Methyl blue adsorption properties and bacteriostatic activities of Mg-Al layer oxides via a facile preparation method

The methods and materials for more effective elimination of carcinogenic dyes and bacteria in domestic wastewater have drawn great attention. In this study, methyl blue, Escherichia coli and Staphylococcus aureus could be removed and inhibited by versatile Mg-Al layer oxides. Mg-Al layered double hydroxide (LDH) was synthesized via a facile one-step method. Especially, the layered double metal oxide (LDO) as the calcined product of LDH was obtained. The adsorption efficiency for methyl blue from aqueous solutions on these samples was studied in a batch experiment. The results showed that as-prepared Mg-Al LDO exhibited an excellent adsorption performance for methyl blue, and in comparison with LDH, the removal efficiency of Mg3Al LDO could reach more than 94%. In addition, the antimicrobial activity of LDH and corresponding LDO against the gram-negative bacterial species E. coli and the gram-positive bacterial species S. aureus were investigated. The antibacterial efficiency increased from 49.65% (Mg3Al LDH) to 99.30% (Mg3Al LDO). The results revealed that the Mg-Al LDO exhibited an excellent antibacterial performance for these bacterial species compared with LDH. All above results showed that the as-prepared versatile materials provide a broad application prospect in wastewater purification.