Dissolved air flotation as a potential treatment process to remove Giardia cysts from anaerobically treated sewage

Author(s)

dos Santos, Priscila Ribeiro ; Daniel, Luiz Antonio

• Document type: Journal article
• Source: ENVIRONMENTAL TECHNOLOGY; v. 38, n. 19, p. 2392-2399, 2017.
• Web of Science Citations: 0

Abstract

Controlling Giardia cysts in sewage is an essential barrier for public health protection, reducing possible routes of protozoa transmission. The aim of this study was to evaluate the capability of dissolved air flotation (DAF), on a bench scale, to remove Giardia cysts from anaerobic effluent. Moreover, removals of indicator microorganisms and physical variables were also investigated. Flocculation conditions were studied, associating different flocculation times with different mean velocity gradients. DAF treatment achieved mean log removals in the range of 2.52-2.62 for Giardia cysts, depending on the flocculation condition. No statistical differences were observed among the flocculation conditions in terms of cyst removal. Low levels of turbidity and apparent color obtained from the treated effluent may indicate good treatment conditions for the DAF process in cyst removal. Indicator microorganisms were not able to predict the parasitological quality of the wastewater treated by flotation in terms of cyst concentrations. The DAF process provided an effective barrier to control cysts from sewage, which is an important parasite source. (AU)

• FAPESP's process: 12/50522-0 - Environmental contamination by protozoa Giardia spp. and Cryptosporidium spp. and Ascaris suum: challenges of detection, removal and inactivation of infective forms
• Grantee: Regina Maura Bueno Franco
• Support Opportunities: Research Projects - Thematic Grants