Application of Tea Polyphenols and Their Effects on Ultrafiltration Effluent Disinfection and Microbial Risk

Abstract

To reduce the risk of by-products from traditional disinfection technology and to ensure safe water quality, tea polyphenols (TP) were used as disinfectants after the ultrafiltration (UF) process. The disinfectant effect of TP was tested on the total number of bacteria and changes in bacterial community structure, and pathogen virulence factors were detected by Illumina’s high-throughput sequencing technology. The results showed that the recommended dosage of TP for water treatment after UF was 5 mg/L, which can effectively inhibit bacterial growth and maintain the disinfectant effect for up to 48 h later. In the disinfection process, the degradation of the tea polyphenols concentration was fitted to the equation of the second order reaction kinetics. The lower the initial concentration and the higher the reaction temperature, the faster the TP decay. The metagenomic analysis of the microorganisms indicated that disinfection with tea polyphenols reduced the diversity of microorganisms in the water and altered the structure of the bacterial community. The existence of tea polyphenols also significantly inhibited the growth of potential common Gram-negative pathogens, especially Mycobacterium. TP disinfectant can also reduce the diversity and abundance of pathogenic bacterial virulence factors and improve biological safety in drinking water.

Current understanding on antibacterial mechanisms and research progress of tea polyphenols as a supplementary disinfectant for drinking water

“…This indicates that the long-lasting tea polyphenol disinfecting property is more pronounced for the ozone-tea polyphenol disinfection strategy. Feng et al (2021b) found that the decay characteristics of tea polyphenols when used as the only disinfectant together with ultrafiltrated effluent fit the second-order kinetics equation. The attenuation of tea polyphenols was greatly affected by the initial concentration and reaction temperature.…”

“…This indicates that tea polyphenols are advantageous in inhibiting chlorine-resistant bacteria and pathogenic bacteria. Feng et al (2021b) used the BLAST similarity comparison search method to establish the MvirDB protein database. Their analysis found that the types of water-based toxicity factors decreased by 56 following tea polyphenol treatment, and the total absolute abundance decreased by 51%.…”