In this paper,the synthesis and measurement of X-ray crystal structures ofCd￡¨C ￡μH￡μ N￡(c) ￡2￡¨S￡2CO￡-n￡-C￡′H￡1￡(c)￡2andCd￡¨S￡2CO￡-n￡-C￡′H￡1￡(c)2n were reported￡(r)The reaction...In this paper,the synthesis and measurement of X-ray crystal structures ofCd￡¨C ￡μH￡μ N￡(c) ￡2￡¨S￡2CO￡-n￡-C￡′H￡1￡(c)￡2andCd￡¨S￡2CO￡-n￡-C￡′H￡1￡(c)2n were reported￡(r)The reaction ofCd￡¨S ￡2 CO￡-n￡-C ￡′ H ￡1 ￡(c) 2 n with pyridine destroyed the original polymeric structure to and yielded t he bis￡-￡¨lewis bases￡(c)adduct￡(r)The crystals belong to monoclinic system,space group P￡2￡¨￡±￡(c)￡ˉc￡(r)The cell dimensions ofCd￡¨C ￡μ H￡μN￡(c)2(S2CO-n-C4H￡1￡(c)￡2re a￡1/2￡±￡(r)￡±￡°￡1￡′￡¨￡±￡2￡(c)￡?b￡1/2￡°￡(r)￡?￡±￡μ￡2￡¨￡?￡(c)￡?c￡1/2￡±￡(r)7985(1￡1￡(c)nm￡?|?￡1/2￡1￡?￡(r)￡±￡′￡?￡¨￡2￡(c)??￡?V￡1/2￡±￡(r)￡2￡2￡°￡′￡¨￡2￡(c)nm￡3 ￡(r)The structure was refined to R￡± ￡1/2￡°￡(r)￡°￡2￡′￡?and w R ￡2 ￡1/20?r)￡°￡?￡′￡μ￡(r)The complex has a centro-sym metric molecule structure￡(r)The cell dimensions of Cd￡¨S￡2CO￡-n￡-C ￡′ H ￡1 ￡(c) 2 n are a￡1/2￡2￡(r)￡μ￡?￡′￡1￡¨￡′￡(c)￡?b￡1/2￡°￡(r)￡μ￡?￡±￡°￡¨￡*￡(c)￡?c￡1/2￡±￡(r)￡±￡3￡′￡?￡¨￡′￡±￡(c)nm￡?|?￡1/2￡±￡°￡±￡(r)￡*￡°￡±￡¨￡2￡(c)??￡?V￡1/2￡±￡(r)6566(3￡(c)nm￡3 ￡(r)The structure was refined to R￡± ￡1/2￡°￡(r)0711and w R￡2￡1/2￡°￡(r)￡±￡*￡μ￡μ￡(r)展开更多
Sedum alfredii Hance has been identified as a new Zn-hyperaccumulator native to China. In this study, responses and metal accumulation of S alfredii were examined under Zn/Cd complex polluted conditions. The results s...Sedum alfredii Hance has been identified as a new Zn-hyperaccumulator native to China. In this study, responses and metal accumulation of S alfredii were examined under Zn/Cd complex polluted conditions. The results showed that optimal growth of S alfredii in terms of the maximum dry matter yield was observed at Zn/Cd complex level of 500/100 mumol/L. Plant cadmium (Cd) or zinc (Zn) concentrations increased with increasing Cd or Zn supply. During the 20 d treatment, the highest Cd concentration in the leaves reached 12.1 g/kg at Zn/Cd level of 50/400 mumol/L and that of Zn in the stems was 23.2 g/kg at Zn/Cd level of 1000/50 mumol/L. The distribution of Cd in different plant parts decreased in the order: leaf > stem greater than or equal to root, whereas that of Zn was: stem > leaf greater than or equal to root. The accumulation of Cd and Zn in the shoots and roots of S. alfredii increased with the increasing of Zn/Cd supply levels, peaked at Zn/Cd levels of 250/400 and 500/100 mumol/L, respectively. The highest Cd and Zn uptake by the shoots was approximately 5 and 11 mg/plant, and was over 20 and 10 times higher than those in the roots, respectively. Zn supply at levels less than or equal to 500 mumol/L increased plant Cd concentrations, whereas high Zn supply decreased root Cd but did not affect leaf Cd concentrations in S alfredii Low Cd supply increased Zn concentration in the leaves, but Cd supply higher than 50 mumol/L considerably reduced root Zn concentrations, especially at low Zn level. These results indicate that S. alfredii can tolerate high Zn/Cd complex levels and has an extraordinary ability to hyperaccumulate not only Zn but also Cd. It could provide a new valuable plant material for understanding the mechanisms responsible for co-hyperaccumulation of Zn and Cd as well as for phytoremediation of the Cd/Zn complex polluted soils.展开更多
