The pathogenic protozoa Giardia and Cryptosporidium have been included by the
World Health Organization (WHO) among the emergent pathogenic microorganisms of prior interest, because of
the numerous waterborne outbreaks of giardiasis and cryptosporidiosis that have occurred all
over the world. Some rules about drinking water already include them among the
regulated parameters, while in the field of wastewater reuse the problem of the
presence of protozoan cysts has been considered only recently.
This paper presents the results of an experimental study, carried out at Pistoia's
Waste Water Treatment Plant (WWTP), aimed at determining the presence of such
protozoa in raw wastewater and at estimating and comparing the removal achievable
by a conventional WWTP and by a pilot plant scale tertiary treatment which consists
of a double stage filtration. According to the literature data, experimental results
show that the average values of Giardia cysts and Cryptosporidium oocysts removal
obtained by a conventional WWTP are about 98% and 92%, respectively. Also, it was determined that physical removal through filtration is a treatment suitable and
reliable for an effective elimination of cysts and oocysts in wastewater. By filtering the
secondary effluent an average removal value of 98% for Giardia cysts and 90% for
Cryptosporidium oocysts has been obtained.
Includes 13 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 160 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 6 |
| Published : | 09/22/2002 |
