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Remediation of Polluted Soils
Journal of Geochemical Exploration 174 (2017) 1–3
Contents lists available at ScienceDirect
Journal of Geochemical Exploration journal homepage: www.elsevier.com/locate/gexplo
Preface
Remediation of Polluted Soils
The collection of papers presented in this special issue is an outcome of the SSS8.3 Session “Remediation of Polluted Soils” of the International European Geosciences Union (EGU) Conference held in Vienna, April 2015. Soils are essential components of the environment, the basis of terrestrial ecosystems and a crossroad for biogeochemical cycles at the lithosphere-hydrosphere-biosphere-atmosphere interface. Therefore, soils are a limited, precious and fragile resource, the quality of which should be preserved. However, the increased concentration and distribution of heavy metals, metalloids, radionuclides and organic xenobionts in soils by anthropogenic mismanagement of industrial and mining activities, overuse of agrochemicals, sewage sludge and waste disposal cause contamination, environmental problems and health concerns. Therefore, soil pollution needs innovative technologies of remediation consisting of two main groups: the first deals with containment and confinement of the pollutants, minimizing their toxicity, mobility and bioavailability. Containment measures include covering, sealing, solidification and stabilization with amendments. The second group includes decontamination by remotion, clean up and destruction of contaminants with physical, chemical and biological technologies such as soil washing, soil flushing, thermal and electrokinetics treatments, bioremediation and phytoremediation. These latter ones are more ecofriendly and soil protective. This special issue contains 23 papers written by authors from 13 countries: Bulgaria, Finland, Germany, Italy, Lithuania, Pakistan, Portugal, Russian Federation, Spain, Sweden, Switzerland, Turkey and UK. This collection of original studies focuses mainly on seven topics: 1) phytoremediation,2) salt-affected soils, 3) biological activity, 4) organic pollutants, 5) soil properties and heavy metals pollution, 6) radionuclides and 7) waste reuse. There are six papers dealing with the first topic, phytoremediation: Microbial community patterns and their potential substrate utilization were examinated by Schindler et al. to test for sustainability in metal polluted soil. The acid mine drainage was characterized for total soil respiration and the functional diversity using BIOLOG EcoPlate assays. The authors conclude that inoculation with indigenous bacteria and a mycorrizal fungus results in improved vitality for plant growth at heavy metal polluted soils. Fernandez et al. analyzed As, Cd, Hg, Pb and Zn of soils and native plants of six ancient mining tailing of Asturias (northern Spain). The authors found some hyperaccumulator and excluder species. They concluded that the researched mining area is an important reservoir of plant species with high potential for phytostabilization or phytoextraction of contaminated soils by the above citated heavy metals. Shtangeeva et al. studied the uptake of Br by wheat and pea to assess their potential for purposes of phytoextraction of Br from contaminated
http://dx.doi.org/10.1016/j.gexplo.2016.11.019 0375-6742/© 2016 Published by Elsevier B.V.
soil. Were used greenhouse pot experiments. The authors found that the concentration of Br in leaves of wheat was higher than leaves of pea. Wheat was more tolerant to contamination of soil with Br compounds. Gonzalez et al. assessed the effectiveness of Brassica juncea associated with marble sludge as amendment in phytoextraction processes. The authors found this procedure suitable for phytostabilisation purposes, promote plant growth and improving soil structure. It can be used for long term remediation of contaminated acid soils . In those Zn and Pb can be accumulated in shoots of hyperaccumulator plants. In basic soils As is mainly immobilized by CaCO3. Mingorance et al. developed a reclamation method of a mining area combining the application of different soil conditioners with two different plant species: Cistus ladanifer L. and Medicago sativa L. Both species even though there are non-accumulator of As, Cr, Pb and Cu, contain toxic concentrations of these elements. In Medicago such toxic concentrations should represent a risk for domestic animals. Beesley et al. assessed the efficiency of organic and mineral based amendments to reduce metal[loid] mobility and uptake (Lolium perenne) from a pyrite waste contaminated soil. The authors concluded that Fe-based amendments can be adjudged as the most suitable to deploy for the remediation of this mine site. The tested Fe2++CaCO3 reduce the metal[loid] mobility, uptake to ryegrass and to enhance ryegrass growth. There are two papers