The pyrolysis of phytoremediated giant reed(Arundo donax)biomass could cause secondary pollution of heavy metals.The stabilization of heavy metals in the pyrolysis process with external materials such as Al2O3,CaCO3,F...The pyrolysis of phytoremediated giant reed(Arundo donax)biomass could cause secondary pollution of heavy metals.The stabilization of heavy metals in the pyrolysis process with external materials such as Al2O3,CaCO3,FeCl3and NaOH,wasstudied.The results showed that37%As and97%Cd in biochar were stabilized when giant reed powder was pyrolyzed at250°Cwith5%Al2O3for2h.Furthermore,59%Pb in biochar was stabilized at400°C with5%CaCO3for1h.Under biochar produced inoptimized pyrolysis conditions,Cd mainly existed in a residual fraction,while Pb and As mainly existed in oxidizable fraction inBCR analysis.In XRD analysis,As was only found in Ca2As2O7;Cd in biochar mainly existed in Cd(AlCl4)2,CdPbO3or CdSO3;and Pb mainly existed as Pb3O2SO4.展开更多
Industrial activities have caused widespread arsenic(As)contamination in soil and medicinal crops across south-ern Asia.This study constructed interplanting systems combing medicinal crops with Pteris vittata L.,aimin...Industrial activities have caused widespread arsenic(As)contamination in soil and medicinal crops across south-ern Asia.This study constructed interplanting systems combing medicinal crops with Pteris vittata L.,aiming to mitigate the risk of As exposure in medicinal crops,while simultaneously achieving ecological remediation of contaminated soil.The results revealed that interplanting with P.vittata significantly enhanced the yield of Gynos-temma pentaphyllum by 31.90%(P<0.05)compared with monoculture systems.Under monoculture conditions,the As concentration in G.pentaphyllum leaves reached 2.34 mg/kg,exceeding the national food safety standard(GB2762–2017,2 mg/kg).However,interplanting with P.vittata effectively reduced the As concentration in G.pentaphyllum leaves to 1.82 mg/kg.Furthermore,the interplanting of P.vittata with Rhus chinensis significantly inhibited As translocation from belowground to aboveground tissues in R.chinensis.Compared to monoculture,the stem biomass of P.vittata was significantly increased by 57.50%and 70.32%when interplanted with G.pentaphyllum and Cassia obtusifolia L.(P<0.05).So the As enrichment of P.vittata was enhanced in interplanting systems,which is beneficial for the As removal from contaminated soil.The study demonstrated that interplant-ing primarily regulates plant As uptake through modifications of rhizosphere physicochemical properties and As bioavailability,especially for water-soluble As that is easily absorbed by plants.In conclusion,the interplant-ing models integrating medicinal crops and P.vittata can achieve the goal of“remediating while producing”in As-contaminated soil.展开更多
The surge in environmental pollution in recent years driven by numerous pollutants has necessitated the search for efficient removal methods.Phytoremediation is an eco-friendly technique that provides multiple benefit...The surge in environmental pollution in recent years driven by numerous pollutants has necessitated the search for efficient removal methods.Phytoremediation is an eco-friendly technique that provides multiple benefits over conventional methods of removing contaminants.Despite the numerous benefits of this technique,it has certain limitations that can be addressed by incorporating nanoparticles to improve its effectiveness.This review paper aims to explore the impact of heavy metal pollution on plants and human health.It highlights the role and mechanism of nanoparticles in enhancing phytoremediation,their application in the detection of heavy metals,and the strategies for the safe disposal of phytoremediation biomass.Biosynthesized nanoparticles are eco-friendly and non-toxic,with applications in biomedical and environmental fields.Nanoparticles can be used in the form of nano biosensors like smartphone-operated wireless sensors made from Cinnamomum camphora,enabling efficient detection of heavy metal ions.According to the studies,nanoparticles remove 80%–97%of heavy metals by various methods like reduction,precipitation,adsorption,etc.The phytoremediation biomass disposal can be done by heat treatment,phytomining,and microbial treatment with some modifications to further enhance their results.Phytoremediation is an environmentally friendly technique but requires further research and integration with biomass energy production to overcome scalability challenges and ensure safe biomass disposal.展开更多
Pollution accident of nonferrous metallurgy industry often lead to serious heavy metal pollution of the surrounding soil.Phytoremediation of contaminated soil is an environmental and sustainable technology,and soil na...Pollution accident of nonferrous metallurgy industry often lead to serious heavy metal pollution of the surrounding soil.Phytoremediation of contaminated soil is an environmental and sustainable technology,and soil native microorganisms in the process of phytoremediation also participate in the remediation of heavy metals.However,the effects of high concentrations of multiple heavy metals(HCMHMs)on plants and native soil microorganisms remain uncertain.Thus,further clarification of themechanism of phytoremediation of HCMHMs soil by plants and native soil microorganisms is required.Using the plant Sedum alfredii(S.alfredii)to restore HCMHM-contaminated soil,we further explored the mechanism of S.alfredii and native soil microorganisms in the remediation of HCMHM soils.The results showed that(i)S.alfredii can promote heavy metals from non-rhizosphere soil to rhizosphere soil,which is conducive to the effect of plants on heavy metals.In addition,it can also enrich the absorbed heavy metals in its roots and leaves;(ii)native soil bacteria can increase the abundance of signal molecule-synthesizing enzymes,such as trpE,trpG,bjaI,rpfF,ACSL,and yidC,and promote the expression of the pathway that converts serine to cysteine,then synthesize substances to chelate heavy metals.In addition,we speculated that genes such as K19703,K07891,K09711,K19703,K07891,and K09711 in native bacteria may be involved in the stabilization or absorption of heavy metals.The results provide scientific basis for S.alfredii to remediate heavy metals contaminated soils,and confirm the potential of phytoremediation of HCMHM contaminated soil.展开更多
