In this study,to efficiently remove Pb(Ⅱ) from aqueous environments,a novel L-serine-modified polyethylene/polypropylene nonwoven fabric sorbent(NWF-serine)was fabricated through the radiation grafting of glycidyl me...In this study,to efficiently remove Pb(Ⅱ) from aqueous environments,a novel L-serine-modified polyethylene/polypropylene nonwoven fabric sorbent(NWF-serine)was fabricated through the radiation grafting of glycidyl methacrylate and subsequent L-serine modification.The effect of the absorbed dose was investigated in the range of 5–50 kGy.NWF-serine was characterized by Fourier transform infrared spectroscopy,thermogravimetric analysis,and scanning electron microscopy.Batch adsorption tests were conducted to investigate the influences of pH,adsorption time,temperature,initial concentration,and sorbent dosage on the Pb(Ⅱ) adsorption performance of NWF-serine.The results indicated that Pb(Ⅱ) adsorption onto NWF-serine was an endothermic process,following the pseudo-second-order kinetic model and Langmuir isotherm model.The saturated adsorption capacity was 198.1 mg/g.NWF-serine exhibited Pb(Ⅱ) removal rates of 99.8% for aqueous solutions with initial concentrations of 100 mg/L and 82.1% for landfill leachate containing competitive metal ions such as Cd,Cu,Ni,Mn,and Zn.Furthermore,NWF-serine maintained 86% of its Pb(Ⅱ) uptake after five use cycles.The coordination of the carboxyl and amino groups with Pb(Ⅱ) was confirmed using X-ray photoelectron spectroscopy and extended X-ray absorption fine structure analysis.展开更多
In this work,the effect of ammonium sulfate on the adsorption characteristics of low-concentration Pb(Ⅱ)ions on the sulfidized hemimorphite surface was comprehensively investigated.The results showed that ammonium su...In this work,the effect of ammonium sulfate on the adsorption characteristics of low-concentration Pb(Ⅱ)ions on the sulfidized hemimorphite surface was comprehensively investigated.The results showed that ammonium sulfate could increase the maximum recovery of hemimorphite from 69.42%to 88.24%under a low concentration of Pb(Ⅱ)ions.On the hemimorphite surface pretreated with ammonium sulfate,the adsorption of Pb(Ⅱ)ions was enhanced and the main species of Pb adsorbed was changed from Pb―O/OH to PbS.This was due to the larger amount of ZnS providing more effective adsorption sites for Pb components to generate Pb S.Meanwhile,the intensity of ZnS decreased with the formation of PbS,demonstrating that ZnS was covered by PbS which formed later on the mineral surface.It was beneficial for the adsorption of butyl xanthate on the hemimorphite surface to form more hydrophobic substances.As a result,ammonium sulfate played a crucial role in realizing the efficient recovery of hemimorphite.展开更多
壳聚糖-果胶凝胶珠(Chitosan-pectin gel beads,CPB)吸附去除食品中重金属具有较高的潜力,为提高其稳定性、再生利用性及吸附能力,本文采用明胶(Gel)和羧甲基纤维素钠(CMC)对CPB进行改性,利用扫描电镜(SEM)、比表面积与孔隙度分析(BET)...壳聚糖-果胶凝胶珠(Chitosan-pectin gel beads,CPB)吸附去除食品中重金属具有较高的潜力,为提高其稳定性、再生利用性及吸附能力,本文采用明胶(Gel)和羧甲基纤维素钠(CMC)对CPB进行改性,利用扫描电镜(SEM)、比表面积与孔隙度分析(BET)、傅里叶变换红外光谱(FTIR)、热重分析(TG)、Zeta电位仪、X射线光电子能谱(XPS)及等技术表征其结构特性,优化吸附解析条件,并评估其对藻蓝蛋白中Pb(Ⅱ)的实际去除效果。结果显示,与CPB和Gel-CPB相比,CMC改性的CPB(CMC-CPB)热稳定性高、表面粗糙多孔、比表面积大(20.28±1.35 m^(2)/g)及Zeta电位低,对金属离子吸附能力强,且解析再生利用率高。FTIR图谱分析显示改性前后CPB官能团结构未发生明显变化,其主要结构官能团为羧基、羟基和氨基。TG分析表明改性前后的CMC-CPB的热稳定性显著高于CPB和Gel-CPB(P<0.05)。XPS光谱分析表明三种吸附剂成功吸附了Pb(Ⅱ),其中CMC-CPB对Pb(Ⅱ)的吸收峰最强。三种吸附剂(CPB、Gel-CPB和CMC-CPB)去除Pb(Ⅱ)的最佳pH和温度分别为6.0和60℃,对Pb(Ⅱ)的吸附过程均符合Langmuir吸附等温模型(R^(2)=0.9543~0.9811)和准二级动力学模型(R^(2)=0.9963~0.9991),该吸附属于单分子层化学吸附,即-COO、-OH、-CO-NH与Pb(Ⅱ)之间的络合作用。根据Langmuir模型曲线评估,CMC-CPB对Pb(Ⅱ)的最大吸附容量q_(max)为69.37 mg/g,显著高于Gel-CPB和CPB(P<0.05)。综合在藻蓝蛋白中的应用效果,CMC-CPB低成本高效安全地去除藻类和藻蓝蛋白食品中Pb(Ⅱ)具有更广阔的前景。展开更多