concerned with the second topic, salt- affected soils: Bas et al. used ordinary kriging to assess soil salinity and cropping systems as soil phytoremediation strategy for soil remediation. The spatial distribution of salinity and texture can help to select the cropping system as an efficient management strategy in saline environments. Geostatistic analyses of soil properties is a valuable tool to improve farming productivity and land management. Jamil et al. improved the phytoremediation of salt affected soils using the halophilic bacteria Thalassobacillus denorans (NCCP-58) and Oceanobacillus kapialis (NCCP-76) from salt mines near Karak (Pakistant). The authors evaluate its effect on rice variety Basmati385. Both bacterial strains were effective to improve plant growth, but NCCP-76 was more responsive in alleviating the salt stress. Three papers cover the third topic, biological activity: Gulser et al. investigated the changes of soil hydraulic properties and microbiological activity during the decomposition of hazelnut husk (HH) in a coarse textured soil during 16 weeks of incubation. The authors noticed an increased of organic carbon, basal soil respiration, saturated hydraulic conductivity and aggregate stability. The decomposition products of HH might be fixed by micro aggregates. Minnikova et al. assessed the effect of heavy metals from the Novocherkassk ( Russia) power plant emissions on the biological
2
Preface
activity of soils in the adjacent areas. The authors used an integrated biological index (IBI) and a total technogenic pollution index (Zc). The first was calculated from the enzimatic activity (of the dehydrogenases and urease), the phytotoxicity (radish root length) and abundance of soil bacteria. The Zc was estimated using a table based on population health parameters and children morbility. A close correlation is revealed between the IBI and Zc values. Bravo-Martin-Consuegra et al. researched the influence of the pH in the uptake and bioaccumulation of heavy metals (Fe, Zn,Cu, Pb and Mn) and other elements (Ca, K, Al, Sr and Ba) in vine leaves selected in 101 vinyeard plots in Castilla-La Mancha region (Spain). Soils and leaf samples have been analysed by XRF and the biological absorption coefficient was calculated. The accumulation of mineral elements in the vine leaves and soils depend on the soil pH. Three papers in this special issue refer to the fourth topic, organic pollutants: Santos et al. focused their work researching bioextracts of Cistus ladanifer L. growing in Sao Domingos mine (IPB, SE Portugal) as a source of valuable compounds. The authors compared the organic composition of bioextracts from shoots of C. ladanifer growing in contaminated and no contaminated areas using n-hexane. They assessed some valuable organic compounds of these bioextracts, their quality and possible human health risk. This is an exemple of phytostablisation with an economic return. Falciglia et al. investigated the limits of microwave (MW) heating in situ application for the remediation of hydrocarbon polluted soils by means of the application on a dedicated simulation model. Results showed that all investigated parameters (soil texture, soil moisture and incident electric field) significantly influenced the MW penetration and the inducted soil temperature variation effects. The proposed model represents a powerful and suitable tool to predict the impact of operating conditions on the effectiveness of the MW techniques. Sushkova et al. studied the main tendences in the accumulation and distribution of benzo[a] pyrene (BaP) in soils of the monitoring plots of the affected zone of the Novocherkassk (Russia) regional power plant. The particle size distribution in the soils affects the accumulation of BaP in soil profile. It was found that the maximum accumulation was at northwest predominant wind direction, at 1.6 Km. from the power station. Five papers deal with the fifth topic, soil properties and heavy metals pollution: Minkina et al. carried out an experiment under laboratory conditions of the adsorption of copper by chernozems and parent rocks in Rostov (Southern Russia). It is shown that the adsorption isotherms are described by the Langmuir equation. XANES and EXAFS analysis indicates a possibility for the formation of chelate Cu2+ complexes with humic acids and the substitution of Al3+ in octahedral positions by Cu2+ during the interactions with clay minerals. Minkina et al. assessed the content and distribution of heavy metals in herbaceous plants under the effect of aerosol emissions from the Novocherkassk (Russia) power satation. The accumulation factor and the acropetal coefficient were determined. Ambrosia artemisiifolia, Artemisia austriaca, Achillea nobilis and Tanacetum vulgare are accumulators of heavy metals. Alekseenko et al. proposed an isolation method of metal mining site soils to prevent environmental pollution through the use of waste polyethylene and polypropylene. The authors select a number of areas of ore minings such Kurksregion, Novorossiyk, Severonickel, Murmask, Monchegorsk, Severstal, Cherepovets, in Russia and Koksu-Tekeli, Jungar Alatu and Ust-Kamenogorst in Kazakstan. Krasovskaya et al. studied toxic metals in soils from different regions of the Northern Russia, from the Kola peninsula at the West and to the Chucki peninsula at the East. Heavy metals of mining soils of the Murmansk, Severonickel, Severstal (Northwest), Norislky Nickel, Krasnoyarsky Kray (Middle Siberia) and Vorkuta, Timano-
