Percorrer por autor "Caetano, Nídia S."
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- Assessment of the biofuel production potential from phytoremediation sunflower biomassPublication . Marques, Ana P. G. C.; Domingues, Patrícia; Prata, Nuno; Caetano, Nídia S.; Castro, Paula M. L.There are presently more than 3 million contaminated sites all over EU, according to the EEA (report 25186 EN). Heavy metal contamination is of particular concern, as metals are not degradable. Phytoremediation is gaining attention from the public and is an attractive low cost alternative for soil requalification, by establishing a vegetation cover which will stabilize the site, avoiding dispersion of contamination and simultaneously removing pollutants. Although the fate of harvested biomass is a common obstacle for its implementation, it may represent an opportunity for producing energy. This work presents a novel integrated strategy comprising the utilization of all plant parts for the generation of biodiesel. Combinations of sunflower and plant growth promoting microbiota were assessed growing in agricultural and metal contaminated soils. Harvested plant tissues were analysed and it was possible to observe that accumulation of Zn and Cd was made mainly in the roots, followed by the stems and the flowers, with the values registered for plants grown in contaminated soils being higher than the reported phytotoxic levels described in literature. Also, plants grown in the agricultural soil presented higher biomass rates. Sunflower seeds were then used for oil extraction and it was possible to observe efficiencies of up to 20 ml oil/m2, with only the oil from plants grown in industrial soil presenting levels of 1.8 mg Zn/l. Plant stems were used for bioethanol fermentation with yields of up to 280 and 162 ml/m2 for plants growing respectively in agricultural and industrial soils. Once again only plants grown in the industrial soil presented detectable levels of 1.1 mg Zn/l (and no Cd).
- Assessment of the energy production potential form phytoremediation derived biomassPublication . Marques, Ana P. G. C.; Castro, Paula M. L.; Caetano, Nídia S.There are presently more than 3 million contaminated sites all over EU, according to the EEA (report 25186 EN). Heavy metal (HM) contamination is of particular concern, as metals are not degradable. Phytoremediation is gaining attention from the public and is an attractive low cost alternative for soil requalification, by establishing a vegetation cover which will stabilize the site, avoiding dispersion of contamination and simultaneously removing pollutants. Although the fate of harvested biomass is a common obstacle for its implementation, it may represent an opportunity for producing energy. However, and although it has been proposed theoretically as an excellent option, the information available in literature concerning practical applications is scarce, despite the considerable degree of success reported. The use of biomass grown in degraded and abandoned soils, not involving agricultural soils for energy crop cultivation, may increase the sustainability of utilizing biomass for energy generation, while it may allow for increasing the available agricultural soil through the consequent gradual decontamination of such brownfields. This work presents a novel integrated strategy comprising the utilization of all plant parts for the generation of biodiesel. Combinations of sunflower and plant growth promoting microbiota were assessed growing in agricultural and metal contaminated indutrial soils, and monitored to further understand the effects on crop productivity and soil remediation. Harvested plant tissues were used for oil extraction and bioethanol production. The quality of the generated products was assessed to understand the effect of the HM soil contamination.