[Objective] The aim was to research effects of substrate complexing light rare earth on growth, Cd absorption and organ distribution of sweet pepper to pro- vide references for development of rhizosphere regulation pr...[Objective] The aim was to research effects of substrate complexing light rare earth on growth, Cd absorption and organ distribution of sweet pepper to pro- vide references for development of rhizosphere regulation products in farmland seri- ously polluted. [Method] In the test, effects of substrate cakes （at the same size） and light rare earth （in different doses） on growth, Cd absorption and distribution of green peppers under stress from Cd were explored with a pot experiment. [Result] When 40 mg/kg of rare earth was added into a substrate cake, plant height of pep- per seedlings and the dry weight increased by 21.52% and 11.11%, compared with control group; when Cd was at 5.19 mg/kg （a highly graded pollution）, the shoot biomass, olant biomass and dry weight of fruits all enhanced significantly, but root system changed little in the groups where substrate cakes were saved, compared with the group where the substrate cake was washed away. No matter RE was added into substrate cakes or not, root system was significantly inhibited by Cd stress （5.19 mg/kg）, but RE at proper dose improved growth of green pepper and had little effect on fruit yielding. In addition, RE had little inhibition on Cd content in roots. RE at 10 mg/kg promoted Cd contents in stems and leaves, but reduced the content in fruits substantially. The regressive equation of Cd content and rare dose in leaves was as follows： y=4E-05x%0.009 6x＋0.655 6, FF=0.542 6; the regression equations of Cd content in root, stem and fruit did not make sense. [Conclusion] The experiment lays foundation for further research on heavy metals rhizosphere complexing controlling.展开更多
Five cytoplasmic male sterile （CMS） lines were used as parents in an incomplete diallet cross and six restorer lines of rice design （Nc II design）. Thirty hybrid combinations with the same growth period were selec...Five cytoplasmic male sterile （CMS） lines were used as parents in an incomplete diallet cross and six restorer lines of rice design （Nc II design）. Thirty hybrid combinations with the same growth period were selected as experimental ma- terials to investigate the heterosis, combined ability and heredity of Cd content in brown rice of indica hybrid rice. According to the results, Cd content in brown rice showed a significantly negative heterosis; the general combining ability and specific combination ability of Cd content in CMS and restorer lines both reached extremely significant level （P〈0.01）, indicating that both genetic improvement of parents and e- valuation of combinations are important to the breeding of hybrid combinations with low accumulation of Cd; the broad-sense heritabitity and narrow-sense heritability of Cd content were both relatively high with slight differences, which respectively reached 97.73% and 80.10%, indicating that Cd content in brown rice mainly de- pends on the additive action of genes; in addition, parent improvement showed bet- ter effect on the selection of early generation.展开更多
Soil contaminated with typical heavy metals (Pb,Cd,Cu,and Zn) was remedied by using the polymeric aluminum salt coagulants including polyaluminum chloride (PAC) and polyaluminum sulfate (PAS).The remediation efficienc...Soil contaminated with typical heavy metals (Pb,Cd,Cu,and Zn) was remedied by using the polymeric aluminum salt coagulants including polyaluminum chloride (PAC) and polyaluminum sulfate (PAS).The remediation efficiencies are influenced by reaction time,water amount,and dosage of remediation agent.The optimal remediation conditions are as follows:6 h of reaction time,1 kg/kg of water addition amount,and 0.25 kg/kg of remediation agent dosage.After PAC addition,the remediation efficiencies of diethylenetriamine-pentaacetic acid (DTPA)-extractable Pb,Cd,Cu,and Zn reach 88.3%,85.1%,85.4%,and 73.7%,respectively;and those for PAS are 89.7%,88.7%,83.5%,and 72.6%,respectively.The main remediation mechanism of the polymeric aluminum salt may contribute to the ionization and hydrolysis of PAC and PAS.H + released from ionization of polymeric aluminum salt can cause the leaching of heavy metals,while the multinuclear complex produced from hydrolysis may result in the immobilization of heavy metals.For PAC,the immobilization of heavy metals is the main remediation process.For PAS,both leaching and immobilization are involved in the remediation process of heavy metals.展开更多