Enhancing soil organic matter characteristics,ameliorating physical structure,mitigating heavy metal toxicity,and hastening mineral weathering processes are crucial approaches to accomplish the transition of tailings ...Enhancing soil organic matter characteristics,ameliorating physical structure,mitigating heavy metal toxicity,and hastening mineral weathering processes are crucial approaches to accomplish the transition of tailings substrate to a soil-like substrate.The incorporation of biomass co-pyrolysis and plant colonization has been established to be a significant factor in soil substrate formation and soil pollutant remediation.Despite this,there is presently an absence of research efforts aimed at synergistically utilizing these two technologies to expedite the process of mining tailings soil substrate formation.The current study aimed to investigate the underlying mechanism of geochemical changes and rapid mineral weathering during the process of transforming tailings substrate into a soil-like substrate,under the combined effects of biomass co-smoldering pyrolysis and plant colonization.The findings of this study suggest that the incorporation of smoldering pyrolysis and plant colonization induces a high-temperature effect and biological effects,which enhance the physical and chemical properties of tailings,while simultaneously accelerating the rate of mineral weathering.Notable improvements include the amelioration of extreme pH levels,nutrient enrichment,the formation of aggregates,and an increase in enzyme activity,all of which collectively demonstrate the successful attainment of tailings substrate reconstruction.Evidence of the acceleratedweathering was verified by phase and surfacemorphology analysis using X-ray diffraction and scanning electron microscopy.Discovered corrosion and fragmentation on the surface ofminerals.The weathering resulted in corrosion and fragmentation of the surface of the treated mineral.This study confirms that co-smoldering pyrolysis of biomass,combined with plant colonization,can effectively promote the transformation of tailings into soil-like substrates.This method has can effectively address the key challenges that have previously hindered sustainable development of the mining industry and provides a novel approach for ecological restoration of tailings deposits.展开更多
Several studies have demonstrated that reintroducing crop straw to fields may intensify cadmium(Cd)contamination in agricultural soils.However,the specific effects of long-term straw management practices on Cd concent...Several studies have demonstrated that reintroducing crop straw to fields may intensify cadmium(Cd)contamination in agricultural soils.However,the specific effects of long-term straw management practices on Cd concentration and its bioavailability in soil-rice ecosystems remain unclear.In this context,to explore the influence of straw return(SR)and straw removal(NSR)on Cd accumulation in both soil and rice within a double-cropping system,we conducted a four-year field study.Our research study unveiled that NSR consistently decreased soil Cd concentration and its bioavailability by approximately 16.93%–27.30%and 8.23%–21.05%respectively across both study sites.Conversely,SR resulted in a substantial increase in soil Cd bioavailability,ranging from 38.64%–53.95%.Notably,compared to NSR,SR significantly increased total soil Cd by 5.47%–36.58%and increased Cd content in brown rice by 8.00%–100.24%.Remarkably,after four consecutive years of NSR,brown rice Cd concentration at the Changfeng site compiled with national safety standards(GB 2762–2022).Additionally,returning early rice strawsignificantly raised soil Cd bioavailability for the subsequent crop,more so than late rice straw did for the early rice the following year.The findings suggest that traditional double-cropping cultivation with straw removal can effectively mitigate Cd contamination risks in crops and farmland in Hunan Province.展开更多
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
Cadmium(Cd)or excess copper(Cu)has a great impact in terms of toxicity on living organisms as it severely affects crop growth,yield and food security;thus,warranting appropriate measures for the remediation of Cd or C...Cadmium(Cd)or excess copper(Cu)has a great impact in terms of toxicity on living organisms as it severely affects crop growth,yield and food security;thus,warranting appropriate measures for the remediation of Cd or Cu polluted soils.Phytoextraction of heavy metal(HM)using tolerant plants along with organic chelators has gained global attention,and this study provided further insights into this issue.Pot experiments were performed to evaluate the effects of different types of chelators[ethylenediamine tetraacetic acid(EDTA),ethylenediamine disuccinic acid(EDDS)and citric acid(CA)]to improve the phytoextraction capacity of Ricinus communis L.for the metals Cd and Cu.Contaminated soil from a copper smelter was used in this study.A rhizon soil sampler was used to determine the metal concentrations in soil pore water.The results indicated that R.communis was an adequate candidate for chelator induced phytoextraction under the experimental conditions and that EDDS would be a good candidate chelator for the phytoextraction of Cu in soils.EDTA addition obviously improved the uptake of Cd and Cu in R.communis;however,it posed the greatest risk because the concentration of HMs in soil pore water was very high even after 40 days.Compared with EDTA and EDDS,CA had few effects on Cd or Cu uptake in R.communis.Linear relationships between the metal uptake in R.communis shoots and the maximum HM concentrations in soil pore water under HM,2.5,5,and 10 mmol·kg^(-1) treatments were typically observed.From the results of this study,it could be concluded that EDDS treatments played a promising role in increasing the uptake of Cd or Cu and reducing its phytotoxicity.EDDS application could be an effective approach for the phytoextraction of Cd or Cu from polluted soils by growing Ricinus communis L.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
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
