Removing bacteria contaminants from raw surface water using multiple barriers pilot-scale reactor: sand filtration, activated carbon, and advanced oxidation processes

Abstract

The presence of bacteria in drinking water poses significant health risks, highlighting the global need for advanced and sustainable water treatment technologies. Our research aims to effectively control microbiological contaminants in drinking water, reducing health risks associated with pathogenic bacteria. This study focuses on developing and applying advanced water treatment techniques, including an investigation into the dynamics of bacterial communities. We evaluate a multi-barrier water treatment system, integrating advanced oxidation processes, in a pilot-scale reactor for potential drinking water production. The treatment led to substantial bacterial reduction, achieving a 2 to 4 log10 unit decrease. Post-treatment, the average count of pathogenic bacteria was reduced to 0 /100 CFU mL in the surface water. Flow Cytometry results indicated a count of 103 cells/mL injured bacteria in the treated water. Analysis using Illumina MiSeq sequencing of 16 S rRNA genes in water samples revealed that disinfectants significantly altered the microbial community structure, while filtration stages synergized with the disinfection process for treating raw surface water. Notably, bacterial groups such as Actinobacteria and Proteobacteria demonstrated notable resistance to the disinfectants. Furthermore, canonical correspondence analysis indicated that environmental factors and treatment methods influenced microbial community profiles. This study underscores the efficacy of advanced water treatment processes in eliminating bacteria, assessing their viability and potential for regrowth, and ensuring the treated water meets established drinking water guidelines relative to microbiology bacteria in drinking water.