Browsing by Author "Ginocchio, Rosanna"

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    A novel fast-vegetative propagation technique of the pioneer shrub Baccharis linearis on mine tailings by adding compost
    (TAYLOR & FRANCIS INC, 2021) Ginocchio, Rosanna; Maria de la Fuente, Luz; Orrego, Fabiola; Jose Diaz, Maria; Baez, Javiera; Francisco Ovalle, Juan
    Interest in Baccharis linearis has increased as an alternative for assisted phytostabilization due to its spontaneous colonization of tailings dumps. The search for a novel fast-vegetative propagation technique to accelerate its coverage on mine tailings is a promising research area for sustainable mine closure plans. In this study, we determined the optimal proportion of compost and tailings as growing media to promote fast B. linearis propagation through a compound layering technique. The assessed growing substrates were: 100% tailings, 70% tailings + 30% compost, and 50% tailings + 50% compost. After 84 days of growth, the change in number and height of layering branches, root and shoot dry mass, percentage of ground coverage, and substrate chemical properties were assessed. The main results showed that compound layering of B. linearis is possible with compost addition. The growth of new roots and layering branches was significantly improved by either 30% or 50% compost addition into tailings, due to chemical improvements of substrate (higher nutrients and pH and decreased copper bioavailability). The study confirms that the compound layering of B. linearis may be an effective and novel technique for speeding the reclamation of post-operative mine tailings, which is improved by the incorporation of compost.
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    Effect of Pyrolysis Temperature on Copper Aqueous Removal Capability of Biochar Derived from the Kelp Macrocystis pyrifera
    (MDPI, 2021) Araya, Matias; Rivas, Jorge; Sepulveda, Graciela; Espinoza Gonzalez, Camila; Lira, Sebastian; Meynard, Andres; Blanco, Elodie; Escalona, Nestor; Ginocchio, Rosanna; Garrido Ramirez, Elizabeth; Contreras Porcia, Loretto
    Seaweed biochar is an efficient alternative bioadsorbent for Cu2+ removal due to its low cost and heavy metal removal capacity. Using the slow pyrolysis process, we produced biochars from Macrocystis pyrifera at 300 (BC300), 450 (BC450), and 600 & DEG;C (BC600). The physicochemical and structural properties of the biochar samples improved with increasing pyrolysis temperature from 300 to 450 & DEG;C, whereas no significant differences were observed with further increases in temperature to 600 & DEG;C. The yield ranged between 49% and 62% and had a high ash content (57.5-71.1%). BC450 and BC600 presented the highest surface areas and higher porosities. The FTIR spectra indicated that an increase of temperature decreased the acidic functional groups due to depolymerization and the dehydration processes, increasing the aromatic structures and the presence of calcium carbonate. The fittings of the kinetic models were different for the BCs: for the BC450 and BC600 samples, the Cu2+ adsorption was well-represented by a pseudo-first-order model; for BC300, a better fit was obtained with the pseudo-second-order model. The rate-limiting step of Cu2+ adsorption on BCs was represented by both models, liquid film diffusion and intraparticle diffusion, with surface diffusion being more important in BC300 and BC600, and intraparticle diffusion in BC450, in agreement with the pore size of the biochar samples. The adsorption isotherms of all BCs showed Langmuir behavior, representative of a chemisorption process, which was corroborated by the energy adsorption values determined by the D-R model. The maximum monolayer Cu2+ adsorption capacities were 93.55 and 58.0 mg g(-1) for BC600 and BC450, respectively, whereas BC450 presented the highest affinity. Other mechanisms involved in controlling heavy metal removal from aqueous suspensions using these seaweed biochars remain to be explored. We conclude that BC450 and BC600 from M. pyrifera are the most efficient adsorbents for Cu2+ aqueous removal and are thus an appropriate alternative for bioremediation.
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    SOIL ACIDIFICATION AS A CONFOUNDING FACTOR ON METAL PHYTOTOXICITY IN SOILS SPIKED WITH COPPER-RICH MINE WASTES
    (WILEY, 2009) Ginocchio, Rosanna; Maria de la Fuente, Luz; Sanchez, Pablo; Bustamante, Elena; Silva, Yasna; Urrestarazu, Paola; Rodriguez, Patricio H.