The effect of sulfur compounds （including sulfur, sulfide, sulfite and sulfate）, initial concentration of heavy metal and operating conditions on Cd emission in municipal solid waste （MSW） incineration were invest...The effect of sulfur compounds （including sulfur, sulfide, sulfite and sulfate）, initial concentration of heavy metal and operating conditions on Cd emission in municipal solid waste （MSW） incineration were investi-gated using a simulated tubular furnace and simulated MSW spiked with Cd. The concentration of Cd was meas-ured by inductively coupled plasma-atomic emission spectrometry （ICP-AES） after digesting the samples including bottom ash, fly ash and flue gas according to related USEPA methods. The results show that S and Na2S tend to in- crease Cd partitioning in bottom ash, whereas Na2SO3 and Na2SO4 tend to reduce Cd partitioning in bottom ash. The effect of sulfur compounds on Cd partitioning in bottom ash was in the sequence of Na2S〉S〉Na2SO3〉 Na2SO4. chemical equilibrium analysis is also performed to determine the effect of sorbents on Cd adsorption. The calculations show that S presents strong affinity for Cd and restrains Cd adsorption by SiO2, whereas when temperature rises to between 830℃ and 1030℃, Cd adsorption efficiency of SiO2 is over 80% and the efficiency of Al2O3 is up to 85%.展开更多
A magnetic CoFe2O4/Cd S nanocomposite was prepared via one-step hydrothermal decomposition of cadmium diethanoldithiocarbamate complex on the surface of CoFe2O4 nanoparticles at a low temperature of 200 ℃.The nanocom...A magnetic CoFe2O4/Cd S nanocomposite was prepared via one-step hydrothermal decomposition of cadmium diethanoldithiocarbamate complex on the surface of CoFe2O4 nanoparticles at a low temperature of 200 ℃.The nanocomposite was characterised by X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FT-IR）,scanning electron microscopy,energy-dispersive X-ray spectroscopy（EDX）,UV-visible spectroscopy,transmission electron microscopy（TEM）,N2 gas sorption analysis,X-ray photoelectron spectroscopy（XPS）,and vibrating sample magnetometry.The FT-IR,XRD,EDX and XPS results confirmed the formation of the CoFe2O4/Cd S nanocomposite.Based on the TEM analysis,the CoFe2O4/Cd S nanocomposite constituted nearly uniform,sphere-like nanoparticles of ～20 nm in size.The optical absorption spectrum of the CoFe2O4/Cd S nanocomposite displayed a band gap of 2.21 e V,which made it a suitable candidate for application in sono/photocatalytic degradation of organic pollutants.Accordingly,the sonocatalytic activity of the CoFe2O4/Cd S nanocomposite was evaluated towards the H2O2-assisted degradation of methylene blue,rhodamine B,and methyl orange under ultrasonic irradiation.The nanocomposite displayed excellent sonocatalytic activity towards the degradation of all dyes examined—the dyes were completely decomposed within 5–9 min.Furthermore,a comparison study revealed that the CoFe2O4/Cd S nanocomposite is a more efficient sonocatalyst than pure Cd S;thus,adopting the nanocomposite approach is an excellent means to improve the sonoactivity of Cd S.Moreover,the magnetic properties displayed by the CoFe2O4/Cd S nanocomposite allow easy retrieval of the catalyst from the reaction mixture for subsequent uses.展开更多
