Freeze–dried synthesized bifunctional biopolymer nanocomposite for efficient fluoride removal and antibacterial activity  

作　　者：Sapna Nehra Ankita Dhillon Dinesh Kumar 

机构地区：[1]Department of Chemistry,Banasthali Vidyapith,Banasthali,Rajasthan 304022,India [2]School of Chemical Sciences,Central University of Gujarat,Gandhinagar 382030,India

出　　处：《Journal of Environmental Sciences》2020年第8期52-63,共12页环境科学学报（英文版）

基　　金：Dinesh Kumar is thankful to Department of Science&Technology(DST),New Delhi,for the financial support offered to this work(sanctioned vide project Sanction Order F.No.DST/TM/WTI/WIC/2K17/124(C)).

摘　　要：Local fluoride contamination and bacterial infections in potable water have dangerous effects on the human body and are today a global concern.In this study,we have synthesized a pH-responsive bifunctional biopolymer nanocomposite(HAZ)of humic acid with incorporating aluminum zirconium bimetallic oxide by deep freeze–drying method.Fast nucleation and interconnection of nanoparticles form a highly porous network because of sublimation of frozen HAZ.This duo nanocomposite has efficiently worked for fluoride removal and showed potent antibacterial activity against the Escherichia coli Gram-negative and Staphylococcus aureus Gram-positive bacteria.The X-ray photoelectron spectroscopy(XPS)analysis demonstrates that the hydroxyl groups act as a pivot in the ion exchange process of adsorption,each element of bimetallic oxide primarily takes part in the adsorption mechanism.The maximum adsorption capacity of the adsorbent was 180.62 mg/g at pH seven.Thermodynamic parameters like Gibbs free energy change(△G0),entropy(△S0),and enthalpy(△H0)indicate that the process was endothermic,feasible,and taken place by a chemisorption mechanism.This is the first novel freeze–dried bifunctional biopolymer nanocomposite composed of humic acid natural polymer incorporated with Al–Zr metal oxide,and it exhibited three times higher adsorption efficacy with excellent antibacterial action at a concentration of 5μg/mL of the nanocomposite.

关 键 词：BIFUNCTIONAL DISINFECTION Freeze–dried LANGMUIR SPONTANEOUS 

分 类 号：TB33[一般工业技术—材料科学与工程] TU991.15[建筑科学—市政工程]