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Cadmium is one of the most toxic heavy metals and its accumulation in the upper layers of forest soils affects plants, microorganisms and their interactions. Adequate strategies for the reforestation of metal contaminated sites are of vital importance. The aim of this work was to evaluate the response of Pinus pinaster seedlings to Cd exposure and to assess the effect of inoculation with two selected ectomycorrhizal fungi, Suillus bovinus and Rhizopogon roseolus on that response. Seedlings were exposed to soil contaminated at 15 and 30mgCdkg-1. Shoot biomass of P. pinaster decreased ca. 36% when exposed to 15mgCdkg-1. Overall, colonization by S. bovinus significantly enhanced shoot development up to 30% in contaminated soil while colonization by R. roseolus produced no significant effect at both Cd concentrations tested and significantly increased the level of Cd in the shoots at both Cd concentrations. Metal accumulation in the shoots and roots of non-inoculated and S. bovinus-inoculated seedlings increased at the higher Cd levels whereas R. roseolus-inoculated seedlings were not sensitive to Cd variation in the soil. The results from our research show that inoculation with ECM fungi has a significant impact on metal uptake and development of P. pinaster seedlings; the differential response induced by the two tested species highlights the importance of selecting the appropriate strains for nursery inoculation, and, as such, this biological tool ought to be considered in reforestation processes of heavy metal contaminated areas by woody species.

Zn accumulation in Solanum nigrum grown in naturally contaminated soil in the presence of different types of organic amendments was assessed. Under the same conditions, the response of the plant to inoculation with two different isolates of arbuscular mycorrhizal fungi (AMF) (Glomus claroideum and Glomus intraradices) was also evaluated. S. nigrum grown in the non-amended soil always presented higher Zn accumulation in the tissues, with the addition of amendments inducing reductions of up to 80 and 40%, for manure and compost, respectively, and enhancing plant biomass yields. The establishment of S. nigrum in the Zn contaminated soil combined with the application of amendments led to a 70-80% reduction in the amount of Zn leached through the soil. The use of S. nigrum in combination with manure appeared as an effective method for reducing the effects of soil contamination, diminishing Zn transfer to other environmental compartments via percolation.

The levels of zinc accumulated by roots, stems, and leaves of two plant species, Rubus ulmifolius and Phragmites australis, indigenous to the banks of a stream in a Portuguese contaminated site were investigated in field conditions. R. ulmifolius, a plant for which studies on phytoremediation potential are scarce, dominated on the right side of the stream, while P. australis proliferated on the other bank. Heterogeneous Zn concentrations were found along the banks of the stream. Zn accumulation in both species occurred mainly in the roots, with poor translocation to the aboveground sections. R. ulmifolius presented Zn levels in the roots ranging from 142 to 563 mg kg-1, in the stems from 35 to 110 mg kg-1, and in the leaves from 45 to 91 mg kg-1, vs. average soil total Zn concentrations varying from 526 to 957 mg kg-1. P. australis showed Zn concentrations in the roots from 39 to 130 mg kg-1, in the stems from 31 to 63 mg kg-1, and in the leaves from 37 to 83 mg kg-1, for the lower average soil total Zn levels of 138 to 452 mg kg-1 found on the banks where they proliferated. Positive correlations were found between the soil total, available and extractable Zn fractions, and metal accumulation in the roots and leaves of R. ulmifolius and in the roots and stems of P. australis. The use of R. ulmifolius and P. australis for phytoextraction purposes does not appear as an effective method of metal removing, but these native metal tolerant plant species may be used to reduce the effects of soil contamination, avoiding further Zn transfer to other environmental compartments.