Microbe-assisted phytoremediation is of great significance for the remediation of soil contaminated with heavy metals(HMs),and probiotics are beneficial microorganisms that can improve soil structure and fertility and...Microbe-assisted phytoremediation is of great significance for the remediation of soil contaminated with heavy metals(HMs),and probiotics are beneficial microorganisms that can improve soil structure and fertility and promote plant growth.However,there are few studies on probiotics applied to remediate soil contaminated with HMs,and whether probiotics can improve the efficiency of phytoremediation still needs to be further investigated.This study aimed to investigate the effects of two kinds of probiotics,Lactobacillus casei(Lc)and Bacillus licheniformis(Bl),on activating the remediation potential of leaf mustard,Brassica juncea(L.)Czerniak.,for soil contaminated with Cd and Zn using incubation and pot experiments.The results showed that the addition of the two probiotics significantly reduced soil pH by 0.05–0.32 units and improved the available contents of soil HMs(by 15.3%–60.0%and 7.1%–23.8%for Cd and Zn,respectively)in the incubation experiment.After probiotic addition,available Cd and Zn contents in soil treated with 1×10^(9) colony forming units(cfu)mL^(-1) Bl were 1.65-and 1.66-folds of those in the control without probiotic,respectively,in the pot experiment.Meanwhile,soil alkaline phosphatase,urease,and sucrose activities were increased,indicating that soil microbial metabolic activities were also stimulated.Addition of Lc and Bl significantly improved the biomass and chlorophyll contents of leaf mustard.The contents of Cd and Zn in shoots and roots were significantly increased in the treatment with 1×10^(5) cfu mL^(-1) Lc.Furthermore,the activities of plant antioxidant enzymes,including superoxide dismutase,peroxidase,and catalase,were increased,and the content of plant malondialdehyde was reduced,indicating that the resistance of plants to HMs was enhanced.These results indicated that these two kinds of probiotics could enhance the availability of Cd and Zn directly in soil and promote the growth of leaf mustard,thereby increasing the efficiency of phytoremediation for HMs.The study provides a useful reference for probiotic-assisted phytoremediation of soil contaminated with HMs.展开更多
Wetland plants and their related environmental interfaces are colonized by a wide range of microbial communities,and the symbiotic system of plants and microorganisms can interact and cooperate with each other,playing...Wetland plants and their related environmental interfaces are colonized by a wide range of microbial communities,and the symbiotic system of plants and microorganisms can interact and cooperate with each other,playing an important role in environmental remediation of metal pollution,which has garnered significant attention.The dominant communities of wetland plants still have high treatment performance and survival rate under pollution conditions.Many studies show that hyperaccumulating metallophytes have the capacity to accumulate heavy metal up to several times higher than the plants in sterile soil,due to the interaction of microbes within the rhizosphere.Thus,biotechnological efforts are being explored to modify plants for heavy metal phytoremediation and to improve the adaptation of wetland plants,endophytes,and rhizospheric microorganisms to adverse environment.New phytoremediation techniques and enhanced symbiosis technique for endophytic bacteria inoculation with high efficiency are being pursued and utilized in heavy metal phytoremediation in wetland systems.Therefore,in this review,we systematically summarized the interface characteristics of wetland systems and the interaction of symbionts,with emphasis on the enhanced removal potential and regulation mechanisms of heavy metals by plant-microbe symbiosis in wetland systems,along with the applications of plant-microbiomes for heavy metal remediation in wetlands.Moreover,we explored the remediation mechanisms of combined endogenic-ecophytic microorganisms for wetland systems.In recent research,the exogeneous bacteria drastically remodeled the rhizospheric microbiome and further improved the activity of rhizospheric functional enzymes,with the metal removal at the rhizospheric region reaching up to 95%.In order to increase the effectiveness of plant-microbiome engineering in addressing wetland environmental pollution,the significance of incorporating synergistic techniques and taking a variety of environmental factors was discussed.展开更多
Phyllosphere microbiome plays an irreplaceable role in maintaining plant health under stress,but its structure and functions in heavy metal-hyperaccumulating plants remain elusive.Here,the phyllosphere microbiome,inha...Phyllosphere microbiome plays an irreplaceable role in maintaining plant health under stress,but its structure and functions in heavy metal-hyperaccumulating plants remain elusive.Here,the phyllosphere microbiome,inhabiting hyperaccumulating(HE)and non-hyperaccumulating ecotype(NHE)of Sedum alfredii grown in soils with varying heavy metal concentration,was characterized.Compared with NHE,the microbial communityα-diversity was greater in HE.Core phyllosphere taxa with high relative abundance(>10%),including Streptomyces and Nocardia(bacteria),Cladosporium and Acremonium(fungi),were significantly related to cadmium(Cd)and zinc(Zn)concentration and biomass of host plants.Moreover,microbial co-occurrence networks in HE exhibited greater complexity than those in NHE.Additionally,proportions of positive associations in HE bacterial networks increased with the rising heavy metal concentration,indicating a higher resistance of HE phyllosphere microbiome to heavy metal stress.Furthermore,in contrast to NHE,microbial community functions,primarily involved in heavy metal stress resistance,were more abundant in HE,in which microbiome assisted hosts to resist heavy metal stress better.Collectively,this study indicated that phyllosphere microbiome of the hyperaccumulator played an indispensable role in assisting hosts to resist heavy metal stress,and provided new insights into phyllosphere microbial application potential in phytoremediation.展开更多
The increasing challenges of environmental degradation,soil erosion,and climate change have driven interest in sustainable solutions like enhanced weathering(EW)and phytoremediation.Elephant Grass(Cenchrus purpureus),...The increasing challenges of environmental degradation,soil erosion,and climate change have driven interest in sustainable solutions like enhanced weathering(EW)and phytoremediation.Elephant Grass(Cenchrus purpureus),a fast-growing perennial species,shows promise as a bioaccumulator and agent for soil weathering.This study assessed the potential of C.purpureus to improve soil quality through heavy metal(HM)uptake and EW facilitation.A 60-day greenhouse pot experiment at Jackson State University evaluated plant performance in soils amended with metabasalt rock powder at 1:1 and 2:1 rock-to-soil ratios.Biomass,growth,and HM concentrations in roots and shoots were measured via ICP-MS after wet digestion.Soil pH and magnesium(Mg)release were also monitored to assess weathering and carbon drawdown.Results showed that C.purpureus accumulated more HMs in roots at higher amendment levels,while at lower levels,metals like As,Cd,and Cr were more translocated to shoots,enhancing phytoextraction potential.High treatment favored Fe and Al uptake,possibly reducing toxic metal accumulation in edible parts.Notably,C.purpureus contributed to the weathering of 38%of metabasalt rock,leading to a 42%increase in Mg release.With high biomass,HM tolerance,and weathering capacity,C.purpureus offers a sustainable strategy for soil remediation,improved soil health,and potential support for renewable energy systems.展开更多
