Sponsored by college of chemistry and molecular engineering, Peking University and Thermo Fisher Scientific, The Asian Regional Conference on 2DCOS （2DCOS-2014） was held （19, April, 2014 - 20, April, 2014） at the ...Sponsored by college of chemistry and molecular engineering, Peking University and Thermo Fisher Scientific, The Asian Regional Conference on 2DCOS （2DCOS-2014） was held （19, April, 2014 - 20, April, 2014） at the beautiful campus of Peking University. Prof. lsao Noda,展开更多
A number of useful techniques associated with two-dimensional correlation spectroscopy(2DCOS)to improve its performance and utility have been developed in the last 30years.Evolution of these 2DCOS techniques,including...A number of useful techniques associated with two-dimensional correlation spectroscopy(2DCOS)to improve its performance and utility have been developed in the last 30years.Evolution of these 2DCOS techniques,including some of the very recent developments,is reviewed with examples.Topics include merged or modified asynchronous 2Dcorrelation spectrum,two-dimensional codistribution spectroscopy(2DCDS),Pareto scaling,and null-space projection treatment of spectral dataset.展开更多
Biochar-derived dissolved organic matter(DOM)is a highly active component that plays a critical and complex role in the immobilization of heavy metals.This study systematically investigated the impact of DOM on Pb(Ⅱ)...Biochar-derived dissolved organic matter(DOM)is a highly active component that plays a critical and complex role in the immobilization of heavy metals.This study systematically investigated the impact of DOM on Pb(Ⅱ)adsorption by comparing the adsorption capacities of biochar before and after DOM removal,thereby unveiling the underlying mechanisms through advanced spectroscopic techniques.Adsorption experiments demonstrated that water-washed biochar(WBC)exhibited a markedly reduced adsorption capacity(35.0 mg g^(−1))compared to untreated biochar(BC)(96.2 mg g^(−1)),highlighting the essential role of DOM in enhancing Pb(Ⅱ)adsorption.Kinetic and isothermal analyses revealed that the adsorption process was predominantly chemical in nature,as evidenced by the excellent fit of experimental data to the pseudo-second-order,Freundlich,and Temkin models.FTIR and XPS analyses confirmed that oxygen-containing functional groups,including hydroxyl,carboxyl,carbonyl,and ether groups,actively participated in Pb(Ⅱ)complexation in BC,WBC,and DOM.Spectral shifts and changes in the relative abundance of C–O and C=O bonds further supported this conclusion.The Pb 4f spectra indicated that Pb(Ⅱ)was primarily retained as Pb_(3)(OH)_(2)(CO_(3))_(2),with complexation identified as the dominant mechanism,followed by co-precipitation.UV differential log-transformed absorption spectra derived from titration experiments,revealed the heterogeneity of Pb(Ⅱ)binding sites within DOM.Furthermore,excitation-emission matrix fluorescence spectroscopy coupled with parallel factor analysis(EEM-PARAFAC)identified three humic-like components.Among these,component C3(humic-like and tyrosine substance)exhibited the strongest binding affinity for Pb(Ⅱ).Hetero-2DCOS analysis,combined with additional spectroscopic techniques,demonstrated that carboxyl groups in humic-like substances were the most reactive sites for Pb(Ⅱ)binding.These findings provide molecular-level insights into the structural and functional characteristics of biochar-derived DOM-Pb(Ⅱ)complexes,offering a scientific basis for optimizing biochar-based strategies for heavy metal pollution remediation.展开更多
Particles of aerodynamic diameter〈2.5 pm （PM/.5） caused extremely severe and persistent haze pollution is of concern in many cities. In this study, samples of PM2.5 were collected from atmosphere environment of Bei...Particles of aerodynamic diameter〈2.5 pm （PM/.5） caused extremely severe and persistent haze pollution is of concern in many cities. In this study, samples of PM2.5 were collected from atmosphere environment of Beijing and Shanxi Province, and analyzed using terahertz （THz） radiation. The transmission spectrum of PM2.5 in Shanxi Province had two distinct absorption peaks at 6.0 and 6.7 THz, and the curve was increasing on the whole. However, the transmission spectrum of PMa.5 in Beijing had obviously different variation tendency and the absorption peak was studied by monitoring PM2.5 masses in conjunction with two-dimensional correlation spectro- scopy （2DCOS）. By comparing the pollutant species and concentrations of Shanxi Province and Beijing over the time of collecting samples, the concentrations of sulfate and ammonium were similar, which contributed to emerge absorption bands in the same position. While the concentrations of organic matter （OM）, nitrate, chloride and elemental carbon （EC） were different. Furthermore, dust and some other inorganic ion are unique to Shanxi province, which lead to different variation tendency of the transmission spectrum of PM2.5. These results will be of importance for environmental monitoring and for control- ling PM emissions. According to this research, optical techniques, and especially spectral methods, should be considered for PM2.5 monitoring.展开更多
文摘Sponsored by college of chemistry and molecular engineering, Peking University and Thermo Fisher Scientific, The Asian Regional Conference on 2DCOS （2DCOS-2014） was held （19, April, 2014 - 20, April, 2014） at the beautiful campus of Peking University. Prof. lsao Noda,
文摘A number of useful techniques associated with two-dimensional correlation spectroscopy(2DCOS)to improve its performance and utility have been developed in the last 30years.Evolution of these 2DCOS techniques,including some of the very recent developments,is reviewed with examples.Topics include merged or modified asynchronous 2Dcorrelation spectrum,two-dimensional codistribution spectroscopy(2DCDS),Pareto scaling,and null-space projection treatment of spectral dataset.
