A New Microbial Enrichment and Recovery Technology Based on Layered Double Hydroxides

The current common detection techniques are difficult to achieve in the on-site detection of low-concentration water samples. To recover pathogenic microorganisms from water, a concentration filtration system and enrichment technology was constructed with bimetallic layered hydroxides. Specifically, Mg/Al bimetallic hydroxides (Mg/Al LDH) with a Mg:Al ratio of 2.14:1 were synthesized by coprecipitation, and bimetallic oxides (CLDHs) with larger specific surface areas were obtained by high-temperature calcination. This study revealed that the adsorption kinetics of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) reached a stable equilibrium at 30 and 40 min, respectively, through static-condition experiments. The adsorption capacity of CLDHs for E. coli was about 5.321 × 109 CFU/g, while that for S. aureus was about 1.679 × 107 CFU/g. Moreover, a concentrated recovery system was designed and constructed. This study found that the system could effectively remove 99% of E. coli, S. aureus, and Candida albicans (C. albicans) from water, with a bacterial recovery rate exceeding 80%. In conclusion, the established concentration and recovery system offers an efficient means of recovering pathogenic microorganisms from water, thereby providing great convenience for subsequent microbial detection.