The low efficiency of phytoextraction of lead(Pb)from agricultural fields poses a significant agricultural challenge.Organic chelating agents can influence Pb bioavailability in soil,affecting its uptake,transport,and...The low efficiency of phytoextraction of lead(Pb)from agricultural fields poses a significant agricultural challenge.Organic chelating agents can influence Pb bioavailability in soil,affecting its uptake,transport,and toxicity in plants.This study aimed to assess the impact of citric acid(CA)and diethylenetriaminepentaacetic acid(DTPA)on chelate-assisted phytoextraction of Pb and its effect on growth and physiology of two cultivars(07001;07002)of mung bean(Vigna radiata).The cultivars of mung bean were exposed to 60 lead chloride(PbCl_(2))solution,mg⋅L-1with or without the addition of 300 CA or 500 DTPA,until maturity.The exposure of plants to Pb mg⋅L^(-1) mg⋅L^(-1) stress increased the accumulation of Pb in roots(49%of control),stems(58%of control),leaves(67%of control),and seeds(61%of control).Maximum accumulation of Pb was observed in roots and the least accumulation was found in seeds of both mung bean cultivars.The extent of Pb accumulation in different plant parts correlated positively with Pb toxicity and reduced growth of both mung bean cultivars(33%to 40%).The cultivar cv 07001 was more susceptible to Pb stress.The addition of CA and DTPA increased the accumulation of Pb in plant parts of mung bean cultivars-phytoextraction(10.8%to 21.5%).However,the addition of CA partitioned Pb in vegetative parts,i.e.,root,stem thus mitigated the toxic effects of Pb on the growth of mung bean cultivars(6.25%–10.5%).In contrast,the addition of DTPA had adverse effects on the growth of mung bean cultivars.The addition of CA facilitated a greater uptake and accumulation of nitrogen,phosphorous,and potassium in the roots and leaves of mung bean cultivars.In addition,CA also improved the photosynthetic pigments(11%–14%)and photosynthetic rate(5%–12%)under both control and Pb stress conditions.The ameliorative effect of CA on the photosynthetic capacity of mung bean cultivars was likely associated with photosynthetic metabolic factors rather than stomatal factors.Furthermore,cv 07002 was found to be more tolerant to Pb stress and showed better performance in CA application.Overall,the application of CA demonstrated significant potential as a chelating agent for remediating Pb-contaminated soil.展开更多
Three bacterial endophytes of Sedum alfredii, VI8L2, II8L4 and VI8R2, were examined for promoting soil Zn bioavailability and Zn accumulation in S. alfredii. Results showed that three strains were re-introduced into S...Three bacterial endophytes of Sedum alfredii, VI8L2, II8L4 and VI8R2, were examined for promoting soil Zn bioavailability and Zn accumulation in S. alfredii. Results showed that three strains were re-introduced into S. alfredii rhizosphere soils under Zn stress and resulted in better plant growth, as roots biomass increased from 80% to 525% and shoot biomass from 11% to 47% compared with the uninoculated ones. Strains IVsLz, II8L4 and IVsR2 significantly increased shoot and root Zn concentrations in the ZnCO3 contaminated soil. Inoculation with strain IVsL2 resulted in 44% and 39% higher shoot and root Zn concentrations, while strain IV8R2 significantly decreased shoot Zn concentration in the Zn3（PO4）2 contaminated soils. In the aged contaminated soil, isolates IVsL2, IIsL4 and IVsR2 significantly increased root Zn concentration, but decreased shoot Zn concentration of Sedum alfredii. It suggested that endophytes might be used for enhancing phytoextraction efficiency.展开更多
The effects of five amendments such as acetic acid（AA）, citric acid （CA）, ethylenediamine tetraacetic acid （EDTA）, sepiolite and phosphogypsum on growth and metal uptake of giant reed （Arundo donax L.） grown o...The effects of five amendments such as acetic acid（AA）, citric acid （CA）, ethylenediamine tetraacetic acid （EDTA）, sepiolite and phosphogypsum on growth and metal uptake of giant reed （Arundo donax L.） grown on soil contaminated by arsenic （As）, cadmium （Cd） and lead （Pb） were studied. The results showed that the shoot biomass of giant reed was enhanced by 24.8% and 15.0%, while superoxide mutase and catalase activities slightly varied when adding 5.0 mmol/kg CA and 2.5 mol/kg EDTA to soil as compared to the control, respectively. The concentrations of As, Cd and Pb in shoots were remarkably increased by the addition of 2.5 mmol/kg AA and CA, 5.0 mmol/kg EDTA, and 4.0 g/kg sepiolite as compared to the control. The accumulations of As and Cd were also significantly enhanced in the above condition, while the shoot Pb accumulation was noticeably enhanced by amending with 4.0 g/kg sepiolite and 8.0 g/kg phosphogysum, respectively. The results suggested that AA, CA and sepiolite could be used as optimum soil amendments for giant reed remediation system.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
基金Projects(21577176,41271330) supported by the National Natural Science Foundation of China
文摘The pyrolysis of phytoremediated giant reed(Arundo donax)biomass could cause secondary pollution of heavy metals.The stabilization of heavy metals in the pyrolysis process with external materials such as Al2O3,CaCO3,FeCl3and NaOH,wasstudied.The results showed that37%As and97%Cd in biochar were stabilized when giant reed powder was pyrolyzed at250°Cwith5%Al2O3for2h.Furthermore,59%Pb in biochar was stabilized at400°C with5%CaCO3for1h.Under biochar produced inoptimized pyrolysis conditions,Cd mainly existed in a residual fraction,while Pb and As mainly existed in oxidizable fraction inBCR analysis.In XRD analysis,As was only found in Ca2As2O7;Cd in biochar mainly existed in Cd(AlCl4)2,CdPbO3or CdSO3;and Pb mainly existed as Pb3O2SO4.
