Fabrication porous adsorbents templated from aqueous foams using astragalus membranaceus and attapulgite as stabilizer for efficient removal of cationic dyes

The water-based foam stabilized by the natural surfactant applied in the fabrication of porous materials has attracted extensive attention,as the advantages of cleanness,convenience and low cost.Particularly,the development of a green preparation method has became themain research focus and frontier.In thiswork,a green liquid foamwith high stability was prepared by synergistic stabilization of natural plant astragalus membranaceus(AMS)and attapulgite(APT),and then a novel porous material with sufficient hierarchical pore structure was templated from the foam via a simple free radical polymerization of acrylamide(AM).The characterization results revealed that the amphiphilic molecules from AMS adsorbed onto thewater-air interface and formed a protective shell to prevent the bubble breakup,and APT gathered in the plateau border and formed a three-dimensional network structure,which greatly slowed down the drainage rate.The porous material polyacrylamide/astragalus membranaceus/attapulgite(PAM/AMS/APT)showed the excellent adsorption performance for cationic dyes of Methyl Violet(MV)and Methylene Blue(MB)in water,and the maximum adsorption capacity could reach to 709.13 and 703.30 mg/g,respectively.Furthermore,the polymer material enabled to regenerate and cycle via a convenient calcination process,and the adsorption capacitywas still higher than 200 mg/g after five cycles.In short,this research provided a new idea for the green preparation of porous materials and the treatment of water pollution.

Removal of antibiotics from aqueous solution by using porous adsorbent templated from eco-friendly Pickering aqueous foams

The aqueous foam template without any solvent and only using the particles stabilizer has attracted much attention for preparation of the porous adsorbents.Herein,a novel porous adsorbent was fabricated via thermal-initiated polymerization of Pickering aqueous foams,which was stabilized by the natural sepiolite(Sep)and pine pollen,and utilized for the removal of antibiotic from aqueous solution.The stabilizing mechanism of Pickering aqueous foam of that the Sep was modified with the leaching substance from pine pollen and arranged orderly around the bubble to form a dense"shell"structure was revealed.The adsorbents possessed the hierarchical porous structure and excellent adsorption performance for antibiotic of chlorotetracycline hydrochloride(CTC)and tetracycline hydrochloride(TC).The equilibrium adsorption capacities of CTC and TC were achieved with 465.59 and 330.59 mg/g within 60 min at 25℃,respectively.The adsorption process obeyed Langmuir model and pseudo-second-order adsorption kinetic model.This work provided eco-friendly approach for fabricate porous adsorbents for wastewater treatment.

Facile fabrication of the porous adsorbent from natural plant Angelica Sinensis stabilized liquid foam for dye removal

Porous materials as emerging high-efficiency adsorbents have attracted increasing attention in recent years,due to the high specific surface area,fast adsorption rate,favorable adsorption capacity to heavy metal,dyes,and other pollutants,etc.Among various approaches,the foam template method with the advantage of flexible operation and controllable pores structure is proposed to prepare net type of porous adsorbents with superior adsorption capacity and rapid adsorption rate.In this process,natural plant Angelica Sinensis(AS)was treated with a simple alkalineheat process,and the resultant product was used firstly to prepare foam with high stability,and the positive effect of the cellulose dissociation and the conversion of ligustilide into amphiphilic moleculars on improving the stability of Pickering foam was revealed.The liquid foam can serve as pore-foaming template and precursor of polymerization for synthesizing porous adsorbent by one-step integrated process of free radical polymerization and silane hydrolysis.The porous adsorbent showed the sufficient porous structure and excellent adsorption performance for cationic dye,with maximum adsorption capacities of 386.13 mg g^(-1) and 284.20 mg g^(-1) for methyl violet(MV)and malachite green(MG).In a word,the novel approach can provide an important reference for green synthesis of high stable foam and the superporous material,and the adsorbent showed great application potential in the field of water treatment.