Reductive immobilization of radioactive pertechnetate(99TcO4^-) in simulated groundwater was studied by prepared carboxymethyl cellulose(CMC) and starch stabilized zero valent iron nanoparticles(nZVI),and long-term re...Reductive immobilization of radioactive pertechnetate(99TcO4^-) in simulated groundwater was studied by prepared carboxymethyl cellulose(CMC) and starch stabilized zero valent iron nanoparticles(nZVI),and long-term remobilization of reduced Tc was also evaluated under anoxic and oxic conditions.The stabilized nZVI can effectively reduce soluble 99Tc(Ⅶ) to insoluble 99 Tc(Ⅳ),and they can be easily delivered into a contaminated groundwater zone and facilitate in situ remediation.In this study,CMCstabilized nZVI showed higher reactivity than that using starch as the stabilizer.Batch experiments indicated that more than 99% of 99 Tc(Ⅶ)(CO=12 mg/mL) was reduced and removed from groundwater by CMC-stabilized nZVI with a CMC content of 0.2%(w/w) at a broad pH of 5-8.X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS) analyses further confirmed that 99Tc(Ⅶ)O4^-transformed into 99Tc(Ⅳ)O2(s).The presence of bicarbonate exhibited insignificant effect on Tc immobilization,while humic acid(HA) inhibited reaction mainly due to retardation on electron transfer and formation of Tc(IV)-HA complexes.More interesting,the immobilized Tc(Ⅳ) remained insoluble even after 120 d under anoxic condition,while only^21 % was remobilized when exposed to air.Therefore,biomacromolecules stabilized nZVI nanoparticles could be a viable alternative for in situ remediation of radioactive contamination in groundwater.展开更多
Due to improved soil deliverability and high reactivity,stabilized nanoparticles have been studied for nearly two decades for in situ remediation of soil and groundwater contaminated with organic pollutants.While larg...Due to improved soil deliverability and high reactivity,stabilized nanoparticles have been studied for nearly two decades for in situ remediation of soil and groundwater contaminated with organic pollutants.While large amounts of bench-and field-scale experimental data have demonstrated the potential of the innovative technology,extensive research results have also unveiled various merits and constraints associated different soil characteristics,types of nanoparticles and particle stabilization techniques.Overall,this work aims to critically overview the fundamental principles on particle stabilization,and the evolution and some recent developments of stabilized nanoparticles for degradation of organic contaminants in soil and groundwater.The specific objectives are to:1)overview fundamental mechanisms in nanoparticle stabilization;2)summarize key applications of stabilized nanoparticles for in situ remediation of soil and groundwater contaminated by legacy and emerging organic chemicals;3)update the latest knowledge on the transport and fate of stabilized nanoparticles;4)examine the merits and constraints of stabilized nanoparticles in environmental remediation applications;and 5)identify the knowledge gaps and furore research needs pertaining to stabilized nanoparticles for remediation of contaminated soil and groundwater.Per instructions of this invited special issue,this review is focused on contributions from our group(one of the pioneers in the subject field),which,however,is supplemented by important relevant works by others.The knowledge gained is expected to further advance the science and technology in the environmental applications of stabilized nanoparticles.展开更多
CeO_2 stabilized ZrO_2 ultra fine nanoparticles were successfully synthesized via a simple and effective sol-gel synthetic approach by using zirconylchloride octahydrate, cerium nitrate hexahydrate, and citric acid as...CeO_2 stabilized ZrO_2 ultra fine nanoparticles were successfully synthesized via a simple and effective sol-gel synthetic approach by using zirconylchloride octahydrate, cerium nitrate hexahydrate, and citric acid as starting materials. A series of techniques, including X-ray diffraction（XRD）, thermogravimetry（TG）, differential scanning calorimetry（DSC）, Fourier transform infrared spectroscopy（FTIR）, transmission electron microscopy（TEM）, and N_2-sorption analysis, were used to characterize the structure and morphology of the asprepared samples. XRD studies indicate that the as-synthesized sample is of well crystallized tetragonal phase of CeO_2 stabilized ZrO_2 with high purity. TEM images show that the as-synthesized sample is composed of a large number of fine dispersive nanoparticles with an average size about 10 nm. The as-synthesized tetragonal CeO_2 stabilized ZrO_2 sample was heated at different temperatures in order to evaluate its thermal stability. The exprimental results reveal that the as-synthesized tetragonal CeO_2 stabilized ZrO_2 sample exhibits excellent stability without the occurrence of phase transformation.展开更多