Solanum nigrum was found to proliferate in sediments with high levels of metal pollution. The effect of Zn on plant growth and tissue metal accumulation was assessed. The response of the plant to the inoculation with four different isolates of arbuscular mycorrhizal fungi (AMF) (Glomus sp. BEG140, Glomus claroideum, Glomus mosseae and Glomus intraradices) was studied. While the isolates of AMF did not have a significant (P < 0.05) influence on mycorrhizal colonisation, increasing Zn concentration to high levels (500 and 1000 mg kg-1) induced significant (P < 0.05) decrease of the AMF colonisation. In general, the presence of AMF did not affect the growth and biomass of S. nigrum individuals. However, the level of metal in the matrix affected S. nigrum growth; plants grown at 100 mg kg-1 had significantly (P < 0.05) lower leaf, stem, root and total biomass than control ones and plants growing at 500 and 1000 mg kg-1 had the significantly (P < 0.05) lowest biomass. Plants inoculated with the AMF G. claroideum and G. intraradices presented significantly (P < 0.05) higher Zn accumulation in all plant tissues. In general, the stem tissues had the higher Zn content while the leaves registered the lowest values, which indicate a high translocation of the metal. AMF inoculation had no significant (P < 0.05) influence on the metal translocation within the plant. This study suggests that inoculation with the AMF G. claroideum or G. intraradices, can enhance the Zn accumulation in the tissues of S. nigrum, not affecting the plant translocation capacities.

The main aim of this study was to investigate the performance of an aerobic granular sludge sequencing batch reactor (AGS-SBR) receiving water streams supplied with different loads of Zn(2+) (50 and 100 mg L(-1)) during an operation of 866 cycles (ca. 109 days). When the metal was not fed, chemical oxygen demand (COD), PO4(3-) and NH4(+) were efficiently removed, with efficiencies of 56, 23 and 72% respectively. DGGE profiles showed that Zn(2+) supply negatively affected the bacterial diversity and community structure of the granules. Consequently, the shock loadings with Zn(2+), particularly at the higher levels (100 mg L(-1)), affected the nutrient removal in the AGS-SBR, although the reactor still generally complied with admissible legal values concerning organic matter, nitrogen and Zn. Simultaneous removal of PO4(3-) and TSS in such conditions needs further refining but the application of aerobic granular SBR in the treatment of Zn(2+) contaminated wastewaters seems viable.

Increased soil pollution with heavy metals due to various human and natural activities has led to a growing need to address environmental contamination. Some remediation technologies have been developed to treat contaminated soil, but a biology-based technology, phytoremediation, is emerging. Phytoremediation includes phytovolatilization, phytostabilization, and phytoextraction using hyperaccumulator species or a chelate-enhancement strategy. To enhance phytoremediation as a viable strategy, microbiota from the rhizosphere can play an important role, but the use of genetic engineering can also increase the success of the technique. Here we review the key information on phytoremediation, addressing both potential and limitations, resulting from the research established on this topic.

Submitted by Anabela Morais (ajmorais@porto.ucp.pt) on 2011-08-05T10:56:56Z No. of bitstreams: 1 trab_inter_2009_ESB_382_Moreira_Helena_01.pdf: 26964 bytes, checksum: 006ce8a08da87a6190fb456f410b9378 (MD5) Made available in DSpace on 2011-10-15T11:59:57Z (GMT). No. of bitstreams: 1 trab_inter_2009_ESB_382_Moreira_Helena_01.pdf: 26964 bytes, checksum: 006ce8a08da87a6190fb456f410b9378 (MD5) Previous issue date: 2009

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Submitted by Anabela Morais (ajmorais@porto.ucp.pt) on 2011-08-05T14:44:33Z No. of bitstreams: 1 trab_nac_2007_ESB_382_Marques_Ana_01.pdf: 40623 bytes, checksum: 102ea5ae11ab3075129062335265dadf (MD5) Made available in DSpace on 2011-10-14T23:56:55Z (GMT). No. of bitstreams: 1 trab_nac_2007_ESB_382_Marques_Ana_01.pdf: 40623 bytes, checksum: 102ea5ae11ab3075129062335265dadf (MD5) Previous issue date: 2007

S. nigrum was found to proliferate in sediments with high levels of metal pollution. Toxicity tests were performed using seed germination, root elongation, shoot length and biomass as parameters for establishing growth inhibition of S. nigrum and T. incarnatum by arsenic, lead and zinc. All the elements had a higher inhibitory action on the ger-mination and growth of T. incarnatum – inhibition occur-ring at 3 mg element per kg of dry sand. S. nigrum presented germination and growth at higher concentrations of those elements - 7 mg Pb kg-1, 10 mg Zn kg-1 and 10 mg As kg-1. Although inhibitory concentrations for each plant were dif-ferent, increasing the elements concentration reduced seed germination, root elongation and shoot length in T. incar-natum, but not always in S. nigrum. For the latter, low con-centrations (3 mg kg-1 dry sand) of Zn and As seemed to have stimulatory effects on germination. The addition of nu-trients did not cause a significant (P < 0.05) difference in the germination of both plants, except for high metal/ metal-loid concentration in S. nigrum. Concerning growth char-acteristics, nutrient addition was only a differentiation factor for shoot length at low metal/metalloid concentrations. S. nigrum could be a promising plant to be used in further ex-periments concerning the potential of phytoremediation of metal contaminated sites, as long as an adequate planting strategy is followed.

