Fabrication and characterization of nanoporous anodic alumina membrane using commercial pure aluminium to remove coliform bacteria from wastewater

Abstract

Nanoporous anodic alumina (NAA) membranes were produced by anodizing process using commercially pure aluminium (1050 alloy). The optimization of processing parameters, such as applied potential, temperature and time in two different electrolyte solutions, has been performed to produce the ordered alumina nano-membrane. Nanoporous anodic alumina membrane (NAAM) was obtained by removing the aluminium substrate and opening the bottom of the pores. The microstructure of samples was studied and analysed by field emission scanning electron microscopy (FESEM). Image processing of FESEM pictures was performed with MATLAB. The results showed that at the optimum conditions of anodizing, the percentage of porosity and ordering of pores in the samples were similar to the productions of the high purity aluminium base. NAA layers that formed in sulphuric acid solution in comparison with oxalic acid had lower pore diameter (20 nm), lower inter-pore distance (45-50 nm) and higher hardness (325 HV). The optimized membranes which have been produced with the same thickness were used for separation of Coliform bacteria from the secondary clarified wastewater. The results showed that these membranes can be used as selective filters because of their desirable physical properties.

Recent Advances in Nanoporous Anodic Alumina: Principles, Engineering, and Applications

“…For example, NAA membranes with zinc oxide nanosheets grown on the surface were reported by Stroe et al [ 233 ]. Their performance was demonstrated to decrease E. coli population by 73% in UV light over 24 h. What is more, just the pore size itself enables to separate bacteria from water [ 234 ].…”

Structure and Prospects for Application of Porous Oxidized Aluminum as an Adsorbent

“…Отмеченные свойства позволяют рассматривать МДО-покрытие на алюминии в качестве перспективного материала для создания адсорбентов и фильтрующих устройств избирательного действия. Такие устройства могут быть высокоэффективны для разделения многокомпонентных сред, очистки моторных и индустриальных масел от продуктов деградации [10], воды от трех-и шестивалентного хрома, никеля, мышьяка, остаточного железа, а также микробиологических загрязнений [11][12][13][14].…”

Nanoporous alumina microtubes for metamaterial and plasmonic applications

“…The size of the nanopores can be reduced (or increased) during anodisation by changing the physical and/or chemical parameters. Keeping chemical parameters fixed and decreasing the voltage [18] or temperature [19], the pore size can be decreased. Keeping physical parameters the same and by lowering the concentration of the electrolyte, the pore dimension can be reduced [20,21].…”

“…Using this system, one can create radially increasing or decreasing optical inhomogeneity (effective refractive index) depending on the material filled in the nanopores. For a fixed dimension of the nanoporous alumina microtube, the size of the nanopore plays an important role in the degree of anisotropy or inhomogeneity of the cylindrical nanoporous alumina which can be controlled during anodisation process [18][19][20][21].…”