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21.
《环境科学学报(英文版)》2023,35(3):73-81
The ultimate purpose of phytoextraction is not only to remove heavy metals from soil but also to improve soil quality. Here, we evaluated how the joint effect of Streptomyces pactum (strain Act12) and inorganic (Hoagland's solution) and organic (humic acid and peat) nutrients affected the phytoextraction practice of cadmium (Cd) and zinc (Zn) by potherb mustard, and the microbial community composition within rhizosphere was also investigated. The results indicated that the nutrients exerted synergistically with Act12, all increasing the plant biomass and Cd/Zn uptakes. The inoculation of Act12 alone significantly increased dehydrogenase activity of rhizosphere soil (P < 0.05), while urease and alkaline phosphatase activities varied in different dosage of Act12. Combined application of microbial strain with nutrients increased enzymatic activities with the elevated dosage of Act12. 16S ribosomal RNA high-throughput sequencing analysis revealed that Act12 inoculation reduced the diversity of rhizosphere bacteria. The Act12 and nutrients did not change dominant phyla i.e., Proteobacteria, Bacteroidetes, Gemmatimonadetes, Actinobacteria and Acidobacteria, but their relative abundance differed among the treatments with: Peat > Act12 > Humic acid > Hoagland's solution. Comparatively, Sphingomonas replaced Thiobacillus as dominant genus after Act12 application. The increase in the Sphingomonas and Flavisolibacter abundances under Act12 and nutrients treatments gave rise to growth-promoting effect on plant. Our results revealed the important role for rhizosphere microbiota in mediating soil biochemical traits and plant growth, and our approach charted a path toward the development of Act12 combined with soil nutrients to enhance soil quality and phytoextraction efficiency in Cd/Zn-contaminated soils. 相似文献
22.
A soil–plant biological system was developed from chromium(Cr) polluted soil treated by the compost-phytoremediation method. The transformation and migration of the Cr in this system is comprehensively studied in this research. The results illustrated that the co-composting treatment can reduce the Cr availability from 39%(F1 was about 31% of total, F2 was about 8% of total) to less than 2% by stabilizing the Cr. However, herbaceous plants can accumulate the concentrations of Cr from 113.8 to 265.2 mg/kg in the two crops,even though the concentration of soluble Cr in the substrate soil was below 0.1 mg/L.Cr can be assimilated and easily transferred in the tissues of plants because the lowmolecular-weight organic-acids(LMWOAs) derived from the plant root increase the bioavailability of Cr. The amount of extracted Cr dramatically increased when the organic acids were substituted in this order: citric acid malic acid tartaric acid oxalic acid acetic acid. On average the maximum(147.4 mg/kg) and the minimum(78.75 mg/kg) Cr were extracted by 20 mmol/L citric acid and acetic acid, respectively. The desorption of Cr in different acid solutions can be predicted by the pseudo second-order kinetics. The exchangeable Cr, carbonate-bound Cr, and residual Cr decreased, while Fe–Mn oxide bound Cr and organic bound Cr increased in the soil solid phase. According to the experimental results, the organic acids will promote the desorption and chelation processes of Cr, leading to the remobilization of Cr in the soil. 相似文献
23.
The heavy metal bioavailable fraction of a soil is a core parameter to verify the potential risks of contaminant exposure
to organisms or plants. The purpose of the present work is to identify the bioavailable metal fraction in soils treated with
chelates. This fraction was evaluated directly by analyzing metal concentrations in soil solution and indirectly using sequential
extraction procedures. The metal bioavailable fraction was compared with metal accumulated in plant leaves, grown in both
untreated and chelate-treated reactors. In order to verify the effect of the readily and slowly biodegradable chelates [S,S]-ethylenediaminedisuccinic
acid (EDDS), methylglycine diacetic acid (MGDA), and ethylenediaminetetraacetic acid (EDTA) on metal speciation in soils,
a simulation of chelate treatment was made and metal concentrations in different soil compartments before and after the simulation
were compared. Lead concentration in the soil solution was positively correlated with metal concentration in the test plants.
The soluble fraction showed the best correlation with metal concentration in soil solution. The simulation of the chelate
treatment demonstrated that EDTA and EDDS were able to extract part of the organic- and sulfide-bound fraction, which are
less available to plants. 相似文献
24.