Submitted by Anabela Morais (ajmorais@porto.ucp.pt) on 2011-08-04T15:10:20Z No. of bitstreams: 1 trab_inter_2007_ESB_382_Marques_Ana_01.pdf: 41299 bytes, checksum: 8d40fc815ac6251533523b893af689a9 (MD5) Made available in DSpace on 2011-10-14T23:39:50Z (GMT). No. of bitstreams: 1 trab_inter_2007_ESB_382_Marques_Ana_01.pdf: 41299 bytes, checksum: 8d40fc815ac6251533523b893af689a9 (MD5) Previous issue date: 2007

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Submitted by Anabela Morais (ajmorais@porto.ucp.pt) on 2011-08-04T11:28:52Z No. of bitstreams: 1 trab_inter_2005_ESB_382_Marques_Ana_02.pdf: 33189 bytes, checksum: e617751526810abc419bfe57218d9a81 (MD5) Made available in DSpace on 2011-10-24T11:03:27Z (GMT). No. of bitstreams: 1 trab_inter_2005_ESB_382_Marques_Ana_02.pdf: 33189 bytes, checksum: e617751526810abc419bfe57218d9a81 (MD5) Previous issue date: 2005

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Submitted by Anabela Morais (ajmorais@porto.ucp.pt) on 2011-08-04T13:51:04Z No. of bitstreams: 1 trab_inter_2005_ESB_382_Marques_Ana_03.pdf: 23389 bytes, checksum: 41f7b70377c74c01a71690b537f09539 (MD5) Made available in DSpace on 2011-10-15T13:46:53Z (GMT). No. of bitstreams: 1 trab_inter_2005_ESB_382_Marques_Ana_03.pdf: 23389 bytes, checksum: 41f7b70377c74c01a71690b537f09539 (MD5) Previous issue date: 2005

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The off-site migration of contaminants, when not controlled, can cause serious damage on ecossistems and affect public health. These and other reasons bring up the need for new solutions of remediation, to stop the dissemination of the contaminants in the environmental compartments. Phytoremediation is an emergent technology that uses plants to remove, degradate or imobilize the contaminants. The selection of the plant species that should be used depends mainly on it’s biomass, it’s capacity to tolerate and bioacumulate the contaminants and on the location and characteristics of the contamination. The region of Estarreja is known for its strong industrial complex, composed essentially by chemical facilities. For many years, several of these industries have discharged its solid residues in an improvised park in the surrounding area, and conducted its wastewaters into a stream nearby (“Esteiro de Estarreja”). Therefore, the levels of Pb, Zn, As and Hg, in the sediments of this stream, to a depth of 50 cm, are above the limits established by EC Directive 86/278/EC - Atkins (1999). Metals pose a specific environmental problem: they can not be destroyed, so they have to be removed and recycled. This environmental risk cenario is aggravated by the high permeability of the soils and the intensive agriculture in the area. Nevertheless, in the banks of the stream, the vegetation remains proliferous. The purpose of this study is to identify plant species endemic to the site and to determine their ability to uptake heavy metals. Three plant species, present in a larger amount, were collected from that area and were tested for the content of the above metals.

Submitted by Anabela Morais (ajmorais@porto.ucp.pt) on 2011-08-02T15:13:17Z No. of bitstreams: 1 com_nac_2003_ESB_383_Marques_Ana_01.pdf: 1706358 bytes, checksum: 24dd14c293963a183b4269ea5a28e6ff (MD5) Made available in DSpace on 2011-10-15T11:39:33Z (GMT). No. of bitstreams: 1 com_nac_2003_ESB_383_Marques_Ana_01.pdf: 1706358 bytes, checksum: 24dd14c293963a183b4269ea5a28e6ff (MD5) Previous issue date: 2003