基金supported by the National Key R&D Program of China(2024YFD1501700)the Distinguished Youth Science Foundation of Heilongjiang Province,China(JQ2023E001)the Young Leading Talents Project of Northeast Agricultural University,China(NEAU2023QNLJ-013,NEAU2024QNLJ-01).
文摘Biochar-derived dissolved organic matter(DOM)is a highly active component that plays a critical and complex role in the immobilization of heavy metals.This study systematically investigated the impact of DOM on Pb(Ⅱ)adsorption by comparing the adsorption capacities of biochar before and after DOM removal,thereby unveiling the underlying mechanisms through advanced spectroscopic techniques.Adsorption experiments demonstrated that water-washed biochar(WBC)exhibited a markedly reduced adsorption capacity(35.0 mg g^(−1))compared to untreated biochar(BC)(96.2 mg g^(−1)),highlighting the essential role of DOM in enhancing Pb(Ⅱ)adsorption.Kinetic and isothermal analyses revealed that the adsorption process was predominantly chemical in nature,as evidenced by the excellent fit of experimental data to the pseudo-second-order,Freundlich,and Temkin models.FTIR and XPS analyses confirmed that oxygen-containing functional groups,including hydroxyl,carboxyl,carbonyl,and ether groups,actively participated in Pb(Ⅱ)complexation in BC,WBC,and DOM.Spectral shifts and changes in the relative abundance of C–O and C=O bonds further supported this conclusion.The Pb 4f spectra indicated that Pb(Ⅱ)was primarily retained as Pb_(3)(OH)_(2)(CO_(3))_(2),with complexation identified as the dominant mechanism,followed by co-precipitation.UV differential log-transformed absorption spectra derived from titration experiments,revealed the heterogeneity of Pb(Ⅱ)binding sites within DOM.Furthermore,excitation-emission matrix fluorescence spectroscopy coupled with parallel factor analysis(EEM-PARAFAC)identified three humic-like components.Among these,component C3(humic-like and tyrosine substance)exhibited the strongest binding affinity for Pb(Ⅱ).Hetero-2DCOS analysis,combined with additional spectroscopic techniques,demonstrated that carboxyl groups in humic-like substances were the most reactive sites for Pb(Ⅱ)binding.These findings provide molecular-level insights into the structural and functional characteristics of biochar-derived DOM-Pb(Ⅱ)complexes,offering a scientific basis for optimizing biochar-based strategies for heavy metal pollution remediation.
文摘Particles of aerodynamic diameter〈2.5 pm （PM/.5） caused extremely severe and persistent haze pollution is of concern in many cities. In this study, samples of PM2.5 were collected from atmosphere environment of Beijing and Shanxi Province, and analyzed using terahertz （THz） radiation. The transmission spectrum of PM2.5 in Shanxi Province had two distinct absorption peaks at 6.0 and 6.7 THz, and the curve was increasing on the whole. However, the transmission spectrum of PMa.5 in Beijing had obviously different variation tendency and the absorption peak was studied by monitoring PM2.5 masses in conjunction with two-dimensional correlation spectro- scopy （2DCOS）. By comparing the pollutant species and concentrations of Shanxi Province and Beijing over the time of collecting samples, the concentrations of sulfate and ammonium were similar, which contributed to emerge absorption bands in the same position. While the concentrations of organic matter （OM）, nitrate, chloride and elemental carbon （EC） were different. Furthermore, dust and some other inorganic ion are unique to Shanxi province, which lead to different variation tendency of the transmission spectrum of PM2.5. These results will be of importance for environmental monitoring and for control- ling PM emissions. According to this research, optical techniques, and especially spectral methods, should be considered for PM2.5 monitoring.
