Coastal wetlands face dual pressures from high salinity and heavy metal pollution,presenting significant ecological challenges.Halophytes like Sesuvium portulacastrum possess unique physiological mechanisms to mitigat...Coastal wetlands face dual pressures from high salinity and heavy metal pollution,presenting significant ecological challenges.Halophytes like Sesuvium portulacastrum possess unique physiological mechanisms to mitigate metal toxicity.This study investigates how silicon (Si) availability influences the accumulation of copper (Cu) and cadmium (Cd) in S.portulacastrum.Our results show that Si supplementation at environmentally relevant levels significantly increases Cu and Cd concentrations in the roots,while simultaneously reducing the root-to-shoot translocation of these metals.In situ non-invasive micro-testing revealed decreased metal efflux from the xylem,indicating an enhanced retention of metals in the roots.Furthermore,analyses using X-ray photoelectron spectroscopy and atomic force microscopy demonstrated a higher density of oxygen-containing functional groups and SiO-on the extracellular matrix of Si-enriched roots.This structural transformation resulted in a significant reduction in root surface potential,facilitating greater metal ion attraction and uptake.The findings from this study provide critical insights into the mechanisms by which Si availability regulates metal accumulation in halophytes,suggesting potential strategies for mitigating metal pollution in coastal wetland ecosystems.展开更多
Soil metal pollution is a global issue due to its toxic nature affecting ecosystems and human health. This has become a concern since metals are non-biodegradable and toxic. Most of the reclamation methods currently u...Soil metal pollution is a global issue due to its toxic nature affecting ecosystems and human health. This has become a concern since metals are non-biodegradable and toxic. Most of the reclamation methods currently used for soils rely on the use of physical and chemical means, which tend to be very expensive and result in secondary environmental damage. However, microbe-aided phytoremediation is gaining attention as it is an eco-friendly, affordable, and technically advanced method to restore the ecosystem. It is essential to understand the complex interaction between plants and microbes. The primary function of plant growth-promoting bacteria (PGPB) is to stimulate plant development, aid in metal elimination, and reduce their bioavailability in the soil. These microbes regulate phytohormones, stimulate processes such as phytoextraction and phyto-stabilization, and improve the uptake of essential nutrients, such as nitrogen and phosphorus. PGPBs secrete a range of enzymes and chemicals, fix nitrogen, solubilize minerals, increase the bioavailability of nutrients under diverse biological environments with high salinities, excessive metal-contaminated soil, and organic pollutants, increase the soil fertility and help in the reclamation of agriculture and regenerate the native flora. The integration of CRISPR-Cas9 gene-editing technology with microbial-aided phytoremediation and the use of genetically modified microbes with nanomaterials further enhance the efficacy of the approaches in polluted environments for sustainable restoration of the soil.展开更多
Mining activities are often associated with significant environmental degradation,particularly due to the accumulation of mine tailings(MTs).These waste materials are frequently stored in dams or open ponds without ad...Mining activities are often associated with significant environmental degradation,particularly due to the accumulation of mine tailings(MTs).These waste materials are frequently stored in dams or open ponds without adequate treatment,posing serious risk of heavy metals(HMs)contamination to surrounding ecosystems.Given these challenges,restoration of MTs to mitigate their negative impacts has become highly important.This study attempts to compile different types of MTs,their characteristics,and associated issues such as acid mine drainage(AMD)and HMs contamination,along with other environmental impacts.It also explores the fundamentals of phytoremediation,highlighting key processes,recent advancements,benefits,limitations,and strategies for post-harvest management.The findings indicate that MTs are a major source of HM pollution and contribute significantly to environmental deterioration.Phytoremediation has emerged as a promising,cost-effective,and eco-friendly solution for MT restoration.In addition to mitigating contamination,phytoremediation enhances soil quality,prevents erosion,reduces HM leaching into groundwater,and improves the visual appeal of degraded sites.Research suggests that revegetating MT-contaminated soils with specific plant species can effectively remediate these areas,reducing HM leaching risks while improving soil properties.This review serves as a valuable resource for researchers working on MT restoration,offering insights into the latest advancements in phytoremediation technology and its potential to address the environmental challenges posed by MTs.展开更多
Phytoremediation is an efficient and economic ecological technology. It includes phytostabilization, phytovolatilization, and plant absorption. In the research, status quo and progress of Phytostabilization and plant ...Phytoremediation is an efficient and economic ecological technology. It includes phytostabilization, phytovolatilization, and plant absorption. In the research, status quo and progress of Phytostabilization and plant absorption in soils polluted with heavy metals in metal mines were summarized, including the characteristics and status quo of phytoremediation and selection method of hyperaccumulator. In addition, further research was proposed as well.展开更多
[Objective] The aim was to study the phytoremediation of heavy metal pollution in river sediment by Medicago sativa L.,so as to provide reliable references for the phytoremediation of heavy metal pollution in river se...[Objective] The aim was to study the phytoremediation of heavy metal pollution in river sediment by Medicago sativa L.,so as to provide reliable references for the phytoremediation of heavy metal pollution in river sediment.[Method] The air-dried,screened and mixed sediment was put in rectangular PVC box（0.6 m×0.5 m×0.4 m） with seepage vent at the bottom,and the water holding capacity（WHC） of sediment was kept at 30%-60% by deionized water.The seeds of Medicago sativa L.were sown in April 2010,and seedlings were thinned after 7 d.Samples were collected from rhizosphere soil every 30 d,and were used to determine the content of heavy metals,bacteria quantity and enzyme activity in sediment.In addition,the accumulation of heavy metals in the roots,stems and leaves of plant was measured after harvest in October.[Result] Different parts of Medicago sativa L.varied in accumulation capacity to different heavy metals.The accumulation amount of Zn in Medicago sativa L.was the highest,especially in roots.Meanwhile,the accumulation amount of heavy metals like Ni,Cr,Cu and Pb in roots was higher than that of stems and leaves.In contrast,Mn was mainly accumulated in leaves and its amount accounted for 42.47% of the total amount in plant.Besides,the accumulation amount of all heavy metals was the lowest in stems.Ni,Cr,Cu and Pb could be degraded more effectively than Mn,and increasing the planting time and sowing times of crop was beneficial to the degradation of heavy metals.After planted Medicago sativa L.,the quantity of microorganisms in sediment went up obviously,and dehydrogenase activity also showed an increaseing trend.[Conclusion] Medicago sativa L.has certain restoring effect on Zn,Ni,Cr,Cu and Pb,and could be used to restore heavy metal pollution in river sediment.展开更多