基金supported by the National Key Research and Development Program of China(No.2020YFC1807805)the Science and Technology Planning Project of Guangzhou,Guangdong Province,China(No.202206010176).
文摘Industrial activities have caused widespread arsenic(As)contamination in soil and medicinal crops across south-ern Asia.This study constructed interplanting systems combing medicinal crops with Pteris vittata L.,aiming to mitigate the risk of As exposure in medicinal crops,while simultaneously achieving ecological remediation of contaminated soil.The results revealed that interplanting with P.vittata significantly enhanced the yield of Gynos-temma pentaphyllum by 31.90%(P<0.05)compared with monoculture systems.Under monoculture conditions,the As concentration in G.pentaphyllum leaves reached 2.34 mg/kg,exceeding the national food safety standard(GB2762–2017,2 mg/kg).However,interplanting with P.vittata effectively reduced the As concentration in G.pentaphyllum leaves to 1.82 mg/kg.Furthermore,the interplanting of P.vittata with Rhus chinensis significantly inhibited As translocation from belowground to aboveground tissues in R.chinensis.Compared to monoculture,the stem biomass of P.vittata was significantly increased by 57.50%and 70.32%when interplanted with G.pentaphyllum and Cassia obtusifolia L.(P<0.05).So the As enrichment of P.vittata was enhanced in interplanting systems,which is beneficial for the As removal from contaminated soil.The study demonstrated that interplant-ing primarily regulates plant As uptake through modifications of rhizosphere physicochemical properties and As bioavailability,especially for water-soluble As that is easily absorbed by plants.In conclusion,the interplant-ing models integrating medicinal crops and P.vittata can achieve the goal of“remediating while producing”in As-contaminated soil.
文摘The surge in environmental pollution in recent years driven by numerous pollutants has necessitated the search for efficient removal methods.Phytoremediation is an eco-friendly technique that provides multiple benefits over conventional methods of removing contaminants.Despite the numerous benefits of this technique,it has certain limitations that can be addressed by incorporating nanoparticles to improve its effectiveness.This review paper aims to explore the impact of heavy metal pollution on plants and human health.It highlights the role and mechanism of nanoparticles in enhancing phytoremediation,their application in the detection of heavy metals,and the strategies for the safe disposal of phytoremediation biomass.Biosynthesized nanoparticles are eco-friendly and non-toxic,with applications in biomedical and environmental fields.Nanoparticles can be used in the form of nano biosensors like smartphone-operated wireless sensors made from Cinnamomum camphora,enabling efficient detection of heavy metal ions.According to the studies,nanoparticles remove 80%–97%of heavy metals by various methods like reduction,precipitation,adsorption,etc.The phytoremediation biomass disposal can be done by heat treatment,phytomining,and microbial treatment with some modifications to further enhance their results.Phytoremediation is an environmentally friendly technique but requires further research and integration with biomass energy production to overcome scalability challenges and ensure safe biomass disposal.
基金supported by the Fundamental Research Funds for Central PublicWelfare Scientific Research Institutes of China(No.2021-JY-37)the Yellow River Basin Ecological Protection and High-quality Development Joint Study(Phase I)(No.2022-YRUC-01-0202).
文摘Pollution accident of nonferrous metallurgy industry often lead to serious heavy metal pollution of the surrounding soil.Phytoremediation of contaminated soil is an environmental and sustainable technology,and soil native microorganisms in the process of phytoremediation also participate in the remediation of heavy metals.However,the effects of high concentrations of multiple heavy metals(HCMHMs)on plants and native soil microorganisms remain uncertain.Thus,further clarification of themechanism of phytoremediation of HCMHMs soil by plants and native soil microorganisms is required.Using the plant Sedum alfredii(S.alfredii)to restore HCMHM-contaminated soil,we further explored the mechanism of S.alfredii and native soil microorganisms in the remediation of HCMHM soils.The results showed that(i)S.alfredii can promote heavy metals from non-rhizosphere soil to rhizosphere soil,which is conducive to the effect of plants on heavy metals.In addition,it can also enrich the absorbed heavy metals in its roots and leaves;(ii)native soil bacteria can increase the abundance of signal molecule-synthesizing enzymes,such as trpE,trpG,bjaI,rpfF,ACSL,and yidC,and promote the expression of the pathway that converts serine to cysteine,then synthesize substances to chelate heavy metals.In addition,we speculated that genes such as K19703,K07891,K09711,K19703,K07891,and K09711 in native bacteria may be involved in the stabilization or absorption of heavy metals.The results provide scientific basis for S.alfredii to remediate heavy metals contaminated soils,and confirm the potential of phytoremediation of HCMHM contaminated soil.
