The presence of toxic dyes in the aqueous medium has threatened environmental safety, and thereby re- moving them from wastewater in an efficient way is highly desired. Herein, the efficient biosorbents were successfu...The presence of toxic dyes in the aqueous medium has threatened environmental safety, and thereby re- moving them from wastewater in an efficient way is highly desired. Herein, the efficient biosorbents were successfully fabricated via a facile physical gelation process of sodium alginate (SA) and carboxymethyl chitosan (CMCTS) in an acidic aqueous solution. The as-prepared hydrogel beads not only displayed water superabsorbent properties and pH-responsive swelling characters but also exhibited excellent methylene blue (MB) adsorption capacity removal efficiency with experimental maximum MB adsorption capacity of 2518 and 1005 mg g -1 , which are comparable with most reported lignocellulosic and alginate-based hydrogels. The MB adsorption process fitted well in different kinetic and isotherm models and became more heterogeneous in concentrated MB solutions as verified by principal component analysis results. The adsorption mechanism was proposed, and the high dye absorbency was attributed to the strong electro- static forces between adsorbents and adsorbates. Our current study provides a promising and sustainable composite hydrogels platform targeted to dye decontamination.展开更多
Herein,we report a green and facile preparation and characterization procedure of copper nanoparticles stabilized on magnetically separable sodium alginate support(Cu NPs-Fe_(3)O_(4)-SAlg)using Silybum marianum seeds ...Herein,we report a green and facile preparation and characterization procedure of copper nanoparticles stabilized on magnetically separable sodium alginate support(Cu NPs-Fe_(3)O_(4)-SAlg)using Silybum marianum seeds extract and investigate their catalytic reductive chemistry for reduction of environmental pollutants.Indeed,the phytochemical content of the plant extract are responsible to biosynthesis of copper(Cu)nanoparticles and their stabilization by functionalizing the surface of magnetic alginate.Characterization of the biocatalyst was undertaken with FT-IR,XPS,XRD and STEM equipped with EDS.A standard suite of model compounds on which the reductive chemistry was tested were 4-nitrophenol(4-NP),potassium hexacyanoferrate(K3[Fe(CN)6]),and a variety of organic dyes including Congo Red(CR).The as-synthesized Cu NPs-Fe_(3)O_(4)-SAlg catalyst was highly effective in reducing 4-NP to 4-aminophenol in water and in the presence of sodium borohydride as a reducing agent.Also,a high reduction performance was observed with CR and K3[Fe(CN)6]in presence of the Cu NPs-Fe_(3)O_(4)-SAlg catalyst.The catalyst acted within 190 and 35 s respectively,at room temperature in the presence of NaBH4.Thus,the Cu NPs-Fe_(3)O_(4)-SAlg catalyst is a highly efficient catalyst which is also reusable due to its magnetic nature.This work reports a green synthesis of a high-performance Cu NPs-Fe_(3)O_(4)-SAlg catalyst using an environmental friendly method for reduction of 4-NP,CR,and K3[Fe(CN)6]over a short time.展开更多
文摘The presence of toxic dyes in the aqueous medium has threatened environmental safety, and thereby re- moving them from wastewater in an efficient way is highly desired. Herein, the efficient biosorbents were successfully fabricated via a facile physical gelation process of sodium alginate (SA) and carboxymethyl chitosan (CMCTS) in an acidic aqueous solution. The as-prepared hydrogel beads not only displayed water superabsorbent properties and pH-responsive swelling characters but also exhibited excellent methylene blue (MB) adsorption capacity removal efficiency with experimental maximum MB adsorption capacity of 2518 and 1005 mg g -1 , which are comparable with most reported lignocellulosic and alginate-based hydrogels. The MB adsorption process fitted well in different kinetic and isotherm models and became more heterogeneous in concentrated MB solutions as verified by principal component analysis results. The adsorption mechanism was proposed, and the high dye absorbency was attributed to the strong electro- static forces between adsorbents and adsorbates. Our current study provides a promising and sustainable composite hydrogels platform targeted to dye decontamination.
基金This work was funded by the 2019 Faculty Research and Professional Development award(No.2020–3069),a funding partnership between the Office of Research and Innovation and North Carolina State University.
文摘Herein,we report a green and facile preparation and characterization procedure of copper nanoparticles stabilized on magnetically separable sodium alginate support(Cu NPs-Fe_(3)O_(4)-SAlg)using Silybum marianum seeds extract and investigate their catalytic reductive chemistry for reduction of environmental pollutants.Indeed,the phytochemical content of the plant extract are responsible to biosynthesis of copper(Cu)nanoparticles and their stabilization by functionalizing the surface of magnetic alginate.Characterization of the biocatalyst was undertaken with FT-IR,XPS,XRD and STEM equipped with EDS.A standard suite of model compounds on which the reductive chemistry was tested were 4-nitrophenol(4-NP),potassium hexacyanoferrate(K3[Fe(CN)6]),and a variety of organic dyes including Congo Red(CR).The as-synthesized Cu NPs-Fe_(3)O_(4)-SAlg catalyst was highly effective in reducing 4-NP to 4-aminophenol in water and in the presence of sodium borohydride as a reducing agent.Also,a high reduction performance was observed with CR and K3[Fe(CN)6]in presence of the Cu NPs-Fe_(3)O_(4)-SAlg catalyst.The catalyst acted within 190 and 35 s respectively,at room temperature in the presence of NaBH4.Thus,the Cu NPs-Fe_(3)O_(4)-SAlg catalyst is a highly efficient catalyst which is also reusable due to its magnetic nature.This work reports a green synthesis of a high-performance Cu NPs-Fe_(3)O_(4)-SAlg catalyst using an environmental friendly method for reduction of 4-NP,CR,and K3[Fe(CN)6]over a short time.