According to the extent of fungal infections, to be chronic these such diseases and recently the emerging issue of increased antibiotic resistance in fungal infections, most of scientists are going to find a proper wa...According to the extent of fungal infections, to be chronic these such diseases and recently the emerging issue of increased antibiotic resistance in fungal infections, most of scientists are going to find a proper way to replace antibacterial agent by significant semiconductor ZnO nanoparticles (NPs). They are well known to be one of the most important and special metal oxide nanoparticles in pharmaceutical against the most common fungi. ZnO nanoparticles were synthesized using sol-gel, hydrothermal and functionalized surface methods and formulated in water solutions as nanofluids. XRD, FTIR and SEM techniques and UV-Vis absorbance spectroscopy characterized their ZnO modified nanostructures. Also antimycotic potential according to generally tests such as: (MIC) minimum inhibitory concentration, (MFC) minimum fungicidal concentration and normally well diffusion method with standard strains fungi were performed. Among five common fungi strains using in this research, new various ZnO nanofluids showed noticeable results for dermatophyte fungi like Trichophyton mentagrophytes, Microsporum gypseum, Microsporum canis, Candida albicans and Candid tropicalis which had un growth zones in order 70, 40, 35, 30 and 30 mm in comparing with Clotrimazole reference reagent: 30, 25, 25, 18 and 20 mm by well method. The performance of MIC for ZnO nanofluids on fungi was determined to be equal to 0.35, 3.12, 6.25, 6.25 and 6.25 μgr/ml and MFC of nanoproducts showed the 1.5, 12.5, 25, 25 and 25 μgr/ml. Therefore, the designed ZnO nanofluids could reveal the most effect on fungi which cause dermal (ringworm), mucosal (thrush) and vaginal infections, so we are able to apply these surface high energetic ZnO water-based nanofluid formulations as in vitro nanomedicine and nanohygiene for the first time.展开更多
The 0.7 wt% Pt ＋ 0.3 wt% Rh/Ce0.6Zr0.4O2 catalysts were fabricated via different methods, including ultrasonic-assisted membrane reduction （UAMR） co-precipitation, UAMR separation precipitation, co-impregnation, an...The 0.7 wt% Pt ＋ 0.3 wt% Rh/Ce0.6Zr0.4O2 catalysts were fabricated via different methods, including ultrasonic-assisted membrane reduction （UAMR） co-precipitation, UAMR separation precipitation, co-impregnation, and sequential impregnation. The catalysts were physico-chemically characterized by N2 adsorption, XRD, TEM, and Hz-TPR techniques, and evaluated for three-way catalytic activities with simulated automobile exhaust. UAMR co-precipitation- and UAMR separation precipitation- prepared catalysts exhibited a high surface area and metal dispersion, wide λ window and excellent conversion for NOx reduction under lean conditions. Both fresh and aged catalysts from UAMR- precipitation showed the high surface areas of ca. 60-67 m^2/g and 18-22 m^2/g, respectively, high metal dispersion of 41%-55%, and small active particle diameters of 2.1-2.7 nm. When these catalysts were aged, the catalysts prepared by the UAMR method exhibited a wider working window （△λ = 0.284--0.287） than impregnated ones （△λ = 0.065-0.115） as well as excellent three-way catalytic performance, and showed lower/so （169℃） and T90 （195℃） for NO reduction than the aged catalysts from impregnation processes, which were at 265 and 309℃, respectively. This implied that the UAMR-separation precipitation has important potential for industrial applications to improve catalytic performance and thermal stability. The fresh and aged 0.7 wt% Pt ＋ 0.3 wt% Rh/Ce0.6Zr0.4O2 catalysts prepared by the UAMR-separation precipitation method exhibited better catalytic performance than the corresponding catalysts prepared by conventional impregnation routes.展开更多
The stabilizing process of glass particle in water by optical trap using the pulsed counter-propagating Gaussian beams is investigated. The influence of the optical power and the particle dimension on the rate and tim...The stabilizing process of glass particle in water by optical trap using the pulsed counter-propagating Gaussian beams is investigated. The influence of the optical power and the particle dimension on the rate and time of the stabilizing process is simulated and discussed.展开更多
基金partially supported by the National Natural Science Foundation of China(No.41230638)a grant from the USDA AAES 2015 Hatch and Multistate funding program
