing goals emphasizing relevance and utility. When these conditions are met, the diversity of information related to nuclear energy that media deal with can take effect. Through the above-mentioned organic connections, acceptability of nuclear energy can be enhanced.

Pore Characteristics and Hydrothermal Stability of Mesoporous Silica: Role of Oleic Acid

Choi, Junhyun,Han, Yosep,Park, Soyeon,Park, Jayhyun,Kim, Hyunjung Hindawi Limited 2014 Journal of nanomaterials Vol.2014 No.-

<P>Silicate mesoporous materials were synthesized with nonionic surfactant and their surfaces were modified by oleic acid adsorption. Infrared spectrometer, nitrogen adsorption-desorption isotherm, scanning electron microscopy, and thermogravimetric analyses were used to investigate the structure of oleic acid modified mesoporous material. The effects of heat treatment at various temperatures on oleic acid modified materials were also studied. Oleic acids on silica surfaces were found to be bonded chemically and/or physically and be capable of enduring up to<SUP>180°</SUP>C. The adsorbed oleic acid improved the hydrothermal stability of mesoporous silica and assisted mesopore structure to grow more in hydrothermal treatment process by preventing the approach of water.</P>

Influence of Bentonite on the Transport and Retention of Zinc Oxide Nanomaterials in Soil Environment

Donghyun Kim,Yosep Han,Gilsang Hong,Byoungcheun Lee,lgchun Eom,Pil Je Kim,Seungkon Kim,Hyunjung Kim 대한환경공학회 2013 대한환경공학회 학술발표논문집 Vol.2013 No.6

Synthesis of hierarchical MoO₂/MoS₂ nanofibers for electrocatalytic hydrogen evolution

Rheem, Youngwoo,Han, Yosep,Lee, Kyu Hwan,Choi, Sung-Mook,Myung, Nosang V IOP 2017 Nanotechnology Vol.28 No.10

<P>Perpendicularly attached MoS<SUB>2</SUB> nanosheets on MoO<SUB>2</SUB> conductive nanofibers were synthesized by combining electrospinning, calcination, and sulfurization processes. Compared to randomly stacked MoS<SUB>2</SUB> nanosheets on MoO<SUB>2</SUB> nanofiber, they show greater hydrogen evolution reaction (HER) performance (i.e., onset potential of −180 mV versus normal hydrogen electrode with the Tafel slope of 59 mV dec<SUP>−1</SUP>). HER performance decreases with increasing MoS<SUB>2</SUB> nanocrystal size.</P>

Influence of Surrounding Conditions on Representative Gram Negative and Gram Positive Soil Bacterial Inactivation

Gukhwa Hwang,Yosep Han,Sangho Cho,Hyunjung Kim 대한환경공학회 2013 대한환경공학회 학술발표논문집 Vol.2013 No.6