[Objective] The aim was to research phytoremediation effects on soils with combined pollution. [Method] With simulation experiment, the test selected plants suitable for phytoremediation in soils polluted with Pb-Cd, ...[Objective] The aim was to research phytoremediation effects on soils with combined pollution. [Method] With simulation experiment, the test selected plants suitable for phytoremediation in soils polluted with Pb-Cd, PAHs, and Pb-Cd-PAHs,respectively and ryegrass was grown to explore phytoremediation on contaminated sites by adjusting bio-availability. [Result] After 70 d growing of ryegrass, the content of available Pb in contaminated soils was 375.26 mg/kg, the content of Cd was 4.9mg/kg after 90 d, and the content of B [a]P was 0.60 mg/kg after 100 d, which were all lower compared with soil limits. [Conclusion] Ryegrass is a suitable plant for phytoremediation.展开更多
Biochar (BC) and rhamnolipid (RL) is used in bioremediation of petroleum hydrocarbons,however,the combined effect of BC and RL in phytoremediation has not been studied until now.In this paper,the phytoremediation of p...Biochar (BC) and rhamnolipid (RL) is used in bioremediation of petroleum hydrocarbons,however,the combined effect of BC and RL in phytoremediation has not been studied until now.In this paper,the phytoremediation of petroleum hydrocarbon-contaminated soil using novel plant Spartina anglica was enhanced by the combination of biochar (BC) and rhamnolipid (RL).Samples of petroleum-contaminated soil (10,30 and 50 g/kg) were amended by BC,BC+ RL and rhamnolipid modified biochar (RMB),respectively.After 60 day's cultivation,the removal rate of total petroleum hydrocarbons (TPHs) for unplanted soil (UP),planted soil (P),planted soil with BC addition (P-BC),planted soil with BC and RL addition (P-BC + RL) and planted soil with addition ofRMB (P-RMB) were 8.6%,19.1%,27.7%,32.4% and 35.1% in soil with TPHs concentration of 30 g/kg,respectively.Compared with UP,the plantation of Spartina anglica significantly decreased the concentration of C8-14 and tricyclic PAHs.Furthermore,the application of BC and RMB alleviated the toxicity of petroleum hydrocarbons to Spartina anglica via improving plant growth with increasing plant height,root vitality and total chlorophyll content.High-throughput sequencing result indicated that rhizosphere microbial community of Spartina anglica was regulated by the application of BC and RMB,with increase of bacteria and plant mycorrhizal symbiotic fungus in biochar and RMB amended soil.展开更多
Environmental pollution affects the quality of pedosphere,hydrosphere,atmosphere,lithosphere and biosphere.Great efforts have been made in the last two decades to reduce pollution sources and remedy the polluted soil ...Environmental pollution affects the quality of pedosphere,hydrosphere,atmosphere,lithosphere and biosphere.Great efforts have been made in the last two decades to reduce pollution sources and remedy the polluted soil and water resources.Phytoremediation,being more cost-effective and fewer side effects than physical and chemical approaches,has gained increasing popularity in both academic and practical circles.More than 400 plant species have been identified to have potential for soil and water remediation.Among them,Thlaspi,Brassica,Sedum alfredii H.,and Arabidopsis species have been mostly studied.It is also expected that recent advances in biotechnology will play a promising role in the development of new hyperaccumulators by transferring metal hyperaccumulating genes from low biomass wild species to the higher biomass producing cultivated species in the times to come.This paper attempted to provide a brief review on recent progresses in research and practical applications of phytoremediation for soil and water resources.展开更多
Soil pollution has been attracting considerable public attentions over the last decades. Sorts of traditional physiochemical methods have been used to remove the organic pollutants from soils. However, the enormous co...Soil pollution has been attracting considerable public attentions over the last decades. Sorts of traditional physiochemical methods have been used to remove the organic pollutants from soils. However, the enormous costs and low efficiencies associated with these remediation technologies limit their availabilities. Phytoremediation is an emerging technology that uses plants to cleanup pollutants in soils. As overwhelmingly positive results have been shown, phytoremediation is a most economical and effective remediation technique for organic contaminated soils. In this paper phytoremediation and its models for organic contaminated soils are viewed. The mechanisms of phytoremediation mainly include the direct plant uptake of organic pollutants, degradation by plant-derived degradative enzymes, and stimulated biodegradation in plant rhizosphere. Phytoremediation efficiency is close related to physicochemical properties of organic pollutants, environmental characteristics, and plant types. It is no doubt that soil amendments such as surfactants improve the solubilities and availabilities of organic pollutants in soils. However, little information is available about effects of soil amendments on phytoremediation efficiencies. Phytoremediation models have been developed to simulate and predict the environmental behavior of organic pollutants, and progress of models is illustrated. In many ways phytoremediation is still in its initial stage, and recommendations for the future research on phytoremediation are presented.展开更多
