Loading...
2 results
Search Results
Now showing 1 - 2 of 2
- Dataset of the preparation and characterization of an artificial sludge for ecotoxicological purposesPublication . Gavina, Ana; Freitas, Ana Cristina; Ricardo, Amadeu; Gomes, Ana; Marques, Catarina; Lopes, Isabel; Pereira, RuthThis work describes the protocol developed for preparing an artificial digested sludge to be used for the ecotoxicological evaluation and risk assessment of chemical substances that are previewed to attain the soil through sewage sludge applications for fertilization (e.g. pharmaceutical compounds). Such evaluations have been made with standard protocols for ecotoxicological tests with terrestrial species in which the chemical substances are directly spiked to the test soil. This procedure lacks ecological relevance in terms of the role the sludge organic matter plays on the bioavailability and fate of chemical substances. Here we describe the protocol and the composition for obtaining the artificial sludge, prepared with commercial pet food and eggs white to mimic the composition of domestic sewage sludge in terms of proteins, carbon hydrates, fat and fibers content. Further, the conditions ascertained for the anaerobic digestion of the organic mixture are described, and the final properties of the sludge are presented, after repeating the procedure twice.
- Toxicity abatement of wastewaters from tourism units by constructed wetlandsPublication . Calheiros, Cristina S. C.; Castro, Paula M. L.; Gavina, Ana; Pereira, RuthThe present research intended to investigate the toxicity abatement of domestic wastewater after passing a biosystem composed of a constructed wetland (CW) followed by a pond. The wastewater was generated in a tourism house in a rural and mountainous context and passed through a septic tank before being diverted to a CW followed by a pond. A battery of ecotoxicological tests, comprising microalgae (Raphidocelis subcapitata), macrophytes (Lemna minor), cladocerans (Daphnia magna), and bacteria (Aliivibrio fischeri), was used to assess the toxicity of the wastewater collected before and after the CW and the water of the pond. Physicochemical parameters (pH, conductivity, chemical oxygen demand, biochemical oxygen demand, total suspended solids, phosphates, ammonium, and nitrate) were also determined. The CW was able to remove carbon and nutrients from the water with a concomitant reduction of its toxicity. This study, reinforced the added value of using toxicity tests as a complement to CW operational monitoring to validate the solution and to analyze possible readjustments that may be required to improve efficiency. This study lends further support to the claim that CWs can be a sustainable solution for treating small volumes of domestic wastewater in a rural context.