文摘Reductive immobilization of radioactive pertechnetate(99TcO4^-) in simulated groundwater was studied by prepared carboxymethyl cellulose(CMC) and starch stabilized zero valent iron nanoparticles(nZVI),and long-term remobilization of reduced Tc was also evaluated under anoxic and oxic conditions.The stabilized nZVI can effectively reduce soluble 99Tc(Ⅶ) to insoluble 99 Tc(Ⅳ),and they can be easily delivered into a contaminated groundwater zone and facilitate in situ remediation.In this study,CMCstabilized nZVI showed higher reactivity than that using starch as the stabilizer.Batch experiments indicated that more than 99% of 99 Tc(Ⅶ)(CO=12 mg/mL) was reduced and removed from groundwater by CMC-stabilized nZVI with a CMC content of 0.2%(w/w) at a broad pH of 5-8.X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS) analyses further confirmed that 99Tc(Ⅶ)O4^-transformed into 99Tc(Ⅳ)O2(s).The presence of bicarbonate exhibited insignificant effect on Tc immobilization,while humic acid(HA) inhibited reaction mainly due to retardation on electron transfer and formation of Tc(IV)-HA complexes.More interesting,the immobilized Tc(Ⅳ) remained insoluble even after 120 d under anoxic condition,while only^21 % was remobilized when exposed to air.Therefore,biomacromolecules stabilized nZVI nanoparticles could be a viable alternative for in situ remediation of radioactive contamination in groundwater.
基金supported by the Auburn University IGP Program,the National Natural Science Foundation of China(No.41807340)the Guangdong Innovative and Entrepreneurial Research Team Program(No.2016ZT06N569).
文摘Due to improved soil deliverability and high reactivity,stabilized nanoparticles have been studied for nearly two decades for in situ remediation of soil and groundwater contaminated with organic pollutants.While large amounts of bench-and field-scale experimental data have demonstrated the potential of the innovative technology,extensive research results have also unveiled various merits and constraints associated different soil characteristics,types of nanoparticles and particle stabilization techniques.Overall,this work aims to critically overview the fundamental principles on particle stabilization,and the evolution and some recent developments of stabilized nanoparticles for degradation of organic contaminants in soil and groundwater.The specific objectives are to:1)overview fundamental mechanisms in nanoparticle stabilization;2)summarize key applications of stabilized nanoparticles for in situ remediation of soil and groundwater contaminated by legacy and emerging organic chemicals;3)update the latest knowledge on the transport and fate of stabilized nanoparticles;4)examine the merits and constraints of stabilized nanoparticles in environmental remediation applications;and 5)identify the knowledge gaps and furore research needs pertaining to stabilized nanoparticles for remediation of contaminated soil and groundwater.Per instructions of this invited special issue,this review is focused on contributions from our group(one of the pioneers in the subject field),which,however,is supplemented by important relevant works by others.The knowledge gained is expected to further advance the science and technology in the environmental applications of stabilized nanoparticles.
基金Funded by the National Natural Science Foundation of China(Nos.U1304520 and U1404613)the State Key Lab of Materials Synthesis and Processing of Wuhan University of Technology for the fund support(2012-KF-5)+1 种基金the Education Department of Henan Province(2013GGJS-185)the program for New Century Excellent Talents in University(NECT-12-0655)
文摘CeO_2 stabilized ZrO_2 ultra fine nanoparticles were successfully synthesized via a simple and effective sol-gel synthetic approach by using zirconylchloride octahydrate, cerium nitrate hexahydrate, and citric acid as starting materials. A series of techniques, including X-ray diffraction（XRD）, thermogravimetry（TG）, differential scanning calorimetry（DSC）, Fourier transform infrared spectroscopy（FTIR）, transmission electron microscopy（TEM）, and N_2-sorption analysis, were used to characterize the structure and morphology of the asprepared samples. XRD studies indicate that the as-synthesized sample is of well crystallized tetragonal phase of CeO_2 stabilized ZrO_2 with high purity. TEM images show that the as-synthesized sample is composed of a large number of fine dispersive nanoparticles with an average size about 10 nm. The as-synthesized tetragonal CeO_2 stabilized ZrO_2 sample was heated at different temperatures in order to evaluate its thermal stability. The exprimental results reveal that the as-synthesized tetragonal CeO_2 stabilized ZrO_2 sample exhibits excellent stability without the occurrence of phase transformation.
