This study aims to optimize the use of lacquer residue biomass(LBM).We investigated the ability of LBM to remove Pb^(2+)heavy metal ions and the typical cationic dye methylene blue(MB)and anionic dye Congo red(CR)by s...This study aims to optimize the use of lacquer residue biomass(LBM).We investigated the ability of LBM to remove Pb^(2+)heavy metal ions and the typical cationic dye methylene blue(MB)and anionic dye Congo red(CR)by simultaneous adsorption from composite systems,as well as the relevant factors.Scanning electron microscopy(SEM),X-ray diffraction(XRD),and Fourier transform infrared spectroscopy(FTIR)were used to characterize adsorption behavior.The adsorption kinetics of Pb^(2+)-MB/CR composite systems can be effectively characterized by the pseudo-second-order kinetic model(R^(2)>0.97).In the Pb^(2+)-MB composite system,adsorption was antagonistic with similar adsorption sites.However,in the Pb^(2+)-CR composite system,we found that adsorption was synergistic with different adsorption sites,which led to a higher simultaneous adsorption capacity for a higher initial Pb^(2+)-CR concentration,unlike the Pb^(2+)-MB system.In both composite systems,an appropriate increase in LBM dosage and system temperature within a certain range was conducive to simultaneous adsorption and removal of Pb^(2+)-MB/CR composite systems.The optimal solid-liquid ratio and temperature were 1:75 and 30℃,respectively.The adsorption and removal rates of Pb^(2+)and MB were 99.98%and 90.49%,respectively,and those of Pb^(2+)and CR were 93.99%and 77.39%,respectively,in(50,50)mg/L of Pb^(2+)-MB/CR composite systems under these conditions.Adsorption removal of Pb^(2+)and MB improved with higher pH levels,and worsened with the increase of ionic strength in the solution,while the removal rate of CR showed an opposite trend.The coexisting anion and cation types had limited influence on the simultaneous adsorption removal of Pb^(2+),MB,and CR.The results of desorption showed that LBM can be utilized as a disposable material for simultaneously treating Pb^(2+)-MB/CR composite systems.The simultaneous adsorption mechanisms of Pb^(2+)-MB/CR mainly involved hydrogen bonding,π-πbonding interaction,and electrostatic interaction.展开更多
Arsenic and cadmium contamination frequently coexist in the real environment.However it remains a challenge for their simultaneous removal due to their distinct physicochemica properties at low cost.To this end,a cost...Arsenic and cadmium contamination frequently coexist in the real environment.However it remains a challenge for their simultaneous removal due to their distinct physicochemica properties at low cost.To this end,a cost-effective magnetic biochar adsorbent (ITBNa800was prepared using biomass waste and iron tailings slag.This composite adsorbent exhibits excellent performance in the simultaneous removal of aqueous As(Ⅴ) and Cd(Ⅱ) even at high concentrations with removal efficiencies of up to 99.98%and 96.04%,respectively.Electro static action,precipitation,and complexation were adsorption mechanisms.As(Ⅴ) and Cd(Ⅱ were synergistic and competitive adsorption.As(Ⅴ) removal was mainly due to physical and chemical adsorption,and 42.40%-58.59%of As(Ⅴ) had been converted to As(Ⅲ ).Cd(Ⅱ) re moval was mainly due to chemical adsorption.Iron oxide and aluminum oxide in ITBNa800were the keys to As(Ⅴ),As(Ⅲ ),and Cd(Ⅱ) adsorption.DFT calculations revealed iron oxide complex As(Ⅴ),As(Ⅲ ),and Cd(Ⅱ) molecular clusters through bidentate binuclear,bidentate binuclear,and monodentate binuclear pathways,respectively.Aluminum oxide complex Cd(Ⅱ) molecular cluster through a bidentate mononuclear pathway.We hope the ITBNa800adsorbent and its involved mechanism could offer inspiration in the simultaneous treat ment of As and Cd pollution.展开更多
To compare the adsorption kinetics of Cu, Zn and Cd introduced into red soils simultaneously and sequentially as well as their distribution coefficients, the ability of red soils to retain heavy metals was evaluated b...To compare the adsorption kinetics of Cu, Zn and Cd introduced into red soils simultaneously and sequentially as well as their distribution coefficients, the ability of red soils to retain heavy metals was evaluated by performing batch experiments. The results indicate that Cu is preferentially adsorbed by red soils no matter in simultaneous or in sequential situation. The adsorption amount of Cd is the minimum in simultaneous competitive adsorption experiment. As heavy metals are added into red soils sequentially, the heavy metal adsorptions are relatively hard to reach equilibrium in 2 h. Red soils retain more Cd than Zn, which is opposite to the result in simultaneous adsorption. The addition sequences of heavy metals affect their adsorbed amounts in red soils to a certain extent. The joint distribution coefficients of metals in simultaneous adsorption are slightly higher than those in sequential adsorption.展开更多
基金National Key Research and Development Program of China(Nos.2023YFD1702003 and 2023YFC3709001).
