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- Field study on the accumulation of trace elements by vegetables produced in the vicinity of abandoned pyrite minesPublication . Alvarenga, Paula; Simoes, Isabel; Palma, Patrícia; Amaral, Olga; Matos, Joao XavierTo evaluate the accumulation of trace elements (TE) by vegetables produced in the vicinity of abandoned pyrite mines, eighteen different small farms were selected near three mines from the Portuguese sector of the Iberian Pyrite Belt (Sao Domingos, Aljustrel and Lousal). Total and bioavailable As, Cu, Pb, and Zn concentrations were analyzed in the soils, and the same TE were analyzed in three different vegetables, lettuce (Lactuca sativa), coriander (Coriandrum sativum), and cabbage (Brassica oleracea), collected at the same locations. The soils were contaminated with As, Cu, Pb, and Zn, since their total concentrations exceeded the considered soil quality guideline values for plant production in the majority of the sampling sites. The maximum total concentrations for those TE were extremely high in some of the sampling sites (e.g. 1851 mg As kg(-1) in Sao Domingos, 1126 mg Cu kg(-1) in Aljustrel, 4946 mg Pb kg(-1) in Sao Domingos, and 1224 mg Zn kg(-1) in Aljustrel). However, the soils were mainly circumneutral, a factor that contributes to their low bioavailable fractions. As a result, generally, the plants contained levels of these elements characteristic of uncontaminated plants, and accumulation factors for all elements <1, typical of excluder plants. Furthermore, the estimated daily intake (EDI) for Cu and Zn, through the consumption of these vegetables, falls below the recommended upper limit for daily intake of these elements. The sampling site that stood out from the others was located at Sao Joao de Negrilhos (Aljustrel), where bioavailable Zn levels were higher, a consequence of the slight acidity of the soil. Therefore, the Zn content in vegetables was also higher, characteristic of contaminated plants, emphasizing the risk of Zn entering the human food chain via the consumption of crops produced on those soils. (C) 2013 Elsevier B.V. All rights reserved.
- Ecotoxicological endpoints, are they useful tools to support ecological status assessment in strongly modified water bodies?Publication . Palma, Patrícia; Ledo, L.; Alvarenga, P.Although man-made reservoirs represent an important water supply source in countries where water scarcity has become a problem, little work has been done on the evaluation of their ecological status. Taking this in account, the general aim of this study was to assess the usefulness of ecotoxicological endpoints in the potential ecological status characterization of water reservoirs, with the purpose of their possible integration in evaluation programs developed under the Water Framework Directive (WFD). To achieve this purpose, a group of bioassays were selected to evaluate both water and sediment compartments at the Alqueva reservoir (the biggest from the Iberian Peninsula), with representative species from different taxonomic and functional groups: Vibrio fischeri, Thamnocephalus platyurus, Daphnia magna and Heterocypris incongruens. The ecotoxicological assessment showed that sublethal endpoints (e.g., luminescence, growth or reproduction), would be more useful and sensitive to identify toxicity patterns in this type of water body. In general, the results from this ecotoxicological tool-box agreed with the potential ecological status established according to the WFD, which indicates that the bioassays complement the ecological assessment. Furthermore, the use of an ecotoxicological approach can be extremely useful, especially in cases where the biotic indices are difficult to establish, such as in man-made reservoirs. However, when pollutant concentrations are very low, and/or when nutrients and organic matter concentrations are high, the two approaches do not fit, requiring further research to determine which organisms are more sensitive and the best biotic indices to use under those conditions. (C) 2015 Elsevier B.V. All rights reserved.