文摘According to the extent of fungal infections, to be chronic these such diseases and recently the emerging issue of increased antibiotic resistance in fungal infections, most of scientists are going to find a proper way to replace antibacterial agent by significant semiconductor ZnO nanoparticles (NPs). They are well known to be one of the most important and special metal oxide nanoparticles in pharmaceutical against the most common fungi. ZnO nanoparticles were synthesized using sol-gel, hydrothermal and functionalized surface methods and formulated in water solutions as nanofluids. XRD, FTIR and SEM techniques and UV-Vis absorbance spectroscopy characterized their ZnO modified nanostructures. Also antimycotic potential according to generally tests such as: (MIC) minimum inhibitory concentration, (MFC) minimum fungicidal concentration and normally well diffusion method with standard strains fungi were performed. Among five common fungi strains using in this research, new various ZnO nanofluids showed noticeable results for dermatophyte fungi like Trichophyton mentagrophytes, Microsporum gypseum, Microsporum canis, Candida albicans and Candid tropicalis which had un growth zones in order 70, 40, 35, 30 and 30 mm in comparing with Clotrimazole reference reagent: 30, 25, 25, 18 and 20 mm by well method. The performance of MIC for ZnO nanofluids on fungi was determined to be equal to 0.35, 3.12, 6.25, 6.25 and 6.25 μgr/ml and MFC of nanoproducts showed the 1.5, 12.5, 25, 25 and 25 μgr/ml. Therefore, the designed ZnO nanofluids could reveal the most effect on fungi which cause dermal (ringworm), mucosal (thrush) and vaginal infections, so we are able to apply these surface high energetic ZnO water-based nanofluid formulations as in vitro nanomedicine and nanohygiene for the first time.
基金supported by the National Nature Foundation of China(No.21277009)the Beijing National Nature Foundation(No.2101002)+2 种基金the Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality(No.PHR201107104,PHR200907105)the National Research and Development Program(863)of China(No.2011AA03A406)the National Industrial Project of New Rare Earth Materials
文摘The 0.7 wt% Pt ＋ 0.3 wt% Rh/Ce0.6Zr0.4O2 catalysts were fabricated via different methods, including ultrasonic-assisted membrane reduction （UAMR） co-precipitation, UAMR separation precipitation, co-impregnation, and sequential impregnation. The catalysts were physico-chemically characterized by N2 adsorption, XRD, TEM, and Hz-TPR techniques, and evaluated for three-way catalytic activities with simulated automobile exhaust. UAMR co-precipitation- and UAMR separation precipitation- prepared catalysts exhibited a high surface area and metal dispersion, wide λ window and excellent conversion for NOx reduction under lean conditions. Both fresh and aged catalysts from UAMR- precipitation showed the high surface areas of ca. 60-67 m^2/g and 18-22 m^2/g, respectively, high metal dispersion of 41%-55%, and small active particle diameters of 2.1-2.7 nm. When these catalysts were aged, the catalysts prepared by the UAMR method exhibited a wider working window （△λ = 0.284--0.287） than impregnated ones （△λ = 0.065-0.115） as well as excellent three-way catalytic performance, and showed lower/so （169℃） and T90 （195℃） for NO reduction than the aged catalysts from impregnation processes, which were at 265 and 309℃, respectively. This implied that the UAMR-separation precipitation has important potential for industrial applications to improve catalytic performance and thermal stability. The fresh and aged 0.7 wt% Pt ＋ 0.3 wt% Rh/Ce0.6Zr0.4O2 catalysts prepared by the UAMR-separation precipitation method exhibited better catalytic performance than the corresponding catalysts prepared by conventional impregnation routes.
文摘The stabilizing process of glass particle in water by optical trap using the pulsed counter-propagating Gaussian beams is investigated. The influence of the optical power and the particle dimension on the rate and time of the stabilizing process is simulated and discussed.