Pechora and Bol’shezemel’skaya at North-East of the European Russia. The heavy metals concentration and distribution were compared with background regions. Each region and soil type has its own concentration level. Ballesteros et al. proposed a vitrification process as remediation method of Cr6 + polluted soils.The authors carried out a laboratoryscale immobilization by vitrification in graphite crucibles at 1600oC using a dolomite-silica additive. The soluble chromates were confined as stable spinels and pyroxenes such diopside and augite, that contain in their crystal lattice Cr3 +. The glass-ceramic obtained showed adequate properties for industrial uses. Three papers constitute the sixth topic, radionuclides: Falciglia et al. carried out lab-scale experiments in order to simulate γray shielding unconfined compresive strength and contaminant immobilisation performances of barite (Ba)- Portland cement (PC) grouts in Stabilisation/Solidification (S/S) treatment of 232Th contaminated soils to investigate the influence of the Ba and grout (G) content used in S/S mixes. It was found that the replacement of PC by Ba up to a maximum of 50% increases RS index. The use of Ba in PC grout allows to achievement of the almost total 232Th immobilisation. Georgiev et al. studied the transport of radionuclides and heavy metals during the cleanup of a polluted cinnamonic soil in lysimeters by means of different variants. It was found that a considerable fraction of pollutants were removed from the A horizon by leach waters with ammonium and phosphate ions together the natural soil microflora and mulching. In subhorizons B3 and B4, Pb, Cu and U were precipited, but the microbial reductive barrier in B3 and B4 was no so effective to stop Ra. Konstantinova et al. estimated the 134Cs accumulation by litter, moss and grass in Lithuania attributed to the Fukushima Daiichi NPP accident. Samples collected before and after the accident were used to compare the radionuclide accumulation efficiences. The values of the accumulation coefficient for moss and litter were determined to be much higher than for grass, so the use of moss and litter samples seems to be suitable for biomonitoring after the nuclear accidents or non radiactive events. One paper deals with the seventh and last topic, waste reuse: Rincón-Mora et al. identified and evaluated risks of Arnela (Galicia, Spain) beach coastal depositad material. The authors developed remediation strategies to minimize those risks using chemical and mineralogical studies (XRF, XRD, SEM, EDS, DTA, TG as well as HSM). The analytical results indicated that this waste material is a metallurgical slag with a possible use as a secondary raw material. All these papers described above cover important aspects of fundamental and applied research and provide advances in relation to existing knowledge on Remediation of Polluted Soils. I would firstly like to thank the Co-Guest Editors Prof. Dr. Elena Korobova (Vernadsky Institute of Geochemistry and Analytical Chemistry, Moscow, Russia, ), Prof. Dr. Maria Manuela Abreu, Universidade de Lisboa, Instituto Superior de Agronomia, Linking Landscape, Environment, Agriculture and Food Research Centre, LEAF (Portugal), Prof. Dr. Claudio Bini (Department of Environmental Sciences, University of Venice, Venice, Italy), Prof. Dr. Annamaria Lima (University of Napoli, Italy), Prof. Dr. Domenico Cicchella (University of Sannio, Benavento, Italy), Prof. Dr. Carmen Pérez-Sirvent (Faculty of Chemistry, University of Murcia, Spain), Prof. Dr. Núria Roca (Universitat de Barcelona, Facultat de Biologia, Biologia Vegetal, Spain) for their excellent collaboration. Moreover, I would like to thank the authors for their contributions and for their patience with the review process as well as the reviewers for their observations. Their efforts have improved the quality of this Special Issue. The language and IT assistance of Oriol Bech is greatly appreciated. I am also extremely grateful to Prof. Dr. Benedetto De Vivo and Prof. Dr. Robert Ayuso, Editors-in-Chief of the Journal of Geochemical Exploration, to Arnold Stanly, Journal Manager, Yanping Hou, without whose wisdom and experience this Special Issue could not have been published.