Heavy metal pollution of soil is a significant environmental problem and has its negative impact on human health and agriculture. Rhizosphere, as an important interface of soil and plant, plays a significant role in p...Heavy metal pollution of soil is a significant environmental problem and has its negative impact on human health and agriculture. Rhizosphere, as an important interface of soil and plant, plays a significant role in phytoremediation of contaminated soil by heavy metals, in which, microbial populations are known to affect heavy metal mobility and availability to the plant through release of chelating agents, acidification, phosphate solubilization and redox changes, and therefore, have potential to enhance phytoremediation processes. Phytoremediation strategies with appropriate heavy metal-adapted rhizobacteria have re-ceived more and more attention. This article paper reviews some recent advances in effect and significance of rhizobacteria in phytoremediation of heavy metal contaminated soils. There is also a need to improve our understanding of the mechanisms in-volved in the transfer and mobilization of heavy metals by rhizobacteria and to conduct research on the selection of microbial isolates from rhizosphere of plants growing on heavy metal contaminated soils for specific restoration programmes.展开更多
The potential of kenaf (Hibiscus cannabinus L.) for phytoremediation of lead (Pb) on sand tailings was investigated.A pot experiment employing factorial design with two main effects of fertilizer and lead was conducte...The potential of kenaf (Hibiscus cannabinus L.) for phytoremediation of lead (Pb) on sand tailings was investigated.A pot experiment employing factorial design with two main effects of fertilizer and lead was conducted in a nursery using sand tailings from an ex-tin mine as the growing medium.Results showed that Pb was found in the root,stem,and seed capsule of kenaf but not in the leaf.Application of organic fertilizer promoted greater biomass yield as well as higher accumulation capacity of Pb.In Pb-spike...展开更多
An experimental study of the rhizosphere effect on phytoremediation of petroleum polluted soil was carried out with three species of grasses, namely Pannicum, Eleusine indica （L.） Gaerth, and Tall Fescue. After a pe...An experimental study of the rhizosphere effect on phytoremediation of petroleum polluted soil was carried out with three species of grasses, namely Pannicum, Eleusine indica （L.） Gaerth, and Tall Fescue. After a period of 150 days, this pot experiment showed that the rhizosphere of these three species accelerated the degradation of petroleum hydrocarbons to different extents. The results showed that the number of microorganisms in the rhizosphere increased by three orders of magnitude. The induction of the plant rhizosphere and the coercion influence of petroleum changed the species and activity of microorganisms. The degradation of petroleum hydrocarbons in the rhizosphere was 3-4 times that in unplanted soil. The dehydrogenase activity in the rhizosphere was 1.61-2.20 times that in unplanted soil, but the catalase activity was 0.90-0.93 times that in unplanted soil, and soil moisture content increased by 5% compared with the unplanted soil.展开更多
A co-culture of two plant materials, Astragalus sinicus L., a leguminous plant with concomitant nodules, and Elsholtzia splendens Naki-a Cu accumulator, along with treatments of a chelating agent (EDTA), root excretio...A co-culture of two plant materials, Astragalus sinicus L., a leguminous plant with concomitant nodules, and Elsholtzia splendens Naki-a Cu accumulator, along with treatments of a chelating agent (EDTA), root excretions (citric acid), and a control with E. splendens only were used to compare the mobility of heavy metals in chelating agents with a co-culture and to determine the potential for co-culture phytoremediation in heavy metal contaminated soils. The root uptake for Cu, Zn, and Pb in all treatments was significantly greater (P ＜ 0.05) than that of the control treatment. However with translocation in the shoots, only Cu, Zn, and Pb in plants grown with the EDTA treatment and Zn in plants cocropped with the A. sinicus treatment increased significantly (P ＜ 0.05). In addition, when a co-culture in soils with heavy and moderate contamination was compared, for roots in moderately contaminated soils only Zn concentration was significantly less (P ＜ 0.05) than that of heavily contaminated soils, however, Cu, Zn, and Pb concentrations of shoots were all significantly lower (P ＜ 0.05). Overall, this 'co-culture engineering' could be as effective as or even more effective than chelating agents, thereby preventing plant metal toxicity and metal leaching in soils as was usually observed in chelate-enhanced phytoremediation.展开更多
Phytoremediation of soil contaminated with phenanthrene and pyrene was investigated using twelve plant species. Plant uptake and accumulation of these chemicals were evaluated. At the end of the experiment(45 d), the ...Phytoremediation of soil contaminated with phenanthrene and pyrene was investigated using twelve plant species. Plant uptake and accumulation of these chemicals were evaluated. At the end of the experiment(45 d), the remaining respective concentrations of soil phenanthrene and pyrene in spiked vegetated soils, with initial phenanthrene of 133 3 mg/kg and pyrene of 171 5 mg/kg, were 8 71—16 4 and 44 9—65 0 mg/kg, generally 4 7%—49 4% and 7 1%—35 9% lower than their concentrations in the non vegetated soils. The loss of phenanthrene and pyrene in vegetated spiked soils were 88 2%—93 0% and 62 3%—73 8% of the added amounts of these contaminants, respectively. Although plant uptake and accumulation of these compounds were evident, and root concentrations and RCFs(root concentration factors; defined as the ratio of PAH concentrations in roots and in the soils on a dry weight basis) of these compounds significantly positively correlated to root lipid contents, plant uptake and accumulation only accounted for less than 0 01% and 0 23% of the enhanced loss of these chemicals in vegetated versus non vegetated soils. In contrast, plant promoted microbial biodegradation was the dominant mechanism of the phytoremediation for soil phenanthrene and pyrene contamination. Results from this study suggested a feasibility of the establishment of phytoremediation for soil PAH contamination.展开更多
Field investigation and greenhouse experiments were conducted to study the tolerance of Pteris vittata L. （Chinese brake） to cadmium （Cd） and its feasibility for remediating sites co-contaminated with Cd and arsen...Field investigation and greenhouse experiments were conducted to study the tolerance of Pteris vittata L. （Chinese brake） to cadmium （Cd） and its feasibility for remediating sites co-contaminated with Cd and arsenic （As）. The results showed that P. vittata could survive in pot soils spiked with 80 mg/kg of Cd and tolerated as great as 301 mg/kg of total Cd and 26.8 mg/kg of diethyltriaminepenta acetic acid （DTPA）-extractable Cd under field conditions. The highest concentration of Cd in fronds was 186 mg/kg under a total soil concentration of 920 mg As/kg and 98.6 mg Cd/kg in the field, whereas just 2.6 mg/kg under greenhouse conditions. Ecotypes of P. vittata were differentiated in tolerance and accumulation of Cd, and some of them could not only tolerate high concentrations of soil Cd, but also accumulated high concentrations of Cd in their fronds. Arsenic uptake and transportation by P. vittata was not inhibited at lower levels （〈20 mg/kg） of Cd addition. Compared to the treatment without addition of Cd, the frond As concentration was increased by 103.8% at 20 mg Cd/kg, with the highest level of 6434 mg/kg. The results suggested that the Cd-tolerant ecotype of P. vittata extracted effectively As and Cd from the site co-contaminated with Cd and As, and might be used to remediate and revegetate this type of site.展开更多
