Stability of Weakly Acidic Hypochlorous Acid Solution with Microbicidal Activity

Application of Colloidal Dispersions of Bioshell Calcium Oxide (BiSCaO) for Disinfection

“…Separation of two layers due to flocculation/precipitation was observed in all samples, except under acidic conditions. The TC and CF cell counts in supernatants of the BiSCaO and BiSCa(OH) 2 colloidal dispersions at pH ≥ 11 were much lower compared with samples at other pH values (pH ≤ 10), and the antimicrobial effect was more pronounced with BiSCaO colloidal dispersions than with BiSCa(OH) 2 colloidal dispersions at each pH (pH [5][6][7][8][9][10][11][12]. No TC and CF were observed following treatment with BiSCaO colloidal dispersion at pH 12 ( Figure 5).…”

“…CaO hydration generates a strong base, considered the primary mechanism for the antimicrobial action of BiSCaO. For example, the antimicrobial activity of the BiSCaO reaction towards both total viable cells (TC) and coliform bacteria (CF) is higher than that of Ca(OH) 2 or NaOH solutions at the same pH [11,12]. Furthermore, BiSCaO can reduce formaldehyde [13].…”

Comparison of Various Disinfectants on Bactericidal Activity Under Organic Matter Contaminated Environments

“…HClO carries lower risk of generating trihalomethane than NaClO, but HClO solution is less stable under various environmental conditions than NaClO and is thus easily inactivated. Notably, the presence of various organic compounds and inorganic ions results in the rapid depletion of HClO by oxidation reactions, a phenomenon that occurs more frequently for HClO than for NaClO Ishihara et al, 2017 . A bath test sample pH 6.9 with normal bacterial flora total viable counts TC and coliform bacteria CF was prepared by incubating leftover bath water with 10% Dulbecco s Modified Eagle s Medium DMEM; Life Technologies Oriental, Tokyo, Japan without fetal bovine serum and antibiotics at 37 on shaker for 24 h.…”

Behavior of Nitrate-Nitrogen and Nitrite-Nitrogen in Drinking Water

“…In particular, significant increases in NO 2 -N to > 0.1 mg/L were detected in tap water containing NO 3 -N incubated for 24 h at 37 as a result of the addition of exogenous CF and TC and culture medium Figure. 2 . However, not all of the nitrate-Pharmaceutical Co., Ltd. Ishihara et al, 2017 . The plates were incubated for 24 h in a 37 incubator Alp Co., Ltd. , at which time the colonies in each dish were counted.…”

“…The degradation of HOCl is correlated with a reduction in microbicidal activity against CF and TC. Furthermore, the presence of NO 2 -N in water results in more rapid decay of HOCl associated with the oxidation of NO 2 to NO 3 - Ishihara et al, 2017;Inagaki, 2011;Fukuzaki, 2006 . Indeed, 0.15 mg/L NO 2 -N in tap water UV-irradiated for 24 h completely disappeared within 5 min following the addition of 5 ppm of HOCl pH 6.5 data not shown .…”