Peracetic acid and sodium hypochlorite effectiveness in reducing resistant stages of microorganisms.

A comparative study on the efficacy of peracetic acid and sodium hypochlorite in inactivating resistant stages of microorganisms such as Cryptosporidium, Giardia and Cl. perfingens was carried out. Furthermore the evaluation of the potential reciprocal correlation among the concentrations of the organisms was performed. The results obtained indicate that, at the same experimental conditions, peracetic acid and sodium hypochlorite have nearly similar reduction power against the resistant stages of Giardia and Cl. perfringens. Both the oxidants are instead less efficient in the abatement of Cryptosporidium oocysts. Findings have also confirmed our previous studies on the absence of association between Clostridium and the protozoa.