Study On Aerogel Based On Assembly Of Micro-nano Units In Bamboo For Water Purification

Fresh water resources are gradully decreasing.The wastewater treatment and desalination technology are of great importance to alleviate the scarcity of existing freshwater resources.With high surface area,nanomaterials have created a new space for the development of wastewater treatment and desalination technology.The nanofibrillar cellulose aerogel(CNF)was prepared via the "top-down" method from bamboo-based fiber material,derived from low-quality bamboo.With further treatment of a one-step ultrasonication method,nanofibrillar cellulose/graphene oxide aerogel(CNF/GO)and manganese dioxide/ nanofibrillar cellulose aerogel(MCNF)were fabricated successfully.The prepared bamboo cellulose aerogels and complexed materials could be used in the fields of antibiotic adsorption and desalination.These researches could provide scientific basis and theoretical basis for the high value development of low quality bamboo resources.The main results are as follows:Firstly,CNF/GO with interconnected 3D network microstructure was fabricated via a one-step ultrasonication method.The aerogel exhibited superior adsorption capacity toward multiple antibiotics(six categories of antibiotics: chloramphenicol,macrolides,quinolones,?-lactam,sulfonamides and tetracyclines): the maximum adsorption capacities(qm)were 128.3 to 501.1mg·g-1 and the qm for tetracycline was 454.5 mg·g-1.The adsorption mechanisms were proposed to be p-? interaction,?-? interaction,electrostatic attraction,and hydrogen bonds.In addition,the adsorption isotherm was fitted to the Langmuir model,and the adsorption kinetics were well fitted to the pseudo-secondary model.Furthermore,the regenerated aerogels still could be repeatedly used after ten cycles without obvious degradation of adsorption performance.Secondly,MCNF was fabricated via methods of redox reaction and ultrasonication.With its core-shell structure,MCNF had a larger specific surface area than that of CNF.MCNF exhibited excellent desalination behavior towards ions(Ca2+,Mg2+,Na+)in sea water.More interesting,the regenerated MCNF could be repeatedly used after twenty adsorption/desorption cycles without obvious degradation of performance.Moreover,with high desalination efficiency and reusability,and ease of separation operation,the aerogel would be a candidate for desalination.