Browsing by Author "Pereira, Ruth"
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- 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.
- Effect of a soil biofertilizer in the functional profile of the soil microbial community through the biolog assayPublication . Lima, Sonny; Pacheco, João; Ganilho, Catarina; Crespo, Rute; Andreani, Tatiana; Godinho, Mariana; Pereira, Sofia; Pereira, RuthBackground & Aim: The dependency on crops of products with chemical compounds, whether fertilizers or pesticides, for saving the development and yield has been a challenge to the environment, and new alternatives are being sought to change this reality. The excessive use of chemicals affects human health and soil quality. There is a significant need to produce green compounds that are environmentally sustainable, improving or restoring microbial activity in the soil. Biofertilizers are compounds that contain biological substances and may be capable of stimulating plant development, by providing nutrients and other plant-growth promoting compounds and by increasing soil microbial activity, and reducing the impacts generated by mineral fertilizers. The objective was to verify the effects of applying a biofertilizer, Vitasoil™, which contains rhizospheric microorganisms that positively interact with plants, on the functional profile of the soil microbial community. Methods: The first evaluation was conducted one month after the application of the compound, using Biolog EcoPlates. Results: Its composition includes two types of bacteria: Azotobacter sp. and Azospirillum sp. We chose kale (Brassica oleracea) for the tests, with direct application of the compound diluted in the proper proportion to the plant's root, so that we could compare the inoculated soils with the non- inoculated ones. Conclusions: This method was able to show the effects of the inoculant application on the soil with and without B. oleracea plants and inferring about the positive/negative effects on the non-target bulk soil microbial community.
- Effect of a soil biofertilizer in the functional profile of the soil microbial community through the biolog assayPublication . Lima-Filho, Sonny; Pacheco, João; Ganilho, Catarina; Crespo, Rute; Andreani, Tatiana; Godinho, Mariana; Pereira, Sofia; Pereira, RuthIntroduction: The dependency on crops of products with synthetic chemical compounds, whether fertilizers or pesticides, for saving the development and yield has been a challenge to the environment, and new alternatives are being sought to change this reality. The excessive use of chemicals affects human health and soil quality. Therefore, there is a significant need to produce green compounds that are environmentally sustainable, aimed at improving or restoring microbial activity in the soil. Biofertilizers are compounds that contain biological substances capable of stimulating plant development, by providing nutrients and other plant-growth promoting compounds, of increasing soil microbial activity, and of reducing the environmental impacts of mineral fertilizers. Aims: To assess the effects of applying a biofertilizer inoculum, containing rhizospheric microorganisms, that positively interact with plant roots, on the functional profile of the bulk soil microbial community; To evaluate soil microbial activity after 30 and 60 days of organic biofertilizer application through the BIOLOG assay. Conclusion: The soil without inoculum was the one with the lowest microbial activity (measured by the AWCD) after both incubation periods, although the differences do not seem to be significant (data under analysis); The presence of the plant was able to compensate for the possible effect of the biofertilizer on the highest consumption of some substrates in detriment of others, as suggested by the Eveness index (C, D); Both the plant and the biofertilizer inoculum promoted a higher soil functional biodiversity of the soil, as measured by the Shannon Index (E, F) and the Richness (G, H), calculated based on the number and type of carbon substrates mineralized by the soil microbial community.
- Review of the ecotoxicological effects of emerging contaminants to soil biotaPublication . Gomes, Ana R.; Justino, Celine; Rocha-Santos, Teresa; Freitas, Ana C.; Duarte, Armando C.; Pereira, RuthIn recent years, emerging contaminants (e.g. pesticides and their metabolites, pharmaceuticals, personal and house care products, life-style compounds, food additives, industrial products and wastes, as well as nanomaterials) have become a problem to the environment. In fact, the cumulative use of a panoply of chemical substances in agriculture, industrial activities, in our homes and in health care services has led to their recent appearance in detectable levels in soils, surface, and groundwater resources, with unpredictable consequences for these ecosystems. Few data exist regarding the toxicity and potential for bioaccumulation in biota. When available, data were obtained only for some representatives of the main groups of chemical substances, and for a limited number of species, following non-standard protocols. This makes difficult the calculation of predicted no effect concentrations (PNEC) and the existence of sufficient data to set limits for their release into the environment. This is particularly concerning for the soil compartment, since only recently the scientific community, regulators, and the public have realised the importance of protecting this natural resource and its services to guarantee the sustainability of terrestrial ecosystems and human well-being. In this context, this review paper aims to identify the major groups of soil emerging contaminants, their sources, pathways and receptors, and in parallel to analyse existing ecotoxicological data for soil biota.
- 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.