Preface
Co-Guest Editors: Elena Korobova, M. Manuela Abreu, Claudio Bini, Annamaria Lima, Domenico Cicchella, Carmen Pérez-Sirvent, Núria Roca
3
Jaume Bech Managing Guest Editor Faculty of Biology, University of Barcelona (UB)
Contents lists available at ScienceDirect
Journal of Geochemical Exploration journal homepage: www.elsevier.com/locate/gexplo
Preface
Remediation of Polluted Soils
The collection of papers presented in this special issue is an outcome of the SSS8.3 Session “Remediation of Polluted Soils” of the International European Geosciences Union (EGU) Conference held in Vienna, April 2015. Soils are essential components of the environment, the basis of terrestrial ecosystems and a crossroad for biogeochemical cycles at the lithosphere-hydrosphere-biosphere-atmosphere interface. Therefore, soils are a limited, precious and fragile resource, the quality of which should be preserved. However, the increased concentration and distribution of heavy metals, metalloids, radionuclides and organic xenobionts in soils by anthropogenic mismanagement of industrial and mining activities, overuse of agrochemicals, sewage sludge and waste disposal cause contamination, environmental problems and health concerns. Therefore, soil pollution needs innovative technologies of remediation consisting of two main groups: the first deals with containment and confinement of the pollutants, minimizing their toxicity, mobility and bioavailability. Containment measures include covering, sealing, solidification and stabilization with amendments. The second group includes decontamination by remotion, clean up and destruction of contaminants with physical, chemical and biological technologies such as soil washing, soil flushing, thermal and electrokinetics treatments, bioremediation and phytoremediation. These latter ones are more ecofriendly and soil protective. This special issue contains 23 papers written by authors from 13 countries: Bulgaria, Finland, Germany, Italy, Lithuania, Pakistan, Portugal, Russian Federation, Spain, Sweden, Switzerland, Turkey and UK. This collection of original studies focuses mainly on seven topics: 1) phytoremediation,2) salt-affected soils, 3) biological activity, 4) organic pollutants, 5) soil properties and heavy metals pollution, 6) radionuclides and 7) waste reuse. There are six papers dealing with the first topic, phytoremediation: Microbial community patterns and their potential substrate utilization were examinated by Schindler et al. to test for sustainability in metal polluted soil. The acid mine drainage was characterized for total soil respiration and the functional diversity using BIOLOG EcoPlate assays. The authors conclude that inoculation with indigenous bacteria and a mycorrizal fungus results in improved vitality for plant growth at heavy metal polluted soils. Fernandez et al. analyzed As, Cd, Hg, Pb and Zn of soils and native plants of six ancient mining tailing of Asturias (northern Spain). The authors found some hyperaccumulator and excluder species. They concluded that the researched mining area is an important reservoir of plant species with high potential for phytostabilization or phytoextraction of contaminated soils by the above citated heavy metals. Shtangeeva et al. studied the uptake of Br by wheat and pea to assess their potential for purposes of phytoextraction of Br from contaminated
http://dx.doi.org/10.1016/j.gexplo.2016.11.019 0375-6742/© 2016 Published by Elsevier B.V.
soil. Were used greenhouse pot experiments. The authors found that the concentration of Br in leaves of wheat was higher than leaves of pea. Wheat was more tolerant to contamination of soil with Br compounds. Gonzalez et al. assessed the effectiveness of Brassica juncea associated with marble sludge as amendment in phytoextraction processes. The authors found this procedure suitable for phytostabilisation purposes, promote plant growth and improving soil structure. It can be used for long term remediation of contaminated acid soils . In those Zn and Pb can be accumulated in shoots of hyperaccumulator plants. In basic soils As is mainly immobilized by CaCO3. Mingorance et al. developed a reclamation method of a mining area combining the application of different soil conditioners with two different plant species: Cistus ladanifer L. and Medicago sativa L. Both species even though there are non-accumulator of As, Cr, Pb and Cu, contain toxic concentrations of these elements. In Medicago such toxic concentrations should represent a risk for domestic animals. Beesley et al. assessed the efficiency of organic and mineral based amendments to reduce metal[loid] mobility and uptake (Lolium perenne) from a pyrite waste contaminated soil. The authors concluded that Fe-based amendments can be adjudged as the most suitable to deploy for the remediation of this mine site. The tested Fe2++CaCO3 reduce the metal[loid] mobility, uptake to ryegrass and to enhance ryegrass growth. There are two papers concerned