A two-dimensional hydrogen-bonded cadmium(II) compound [Cd(dapm)2- (CH3COO)2(H2O)2] (dapm = diaminodiphenylmethane) has been synthesized and characterized by single-crystal X-ray diffraction analysis. It crystallizes ...A two-dimensional hydrogen-bonded cadmium(II) compound [Cd(dapm)2- (CH3COO)2(H2O)2] (dapm = diaminodiphenylmethane) has been synthesized and characterized by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group C2/c with a = 27.572(3), b = 5.5064(5), c = 23.310(2) , = 124.785(1)o, C15H19Cdo.5ON2O3, Mr =331.52, V = 2906.6(5) ?, Z = 4, Dc = 1.515 g/cm3, F(000) = 1368 and = 0.801 mm-1. The final R = 0.0403 and wR = 0.1014 for 1795 observed reflections with I≥4(I). The centrosymmetric Cd(II) is six- coordinated in a distorted octahedral geometry, and the dapm in a trans mode acts as a monoden- tate ligand. The intermolecular hydrogen bonds among coordinated aqua molecules with coordi- nated acetate oxygen atoms and uncoordinated dapm nitrogen atoms form a two-dimensional supramolecular framework.展开更多
A polymeric hydroxyl ferric phosphate(PHFP)was prepared by using a byproduct of titanium dioxide containing ferrous sulfate and phosphates under alkaline condition.The PHFP was used to immobilize lead(Pb)and cadmium(C...A polymeric hydroxyl ferric phosphate(PHFP)was prepared by using a byproduct of titanium dioxide containing ferrous sulfate and phosphates under alkaline condition.The PHFP was used to immobilize lead(Pb)and cadmium(Cd)in soils.Fourier transform infrared spectra,X-ray diffraction were applied to revealing the characteristics of PHFP,and the modified Tessier sequential extraction and column leaching experiment with simulated acid rain were used to assess the effectiveness of immobilization of Cd and Pb in soils by PHFP.The results showed that PHFP was indeed a polymer with complicated OH-Fe-P structure and consisted of Fe6(OH)5(H2O)4(PO4)4(H2O)2and Fe25(PO4)14(OH)24.Moreover,the removal rates of DTPA-extractable Cd and Pb in soils reached up to33%and45%,and the water-soluble Cd and Pb decreased by56%and58%,respectively,when PHFP was added in soils at4%dosage.In addition,the immobilization of Cd and Pb contributed to transforming water soluble,exchangeable and carbonate-bonded fractions to Fe and Mn oxides-bonded,organic-bonded and residual fractions.Under leaching with simulated acid rain,Cd and Pb release amount in PHFP amended soil declined by53%and52%,respectively,as compared with non-treated soil.The result implied that PHFP had a potential application for the remediation of Cd-and Pb-contaminated soils.展开更多
文摘In this paper,the synthesis and measurement of X-ray crystal structures ofCd￡¨C ￡μH￡μ N￡(c) ￡2￡¨S￡2CO￡-n￡-C￡′H￡1￡(c)￡2andCd￡¨S￡2CO￡-n￡-C￡′H￡1￡(c)2n were reported￡(r)The reaction ofCd￡¨S ￡2 CO￡-n￡-C ￡′ H ￡1 ￡(c) 2 n with pyridine destroyed the original polymeric structure to and yielded t he bis￡-￡¨lewis bases￡(c)adduct￡(r)The crystals belong to monoclinic system,space group P￡2￡¨￡±￡(c)￡ˉc￡(r)The cell dimensions ofCd￡¨C ￡μ H￡μN￡(c)2(S2CO-n-C4H￡1￡(c)￡2re a￡1/2￡±￡(r)￡±￡°￡1￡′￡¨￡±￡2￡(c)￡?b￡1/2￡°￡(r)￡?￡±￡μ￡2￡¨￡?￡(c)￡?c￡1/2￡±￡(r)7985(1￡1￡(c)nm￡?|?￡1/2￡1￡?￡(r)￡±￡′￡?￡¨￡2￡(c)??￡?V￡1/2￡±￡(r)￡2￡2￡°￡′￡¨￡2￡(c)nm￡3 ￡(r)The structure was refined to R￡± ￡1/2￡°￡(r)￡°￡2￡′￡?and w R ￡2 ￡1/20?r)￡°￡?￡′￡μ￡(r)The complex has a centro-sym metric molecule structure￡(r)The cell dimensions of Cd￡¨S￡2CO￡-n￡-C ￡′ H ￡1 ￡(c) 2 n are a￡1/2￡2￡(r)￡μ￡?￡′￡1￡¨￡′￡(c)￡?b￡1/2￡°￡(r)￡μ￡?￡±￡°￡¨￡*￡(c)￡?c￡1/2￡±￡(r)￡±￡3￡′￡?￡¨￡′￡±￡(c)nm￡?|?￡1/2￡±￡°￡±￡(r)￡*￡°￡±￡¨￡2￡(c)??￡?V￡1/2￡±￡(r)6566(3￡(c)nm￡3 ￡(r)The structure was refined to R￡± ￡1/2￡°￡(r)0711and w R￡2￡1/2￡°￡(r)￡±￡*￡μ￡μ￡(r)
