This past week, the International Water Association (IWA) Specialist Group on Wastewater Pond Technology held its bienniel conference in Baru, Colombia. USF was represented at the conference with an oral presentation about our research regarding the removal of helminth eggs in a stabilization pond system with poor hydraulics.
Our paper provides recommendations for updating the WHO Guidelines for Wastewater Use in Agriculture, based on data from a pond system where Taenia spp. eggs were detected in higher concentrations than nematode species such as Ascaris. One Taenia species in particular (Taenia solium) can cause neurocysticercosis, which is the leading cause of acquired epilepsy in the world (1). Previous reports in the literature (2, 3) have proposed design equations for the removal of nematode eggs based on theoretical hydraulic retention time (HRT), however, our results indicate that, despite a very high theoretical HRT, extreme short-circuiting may have caused a lower removal of Taenia eggs than predicted by previous design equation models. In the pond studied, a large portion of the tracer dye was detected in the pond effluent after less than 10% of the theoretical HRT.
Special congratulations goes out to the Conference Organizing and Scientific Committees, in particular Dr. Miguel Peña and Dr. Carlos Madera from Univalle in Cali, Colombia. The team did an excellent job attracting many high-quality presentations by researchers from around the world, which provided for a rich exchange of ideas and opinions!
(1) García, H. H.; Gonzalez, A. E.; Evans, C. A. W.; Gilman, R. H. Taenia solium cysticercosis. The Lancet 2003, 362, 547–556.
(2) Ayres, R. M.; Alabaster, G. P.; Mara, D. D.; Lee, D. L. A Design Equation for Human Intestinal Nematode Egg Removal in Waste Stabilization Ponds. Water Research 1992, 26, 863–865.
(3) Saqqar, M. M.; Pescod, M. B. Modelling nematode egg elimination in wastewater stabilization ponds. Water Science and Technology 1992, 26, 1659–1665.