- Assessment of the potential of sunflower grown in metal-contaminated soils for production of biofuelsPublication . Marques, Ana P. G. C.; Paulo, Ana; Caetano, Nídia S.Environmental biotechnology needs solutions that are associated with a low budget and cleaner remediation, and which are connected to resources and energetic valorization, to be able to encourage a circular bioeconomy. A prospective resolution for heavy-metal-contaminated soils is the application of phytoremediation approaches merged with bioenergy generation using the resulting biomass. Sunflower (Helianthus annuus) has been studied as a feedstock for biodiesel generation, and appears to be very attractive for biogas and bioethanol production. The current study reports an innovative energetic valorization approach of H. annuus biomass derived from the application of a phytoremediation strategy devised to remove Zn and Cd from an industrially contaminated soil (599 mg Zn kg−1 and 1.2 mg Cd kg−1)—and its comparison to the analysis of the same energetic valorization pathway for sunflower plants growing in an agricultural non-contaminated soil. After plant harvesting, bioethanol was produced from the aboveground tissues, and applied in the transesterification of the oil obtained through seed extraction for the generation of biodiesel. Also, biogas production was assessed through the root’s biomass anaerobic digestion. Similar yields of oil extraction—0.32 and 0.28 mL g−1 DW—were obtained when using seeds from H. annuus cultured in contaminated and non-contaminated soils, respectively. The production yield of bioethanol was superior using biomass from the agricultural non-contaminated soil (0.29 mL g−1 DW) when compared to the industrial metal-contaminated soil (0.20 mL g−1 DW). Zinc was measured in minor levels in bioethanol and oil (ca. 1.1 and 1.8 mg mL−1, correspondingly) resulting from the biomass cultivated in the industrialized soil, whereas Cd was not detected. The production yield of biogas was superior when using root biomass from H. annuus cultivated in agricultural non-contaminated soil (VS max. ca. 104 mL g−1) when compared to the one deriving from the industrial contaminated soil (VS max ca. 85 mL g−1). Generally, results demonstrate that substantial production yields of the tested biofuels were attained from biomass resulting from phytoremediation, corroborating this integrated original approach as a valuable alternative for the phytoremediation of HM-polluted soils and as an important strategy for plant biomass valorization.
- Biofuel production from phytoremediation derived plantsPublication . Marques, Ana P. G. C.; Prata, Nuno; Caetano, Nídia S.; Castro, Paula M. L.There are presently more than 3 million contaminated sites all over EU, according to the EEA (report 25186 EN). Heavy metal contamination is of particular concern, as metals are not degradable. Phytoremediation is gaining attention from the public and is an attractive low cost alternative for soil requalification, by establishing a vegetation cover which will stabilize the site, avoiding dispersion of contamination and simultaneously removingpollutants. Although the fate of harvested biomass is a common obstacle for its implementation, it may represent an opportunity for producing energy.This work presents a novel integrated strategy comprising the utilization of all plant parts for the generation of biodiesel. Combinations of sunflower and plant growth promoting microbiota were assessed growing in agricultural and metal contaminated soils. Harvested plant tissues were analysed and it was possible to observe that accumulation of Zn and Cd was made mainly in the roots, followed by the stems and the flowers, with the values registered for plants grown in contaminated soils being higher than the reported phytotoxic levels described in literature. Also, plants grown in the agricultural soil presented higher biomass rates. Sunflower seeds were then used for oil extraction and it was possible to observe efficiencies of up to 20 ml oil/m2, with only the oil from plants grown in industrial soil presenting levels of 1.8 mg Zn/l. Plant stems were used for bioethanol fermentation with yields of up to 280 and 162 ml/m2 for plants growing respectively in agricultural and industrial soils. Once again only plants grown in the industrial soil presented detectable levels of 1.1 mg Zn/l (and no Cd). Biodiesel was then produced via transterification of the extracted oil with the produced ethanol, allowing the complete production of a biofuel from this phytoremediation derived biomass. Reference parameters and heavy metal levels were determined and compared for both the biodiesel derived from plants grown in industrial and agricultural soils
- Biofuel production from phytoremediation derived sunflower biomassPublication . Marques, Ana P. G. C.; Prata, Nuno; Castro, Paula M. L.; Caetano, Nídia S.There are presently more than 3 million contaminated sites all over EU, according to the EEA (report 25186 EN). Heavy metal contamination is of particular concern, as metals are not degradable. Phytoremediation is gaining attention from the public and is an attractive low cost alternative for soil requalification, by establishing a vegetation cover which will stabilize the site, avoiding dispersion of contamination and simultaneously removingpollutants. Although the fate of harvested biomass is a common obstacle for its implementation, it may represent an opportunity for producing energy. This work presents a novel integrated strategy comprising the utilization of all plant parts for the generation of biodiesel. Combinations of sunflower and plant growth promoting microbiota were assessed growing in agricultural and metal contaminated soils.Harvested plant tissues were analysed and it was possible to observe that accumulation of Zn and Cd was made mainly in the roots, followed by the stems and the flowers, with the values registered for plants grown in contaminated soils being higher than the reported phytotoxic levels described in literature. Also, plants grown in the agricultural soil presented higher biomass rates. Sunflower seeds were then used for oil extraction and it was possible to observe efficiencies of up to 20 ml oil/m2, with only the oil from plants grown in industrial soil presenting levels of 1.8 mg Zn/l. Plant stems were used for bioethanol fermentation with yields of up to 280 and 162 ml/m2 for plants growing respectively in agricultural and industrial soils. Once again only plants grown in the industrial soil presented detectable levels of 1.1 mg Zn/l (and no Cd). Biodiesel was then produced via transterification of the extracted oil with the produced ethanol, allowing the complete production of a biofuel from this phytoremediation derived biomass. Reference parameters and heavy metal levels were determined and compared for both the biodiesel derived from plants grown in industrial and agricultural soils.
