624 research outputs found
Do rhizospheric microbiota play a role on decreasing contaminants toxicity to plants growing in heavy metal polluted soils?
info:eu-repo/semantics/publishedVersio
Can phytoremediation be a solution for the food vs fuel problem?
There are currently more than 3 million contaminated sites all over EU, according to the EEA (report 25186 EN). Contamination by heavy metals (HM) is particularly concerning, as they are not biodegradable and can accumulate in the food chains. With remediation being therefore an urgency, phytoremediation, when comparing to the other soil clean up methods, has proven to be an appealing low cost alternative. The technique encompasses the establishment of a vegetation cover that will ultimately stabilize the recipient sites. Nevertheless the end destination of cultivated biomass is a common barrier for its application, it can indeed represent a prospect for generating products with added value. In fact, such kind of strategy can help responding to several environmental and economic problems at once. First by using degraded soils for valuable applications, gradually decontaminating them while simultaneously producing biomass with added value. Second by responding to the growing demand of biomass for energy generation – representing an obvious contribution to the solution of the food vs. fuel dilemma. Although the possibility of using this novel remediation technique with the objective of biomass production for energetic purposes is of significant importance, there are very few developed studies in the area, and only some techniques have been addressed. Therefore this presentation will assess possible strategies for the utilization of phytoremediation derived biomass for the generation of energetic products.info:eu-repo/semantics/publishedVersio
Assessment of the potential of sunflower grown in metal-contaminated soils for production of biofuels
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.info:eu-repo/semantics/publishedVersio
PHYTOENERGY: energetic valorisation of phytoremediation derived biomass
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.info:eu-repo/semantics/publishedVersio
Microbiota-assisted phytoremediation of metal contaminated soils by sunflower
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Biomethane production from phytoremediation derived maize biomass via anaerobic digestion
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Biomethane production from phytoremediation derived maize biomass via anaerobic digestion
info:eu-repo/semantics/publishedVersio
The potential of phytoremediation derived maize biomass for the production of biomethane via anaerobic digestion
Maize is an energetic plant with ability for heavy metals removal from contaminated soil. The growth and ability for heavy metals removal by this energetic culture was tested using an industrialised soil contaminated with zinc (Zn) and cadmium (Cd) vs. an agricultural soil. Plants biomass production and metal accumulation was monitored and resulting biomass (roots, stems and cobs) was used for biogas production in several biomethane assays (BMP) in a factorial design with different inoculum to substrate ratios being tested. The biogas produced during the anaerobic digestion was monitored until stable production and its composition was analysed through gas-chromatography. It was possible to observe that maximum methane production seems to be proportional to the amount of anaerobically degradable substrate and is quickly obtained (ca. 8 days after incubation). It was also noticeable that the metals present in the industrial soil were not damaging to the anaerobic biodegradation of the biomass. The production of biomethane from metal contaminated soils’ phytoremediation derived maize biomass appears thus as a possibility to counterpart biogas production in an increasingly demanding status of renewable energy requirementsinfo:eu-repo/semantics/publishedVersio
Microbiota-assisted phytoremediation of metal contaminated soils by sunflower
info:eu-repo/semantics/publishedVersio
Soil microbiota benefits from phytoremediation coupled to metal-resistant rhizobacteria
Phytoremediation is used for requalifying soils contaminated with heavy metals (HM). Sunflower (Helianthus annuus L.) is one of the most studied species for the remediation of HM-contaminated soils. To increase the bioavailability of nutrients and of metals in soils, metal-resistant plant growth promoting rhizobacteria (PGPR), can be associated to phytoremediation strategies. Soil microbiota can benefit from this association, due to the reduced exposure to HMs toxic effect. In this study, next-generation sequencing (NGS) was applied for investigating shifts in soil microbial community after HMs remediation by sunflowers from a soil amended with Cupriavidus sp. strain 1C2. Sunflower was also grown in a non-contaminated soil (control). Actinobacteria were dominant while Proteobacteria was the second most abundant phylum in both soils. Acidobacteria and Nitrospirae were present in higher relative abundance in the control soil. Results have shown that phytoremediation associated to PGPR induced changes in the contaminated soil microbial community: Acidobacterium (Acidobacteria phylum) and Nitrospira (Nitrospirae phylum) bacterial genera increased their abundance at the end of plant growth. These changes did not occur in the control soil, which presented a more stable bacterial community throughout the experiment. This research increases our knowledge on the relationship between soil microbiota and phytoremediation strategies achievements.info:eu-repo/semantics/publishedVersio
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