- Recycling organic wastes to agricultural land as a way to improve its quality: A field study to evaluate benefits and risksPublication . Alvarenga, P.; Palma, Patrícia; Mourinha, C.; Farto, M.; Dores, J.; Patanita, M.; Cunha-Queda, C.; Natal-da-Luz, T.; Renaud, M.; Sousa, J. P.A field study was established to assess the effects of a sewage sludge (SS), a mixed municipal solid waste compost (MMSWC) and a compost produced from agricultural wastes (AWC), in a Vertisol, using Lolium multiflorum L The amendments were applied for two consecutive years: 6, 12 and 24 t dry matter ha(-1) for SS, and the amendment doses for MMSWC and AWC were calculated to deliver the same amount of organic matter (OM) per unit area. The amendments had significant beneficial effects on some soil properties (e.g. soil OM, N-Kjeldahl, extractable P and K), and on plant productivity parameters (e.g. biomass yield, chlorophyll, foliar area). For instance, soil OM increased from 0.78% to 1.71, 2.48 and 2.51%, after two consecutive years of application of 24 t dry matter ha(-1) of SS, MMSWC and AWC, respectively, while the plant biomass obtained increased from 7.75 t ha(-1) to 152.41, 78.14 and 29.26 t ha(-1), for the same amendments. On the plant, effects were more pronounced for SS than for both compost applications, a consequence of its higher capacity to provide N to the plant in a readily available form. However, after two years of application, the effects on foil properties were more noticeable for both composts, as their OM is more-resistant to mineralization, which endures their beneficial effects on soil. Cadmium, Cr, Ni and Pb pseudo-total concentrations, were not affected significantly by the application of the organic wastes to soil, in all tested doses, neither their extractability by 0.01 M CaCl2. On the contrary, Cu and Zn pseudo-total concentrations increased significantly in the second year of the experiment, following the application of the higher rate of MMSWC and AWC, although their extractability remained very low (<0.5% of their pseudo-total fraction). Trace elements concentrations in the aboveground plant material were lower than their maximum tolerable levels for cattle, used as an indicator of risk of their entry into the human food chain. Despite these results, it is interesting to note that the SS promoted a significant increase in the foliar concentrations of Cu, Ni and Zn that did not happen in composts application, which can be explained by the reduction of the soil pH, as a consequence of SS degradation in soil. Concluding, if this type of organic wastes were to be used in a single application, the rate could be as high as 12 or even 24 t ha(-1), however, if they are to be applied in an annual basis, the application rates should be lowered to assure their safe application (e.g. to 6 t ha(-1)). Moreover, it is advisable to use more stable and mature organic wastes, which have longer lasting positive effects on soil characteristics. (C) 2017 Elsevier Ltd. All rights reserved.
- Membranes technology used in water treatment: Chemical, microbiological and ecotoxicological analysisPublication . Palma, Patrícia; Fialho, S.; Alvarenga, P.; Santos, C.; Bras, T.; Palma, G.; Cavaco, C.; Gomes, R.; Neves, L. A.The increment of world's Human population, with the consequent demand for water supply, plus the need for sustainable development and the conservation of water resources, highlights the urgency of improving water treatment technologies and management actions.The aim of the present study was to characterize and evaluate the efficiency of nanofiltration (NF90, NF270) and reverse osmosis (SW30) membranes, in improving the quality of three types of waters: irrigation, municipal supply and wastewater. The efficiency of using this technology was assessed by: (i) the study of water permeability and rejection of some chemical parameters, such as total nitrogen, total phosphorus, chemical oxygen demand (COD), biochemical oxygen demand (BOD5), feacal coliforms, nitrates, chlorides, iron and manganese; and (ii) the evaluation of their ecotoxicological effects, through the use of representative species of different taxonomic and functional groups (Vibrio fischeri, Thamnocephalus platyurus, Daphnia magna, and Pseudokirchneriella subcapitata). Results indicated that all three membranes have high rejection percentages for the majority of the studied parameters (>90%). All parameters concentrations in the permeate stream were below the limit values from Portuguese legislation and European Directives. With respect to the ecotoxicological effects, in general, the use of membranes removed the toxicity detected in the initial samples (which exhibited significant toxicity). The SW30 membrane showed a greater efficiency for toxicity removal, comparing with the nanofiltration membranes. Further, among the nanofiltration membranes used, the NF90 promoted a greater decrease in the toxicity of the samples. Thus, treatment with the membranes NF90 and SW30 allowed obtaining waters with high quality and low ecotoxicological potential, without risks for human populations and endangering the environmental balance. (C) 2016 Elsevier B.V. All rights reserved.