Phytoaccumulation prospects of cadmium and zinc by mycorrhizal plant species growing in industrially polluted soils 总被引:2,自引:0,他引:2
The natural vegetation growing along a wastewater channel was subjected to analyze the uptake of Cadmium (Cd) and Zinc (Zn)
and their subsequent accumulation in aboveground and underground plant parts. Species which were mycorrhizal and growing in
soils receiving industrially contaminated wastewater were collected along with their rhizospheric soil samples. The nearby
uncontaminated control (reference) area was also subjected to sampling on similar pattern for comparison. Both Cd and Zn concentrations
were significantly higher in soils of the study area as compared to the reference site. Five plant species i.e. Desmostachya bipinnata, Dichanthium annulatum, Malvastrum coromandelianum, Saccharum bengalense, and Trifolium alexandrinum were analyzed for metal uptake. The maximum phytoaccumulation of Cd was observed in Desmostachya bipinnata (20.41 μg g−1) and Dichanthium annulatum (15.22 μg g−1) for shoot and root tissues, respectively. However, Malvastrum coromandelianum revealed maximum Zn accumulation for both the shoot and the root tissues (134 and 140 μg g−1, respectively). The examination of cleared and stained roots of the plants from both the areas studied revealed that all
of them were colonized to a lesser or a greater degree by arbuscular mycorrhizal (AM) fungi. The Cd hyperaccumulating grasses
i.e. Desmostachya bipinnata and Dichanthium annulatum, from study area had smaller root:shoot (R/S) ratio as compared to those growing on reference area indicating a negative
pressure of soil metal contamination. The lower R/S ratio in the mycorrhizal roots observed was probably due to increased
AM infection and its mediatory role in soil plant transfer of heavy metals. Furthermore, comparatively lower soil pH values
in the study areas may have played a key role in making the overall phytoavailability of both the metals. Consequently variations
in Cd and Zn tissue concentration among species were observed that also indicate the phytoaccumulation potential of the native
species. 相似文献
25.
26.
Michael Komárek Aleš Vaněk Radka Sudová Václav Tejnecký 《Environmental pollution (Barking, Essex : 1987)》2010,158(7):2428-2438
Incubation and pot experiments using poplar (Populus nigra L. cv. Wolterson) were performed in order to evaluate the questionable efficiency of EDDS-enhanced phytoextraction of Cu from contaminated soils. Despite the promising conditions of the experiment (low contamination of soils with a single metal with a high affinity for EDDS, metal tolerant poplar species capable of producing high biomass yields, root colonization by mycorrhizal fungi), the phytoextraction efficiency was not sufficient. The EDDS concentrations used in this study (3 and 6 mmol kg−1) enhanced the mobility (up to a 100-fold increase) and plant uptake of Cu (up to a 65-fold increase). However, despite EDDS degradation and the competition of Fe and Al for the chelant, Cu leaching cannot be omitted during the process. Due to the low efficiency, further research should be focused on other environment-friendly methods of soil remediation. 相似文献
27.
Orłowska E Przybyłowicz W Orlowski D Turnau K Mesjasz-Przybyłowicz J 《Environmental pollution (Barking, Essex : 1987)》2011,159(12):3730-3738
The effect of arbuscular mycorrhizal fungi (AMF) on growth and element uptake by Ni-hyperaccumulating plant, Berkheya coddii, was studied. Plants were grown under laboratory conditions on ultramafic soil without or with the AM fungi of different origin. The AM colonization, especially with the indigenous strain, significantly enhanced plants growth and their survival. AMF affected also the elemental concentrations that were studied with Particle-induced X-ray emission (PIXE). AMF (i) increased K and Fe in shoots, Zn and Mn in roots, P and Ca both, in roots and shoots; (ii) decreased Mn in shoots, Co and Ni both, in shoots and roots. Due to higher biomass of mycorrhizal plants, total Ni content was up to 20 times higher in mycorrhizal plants compared to the non-mycorrhizal ones. The AMF enhancement of Ni uptake may therefore provide an improvement of a presently used technique of nickel phytomining. 相似文献
28.
The use of chelating agents in the remediation of metal-contaminated soils: a review 总被引:12,自引:0,他引:12
This paper reviews current remediation technologies that use chelating agents for the mobilization and removal of potentially toxic metals from contaminated soils. These processes can be done in situ as enhanced phytoextraction, chelant enhanced electrokinetic extraction and soil flushing, or ex situ as the extraction of soil slurry and soil heap/column leaching. Current proposals on how to treat and recycle waste washing solutions after soil is washed are discussed. The major controlling factors in phytoextraction and possible strategies for reducing the leaching of metals associated with the application of chelants are also reviewed. Finally, the possible impact of abiotic and biotic soil factors on the toxicity of metals left after the washing of soil and enhanced phytoextraction are briefly addressed. 相似文献
29.
S.?Gorjanovi?Email author D.?Su?njevi? M.?Beljanski J.?Hranisavljevi? 《Environmental Chemistry Letters》2004,2(3):113-116
A lipid-transfer protein was isolated from a domestic cultivar of brewers barley grain, Hordeum vulgare. The presence of Cu (II), Pb (II), Cd (II) and Zn (II) ions in its structure and its ability to bind Hg (II) and Ni (II) ions is known. We investigated its ability to bind other metal ions by differential pulse polarography. Here we demonstrate that the lipid-transfer protein has an affinity to bind Co (II) and Pb (II) and has no affinity towards Cd (II), Cu (II), Zn (II) and Cr (III). These results suggest a new possible role of barley lipid-transfer protein for phytoextraction.Selected article from the Regional Symposium on Chemistry and Environment, Krusevac, Serbia, June 2003, organised by Dr. Branimir Jovancicevic 相似文献