文摘Sedum alfredii Hance has been identified as a new Zn-hyperaccumulator native to China. In this study, responses and metal accumulation of S alfredii were examined under Zn/Cd complex polluted conditions. The results showed that optimal growth of S alfredii in terms of the maximum dry matter yield was observed at Zn/Cd complex level of 500/100 mumol/L. Plant cadmium (Cd) or zinc (Zn) concentrations increased with increasing Cd or Zn supply. During the 20 d treatment, the highest Cd concentration in the leaves reached 12.1 g/kg at Zn/Cd level of 50/400 mumol/L and that of Zn in the stems was 23.2 g/kg at Zn/Cd level of 1000/50 mumol/L. The distribution of Cd in different plant parts decreased in the order: leaf > stem greater than or equal to root, whereas that of Zn was: stem > leaf greater than or equal to root. The accumulation of Cd and Zn in the shoots and roots of S. alfredii increased with the increasing of Zn/Cd supply levels, peaked at Zn/Cd levels of 250/400 and 500/100 mumol/L, respectively. The highest Cd and Zn uptake by the shoots was approximately 5 and 11 mg/plant, and was over 20 and 10 times higher than those in the roots, respectively. Zn supply at levels less than or equal to 500 mumol/L increased plant Cd concentrations, whereas high Zn supply decreased root Cd but did not affect leaf Cd concentrations in S alfredii Low Cd supply increased Zn concentration in the leaves, but Cd supply higher than 50 mumol/L considerably reduced root Zn concentrations, especially at low Zn level. These results indicate that S. alfredii can tolerate high Zn/Cd complex levels and has an extraordinary ability to hyperaccumulate not only Zn but also Cd. It could provide a new valuable plant material for understanding the mechanisms responsible for co-hyperaccumulation of Zn and Cd as well as for phytoremediation of the Cd/Zn complex polluted soils.
基金Special Fund for Scientific Research for the Public Interest(20100314)National Key Technology R&D Program(2007BAD89B03)Enterprise Service Program by Technicians in the Ministry of Science and Technology(2009GJA00026)~~
文摘[Objective] The aim was to research effects of substrate complexing light rare earth on growth, Cd absorption and organ distribution of sweet pepper to pro- vide references for development of rhizosphere regulation products in farmland seri- ously polluted. [Method] In the test, effects of substrate cakes （at the same size） and light rare earth （in different doses） on growth, Cd absorption and distribution of green peppers under stress from Cd were explored with a pot experiment. [Result] When 40 mg/kg of rare earth was added into a substrate cake, plant height of pep- per seedlings and the dry weight increased by 21.52% and 11.11%, compared with control group; when Cd was at 5.19 mg/kg （a highly graded pollution）, the shoot biomass, olant biomass and dry weight of fruits all enhanced significantly, but root system changed little in the groups where substrate cakes were saved, compared with the group where the substrate cake was washed away. No matter RE was added into substrate cakes or not, root system was significantly inhibited by Cd stress （5.19 mg/kg）, but RE at proper dose improved growth of green pepper and had little effect on fruit yielding. In addition, RE had little inhibition on Cd content in roots. RE at 10 mg/kg promoted Cd contents in stems and leaves, but reduced the content in fruits substantially. The regressive equation of Cd content and rare dose in leaves was as follows： y=4E-05x%0.009 6x＋0.655 6, FF=0.542 6; the regression equations of Cd content in root, stem and fruit did not make sense. [Conclusion] The experiment lays foundation for further research on heavy metals rhizosphere complexing controlling.
