Comparative ecotoxicological evaluation of peracetic acid and the active chlorine of calcium hypochlorite: Use of Dugesia tigrina as a bioindicator of environmental pollution

• Published in: Chemosphere (Oxford) Vol. 233; pp. 273 - 281
• Main Authors: Rodrigues Macêdo, Luana Priscilla, Pereira Dornelas, Aline Silvestre, Vieira, Mayane Marques, Santiago de Jesus Ferreira, Joel, Almeida Sarmento, Renato, Cavallini, Grasiele Soares
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-10-2019
• Subjects: Alternative disinfectant to chlorine; Contamination bioindicators; Preservation of ecosystems; Residual disinfectant; Contamination bioindicators; Alternative disinfectant to chlorine; Preservation of ecosystems; Residual disinfectant
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2019.05.286

Chlorine plays a primary role in the disinfection of drinking water and wastewater due to its effectiveness as a biocide; however, there is evidence of the formation of toxic byproducts from its application, and this has promoted the search for alternatives. Alternative disinfectants can be effective in the inactivation of pathogenic microorganisms and are less damaging to human health and aquatic ecosystems. However, more information is needed on the effect of residual concentrations on the environment. This work compares the ecotoxicological effects of PAA disinfectants and the active chlorine of calcium hypochlorite in relation to the organism Dugesia tigrina (planaria), in terms of the acute effects: LC50, and chronic effects: feeding, locomotion, regeneration, reproduction and fertility. The results indicated that the active chlorine was more toxic than PAA, with LC50 (96 h) of 2.63 mg.L−1 and 3.16 mg.L−1, respectively. Sub-lethal exposure to active chlorine was more toxic when compared to PAA, and there was evidence of significantly reduced feeding and locomotion, causing a greater delay in regeneration and impairment in reproduction and fertility. The results allowed the comparison of the two disinfectants using half-life constants of the compounds and the lowest observed effect level (LOEC) of the oxidants. Chlorine represents a greater risk to the ecosystem for a longer period. The results obtained in this study can help in the establishment of discharge limits for PAA in water bodies.
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•Ecotoxicity of residual peracetic acid utilized Dugesia tigrina.•D. tigrina, a relevant bioindicator: high sensitivity and regeneration capacity.•Comparative bioassay between peracetic acid and active chlorine.