Toxicity and disinfection assessment of metal containing WWTP effluents during ozonation and UV/H2O2

Author(s)

Malvestiti, Jacqueline A. ; Simao, Debora C. ; Dantas, Renato F.

• Document type: Journal article
• Source: JOURNAL OF WATER PROCESS ENGINEERING; v. 46, p. 9-pg., 2022-04-01.

Abstract

Disinfection of effluents by ozonation and UV/H2O2 has growth around the world in the last decades. However, in this type of treatment the composition of the effluent can affect the efficiency due to competition of some components for hydroxyl radicals, thus delaying the inactivation of microorganisms. This work studied the influence of the presence of seven metals during WWTP disinfection by ozonation and UV/H2O2 as well as assessed the toxicity evolution along the reaction time. For this purpose, concentrations 3 times higher than metals allowed in Brazilian legislation were used to verify their effects on effluent disinfection and toxicity after ozonation and UV/H2O2. The microorganisms inactivation, represented by Escherichia coli and total coliforms, were significantly accelerated by the presence of Fe, Cu and all metals added simultaneously to the reactor for both treatments, being the Fe that which presented the highest impact, while the presence of Zn and Ni also accelerated the inactivation during the UV/H2O2 treatment. The other metals showed no statistically significant influences. Regarding the toxicity evaluation, both treatments had a positive influence by reducing acute toxicity of the samples. Cr, Pb, Fe, Cu presence promoted the highest toxicity to the E. sativa and A. salina. Nevertheless, ozonation and UV/H2O2 treatments were able to importantly reduce the acute toxicity in the wastewater samples in presence of these components, proving to be a good option to reduce the acute toxicity caused by industrial contamination in municipal secondary effluents. (AU)

• FAPESP's process: 16/07911-7 - Disinfection of secondary effluents by UV/H2O2
• Grantee: Jacqueline Aparecida Malvestiti
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 14/17774-1 - Influence of the secondary effluent composition on the disinfection by advanced oxidation processes
• Grantee: Renato Falcão Dantas
• Support Opportunities: Research Grants - Young Investigators Grants