Heavy metals are widely distributed contaminants in natural environments and their potential threats to human health have attracted worldwide concerns due to the food chain. Therefore, great efforts have been made to ...Heavy metals are widely distributed contaminants in natural environments and their potential threats to human health have attracted worldwide concerns due to the food chain. Therefore, great efforts have been made to reduce them to a safe level in soil. Compared with the traditional methods, the method using plants to remove them has been accepted as a feasible and efficient way. Herein, the geochemical behavior of heavy metals and the restoration methods with phytoremediation were reviewed. In addition, issues on heavy metal speciation as well as its influencing factors, phytoremediation mechanism, phytoremediation effect and vegetation selection principle used for phytoremediation were discussed.展开更多
Phytoremediation technology is a newly-developed way of soil heavy metal pollution repair with high efficiency and good ecological comprehensive benefit. This paper briefly introduces the soil heavy metal pollution st...Phytoremediation technology is a newly-developed way of soil heavy metal pollution repair with high efficiency and good ecological comprehensive benefit. This paper briefly introduces the soil heavy metal pollution status at home and abroad,and focuses on the analysis of harm,sources and current situation of soil heavy metal pollution at home and abroad as well as mechanism and application of phytoremediation.Finally it discusses the key problems in phytoremediation technology that need to resolve in the future.展开更多
Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils. Bidens is a new Pb hyperaccumulator, which not only has remarkable tolerance to Pb but also extraordinary acc...Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils. Bidens is a new Pb hyperaccumulator, which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb. The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues. The Pb distribution order in the B. was： leaf 〉 stem 〉 root. The effect of amendments on phytoremediation was also studied. The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application. Compared with CK （control check）, EDTA application promoted translocation of Pb to overground parts of the plant. The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg. This research demonstrated that B. maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil, especially, combination with EDTA.展开更多
A hydroponics experiment was aimed at identifying the lead（Pb） tolerance and phytoremediation potential of Moso bamboo（Phyllostachys pubescens） seedlings grown under different Pb treatments. Experimental results i...A hydroponics experiment was aimed at identifying the lead（Pb） tolerance and phytoremediation potential of Moso bamboo（Phyllostachys pubescens） seedlings grown under different Pb treatments. Experimental results indicated that at the highest Pb concentration（400 μmol/L）, the growth of bamboo seedlings was inhibited and Pb concentrations in leaves, stems, and roots reached the maximum of 148.8, 482.2, and 4282.8 mg/kg, respectively. Scanning electron microscopy revealed that the excessive Pb caused decreased stomatal opening, formation of abundant inclusions in roots, and just a few inclusions in stems. The ultrastructural analysis using transmission electron microscopy revealed that the addition of excessive Pb caused abnormally shaped chloroplasts, disappearance of endoplasmic reticulum, shrinkage of nucleus and nucleolus, and loss of thylakoid membranes. Although ultrastructural analysis revealed some internal damage, even the plants exposed to 400 μmol/L Pb survived and no visual Pb toxicity symptoms such as necrosis and chlorosis were observed in these plants. Even at the highest Pb treatment, no significant difference was observed for the dry weight of stem compared with controls. It is suggested that use of Moso bamboo as an experimental material provides a new perspective for remediation of heavy metal contaminated soil owing to its high metal tolerance and greater biomass.展开更多
Sedum alfredii Hance is a cadmium(Cd)/zinc(Zn)hyperaccumulator native to China.However,its relatively low biomass restricted the large-scale application for heavy metal contamination remediation.The chromosome set dou...Sedum alfredii Hance is a cadmium(Cd)/zinc(Zn)hyperaccumulator native to China.However,its relatively low biomass restricted the large-scale application for heavy metal contamination remediation.The chromosome set doubling of S.alfredii in vitro was achieved by 0.1%–0.2%(W/V)colchicine treatment.The plant DNA ploidy was analyzed by flow cytometry and chromosome set doubling plants(CSD)were identified based on the obvious different sharp peak.A tissue culture experiment with different Cd treated levels and a field trial with natural polluted mined soil were conducted to study the effects of chromosome doubling on plant biomass and Cd accumulation in shoots.The results suggested that S.alfredii is a mixoploid.Compared with the wild type plants(WT),CSD exhibited typical"gigas"characteristics in morphology including stem thickness,root hair production,number of leaves and size of stoma guard cell.Fresh weight and dry weight of CSD were increased to 1.62–2.03-fold and 2.26–3.25-fold of WT.And Cd content of CSD showed a17.49%–42.82%increase and 59%increase under tissue culture and field condition,accordingly.In addition,the TF and in BCF of CSD were 2.37-and 1.59-fold of WT,respectively.These results proved that it is feasible to promote phytoextraction efficiency of S.alfredii in Cd contaminated soils through chromosomal engineering,which provides a novel approach for hyperaccumulator application in phytoremediation.展开更多
基金supported by the National Natural Science Foundation of China (Nos.42376152 and 42306155)Guangdong Major Project of Basic and Applied Basic Research(No.2023B0303000017)+2 种基金the Special Program of Key Sectors in Guangdong Universities (No.2022ZDZX4040)the Innovation Team Project of Universities in Guangdong Province (No.2023KCXTD028)Guangxi Key Laboratory of Marine Environmental Change and Disaster in Beibu Gulf,Beibu Gulf University (No.2022KF007)。
