Reducing Free Residual Chlorine Using Four Simple Physical Methods in Drinking Water: Effect of Different Parameters, Monitoring Microbial Regrowth of Culturable Heterotrophic Bacteria, and Kinetic and Thermodynamic Studies Publisher



Sheikhi R^{1, 2} ; Mahvi AH^{1, 2} ; Baghani AN¹ ; Hadi M² ; Sorooshian A^{3, 4} ; Delikhoon M⁵ ; Golbaz S^{1, 2} ; Dalvand A⁶ ; Johar F⁷ ; Ghalhari MR^{1, 2}
Source: Toxin Reviews Published:2021

Abstract

While chlorination is critical for water disinfection, a knowledge gap includes the nature of free residual chlorine (FRC) decay, which was investigated using four physical methods (SSA, SSR with and without a lid, heating, and incubator shaker). Keeping water samples in SSA and SSR methods for 24 h resulted in the FRC decline by 62% and 51%, respectively. The heterotrophic plate count (HPC) increased significantly between initial (3.17 ± 2.6–3.82 ± 1.1 CFU/mL) and final samples (6.7 ± 1.5–94.7 ± 4.72 CFU/mL) for both SSA and SSR methods. Thermodynamic behavior (ΔH versus ΔG) of FRC decay of the different methods was characterized. © 2020 Informa UK Limited, trading as Taylor & Francis Group.