基金Supported by Youth Fund Project of Sichuan Academy of Agricultural Sciences(2009QNJJ015)~~
文摘Five cytoplasmic male sterile （CMS） lines were used as parents in an incomplete diallet cross and six restorer lines of rice design （Nc II design）. Thirty hybrid combinations with the same growth period were selected as experimental ma- terials to investigate the heterosis, combined ability and heredity of Cd content in brown rice of indica hybrid rice. According to the results, Cd content in brown rice showed a significantly negative heterosis; the general combining ability and specific combination ability of Cd content in CMS and restorer lines both reached extremely significant level （P〈0.01）, indicating that both genetic improvement of parents and e- valuation of combinations are important to the breeding of hybrid combinations with low accumulation of Cd; the broad-sense heritabitity and narrow-sense heritability of Cd content were both relatively high with slight differences, which respectively reached 97.73% and 80.10%, indicating that Cd content in brown rice mainly de- pends on the additive action of genes; in addition, parent improvement showed bet- ter effect on the selection of early generation.
基金Project(K1201010-61)supported by the Science and Technology Program of Changsha,ChinaProject(51074191)supported by the National Natural Science Foundation of ChinaProject(2012BAC09B04)supported by National Key Technology Research and Development Program,China
文摘Soil contaminated with typical heavy metals (Pb,Cd,Cu,and Zn) was remedied by using the polymeric aluminum salt coagulants including polyaluminum chloride (PAC) and polyaluminum sulfate (PAS).The remediation efficiencies are influenced by reaction time,water amount,and dosage of remediation agent.The optimal remediation conditions are as follows:6 h of reaction time,1 kg/kg of water addition amount,and 0.25 kg/kg of remediation agent dosage.After PAC addition,the remediation efficiencies of diethylenetriamine-pentaacetic acid (DTPA)-extractable Pb,Cd,Cu,and Zn reach 88.3%,85.1%,85.4%,and 73.7%,respectively;and those for PAS are 89.7%,88.7%,83.5%,and 72.6%,respectively.The main remediation mechanism of the polymeric aluminum salt may contribute to the ionization and hydrolysis of PAC and PAS.H + released from ionization of polymeric aluminum salt can cause the leaching of heavy metals,while the multinuclear complex produced from hydrolysis may result in the immobilization of heavy metals.For PAC,the immobilization of heavy metals is the main remediation process.For PAS,both leaching and immobilization are involved in the remediation process of heavy metals.
文摘The effect of sulfur compounds （including sulfur, sulfide, sulfite and sulfate）, initial concentration of heavy metal and operating conditions on Cd emission in municipal solid waste （MSW） incineration were investi-gated using a simulated tubular furnace and simulated MSW spiked with Cd. The concentration of Cd was meas-ured by inductively coupled plasma-atomic emission spectrometry （ICP-AES） after digesting the samples including bottom ash, fly ash and flue gas according to related USEPA methods. The results show that S and Na2S tend to in- crease Cd partitioning in bottom ash, whereas Na2SO3 and Na2SO4 tend to reduce Cd partitioning in bottom ash. The effect of sulfur compounds on Cd partitioning in bottom ash was in the sequence of Na2S〉S〉Na2SO3〉 Na2SO4. chemical equilibrium analysis is also performed to determine the effect of sorbents on Cd adsorption. The calculations show that S presents strong affinity for Cd and restrains Cd adsorption by SiO2, whereas when temperature rises to between 830℃ and 1030℃, Cd adsorption efficiency of SiO2 is over 80% and the efficiency of Al2O3 is up to 85%.