文摘Coastal wetlands face dual pressures from high salinity and heavy metal pollution,presenting significant ecological challenges.Halophytes like Sesuvium portulacastrum possess unique physiological mechanisms to mitigate metal toxicity.This study investigates how silicon (Si) availability influences the accumulation of copper (Cu) and cadmium (Cd) in S.portulacastrum.Our results show that Si supplementation at environmentally relevant levels significantly increases Cu and Cd concentrations in the roots,while simultaneously reducing the root-to-shoot translocation of these metals.In situ non-invasive micro-testing revealed decreased metal efflux from the xylem,indicating an enhanced retention of metals in the roots.Furthermore,analyses using X-ray photoelectron spectroscopy and atomic force microscopy demonstrated a higher density of oxygen-containing functional groups and SiO-on the extracellular matrix of Si-enriched roots.This structural transformation resulted in a significant reduction in root surface potential,facilitating greater metal ion attraction and uptake.The findings from this study provide critical insights into the mechanisms by which Si availability regulates metal accumulation in halophytes,suggesting potential strategies for mitigating metal pollution in coastal wetland ecosystems.
基金supported by the Yibin Science and Technology Plan(2022NY011).
文摘Soil metal pollution is a global issue due to its toxic nature affecting ecosystems and human health. This has become a concern since metals are non-biodegradable and toxic. Most of the reclamation methods currently used for soils rely on the use of physical and chemical means, which tend to be very expensive and result in secondary environmental damage. However, microbe-aided phytoremediation is gaining attention as it is an eco-friendly, affordable, and technically advanced method to restore the ecosystem. It is essential to understand the complex interaction between plants and microbes. The primary function of plant growth-promoting bacteria (PGPB) is to stimulate plant development, aid in metal elimination, and reduce their bioavailability in the soil. These microbes regulate phytohormones, stimulate processes such as phytoextraction and phyto-stabilization, and improve the uptake of essential nutrients, such as nitrogen and phosphorus. PGPBs secrete a range of enzymes and chemicals, fix nitrogen, solubilize minerals, increase the bioavailability of nutrients under diverse biological environments with high salinities, excessive metal-contaminated soil, and organic pollutants, increase the soil fertility and help in the reclamation of agriculture and regenerate the native flora. The integration of CRISPR-Cas9 gene-editing technology with microbial-aided phytoremediation and the use of genetically modified microbes with nanomaterials further enhance the efficacy of the approaches in polluted environments for sustainable restoration of the soil.
文摘Mining activities are often associated with significant environmental degradation,particularly due to the accumulation of mine tailings(MTs).These waste materials are frequently stored in dams or open ponds without adequate treatment,posing serious risk of heavy metals(HMs)contamination to surrounding ecosystems.Given these challenges,restoration of MTs to mitigate their negative impacts has become highly important.This study attempts to compile different types of MTs,their characteristics,and associated issues such as acid mine drainage(AMD)and HMs contamination,along with other environmental impacts.It also explores the fundamentals of phytoremediation,highlighting key processes,recent advancements,benefits,limitations,and strategies for post-harvest management.The findings indicate that MTs are a major source of HM pollution and contribute significantly to environmental deterioration.Phytoremediation has emerged as a promising,cost-effective,and eco-friendly solution for MT restoration.In addition to mitigating contamination,phytoremediation enhances soil quality,prevents erosion,reduces HM leaching into groundwater,and improves the visual appeal of degraded sites.Research suggests that revegetating MT-contaminated soils with specific plant species can effectively remediate these areas,reducing HM leaching risks while improving soil properties.This review serves as a valuable resource for researchers working on MT restoration,offering insights into the latest advancements in phytoremediation technology and its potential to address the environmental challenges posed by MTs.
文摘Phytoremediation is an efficient and economic ecological technology. It includes phytostabilization, phytovolatilization, and plant absorption. In the research, status quo and progress of Phytostabilization and plant absorption in soils polluted with heavy metals in metal mines were summarized, including the characteristics and status quo of phytoremediation and selection method of hyperaccumulator. In addition, further research was proposed as well.
基金Supported by Major State Basic Research Development Program(973 Program) (2007CB407306)National Natural Science Foun-dation of China (50908159)~~
文摘[Objective] The aim was to study the phytoremediation of heavy metal pollution in river sediment by Medicago sativa L.,so as to provide reliable references for the phytoremediation of heavy metal pollution in river sediment.[Method] The air-dried,screened and mixed sediment was put in rectangular PVC box（0.6 m×0.5 m×0.4 m） with seepage vent at the bottom,and the water holding capacity（WHC） of sediment was kept at 30%-60% by deionized water.The seeds of Medicago sativa L.were sown in April 2010,and seedlings were thinned after 7 d.Samples were collected from rhizosphere soil every 30 d,and were used to determine the content of heavy metals,bacteria quantity and enzyme activity in sediment.In addition,the accumulation of heavy metals in the roots,stems and leaves of plant was measured after harvest in October.[Result] Different parts of Medicago sativa L.varied in accumulation capacity to different heavy metals.The accumulation amount of Zn in Medicago sativa L.was the highest,especially in roots.Meanwhile,the accumulation amount of heavy metals like Ni,Cr,Cu and Pb in roots was higher than that of stems and leaves.In contrast,Mn was mainly accumulated in leaves and its amount accounted for 42.47% of the total amount in plant.Besides,the accumulation amount of all heavy metals was the lowest in stems.Ni,Cr,Cu and Pb could be degraded more effectively than Mn,and increasing the planting time and sowing times of crop was beneficial to the degradation of heavy metals.After planted Medicago sativa L.,the quantity of microorganisms in sediment went up obviously,and dehydrogenase activity also showed an increaseing trend.[Conclusion] Medicago sativa L.has certain restoring effect on Zn,Ni,Cr,Cu and Pb,and could be used to restore heavy metal pollution in river sediment.