with the second topic, salt- affected soils: Bas et al. used ordinary kriging to assess soil salinity and cropping systems as soil phytoremediation strategy for soil remediation. The spatial distribution of salinity and texture can help to select the cropping system as an efficient management strategy in saline environments. Geostatistic analyses of soil properties is a valuable tool to improve farming productivity and land management. Jamil et al. improved the phytoremediation of salt affected soils using the halophilic bacteria Thalassobacillus denorans (NCCP-58) and Oceanobacillus kapialis (NCCP-76) from salt mines near Karak (Pakistant). The authors evaluate its effect on rice variety Basmati385. Both bacterial strains were effective to improve plant growth, but NCCP-76 was more responsive in alleviating the salt stress. Three papers cover the third topic, biological activity: Gulser et al. investigated the changes of soil hydraulic properties and microbiological activity during the decomposition of hazelnut husk (HH) in a coarse textured soil during 16 weeks of incubation. The authors noticed an increased of organic carbon, basal soil respiration, saturated hydraulic conductivity and aggregate stability. The decomposition products of HH might be fixed by micro aggregates. Minnikova et al. assessed the effect of heavy metals from the Novocherkassk ( Russia) power plant emissions on the biological
2
Preface
activity of soils in the adjacent areas. The authors used an integrated biological index (IBI) and a total technogenic pollution index (Zc). The first was calculated from the enzimatic activity (of the dehydrogenases and urease), the phytotoxicity (radish root length) and abundance of soil bacteria. The Zc was estimated using a table based on population health parameters and children morbility. A close correlation is revealed between the IBI and Zc values. Bravo-Martin-Consuegra et al. researched the influence of the pH in the uptake and bioaccumulation of heavy metals (Fe, Zn,Cu, Pb and Mn) and other elements (Ca, K, Al, Sr and Ba) in vine leaves selected in 101 vinyeard plots in Castilla-La Mancha region (Spain). Soils and leaf samples have been analysed by XRF and the biological absorption coefficient was calculated. The accumulation of mineral elements in the vine leaves and soils depend on the soil pH. Three papers in this special issue refer to the fourth topic, organic pollutants: Santos et al. focused their work researching bioextracts of Cistus ladanifer L. growing in Sao Domingos mine (IPB, SE Portugal) as a source of valuable compounds. The authors compared the organic composition of bioextracts from shoots of C. ladanifer growing in contaminated and no contaminated areas using n-hexane. They assessed some valuable organic compounds of these bioextracts, their quality and possible human health risk. This is an exemple of phytostablisation with an economic return. Falciglia et al. investigated the limits of microwave (MW) heating in situ application for the remediation of hydrocarbon polluted soils by means of the application on a dedicated simulation model. Results showed that all investigated parameters (soil texture, soil moisture and incident electric field) significantly influenced the MW penetration and the inducted soil temperature variation effects. The proposed model represents a powerful and suitable tool to predict the impact of operating conditions on the effectiveness of the MW techniques. Sushkova et al. studied the main tendences in the accumulation and distribution of benzo[a] pyrene (BaP) in soils of the monitoring plots of the affected zone of the Novocherkassk (Russia) regional power plant. The particle size distribution in the soils affects the accumulation of BaP in soil profile. It was found that the maximum accumulation was at northwest predominant wind direction, at 1.6 Km. from the power station. Five papers deal with the fifth topic, soil properties and heavy metals pollution: Minkina et al. carried out an experiment under laboratory conditions of the adsorption of copper by chernozems and parent rocks in Rostov (Southern Russia). It is shown that the adsorption isotherms are described by the Langmuir equation. XANES and EXAFS analysis indicates a possibility for the formation of chelate Cu2+ complexes with humic acids and the substitution of Al3+ in octahedral positions by Cu2+ during the interactions with clay minerals. Minkina et al. assessed the content and distribution of heavy metals in herbaceous plants under the effect of aerosol emissions from the Novocherkassk (Russia) power satation. The accumulation factor and the acropetal coefficient were determined. Ambrosia artemisiifolia, Artemisia austriaca, Achillea nobilis and Tanacetum vulgare are accumulators of heavy metals. Alekseenko et al. proposed an isolation method of metal mining site soils to prevent environmental pollution through the use of waste polyethylene and polypropylene. The authors select a number of areas of ore minings such Kurksregion, Novorossiyk, Severonickel, Murmask, Monchegorsk, Severstal, Cherepovets, in Russia and Koksu-Tekeli, Jungar Alatu and Ust-Kamenogorst in Kazakstan. Krasovskaya et al. studied toxic metals in soils from different regions of the Northern Russia, from the Kola peninsula at the West and to the Chucki peninsula at the East. Heavy metals of mining soils of the Murmansk, Severonickel, Severstal (Northwest), Norislky Nickel, Krasnoyarsky Kray (Middle Siberia) and Vorkuta, Timano-