    Pollution of soil with mine wastes results in both Cu enrichment and soil acidification. This confounding effect may be very important in terms of phytotoxicity, because pH is a key parameter influencing Cu solubility in soil solution. Laboratory toxicity tests were used to assess the effect of acidification by acidic mine wastes on Cu solubility and on root elongation of barley (Hordeum vulgare L.). Three contrasting substrates (two soils and a commercial sand) and two acidic, Cu-rich mine wastes (oxidized tailings [OxT] and smelter dust [SmD]) were selected as experimental materials. Substrates were spiked with a fixed amount of either SmD or OxT, and the pH of experimental mixtures was then modified in the range of 4.0 to 6.0 and 7.0 using PIPES (piperazine-1,4-bis(2-ethanesulfonic acid)), MES (2-(N-morpholino) ethanesulfonic acid), and MOPS (3-(N-Morpholino)-propanesulfonic acid) buffers. Chemical (pore-water Cu and pH) and toxicological (root length of barley plants) parameters were determined for experimental mixtures. Addition of SmD and OxT to substrates resulted in acidification (0.11-1.16 pH units) and high levels of soluble Cu and Zn. Neutralization of experimental mixtures with MES (pH 6.0) and MOPS (pH 7.0) buffers resulted in a marked decrease in soluble Cu and Zn, but the intensity of the effect was substrate-dependent. Adjustment of soil pH above the range normally considered to be toxic to plants (pH in water extract, > 5.5) significantly reduced metal toxicity in barley, but phytotoxicity was not completely eliminated. The present results stress the importance of considering confounding effects on derivation of toxicity thresholds to plants when using laboratory phytotoxicity tests.
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    The microbial community from the early-plant colonizer (Baccharis linearis) is required for plant establishment on copper mine tailings
    (NATURE RESEARCH, 2021) Consuelo Gazitua, Maria; Morgante, Veronica; Josefina Poupin, Maria; Ledger, Thomas; Rodriguez Valdecantos, Gustavo; Herrera, Catalina; Del Carmen Gonzalez Chavez, Maria; Ginocchio, Rosanna; Gonzalez, Bernardo
    Plants must deal with harsh environmental conditions when colonizing abandoned copper mine tailings. We hypothesized that the presence of a native microbial community can improve the colonization of the pioneer plant, Baccharis linearis, in soils from copper mining tailings. Plant growth and microbial community compositions and dynamics were determined in cultivation pots containing material from two abandoned copper mining tailings (Huana and Tambillos) and compared with pots containing fresh tailings or surrounding agricultural soil. Controls without plants or using irradiated microbe-free substrates, were also performed. Results indicated that bacteria (Actinobacteria, Gammaproteobacteria, and Firmicutes groups) and fungi (Glomus genus) are associated with B. linearis and may support plant acclimation, since growth parameters decreased in both irradiated (transiently without microbial community) and fresh tailing substrates (with a significantly different microbial community). Consistently, the composition of the bacterial community from abandoned copper mining tailings was more impacted by plant establishment than by differences in the physicochemical properties of the substrates. Bacteria located at B. linearis rhizoplane were clearly the most distinct bacterial community compared with those of fresh tailings, surrounding soil and non-rhizosphere abandoned tailings substrates. Beta diversity analyses showed that the rhizoplane bacterial community changed mainly through species replacement (turnover) than species loss (nestedness). In contrast, location/geographical conditions were more relevant than interaction with the plants, to explain fungal community differences.
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    Trade-Offs between Drought Survival and Rooting Strategy of Two South American Mediterranean Tree Species: Implications for Dryland Forests Restoration
    (MDPI, 2015) Ovalle, Juan F.; Arellano, Eduardo C.; Ginocchio, Rosanna
    Differences in water-acquisition strategies of tree root systems can determine the capacity to survive under severe drought. We evaluate the effects of field water shortage on early survival, growth and root morphological variables of two South American Mediterranean tree species with different rooting strategies during two growing seasons. One year-old Quillaja saponaria ( deep- rooted) and Cryptocarya alba ( shallow- rooted) seedlings were established under two watering treatments ( 2 L . week- 1 . plant- 1 and no water) in a complete randomized design. Watering improved the final survival of both species, but the increase was only significantly higher for the shallow- rooted species. The survival rates of deep- and shallow- rooted species was 100% and 71% with watering treatment, and 96% and 10% for the unwatered treatment, respectively. Root morphological variables of deep- rooted species such as surface area, volume, and diameter were higher under unwatered treatment. On the other hand, shallow- rooted species had a higher total root dry mass, length, surface area with watering treatments. Our findings suggest that deep- rooted species are highly recommended for reforestation in dry conditions, even under low soil water availability. Water supplements during the summer season can attenuate the differences between deep- and shallow- rooted species in their ability to survive drought during the early stage.