基金Supported by Unified Research with Industry-University-Research Cooperation(BY2014037-21)~~
文摘[Objective] The aim was to research phytoremediation effects on soils with combined pollution. [Method] With simulation experiment, the test selected plants suitable for phytoremediation in soils polluted with Pb-Cd, PAHs, and Pb-Cd-PAHs,respectively and ryegrass was grown to explore phytoremediation on contaminated sites by adjusting bio-availability. [Result] After 70 d growing of ryegrass, the content of available Pb in contaminated soils was 375.26 mg/kg, the content of Cd was 4.9mg/kg after 90 d, and the content of B [a]P was 0.60 mg/kg after 100 d, which were all lower compared with soil limits. [Conclusion] Ryegrass is a suitable plant for phytoremediation.
基金supported by the National Natural Science Foundation of China(Nos.U1806216,41877372)the CNPC scientific research and technological development project(No.2016D-4610)+1 种基金the Tianjin S&T Program(Nos.17ZXSTSF00050,17PTGCCX00240,16YFXTSF00520)the 111 program,Ministry of Education,China(No.T2017002)
文摘Biochar (BC) and rhamnolipid (RL) is used in bioremediation of petroleum hydrocarbons,however,the combined effect of BC and RL in phytoremediation has not been studied until now.In this paper,the phytoremediation of petroleum hydrocarbon-contaminated soil using novel plant Spartina anglica was enhanced by the combination of biochar (BC) and rhamnolipid (RL).Samples of petroleum-contaminated soil (10,30 and 50 g/kg) were amended by BC,BC+ RL and rhamnolipid modified biochar (RMB),respectively.After 60 day's cultivation,the removal rate of total petroleum hydrocarbons (TPHs) for unplanted soil (UP),planted soil (P),planted soil with BC addition (P-BC),planted soil with BC and RL addition (P-BC + RL) and planted soil with addition ofRMB (P-RMB) were 8.6%,19.1%,27.7%,32.4% and 35.1% in soil with TPHs concentration of 30 g/kg,respectively.Compared with UP,the plantation of Spartina anglica significantly decreased the concentration of C8-14 and tricyclic PAHs.Furthermore,the application of BC and RMB alleviated the toxicity of petroleum hydrocarbons to Spartina anglica via improving plant growth with increasing plant height,root vitality and total chlorophyll content.High-throughput sequencing result indicated that rhizosphere microbial community of Spartina anglica was regulated by the application of BC and RMB,with increase of bacteria and plant mycorrhizal symbiotic fungus in biochar and RMB amended soil.
基金Project supported by the Higher Education Commission,Government of Pakistan for the faculty training under the R & D Project"Strengthening Department of Soil Science and Soil and Water Conservation" at the University of Florida,USA,a grant from the St. Lucie River Water Initiative (SFWMD contract No. OT060162),USA,in partthe Program for Changjiang Scholars and Innovative Research Team in University (No.IRT0536),China
文摘Environmental pollution affects the quality of pedosphere,hydrosphere,atmosphere,lithosphere and biosphere.Great efforts have been made in the last two decades to reduce pollution sources and remedy the polluted soil and water resources.Phytoremediation,being more cost-effective and fewer side effects than physical and chemical approaches,has gained increasing popularity in both academic and practical circles.More than 400 plant species have been identified to have potential for soil and water remediation.Among them,Thlaspi,Brassica,Sedum alfredii H.,and Arabidopsis species have been mostly studied.It is also expected that recent advances in biotechnology will play a promising role in the development of new hyperaccumulators by transferring metal hyperaccumulating genes from low biomass wild species to the higher biomass producing cultivated species in the times to come.This paper attempted to provide a brief review on recent progresses in research and practical applications of phytoremediation for soil and water resources.
基金The National Excellent Young Scientist Fundation of China (No .2 0 12 5 719)
文摘Soil pollution has been attracting considerable public attentions over the last decades. Sorts of traditional physiochemical methods have been used to remove the organic pollutants from soils. However, the enormous costs and low efficiencies associated with these remediation technologies limit their availabilities. Phytoremediation is an emerging technology that uses plants to cleanup pollutants in soils. As overwhelmingly positive results have been shown, phytoremediation is a most economical and effective remediation technique for organic contaminated soils. In this paper phytoremediation and its models for organic contaminated soils are viewed. The mechanisms of phytoremediation mainly include the direct plant uptake of organic pollutants, degradation by plant-derived degradative enzymes, and stimulated biodegradation in plant rhizosphere. Phytoremediation efficiency is close related to physicochemical properties of organic pollutants, environmental characteristics, and plant types. It is no doubt that soil amendments such as surfactants improve the solubilities and availabilities of organic pollutants in soils. However, little information is available about effects of soil amendments on phytoremediation efficiencies. Phytoremediation models have been developed to simulate and predict the environmental behavior of organic pollutants, and progress of models is illustrated. In many ways phytoremediation is still in its initial stage, and recommendations for the future research on phytoremediation are presented.