- Biofuel production from phytoremediation derived sunflower biomassPublication . Marques, Ana P. G. C.; Prata, Nuno; Caetano, Nídia S.; Castro, Paula M. L.
- Evaluation of the conversion potential of maize stover from soil phytoremediation to bioethanolPublication . Caetano, Nídia S.; Santos, Mariana; Marques, Ana P.This work aimed to evaluate the conversion potential of maize stover (MS) from phytoremediation of heavy metals contaminated soil to bioethanol. Thus, MS was submitted to an acid pretreatment with 3% (v/v) H2SO4, HCl, HNO3 or CH3COOH at 85 °C for 48 hours. An enzymatic hydrolysis step with Accellerase or Ultraflo was applied at 50 °C for 13 hours. Finally, Saccharomyces cerevisiae was used to ferment the glucose at 37 °C, followed by distillation to recover ethanol. The average yield in ethanol for the MS produced in the two contaminated soils was 0.51 and 0.32 gethanol/gMS for the MS treated with HCl and Accellerase and 0.39 and 0.27 gethanol/gMS for the MS treated with HNO3 and Ultraflo, respectively. For the MS produced in the control soil, the yield was 0.37 and 0.44 gethanol/gMS for the treatment with HNO3 and Ultraflo and HCl and Accellerase, respectively, being the differences in ethanol yield assigned to the dif-ferent cellulose/ hemicellulose content of the MS samples. No metals were detected in the ethanol recovered. This research demonstrated the feasibility of val-orization of MS from heavy metals contaminated soil phytoremediation through ethanol production, contributing to a more sustainable process of soil phytoreme-diation.
- PHYTOENERGY: energetic valorisation of phytoremediation derived biomassPublication . Marques, Ana P. G. C.; Caetano, Nídia S.There are presently more than 3 million contaminated sites all over EU, according to the EEA (report 25186 EN), with the contamination with heavy metals being of particular concern, as they are not degradable. Soil recovery is thus becoming an urgency and diverse approaches can be applied. From these, phytoremediation has shown to be an attractive low cost alternative as it promotes the establishment of a vegetation cover, stabilizing these degraded sites and allowing for the slow extraction of the contaminants. In spite that the fate of the harvested plants is a common complication for its implementation, it can also represent an opportunity for producing added value. This work intends to assess the possibility of the production of biodiesel resulting from the transterification of sunflower seed oil with bioethanol resulting from the processing of sunflower stems. Sunflower plants growing either in agricultural and metal contaminated soils were assessed and the quality of the successive energetic products was evaluated. Sunflower seeds were used for oil extraction, with observable extraction efficiencies of up to 20 ml oil/m 2 ; plant stems were used for bioethanol production with yields of up to 280 ml/m 2 ; finally, biodiesel was generated via transterification. The final biodiesel as well as the obtained oil and bioethanol were characterized and it was possible to observe that the contamination of the soils with metals did not affect significantly the quality of the products, namely in concerning metal levels. This study reports thus the successful energetic valorisation of plants grown in degraded soils.