Pechora and Bol’shezemel’skaya at North-East of the European Russia. The heavy metals concentration and distribution were compared with background regions. Each region and soil type has its own concentration level. Ballesteros et al. proposed a vitrification process as remediation method of Cr6 + polluted soils.The authors carried out a laboratoryscale immobilization by vitrification in graphite crucibles at 1600oC using a dolomite-silica additive. The soluble chromates were confined as stable spinels and pyroxenes such diopside and augite, that contain in their crystal lattice Cr3 +. The glass-ceramic obtained showed adequate properties for industrial uses. Three papers constitute the sixth topic, radionuclides: Falciglia et al. carried out lab-scale experiments in order to simulate γray shielding unconfined compresive strength and contaminant immobilisation performances of barite (Ba)- Portland cement (PC) grouts in Stabilisation/Solidification (S/S) treatment of 232Th contaminated soils to investigate the influence of the Ba and grout (G) content used in S/S mixes. It was found that the replacement of PC by Ba up to a maximum of 50% increases RS index. The use of Ba in PC grout allows to achievement of the almost total 232Th immobilisation. Georgiev et al. studied the transport of radionuclides and heavy metals during the cleanup of a polluted cinnamonic soil in lysimeters by means of different variants. It was found that a considerable fraction of pollutants were removed from the A horizon by leach waters with ammonium and phosphate ions together the natural soil microflora and mulching. In subhorizons B3 and B4, Pb, Cu and U were precipited, but the microbial reductive barrier in B3 and B4 was no so effective to stop Ra. Konstantinova et al. estimated the 134Cs accumulation by litter, moss and grass in Lithuania attributed to the Fukushima Daiichi NPP accident. Samples collected before and after the accident were used to compare the radionuclide accumulation efficiences. The values of the accumulation coefficient for moss and litter were determined to be much higher than for grass, so the use of moss and litter samples seems to be suitable for biomonitoring after the nuclear accidents or non radiactive events. One paper deals with the seventh and last topic, waste reuse: Rincón-Mora et al. identified and evaluated risks of Arnela (Galicia, Spain) beach coastal depositad material. The authors developed remediation strategies to minimize those risks using chemical and mineralogical studies (XRF, XRD, SEM, EDS, DTA, TG as well as HSM). The analytical results indicated that this waste material is a metallurgical slag with a possible use as a secondary raw material. All these papers described above cover important aspects of fundamental and applied research and provide advances in relation to existing knowledge on Remediation of Polluted Soils. I would firstly like to thank the Co-Guest Editors Prof. Dr. Elena Korobova (Vernadsky Institute of Geochemistry and Analytical Chemistry, Moscow, Russia, ), Prof. Dr. Maria Manuela Abreu, Universidade de Lisboa, Instituto Superior de Agronomia, Linking Landscape, Environment, Agriculture and Food Research Centre, LEAF (Portugal), Prof. Dr. Claudio Bini (Department of Environmental Sciences, University of Venice, Venice, Italy), Prof. Dr. Annamaria Lima (University of Napoli, Italy), Prof. Dr. Domenico Cicchella (University of Sannio, Benavento, Italy), Prof. Dr. Carmen Pérez-Sirvent (Faculty of Chemistry, University of Murcia, Spain), Prof. Dr. Núria Roca (Universitat de Barcelona, Facultat de Biologia, Biologia Vegetal, Spain) for their excellent collaboration. Moreover, I would like to thank the authors for their contributions and for their patience with the review process as well as the reviewers for their observations. Their efforts have improved the quality of this Special Issue. The language and IT assistance of Oriol Bech is greatly appreciated. I am also extremely grateful to Prof. Dr. Benedetto De Vivo and Prof. Dr. Robert Ayuso, Editors-in-Chief of the Journal of Geochemical Exploration, to Arnold Stanly, Journal Manager, Yanping Hou, without whose wisdom and experience this Special Issue could not have been published.
Preface
Co-Guest Editors: Elena Korobova, M. Manuela Abreu, Claudio Bini, Annamaria Lima, Domenico Cicchella, Carmen Pérez-Sirvent, Núria Roca
3
Jaume Bech Managing Guest Editor Faculty of Biology, University of Barcelona (UB)