基金Project supported by the National Natural Science Foundation of China (No. 20577044)the National Basic Research Program (973) of China (No. 2002CB410804)the Program for Changjiang Scholars and Innovative Research Team in University (No. IRT0536), China
文摘Heavy metal pollution of soil is a significant environmental problem and has its negative impact on human health and agriculture. Rhizosphere, as an important interface of soil and plant, plays a significant role in phytoremediation of contaminated soil by heavy metals, in which, microbial populations are known to affect heavy metal mobility and availability to the plant through release of chelating agents, acidification, phosphate solubilization and redox changes, and therefore, have potential to enhance phytoremediation processes. Phytoremediation strategies with appropriate heavy metal-adapted rhizobacteria have re-ceived more and more attention. This article paper reviews some recent advances in effect and significance of rhizobacteria in phytoremediation of heavy metal contaminated soils. There is also a need to improve our understanding of the mechanisms in-volved in the transfer and mobilization of heavy metals by rhizobacteria and to conduct research on the selection of microbial isolates from rhizosphere of plants growing on heavy metal contaminated soils for specific restoration programmes.
基金the Forest Research Institute Malaysia (TGP 40300402009 and 40310304003)the ASEAN-Korea Environmental Cooperation Project (AKECOP) for financial support
文摘The potential of kenaf (Hibiscus cannabinus L.) for phytoremediation of lead (Pb) on sand tailings was investigated.A pot experiment employing factorial design with two main effects of fertilizer and lead was conducted in a nursery using sand tailings from an ex-tin mine as the growing medium.Results showed that Pb was found in the root,stem,and seed capsule of kenaf but not in the leaf.Application of organic fertilizer promoted greater biomass yield as well as higher accumulation capacity of Pb.In Pb-spike...
基金This work was supported by the National Natural Science Foundation of China under grant No.40672211.
文摘An experimental study of the rhizosphere effect on phytoremediation of petroleum polluted soil was carried out with three species of grasses, namely Pannicum, Eleusine indica （L.） Gaerth, and Tall Fescue. After a period of 150 days, this pot experiment showed that the rhizosphere of these three species accelerated the degradation of petroleum hydrocarbons to different extents. The results showed that the number of microorganisms in the rhizosphere increased by three orders of magnitude. The induction of the plant rhizosphere and the coercion influence of petroleum changed the species and activity of microorganisms. The degradation of petroleum hydrocarbons in the rhizosphere was 3-4 times that in unplanted soil. The dehydrogenase activity in the rhizosphere was 1.61-2.20 times that in unplanted soil, but the catalase activity was 0.90-0.93 times that in unplanted soil, and soil moisture content increased by 5% compared with the unplanted soil.
基金Project supported by the National Natural Science Foundation of China (Nos. 40271060 and 41025005) the National Key Basic Research Support Foundation (NKBRSF) of China (No. 2002CB410809/10).
文摘A co-culture of two plant materials, Astragalus sinicus L., a leguminous plant with concomitant nodules, and Elsholtzia splendens Naki-a Cu accumulator, along with treatments of a chelating agent (EDTA), root excretions (citric acid), and a control with E. splendens only were used to compare the mobility of heavy metals in chelating agents with a co-culture and to determine the potential for co-culture phytoremediation in heavy metal contaminated soils. The root uptake for Cu, Zn, and Pb in all treatments was significantly greater (P ＜ 0.05) than that of the control treatment. However with translocation in the shoots, only Cu, Zn, and Pb in plants grown with the EDTA treatment and Zn in plants cocropped with the A. sinicus treatment increased significantly (P ＜ 0.05). In addition, when a co-culture in soils with heavy and moderate contamination was compared, for roots in moderately contaminated soils only Zn concentration was significantly less (P ＜ 0.05) than that of heavily contaminated soils, however, Cu, Zn, and Pb concentrations of shoots were all significantly lower (P ＜ 0.05). Overall, this 'co-culture engineering' could be as effective as or even more effective than chelating agents, thereby preventing plant metal toxicity and metal leaching in soils as was usually observed in chelate-enhanced phytoremediation.
文摘Phytoremediation of soil contaminated with phenanthrene and pyrene was investigated using twelve plant species. Plant uptake and accumulation of these chemicals were evaluated. At the end of the experiment(45 d), the remaining respective concentrations of soil phenanthrene and pyrene in spiked vegetated soils, with initial phenanthrene of 133 3 mg/kg and pyrene of 171 5 mg/kg, were 8 71—16 4 and 44 9—65 0 mg/kg, generally 4 7%—49 4% and 7 1%—35 9% lower than their concentrations in the non vegetated soils. The loss of phenanthrene and pyrene in vegetated spiked soils were 88 2%—93 0% and 62 3%—73 8% of the added amounts of these contaminants, respectively. Although plant uptake and accumulation of these compounds were evident, and root concentrations and RCFs(root concentration factors; defined as the ratio of PAH concentrations in roots and in the soils on a dry weight basis) of these compounds significantly positively correlated to root lipid contents, plant uptake and accumulation only accounted for less than 0 01% and 0 23% of the enhanced loss of these chemicals in vegetated versus non vegetated soils. In contrast, plant promoted microbial biodegradation was the dominant mechanism of the phytoremediation for soil phenanthrene and pyrene contamination. Results from this study suggested a feasibility of the establishment of phytoremediation for soil PAH contamination.
基金This work was supported by the National Science Foundation for the Distinguished Young Scholar of China(No.40325003).