文摘This study aims to optimize the use of lacquer residue biomass(LBM).We investigated the ability of LBM to remove Pb^(2+)heavy metal ions and the typical cationic dye methylene blue(MB)and anionic dye Congo red(CR)by simultaneous adsorption from composite systems,as well as the relevant factors.Scanning electron microscopy(SEM),X-ray diffraction(XRD),and Fourier transform infrared spectroscopy(FTIR)were used to characterize adsorption behavior.The adsorption kinetics of Pb^(2+)-MB/CR composite systems can be effectively characterized by the pseudo-second-order kinetic model(R^(2)>0.97).In the Pb^(2+)-MB composite system,adsorption was antagonistic with similar adsorption sites.However,in the Pb^(2+)-CR composite system,we found that adsorption was synergistic with different adsorption sites,which led to a higher simultaneous adsorption capacity for a higher initial Pb^(2+)-CR concentration,unlike the Pb^(2+)-MB system.In both composite systems,an appropriate increase in LBM dosage and system temperature within a certain range was conducive to simultaneous adsorption and removal of Pb^(2+)-MB/CR composite systems.The optimal solid-liquid ratio and temperature were 1:75 and 30℃,respectively.The adsorption and removal rates of Pb^(2+)and MB were 99.98%and 90.49%,respectively,and those of Pb^(2+)and CR were 93.99%and 77.39%,respectively,in(50,50)mg/L of Pb^(2+)-MB/CR composite systems under these conditions.Adsorption removal of Pb^(2+)and MB improved with higher pH levels,and worsened with the increase of ionic strength in the solution,while the removal rate of CR showed an opposite trend.The coexisting anion and cation types had limited influence on the simultaneous adsorption removal of Pb^(2+),MB,and CR.The results of desorption showed that LBM can be utilized as a disposable material for simultaneously treating Pb^(2+)-MB/CR composite systems.The simultaneous adsorption mechanisms of Pb^(2+)-MB/CR mainly involved hydrogen bonding,π-πbonding interaction,and electrostatic interaction.
基金supported by the National Natural Science Foundation of China(NSFC)grants(Nos.41473122,41173113,52261145693 and 22106028)the Ministry of Science and Technology of the People’s Republic of China(MOST)+1 种基金the Fundamental Research Funds for the Central Universities(FRF-TP-19-020A1)the Hundred Talents Program of the Chinese Academy of Sciences,and China Postdoctoral Science Foundation(No.2023M730216).
文摘Arsenic and cadmium contamination frequently coexist in the real environment.However it remains a challenge for their simultaneous removal due to their distinct physicochemica properties at low cost.To this end,a cost-effective magnetic biochar adsorbent (ITBNa800was prepared using biomass waste and iron tailings slag.This composite adsorbent exhibits excellent performance in the simultaneous removal of aqueous As(Ⅴ) and Cd(Ⅱ) even at high concentrations with removal efficiencies of up to 99.98%and 96.04%,respectively.Electro static action,precipitation,and complexation were adsorption mechanisms.As(Ⅴ) and Cd(Ⅱ were synergistic and competitive adsorption.As(Ⅴ) removal was mainly due to physical and chemical adsorption,and 42.40%-58.59%of As(Ⅴ) had been converted to As(Ⅲ ).Cd(Ⅱ) re moval was mainly due to chemical adsorption.Iron oxide and aluminum oxide in ITBNa800were the keys to As(Ⅴ),As(Ⅲ ),and Cd(Ⅱ) adsorption.DFT calculations revealed iron oxide complex As(Ⅴ),As(Ⅲ ),and Cd(Ⅱ) molecular clusters through bidentate binuclear,bidentate binuclear,and monodentate binuclear pathways,respectively.Aluminum oxide complex Cd(Ⅱ) molecular cluster through a bidentate mononuclear pathway.We hope the ITBNa800adsorbent and its involved mechanism could offer inspiration in the simultaneous treat ment of As and Cd pollution.
基金Projects(40971179,41271294)supported by the National Natural Science Foundation of ChinaProject(NCET-09-330)supported by the Program for New Century Excellent Talents in University,ChinaProject(11JJ3041)supported by the Natural Science Foundation of Hunan Province,China
文摘To compare the adsorption kinetics of Cu, Zn and Cd introduced into red soils simultaneously and sequentially as well as their distribution coefficients, the ability of red soils to retain heavy metals was evaluated by performing batch experiments. The results indicate that Cu is preferentially adsorbed by red soils no matter in simultaneous or in sequential situation. The adsorption amount of Cd is the minimum in simultaneous competitive adsorption experiment. As heavy metals are added into red soils sequentially, the heavy metal adsorptions are relatively hard to reach equilibrium in 2 h. Red soils retain more Cd than Zn, which is opposite to the result in simultaneous adsorption. The addition sequences of heavy metals affect their adsorbed amounts in red soils to a certain extent. The joint distribution coefficients of metals in simultaneous adsorption are slightly higher than those in sequential adsorption.