基金the Lorestan University and Iran Nanotechnology Initiative Council (INIC) for their financial support
文摘A magnetic CoFe2O4/Cd S nanocomposite was prepared via one-step hydrothermal decomposition of cadmium diethanoldithiocarbamate complex on the surface of CoFe2O4 nanoparticles at a low temperature of 200 ℃.The nanocomposite was characterised by X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FT-IR）,scanning electron microscopy,energy-dispersive X-ray spectroscopy（EDX）,UV-visible spectroscopy,transmission electron microscopy（TEM）,N2 gas sorption analysis,X-ray photoelectron spectroscopy（XPS）,and vibrating sample magnetometry.The FT-IR,XRD,EDX and XPS results confirmed the formation of the CoFe2O4/Cd S nanocomposite.Based on the TEM analysis,the CoFe2O4/Cd S nanocomposite constituted nearly uniform,sphere-like nanoparticles of ～20 nm in size.The optical absorption spectrum of the CoFe2O4/Cd S nanocomposite displayed a band gap of 2.21 e V,which made it a suitable candidate for application in sono/photocatalytic degradation of organic pollutants.Accordingly,the sonocatalytic activity of the CoFe2O4/Cd S nanocomposite was evaluated towards the H2O2-assisted degradation of methylene blue,rhodamine B,and methyl orange under ultrasonic irradiation.The nanocomposite displayed excellent sonocatalytic activity towards the degradation of all dyes examined—the dyes were completely decomposed within 5–9 min.Furthermore,a comparison study revealed that the CoFe2O4/Cd S nanocomposite is a more efficient sonocatalyst than pure Cd S;thus,adopting the nanocomposite approach is an excellent means to improve the sonoactivity of Cd S.Moreover,the magnetic properties displayed by the CoFe2O4/Cd S nanocomposite allow easy retrieval of the catalyst from the reaction mixture for subsequent uses.
文摘A two-dimensional hydrogen-bonded cadmium(II) compound [Cd(dapm)2- (CH3COO)2(H2O)2] (dapm = diaminodiphenylmethane) has been synthesized and characterized by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group C2/c with a = 27.572(3), b = 5.5064(5), c = 23.310(2) , = 124.785(1)o, C15H19Cdo.5ON2O3, Mr =331.52, V = 2906.6(5) ?, Z = 4, Dc = 1.515 g/cm3, F(000) = 1368 and = 0.801 mm-1. The final R = 0.0403 and wR = 0.1014 for 1795 observed reflections with I≥4(I). The centrosymmetric Cd(II) is six- coordinated in a distorted octahedral geometry, and the dapm in a trans mode acts as a monoden- tate ligand. The intermolecular hydrogen bonds among coordinated aqua molecules with coordi- nated acetate oxygen atoms and uncoordinated dapm nitrogen atoms form a two-dimensional supramolecular framework.
基金Project(2012GS430203)supported by Science and Technology Program for Public Wellbeing,ChinaProject(51504299)supported by the National Natural Science Foundation of ChinaProject(2015WK3016)supported by Science and Technology Program of Hunan Province,China
文摘A polymeric hydroxyl ferric phosphate(PHFP)was prepared by using a byproduct of titanium dioxide containing ferrous sulfate and phosphates under alkaline condition.The PHFP was used to immobilize lead(Pb)and cadmium(Cd)in soils.Fourier transform infrared spectra,X-ray diffraction were applied to revealing the characteristics of PHFP,and the modified Tessier sequential extraction and column leaching experiment with simulated acid rain were used to assess the effectiveness of immobilization of Cd and Pb in soils by PHFP.The results showed that PHFP was indeed a polymer with complicated OH-Fe-P structure and consisted of Fe6(OH)5(H2O)4(PO4)4(H2O)2and Fe25(PO4)14(OH)24.Moreover,the removal rates of DTPA-extractable Cd and Pb in soils reached up to33%and45%,and the water-soluble Cd and Pb decreased by56%and58%,respectively,when PHFP was added in soils at4%dosage.In addition,the immobilization of Cd and Pb contributed to transforming water soluble,exchangeable and carbonate-bonded fractions to Fe and Mn oxides-bonded,organic-bonded and residual fractions.Under leaching with simulated acid rain,Cd and Pb release amount in PHFP amended soil declined by53%and52%,respectively,as compared with non-treated soil.The result implied that PHFP had a potential application for the remediation of Cd-and Pb-contaminated soils.