基金supported by the National Natural Science Foundation of China(Nos.11605275 and 11675247)。
文摘In this study,to efficiently remove Pb(Ⅱ) from aqueous environments,a novel L-serine-modified polyethylene/polypropylene nonwoven fabric sorbent(NWF-serine)was fabricated through the radiation grafting of glycidyl methacrylate and subsequent L-serine modification.The effect of the absorbed dose was investigated in the range of 5–50 kGy.NWF-serine was characterized by Fourier transform infrared spectroscopy,thermogravimetric analysis,and scanning electron microscopy.Batch adsorption tests were conducted to investigate the influences of pH,adsorption time,temperature,initial concentration,and sorbent dosage on the Pb(Ⅱ) adsorption performance of NWF-serine.The results indicated that Pb(Ⅱ) adsorption onto NWF-serine was an endothermic process,following the pseudo-second-order kinetic model and Langmuir isotherm model.The saturated adsorption capacity was 198.1 mg/g.NWF-serine exhibited Pb(Ⅱ) removal rates of 99.8% for aqueous solutions with initial concentrations of 100 mg/L and 82.1% for landfill leachate containing competitive metal ions such as Cd,Cu,Ni,Mn,and Zn.Furthermore,NWF-serine maintained 86% of its Pb(Ⅱ) uptake after five use cycles.The coordination of the carboxyl and amino groups with Pb(Ⅱ) was confirmed using X-ray photoelectron spectroscopy and extended X-ray absorption fine structure analysis.
基金the Fundamental Research Funds for the Central Universities(Nos.2022JCCXHH09 and 2022YJSHH01)the Yueqi Outstanding Scholar award of CUMTB+3 种基金the National Key R&D Program of China(No.SQ2022YFC2900065)the Ordos Science&Technology Plan(No.202204)the National Natural Science Foundation of China(No.52274283)the Open Research Fund of State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization(No.CNMRCUKF2107)。
文摘In this work,the effect of ammonium sulfate on the adsorption characteristics of low-concentration Pb(Ⅱ)ions on the sulfidized hemimorphite surface was comprehensively investigated.The results showed that ammonium sulfate could increase the maximum recovery of hemimorphite from 69.42%to 88.24%under a low concentration of Pb(Ⅱ)ions.On the hemimorphite surface pretreated with ammonium sulfate,the adsorption of Pb(Ⅱ)ions was enhanced and the main species of Pb adsorbed was changed from Pb―O/OH to PbS.This was due to the larger amount of ZnS providing more effective adsorption sites for Pb components to generate Pb S.Meanwhile,the intensity of ZnS decreased with the formation of PbS,demonstrating that ZnS was covered by PbS which formed later on the mineral surface.It was beneficial for the adsorption of butyl xanthate on the hemimorphite surface to form more hydrophobic substances.As a result,ammonium sulfate played a crucial role in realizing the efficient recovery of hemimorphite.
文摘壳聚糖-果胶凝胶珠(Chitosan-pectin gel beads,CPB)吸附去除食品中重金属具有较高的潜力,为提高其稳定性、再生利用性及吸附能力,本文采用明胶(Gel)和羧甲基纤维素钠(CMC)对CPB进行改性,利用扫描电镜(SEM)、比表面积与孔隙度分析(BET)、傅里叶变换红外光谱(FTIR)、热重分析(TG)、Zeta电位仪、X射线光电子能谱(XPS)及等技术表征其结构特性,优化吸附解析条件,并评估其对藻蓝蛋白中Pb(Ⅱ)的实际去除效果。结果显示,与CPB和Gel-CPB相比,CMC改性的CPB(CMC-CPB)热稳定性高、表面粗糙多孔、比表面积大(20.28±1.35 m^(2)/g)及Zeta电位低,对金属离子吸附能力强,且解析再生利用率高。FTIR图谱分析显示改性前后CPB官能团结构未发生明显变化,其主要结构官能团为羧基、羟基和氨基。TG分析表明改性前后的CMC-CPB的热稳定性显著高于CPB和Gel-CPB(P<0.05)。XPS光谱分析表明三种吸附剂成功吸附了Pb(Ⅱ),其中CMC-CPB对Pb(Ⅱ)的吸收峰最强。三种吸附剂(CPB、Gel-CPB和CMC-CPB)去除Pb(Ⅱ)的最佳pH和温度分别为6.0和60℃,对Pb(Ⅱ)的吸附过程均符合Langmuir吸附等温模型(R^(2)=0.9543~0.9811)和准二级动力学模型(R^(2)=0.9963~0.9991),该吸附属于单分子层化学吸附,即-COO、-OH、-CO-NH与Pb(Ⅱ)之间的络合作用。根据Langmuir模型曲线评估,CMC-CPB对Pb(Ⅱ)的最大吸附容量q_(max)为69.37 mg/g,显著高于Gel-CPB和CPB(P<0.05)。综合在藻蓝蛋白中的应用效果,CMC-CPB低成本高效安全地去除藻类和藻蓝蛋白食品中Pb(Ⅱ)具有更广阔的前景。
