Zootechnical wastewater reuse: constructed wetland as a challenge for protozoan parasite removal

Samples of soil, well water, and wastewater from a zootechnical farm, water after phytodepuration and maize plants (Zea mays) grown on soils irrigated with these different kinds of water were analysed for indicator bacteria and the protozoa Giardia and Cryptosporidium. Protozoa and bacterial indicators, except coliforms, were not recovered from well water samples. In the effluent from the zootechnical farm, high parasitological concentrations were observed, whilst water after the phytodepuration process showed a concentration reduction of two orders of magnitude. The high numbers of Giardia and Cryptosporidium in the zootechnical effluent could represent a potential risk for the spread of the pathogens. Nevertheless the environmental spread is minimized when data on soils and plants are observed. From the study, it emerges that this water treatment system could represent an alternative option to other conventional wastewater treatments and an economic and environmental advantage.