文摘Field investigation and greenhouse experiments were conducted to study the tolerance of Pteris vittata L. （Chinese brake） to cadmium （Cd） and its feasibility for remediating sites co-contaminated with Cd and arsenic （As）. The results showed that P. vittata could survive in pot soils spiked with 80 mg/kg of Cd and tolerated as great as 301 mg/kg of total Cd and 26.8 mg/kg of diethyltriaminepenta acetic acid （DTPA）-extractable Cd under field conditions. The highest concentration of Cd in fronds was 186 mg/kg under a total soil concentration of 920 mg As/kg and 98.6 mg Cd/kg in the field, whereas just 2.6 mg/kg under greenhouse conditions. Ecotypes of P. vittata were differentiated in tolerance and accumulation of Cd, and some of them could not only tolerate high concentrations of soil Cd, but also accumulated high concentrations of Cd in their fronds. Arsenic uptake and transportation by P. vittata was not inhibited at lower levels （〈20 mg/kg） of Cd addition. Compared to the treatment without addition of Cd, the frond As concentration was increased by 103.8% at 20 mg Cd/kg, with the highest level of 6434 mg/kg. The results suggested that the Cd-tolerant ecotype of P. vittata extracted effectively As and Cd from the site co-contaminated with Cd and As, and might be used to remediate and revegetate this type of site.
基金financially supported by the Special Fund of Shaanxi Education Department (18JK0172)the Initial Funding of Talent in Shaanxi University of Technology (SLGQD201702)
文摘Heavy metals are widely distributed contaminants in natural environments and their potential threats to human health have attracted worldwide concerns due to the food chain. Therefore, great efforts have been made to reduce them to a safe level in soil. Compared with the traditional methods, the method using plants to remove them has been accepted as a feasible and efficient way. Herein, the geochemical behavior of heavy metals and the restoration methods with phytoremediation were reviewed. In addition, issues on heavy metal speciation as well as its influencing factors, phytoremediation mechanism, phytoremediation effect and vegetation selection principle used for phytoremediation were discussed.
基金Supported by Fundamental Research Funds for the GXAAS(2015JZ292015JZ302015YT32)
文摘Phytoremediation technology is a newly-developed way of soil heavy metal pollution repair with high efficiency and good ecological comprehensive benefit. This paper briefly introduces the soil heavy metal pollution status at home and abroad,and focuses on the analysis of harm,sources and current situation of soil heavy metal pollution at home and abroad as well as mechanism and application of phytoremediation.Finally it discusses the key problems in phytoremediation technology that need to resolve in the future.
基金Project supported by the National Natural Science Foundation of China(No.40472129).
文摘Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils. Bidens is a new Pb hyperaccumulator, which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb. The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues. The Pb distribution order in the B. was： leaf 〉 stem 〉 root. The effect of amendments on phytoremediation was also studied. The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application. Compared with CK （control check）, EDTA application promoted translocation of Pb to overground parts of the plant. The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg. This research demonstrated that B. maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil, especially, combination with EDTA.
基金supported by the National Natural Science Foundation of China(No.31300520)the Science and Technology Program of Zhejiang Province(No.2014C33043)the Zhejiang Provincial Natural Science Foundation of China(No.LY12C16004)
文摘A hydroponics experiment was aimed at identifying the lead（Pb） tolerance and phytoremediation potential of Moso bamboo（Phyllostachys pubescens） seedlings grown under different Pb treatments. Experimental results indicated that at the highest Pb concentration（400 μmol/L）, the growth of bamboo seedlings was inhibited and Pb concentrations in leaves, stems, and roots reached the maximum of 148.8, 482.2, and 4282.8 mg/kg, respectively. Scanning electron microscopy revealed that the excessive Pb caused decreased stomatal opening, formation of abundant inclusions in roots, and just a few inclusions in stems. The ultrastructural analysis using transmission electron microscopy revealed that the addition of excessive Pb caused abnormally shaped chloroplasts, disappearance of endoplasmic reticulum, shrinkage of nucleus and nucleolus, and loss of thylakoid membranes. Although ultrastructural analysis revealed some internal damage, even the plants exposed to 400 μmol/L Pb survived and no visual Pb toxicity symptoms such as necrosis and chlorosis were observed in these plants. Even at the highest Pb treatment, no significant difference was observed for the dry weight of stem compared with controls. It is suggested that use of Moso bamboo as an experimental material provides a new perspective for remediation of heavy metal contaminated soil owing to its high metal tolerance and greater biomass.
基金supported by the National Key Research and Development Project of China (No. 2016YFD0800801)the National Natural Science Foundation of China (No. 41771345)the Fundamental Research Funds for the Central Universities (2019FZJD007)
文摘Sedum alfredii Hance is a cadmium(Cd)/zinc(Zn)hyperaccumulator native to China.However,its relatively low biomass restricted the large-scale application for heavy metal contamination remediation.The chromosome set doubling of S.alfredii in vitro was achieved by 0.1%–0.2%(W/V)colchicine treatment.The plant DNA ploidy was analyzed by flow cytometry and chromosome set doubling plants(CSD)were identified based on the obvious different sharp peak.A tissue culture experiment with different Cd treated levels and a field trial with natural polluted mined soil were conducted to study the effects of chromosome doubling on plant biomass and Cd accumulation in shoots.The results suggested that S.alfredii is a mixoploid.Compared with the wild type plants(WT),CSD exhibited typical"gigas"characteristics in morphology including stem thickness,root hair production,number of leaves and size of stoma guard cell.Fresh weight and dry weight of CSD were increased to 1.62–2.03-fold and 2.26–3.25-fold of WT.And Cd content of CSD showed a17.49%–42.82%increase and 59%increase under tissue culture and field condition,accordingly.In addition,the TF and in BCF of CSD were 2.37-and 1.59-fold of WT,respectively.These results proved that it is feasible to promote phytoextraction efficiency of S.alfredii in Cd contaminated soils through chromosomal engineering,which provides a novel approach for hyperaccumulator application in phytoremediation.