基金supported by the National Natural Science Foundation of China(No.52060011).
文摘Enhancing soil organic matter characteristics,ameliorating physical structure,mitigating heavy metal toxicity,and hastening mineral weathering processes are crucial approaches to accomplish the transition of tailings substrate to a soil-like substrate.The incorporation of biomass co-pyrolysis and plant colonization has been established to be a significant factor in soil substrate formation and soil pollutant remediation.Despite this,there is presently an absence of research efforts aimed at synergistically utilizing these two technologies to expedite the process of mining tailings soil substrate formation.The current study aimed to investigate the underlying mechanism of geochemical changes and rapid mineral weathering during the process of transforming tailings substrate into a soil-like substrate,under the combined effects of biomass co-smoldering pyrolysis and plant colonization.The findings of this study suggest that the incorporation of smoldering pyrolysis and plant colonization induces a high-temperature effect and biological effects,which enhance the physical and chemical properties of tailings,while simultaneously accelerating the rate of mineral weathering.Notable improvements include the amelioration of extreme pH levels,nutrient enrichment,the formation of aggregates,and an increase in enzyme activity,all of which collectively demonstrate the successful attainment of tailings substrate reconstruction.Evidence of the acceleratedweathering was verified by phase and surfacemorphology analysis using X-ray diffraction and scanning electron microscopy.Discovered corrosion and fragmentation on the surface ofminerals.The weathering resulted in corrosion and fragmentation of the surface of the treated mineral.This study confirms that co-smoldering pyrolysis of biomass,combined with plant colonization,can effectively promote the transformation of tailings into soil-like substrates.This method has can effectively address the key challenges that have previously hindered sustainable development of the mining industry and provides a novel approach for ecological restoration of tailings deposits.
基金supported by the National Natural Science Foundation of China(No.U20A20108)the National Key Research and Development Program of China(No.2022YFD1700102)the Key Research and Development Program of Hunan Province(No.2022NK2014).
文摘Several studies have demonstrated that reintroducing crop straw to fields may intensify cadmium(Cd)contamination in agricultural soils.However,the specific effects of long-term straw management practices on Cd concentration and its bioavailability in soil-rice ecosystems remain unclear.In this context,to explore the influence of straw return(SR)and straw removal(NSR)on Cd accumulation in both soil and rice within a double-cropping system,we conducted a four-year field study.Our research study unveiled that NSR consistently decreased soil Cd concentration and its bioavailability by approximately 16.93%–27.30%and 8.23%–21.05%respectively across both study sites.Conversely,SR resulted in a substantial increase in soil Cd bioavailability,ranging from 38.64%–53.95%.Notably,compared to NSR,SR significantly increased total soil Cd by 5.47%–36.58%and increased Cd content in brown rice by 8.00%–100.24%.Remarkably,after four consecutive years of NSR,brown rice Cd concentration at the Changfeng site compiled with national safety standards(GB 2762–2022).Additionally,returning early rice strawsignificantly raised soil Cd bioavailability for the subsequent crop,more so than late rice straw did for the early rice the following year.The findings suggest that traditional double-cropping cultivation with straw removal can effectively mitigate Cd contamination risks in crops and farmland in Hunan Province.
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 Joint Funds of the National Natural Science Foundation of China(U2340219)。
文摘Cadmium(Cd)or excess copper(Cu)has a great impact in terms of toxicity on living organisms as it severely affects crop growth,yield and food security;thus,warranting appropriate measures for the remediation of Cd or Cu polluted soils.Phytoextraction of heavy metal(HM)using tolerant plants along with organic chelators has gained global attention,and this study provided further insights into this issue.Pot experiments were performed to evaluate the effects of different types of chelators[ethylenediamine tetraacetic acid(EDTA),ethylenediamine disuccinic acid(EDDS)and citric acid(CA)]to improve the phytoextraction capacity of Ricinus communis L.for the metals Cd and Cu.Contaminated soil from a copper smelter was used in this study.A rhizon soil sampler was used to determine the metal concentrations in soil pore water.The results indicated that R.communis was an adequate candidate for chelator induced phytoextraction under the experimental conditions and that EDDS would be a good candidate chelator for the phytoextraction of Cu in soils.EDTA addition obviously improved the uptake of Cd and Cu in R.communis;however,it posed the greatest risk because the concentration of HMs in soil pore water was very high even after 40 days.Compared with EDTA and EDDS,CA had few effects on Cd or Cu uptake in R.communis.Linear relationships between the metal uptake in R.communis shoots and the maximum HM concentrations in soil pore water under HM,2.5,5,and 10 mmol·kg^(-1) treatments were typically observed.From the results of this study,it could be concluded that EDDS treatments played a promising role in increasing the uptake of Cd or Cu and reducing its phytotoxicity.EDDS application could be an effective approach for the phytoextraction of Cd or Cu from polluted soils by growing Ricinus communis L.
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.
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.
基金supported by the Science and Technology Overall Innovation Project of Shaanxi Province,China(No.2016 KTCQ03-20)the Scientific Research Foundation Project of Quzhou University,China(No.KYQD006224002).