- Organic wastes as soil amendments - Effects assessment towards soil invertebratesPublication . Renaud, Mathieu; Chelinho, Sonia; Alvarenga, Paula; Mourinha, Clarisse; Palma, Patrícia; Sousa, Jose Paulo; Natal-da-Luz, TiagoUsing organic wastes, as soil amendments, is an important alternative to landfilling with benefits to soil structure, water retention, soil nutrient and organic matter concentrations. However, this practice should be monitored for its environmental risk due to the frequent presence, of noxious substances to soil organisms. To evaluate the potential of eight organic wastes with different origins, as soil amendments, reproduction tests with four soil invertebrate species (Folsomia candida, Enchytraeus crypticus, Hypoaspis aculeifer, Eisenia feticta) were performed using gradients of soil waste Mixtures. Results obtained demonstrated that contaminant concentrations required by current legislation might not be a protective measure for the soil ecosystem, as they do not properly translate the potential toxicity of wastes to soil invertebrates. Some wastes with contaminant loadings below thresholds showed higher toxicity than wastes with contaminants concentrations above legal limits. Also, test organism reproduction was differently sensitive to the selected wastes, which highlights the need to account for different organism sensitivities and routes of exposure when evaluating the toxicity of such complex mixtures. Finally this study shows that when combining chemical and ecotoxicological data, it is possible to postulate on potential sources of toxicity, contributing to better waste management practices and safer soil organic amendment products. (C) 2017 Elsevier B.V. All rights reserved.
- Quality assessment of a battery of organic wastes and composts using maturity, stability and enzymatic parametersPublication . Alvarenga, Paula; Mourinha, Clarisse; Farto, Marcia; Palma, Patrícia; Sengo, Joana; Morais, Marie-Christine; Cunha-Queda, CristinaChemical and biological parameters (NH4+-N/NO3--N ratio, humification indices, and the activities of hydrolytic exoenzymes), commonly used to assess compost maturity and/or stability, were considered for the quality evaluation of a battery of organic materials, intended to be land applied. Acid and alkaline phosphatases, beta-glucosidase, proteases and beta-glucosaminidase activities proved to be reliable tests to distinguish the organic materials that were in an active stage of microbial activity, highly correlated to the chemical parameters NH4+-N content and NH4+-N/NO3--N ratio. In fact, these chemical parameters evidenced as important in the quality assessment of an organic material, strongly correlated with the biological parameters. The same was not true for the majority of the humification indices, which proved inadequate to compare the quality of such diverse organic materials. This was demonstrated by a multivariate statistical treatment of data, performed with these results in combination with results from the Dewar self-heating test, respiration activity and germination index, obtained in previous studies. Concluding, in a similar scenario, where the organic materials in evaluation are varied, both in the raw material an in the stability of the organic matter, the quality should be assessed by the integrated use of both chemical and biological parameters.
- Assessment of trace element pollution and its environmental risk to freshwater sediments influenced by anthropogenic contributions: The case study of Alqueva reservoir (Guadiana Basin)Publication . Palma, Patricia; Ledo, Lidia; Alvarenga, PaulaThe Guadiana Basin.(SW Iberian Peninsula) is affected by acid mine drainage (AMD), a consequence of ancient mining activities in the Iberian Pyrite Belt (IPB). Consequently, the sedimerits at the Alqueva reservoir (SE Portugal) in the Guadiana Basin are potentially contaminated by trace elements, which make important: (i) to characterize the status of trace element pollution of the sediments; (ii) to evaluate the mobility and the bioavailability of As, Cd, Cu, Cr, Pb and Zn; and (iii) to assess the environmental risk associated with the total and bioavailable concentrations of trace elements, using the sediment quality guidelines (SQGs) and the risk assessment code (RAC). Metal enrichment factors (EF) and geoaccumulation indexes (I-geo), determined taking into account the regional background levels, revealed that, among the metals analyzed, Cd contributed the highest to pollution levels followed by Pb and As. Despite the trace element contamination of the Alqueva sediments, the sequential extraction showed that Most of them are found in the oxidizable and residual fractions, which indicates that they are sparingly bioavailable, with exception of Cd (acid-labile fraction) and Pb (reducible fraction). Based on the RAC, Cd was the only metal that presented a high risk, while Pb, As and Zn showed a medium risk. Moreover, the SQGs revealed the existence of certain areas of extremely high risk, particularly related to high concentrations of total As and, in less extent, of Pb and Cd, associated with AMD, wastewater discharges and runoff of plant protection products from agricultural fields located near the reservoir. (C) 2015 Elsevier By. All rights reserved.