- The potential for energetic valorization of energetic crops derived from phytoremediationPublication . Marques, Ana P. G. C.; Paulo, Ana M.; Caetano, Nídia S.; Castro, Paula M. L.There are presently more than 3 million contaminated sites all over EU, according to the EEA (report 25186 EN). Heavy metal contamination is of particular concern, as metals are not degradable. Soil remediation is becoming a priority and several methods are constantly being tested an implemented. From these, phytoremediation has proven to be an attractive low cost alternative as it acts by establishing a vegetation cover which will stabilize the target sites. However, the fate of harvested biomass is a common obstacle for its implementation. Nonetheless, it can also represent an opportunity for producing added value products. This work presents a novel integrated strategy comprising the utilization of all plant parts for the generation of energy products. Combinations of sunflower and plant growth promoting microbiota were assessed growing in agricultural and metal contaminated soils. Sunflower seeds were then used for oil extraction, with observable extraction efficiencies of up to 20 ml oil/m 2 ; plant stems were used for bioethanol fermentation with yields of up to 280 ml/m 2 ; finally, biodiesel was then produced via transterification of the extracted oil with the produced ethanol, allowing the complete production of a biofuel from this phytoremediation derived biomass. All the products were characterized and it was possible to observe that the presence of metals in the soils did not affect significantly the metal levels on either the oil, the bioethanol or the biodiesel. Additionally, plant roots were used as carbon and energy source for biomethane assays (BMP) for the production of biogas via anaerobic digestion. Overall, it was possible to conclude that soil contaminated with metals was not found to have an important effect on the anaerobic biodegradability of the sunflower roots. This study reports thus the successful energetic valorisation of plants grown in degraded soils as a whole.
- The potential of bioaugmentation-assisted phytoremediation derived maize biomass for the production of biomethane via anaerobic digestionPublication . Paulo, Ana M.; Caetano, Nídia S.; Marques, Ana P. G. C.Anthropogenic behaviors are causing the severe build-up of heavy metal (HM) pollutants in the environment, particularly in soils. Amongst a diversity of remediation technologies, phytoremediation is an environmentally friendly technology that, when coupling tolerant plants to selected rhizospheric microorganisms, can greatly stimulate HM decontamination of soils. Maize (Zea mays) is a plant with the reported capacity for HM exclusion from contaminated soil but also has energetic importance. In this study, Zea mays was coupled with Rhizophagus irregularis, an arbuscular mycorrhizal fungus (AMF), and Cupriavidus sp. strain 1C2, a plant growth-promoting rhizobacteria (PGPR), as a remediation approach to remove Cd and Zn from an industrial contaminated soil (1.2 mg Cd kg−1 and 599 mg Zn kg−1) and generate plant biomass, by contrast to the conservative development of the plant in an agricultural (with no metal pollution) soil. Biomass production and metal accumulation by Z. mays were monitored, and an increase in plant yield of ca. 9% was observed after development in the contaminated soil compared to the soil without metal contamination, while the plants removed ca. 0.77% and 0.13% of the Cd and Zn initially present in the soil. The resulting biomass (roots, stems, and cobs) was used for biogas generation in several biomethane (BMP) assays to evaluate the potential end purpose of the phytoremediation-resulting biomass. It was perceptible that the HMs existent in the industrial soil did not hinder the anaerobic biodegradation of the biomass, being registered biomethane production yields of ca. 183 and 178 mL of CH4 g−1 VS of the complete plant grown in non-contaminated and contaminated soils, respectively. The generation of biomethane from HM-polluted soils’ phytoremediation-derived maize biomass represents thus a promising possibility to be a counterpart to biogas production in an increasingly challenging status of renewable energy necessities.