Remoção de cistos de Giardia spp. e oocistos de Cryptosporidium spp. na Estação de Tratamento de Esgoto Garcia, no município de Blumenau, SC, Brasil

Abstract

Giardia spp. and Cryptosporidium spp. are responsible for a number of outbreaks of gastroenteritis, particularly associated with the consumption of contaminated water. The cysts and oocysts of these protozoa are resistant to environmental variations, as well as to most of the physical, chemical and microbiological processes used in water treatment and sewage plants. This study therefore aimed to detect and evaluate the removal of Giardia spp. and Cryptosporidium spp. in a combined system anaerobic / aerobic Waste Water Treatment Plant (WWTP) located in the city of Blumenau, SC, Brazil. For the study of cysts and oocysts, samples of effluents and sludge from the WWTP were concentrated by filtration using a membrane of cellulose esters and by centrifugation, followed by direct immuno-fluorescence assay (RID) using the Merifluor diagnostic kit. The analysis followed the standards published in APHA (2012) to obtain the physical, chemical and microbiological parameters. High concentrations of Giardia spp. (Max. 900,000 L -1 cysts) were detected in 83.3% of the analyzed points. Oocysts Cryptosporium spp. were detected at high concentrations (max. 300,000 oocysts L -1 ) in 66.6% of the analyzed points. Neither cysts nor oocysts were detected in treated effluent samples. Thus, the combined system of the Garcia WWTP showed a 99.9% efficiency rate for the removal of resistant forms of pathogens, contributing to the reduction of environmental contamination by these pathogens present in the domestic sewage of Blumenau, SC.

Physicochemical, microbiological and parasitological characterization of the filter backwash water from a water treatment plant of Blumenau - SC and alternatives for treatment and reuse

“…indicates greater circulation of this protozoan in the region. Similar results were observed by Grott et al (2016) analyzing raw water from the Itajaí-Açu River in Blumenau (SC), Miglioli et al (2017) in Sewage Treatment Plant sludge, also in Blumenau (SC), Greinert et al (2004) in pool water in the city of Florianópolis (SC), Franco et al (2001) in Campinas (SP), Cantusio-Neto et al (2006) in Sewage Treatment Plant sludge also in Campinas (SP), Sato et al (2013) in several springs of the state of São Paulo. Grott et al (2016), evaluated the parasitological profile of the raw water uptake of the water treatment station -WTP II of Blumenau, and the results were compared with this research (Table 3).…”

Efficiency of wastewater treatment plants in removal of intestinal parasites: A review approach

“…Also, 5 treatment systems out of 29 systems (17.24%), had 100% efficacy in removing worms and protozoa. While the results of recent studies have shown that about 82.75% of treatment plants had not 100% efficiency in removing worms and protozoa (14,29,43,44,51,53,(55)(56)(57)60,61,72). Overall, helminth infections, including parasitic eggs and larvae, are more easily removed by the treatment systems compared to the protozoans.…”

“…Overall, helminth infections, including parasitic eggs and larvae, are more easily removed by the treatment systems compared to the protozoans. The main protozoa species include Giardia, Cryptosporidium, and Acanthamoeba, which are not completely (100%) eliminated (42,56,77,78). Since retreated wastewater will be reused and given the potential exposure of humans to these sources, it can be an important factor in causing infections in humans.…”