文摘Microbe-assisted phytoremediation is of great significance for the remediation of soil contaminated with heavy metals(HMs),and probiotics are beneficial microorganisms that can improve soil structure and fertility and promote plant growth.However,there are few studies on probiotics applied to remediate soil contaminated with HMs,and whether probiotics can improve the efficiency of phytoremediation still needs to be further investigated.This study aimed to investigate the effects of two kinds of probiotics,Lactobacillus casei(Lc)and Bacillus licheniformis(Bl),on activating the remediation potential of leaf mustard,Brassica juncea(L.)Czerniak.,for soil contaminated with Cd and Zn using incubation and pot experiments.The results showed that the addition of the two probiotics significantly reduced soil pH by 0.05–0.32 units and improved the available contents of soil HMs(by 15.3%–60.0%and 7.1%–23.8%for Cd and Zn,respectively)in the incubation experiment.After probiotic addition,available Cd and Zn contents in soil treated with 1×10^(9) colony forming units(cfu)mL^(-1) Bl were 1.65-and 1.66-folds of those in the control without probiotic,respectively,in the pot experiment.Meanwhile,soil alkaline phosphatase,urease,and sucrose activities were increased,indicating that soil microbial metabolic activities were also stimulated.Addition of Lc and Bl significantly improved the biomass and chlorophyll contents of leaf mustard.The contents of Cd and Zn in shoots and roots were significantly increased in the treatment with 1×10^(5) cfu mL^(-1) Lc.Furthermore,the activities of plant antioxidant enzymes,including superoxide dismutase,peroxidase,and catalase,were increased,and the content of plant malondialdehyde was reduced,indicating that the resistance of plants to HMs was enhanced.These results indicated that these two kinds of probiotics could enhance the availability of Cd and Zn directly in soil and promote the growth of leaf mustard,thereby increasing the efficiency of phytoremediation for HMs.The study provides a useful reference for probiotic-assisted phytoremediation of soil contaminated with HMs.
基金financially supported by the Natural Science Foundation of Hebei Province for Youth,China(No.D2021201003)the Key Research and Development(R&D)Project of Hebei Province,China(No.21373601D)+3 种基金the Science and Technology Planning Project of Shijiazhuang,China(No.221240223A)the Natural Science Interdisciplinary Research Program of Hebei University,China(No.DXK202106)the Hebei Provincial 3-3-3 Talent Project,China(No.A202101120)the Collaborative Innovation Center for Baiyangdian Basin Ecological Protection and Beijing-Tianjin-Hebei Sustainable Development,China。
文摘Wetland plants and their related environmental interfaces are colonized by a wide range of microbial communities,and the symbiotic system of plants and microorganisms can interact and cooperate with each other,playing an important role in environmental remediation of metal pollution,which has garnered significant attention.The dominant communities of wetland plants still have high treatment performance and survival rate under pollution conditions.Many studies show that hyperaccumulating metallophytes have the capacity to accumulate heavy metal up to several times higher than the plants in sterile soil,due to the interaction of microbes within the rhizosphere.Thus,biotechnological efforts are being explored to modify plants for heavy metal phytoremediation and to improve the adaptation of wetland plants,endophytes,and rhizospheric microorganisms to adverse environment.New phytoremediation techniques and enhanced symbiosis technique for endophytic bacteria inoculation with high efficiency are being pursued and utilized in heavy metal phytoremediation in wetland systems.Therefore,in this review,we systematically summarized the interface characteristics of wetland systems and the interaction of symbionts,with emphasis on the enhanced removal potential and regulation mechanisms of heavy metals by plant-microbe symbiosis in wetland systems,along with the applications of plant-microbiomes for heavy metal remediation in wetlands.Moreover,we explored the remediation mechanisms of combined endogenic-ecophytic microorganisms for wetland systems.In recent research,the exogeneous bacteria drastically remodeled the rhizospheric microbiome and further improved the activity of rhizospheric functional enzymes,with the metal removal at the rhizospheric region reaching up to 95%.In order to increase the effectiveness of plant-microbiome engineering in addressing wetland environmental pollution,the significance of incorporating synergistic techniques and taking a variety of environmental factors was discussed.
基金supported by the National Natural Science Foundation of China(Nos.42177008,and 42377005)the fellowship of China Postdoctoral Science Foundation(No.2022M712770)the Fundamental Research Funds for the Central Universities.
文摘Phyllosphere microbiome plays an irreplaceable role in maintaining plant health under stress,but its structure and functions in heavy metal-hyperaccumulating plants remain elusive.Here,the phyllosphere microbiome,inhabiting hyperaccumulating(HE)and non-hyperaccumulating ecotype(NHE)of Sedum alfredii grown in soils with varying heavy metal concentration,was characterized.Compared with NHE,the microbial communityα-diversity was greater in HE.Core phyllosphere taxa with high relative abundance(>10%),including Streptomyces and Nocardia(bacteria),Cladosporium and Acremonium(fungi),were significantly related to cadmium(Cd)and zinc(Zn)concentration and biomass of host plants.Moreover,microbial co-occurrence networks in HE exhibited greater complexity than those in NHE.Additionally,proportions of positive associations in HE bacterial networks increased with the rising heavy metal concentration,indicating a higher resistance of HE phyllosphere microbiome to heavy metal stress.Furthermore,in contrast to NHE,microbial community functions,primarily involved in heavy metal stress resistance,were more abundant in HE,in which microbiome assisted hosts to resist heavy metal stress better.Collectively,this study indicated that phyllosphere microbiome of the hyperaccumulator played an indispensable role in assisting hosts to resist heavy metal stress,and provided new insights into phyllosphere microbial application potential in phytoremediation.
