Molecular monitoring effectiveness of human adenovirus removal in Isfahan water treatment plant

Human adenoviruses transmitted from contaminated water are one of the major pathogens that has been introduced as one of the most important new qualitative water indicators due to their resistance against the purification processes. The main objective of this study was to evaluate efficiency of human adenovirus removal in different units of Isfahan Water Treatment Plant. Sampling was conducted from 5 points of a water treatment plant including raw water, clarifier, ozonation, filtration, and treated water for one year. Virosorb 1MDS electropositive cartridge filter was used for the concentration of water samples. To test the adenovirus antigens, enzyme-linked immunosorbent assay (ELISA) was employed. Real-time PCR and PCR were also employed for quantitative identification and genotyping, respectively. Moreover, total and fecal coliform and physicochemical parameters of the samples were measured. Out of the 60 samples examined, 12 (20%) samples were diagnosed with ELISA and 16 (26.67%) with molecular method. The highest number of adenoviruses detected in autumn was 7 (12%) in raw water influent, 6 (10%) in clarifier, and 3 (5%) samples in ozonation. The high frequency of adenovirus detection was in autumn (50%) and the lowest was in spring (12.5%). Furthermore, it was found that the total coliform in raw water influent was between 102-103 CFU/mL. The results showed that the removal efficiency of adenovirus in filtration and disinfection units of the treatment plant was high and the filtration unit in the plant was an effective unit for the virus removal.