- Assessment of the effects of the carbamazepine on the endogenous endocrine system of Daphnia magnaPublication . Oropesa, A. L.; Floro, A. M.; Palma, PatríciaIn the present study, the endocrine activity of the antiepileptic pharmaceutical carbamazepine (CBZ) in the crustacean Daphnia magna was assessed. To assess the hormonal activity of the drug, we exposed maternal daphnids and embryos to environmental relevant concentrations of CBZ (ranging from 10 to 200 mu g/L) and to mixtures of CBZ with fenoxycarb (FEN; 1 mu g/L). Chronic exposure to CBZ significantly decreased the reproductive output and the number of molts of D. magna at 200 mu g/L. This compound induced the production of male offspring (12 +/- 1.7 %), in a non-concentration-dependent manner, acting as a weak juvenile hormone analog. Results showed that this substance, at tested concentrations, did not antagonize the juvenoid action of FEN. Further, CBZ has shown to be toxic to daphnid embryos through maternal exposure interfering with their normal gastrulation and organogenesis stages but not producing direct embryo toxicity. These findings suggest that CBZ could act as an endocrine disruptor in D. magna as it decreases the reproductive output, interferes with sex determination, and causes development abnormality in offspring. Therefore, CBZ could directly affect the population sustainability.
- Ecotoxicological assessment of the potential impact on soil porewater, surface and groundwater from the use of organic wastes as soil amendmentsPublication . Alvarenga, Paula; Mourinha, Clarisse; Farto, Marcia; Palma, Patrícia; Sengo, Joana; Morais, Marie-Christine; Cunha-Queda, CristinaThis study aimed to assess the potential impact on soil porewater, surface and groundwater from the beneficial application of organic wastes to soil, using their eluates and acute bioassays with aquatic organisms and plants: luminescence inhibition of Vibrio fischeri (15 and 30 min), Daphnia magna immobilization (48 h), Thamnocephalus platyurus survival (24 h), and seed germination of Lolium perenne (7 d) and Lactuca sativa (5 d). Some organic wastes' eluates promoted high toxic responses, but that toxicity could not be predicted by their chemical characterization, which is compulsory by regulatory documents. In fact, when organisms were exposed to the water-extractable chemical compounds of the organic wastes, the toxic responses were mare connected to the degree of stabilization of the organic wastes, or to the treatment used to achieve that stabilization, than to their contaminant load. That is why the environmental risk assessment of the use of organic wastes as soil amendments should integrate bioassays with eluates, in order to correctly evaluate the effects of the most bioavailable fraction of all the chemical compounds, which can be difficult to predict from the characterization required in regulatory documents. According to our results, some rapid and standardized acute bioassays can be suggested to integrate a Tier 1 ecotoxicological evaluation of organic wastes with potential to be land applied, namely luminescence inhibition of V fischeri, D. magna immobilization, and the germination of L. perenne and L sativa.
- Beneficial use of dewatered and composted sewage sludge as soil amendments: behaviour of metals in soils and their uptake by plantsPublication . Alvarenga, Paula; Farto, Márcia; Mourinha, Clarisse; Palma, PatríciaIn Portugal, where soils have a very low topsoil organic matter content, the use of sewage sludge (SS) as organic soil improvers seems an attractive option, because it would enable organic matter, N, P, K and other nutrients to be recycled. However, the risk of this practice must be properly assessed. The aim of this study was to evaluate the potential risk of the use of dewatered and composted SS as soil amendments. For this purpose, SS from two different wastewater treatment plants (SS1 and SS2), and a compost produced from SS and agricultural wastes (AWSSC), were characterized for their total metal concentrations, organic contaminants and indicator pathogens, and used in a pot experiment with three application rates, 6, 12 and 24 ton dry matter/ha, cultivated with a hybrid variety of sorghum and Sudan grass (Sorghum bicolor x Sorghum sudanense var. Rocket). SS1 and AWSSC met the legal requirements to be applied to soils, but SS2 had a high content of pathogens, which compromised its use. Both dewatered SS had a marked beneficial effect on plant production and on soil nutritional characteristics, more pronounced than in the case of AWSSC application, without a significant increase in total and in mobile metals concentration in soils. Bioaccumulation factors for metals in plants were low, and their concentrations in the aboveground plant material were lower than the maximum tolerable level for cattle, used as a risk indicator of metal entry into the human food chain. However, it will be necessary, in future studies, to evaluate the potential risk of the observed increase in the mobilisable content of Cu and Zn in soil, as a consequence of the application of these organic materials.