文摘The increasing challenges of environmental degradation,soil erosion,and climate change have driven interest in sustainable solutions like enhanced weathering(EW)and phytoremediation.Elephant Grass(Cenchrus purpureus),a fast-growing perennial species,shows promise as a bioaccumulator and agent for soil weathering.This study assessed the potential of C.purpureus to improve soil quality through heavy metal(HM)uptake and EW facilitation.A 60-day greenhouse pot experiment at Jackson State University evaluated plant performance in soils amended with metabasalt rock powder at 1:1 and 2:1 rock-to-soil ratios.Biomass,growth,and HM concentrations in roots and shoots were measured via ICP-MS after wet digestion.Soil pH and magnesium(Mg)release were also monitored to assess weathering and carbon drawdown.Results showed that C.purpureus accumulated more HMs in roots at higher amendment levels,while at lower levels,metals like As,Cd,and Cr were more translocated to shoots,enhancing phytoextraction potential.High treatment favored Fe and Al uptake,possibly reducing toxic metal accumulation in edible parts.Notably,C.purpureus contributed to the weathering of 38%of metabasalt rock,leading to a 42%increase in Mg release.With high biomass,HM tolerance,and weathering capacity,C.purpureus offers a sustainable strategy for soil remediation,improved soil health,and potential support for renewable energy systems.
基金funding from the Ongoing Research Funding program,ORF-2025-298,King Saud University,Riyadh,Saudi Arabia.
文摘The low efficiency of phytoextraction of lead(Pb)from agricultural fields poses a significant agricultural challenge.Organic chelating agents can influence Pb bioavailability in soil,affecting its uptake,transport,and toxicity in plants.This study aimed to assess the impact of citric acid(CA)and diethylenetriaminepentaacetic acid(DTPA)on chelate-assisted phytoextraction of Pb and its effect on growth and physiology of two cultivars(07001;07002)of mung bean(Vigna radiata).The cultivars of mung bean were exposed to 60 lead chloride(PbCl_(2))solution,mg⋅L-1with or without the addition of 300 CA or 500 DTPA,until maturity.The exposure of plants to Pb mg⋅L^(-1) mg⋅L^(-1) stress increased the accumulation of Pb in roots(49%of control),stems(58%of control),leaves(67%of control),and seeds(61%of control).Maximum accumulation of Pb was observed in roots and the least accumulation was found in seeds of both mung bean cultivars.The extent of Pb accumulation in different plant parts correlated positively with Pb toxicity and reduced growth of both mung bean cultivars(33%to 40%).The cultivar cv 07001 was more susceptible to Pb stress.The addition of CA and DTPA increased the accumulation of Pb in plant parts of mung bean cultivars-phytoextraction(10.8%to 21.5%).However,the addition of CA partitioned Pb in vegetative parts,i.e.,root,stem thus mitigated the toxic effects of Pb on the growth of mung bean cultivars(6.25%–10.5%).In contrast,the addition of DTPA had adverse effects on the growth of mung bean cultivars.The addition of CA facilitated a greater uptake and accumulation of nitrogen,phosphorous,and potassium in the roots and leaves of mung bean cultivars.In addition,CA also improved the photosynthetic pigments(11%–14%)and photosynthetic rate(5%–12%)under both control and Pb stress conditions.The ameliorative effect of CA on the photosynthetic capacity of mung bean cultivars was likely associated with photosynthetic metabolic factors rather than stomatal factors.Furthermore,cv 07002 was found to be more tolerant to Pb stress and showed better performance in CA application.Overall,the application of CA demonstrated significant potential as a chelating agent for remediating Pb-contaminated soil.
基金Project(40973055) supported by the National Natural Science Foundation of ChinaProject(U0833004) supported by the NSFC-Guangdong Joint Foundation of China
文摘Three bacterial endophytes of Sedum alfredii, VI8L2, II8L4 and VI8R2, were examined for promoting soil Zn bioavailability and Zn accumulation in S. alfredii. Results showed that three strains were re-introduced into S. alfredii rhizosphere soils under Zn stress and resulted in better plant growth, as roots biomass increased from 80% to 525% and shoot biomass from 11% to 47% compared with the uninoculated ones. Strains IVsLz, II8L4 and IVsR2 significantly increased shoot and root Zn concentrations in the ZnCO3 contaminated soil. Inoculation with strain IVsL2 resulted in 44% and 39% higher shoot and root Zn concentrations, while strain IV8R2 significantly decreased shoot Zn concentration in the Zn3（PO4）2 contaminated soils. In the aged contaminated soil, isolates IVsL2, IIsL4 and IVsR2 significantly increased root Zn concentration, but decreased shoot Zn concentration of Sedum alfredii. It suggested that endophytes might be used for enhancing phytoextraction efficiency.
基金Supported by the Key Research of Southwest University of Science and Technology-"Biologic Stability and Mutation under the Radiate Environment and the Mechanism"(07XJGZB05)Research Foundation of Southwest University of Science and Technology for youth(O8zx315208zx3152)
基金Project (2012BAC09B04) supported by National Key Technology Research and Development Program of the Ministry of Science and Technology of ChinaProject (2010-277-027) supported by Science and Technology Foundation of Environmental Protection in Hunan Province,ChinaProject (2011SK3262) supported by Science and Technology Planning of Hunan Province,China
文摘The effects of five amendments such as acetic acid（AA）, citric acid （CA）, ethylenediamine tetraacetic acid （EDTA）, sepiolite and phosphogypsum on growth and metal uptake of giant reed （Arundo donax L.） grown on soil contaminated by arsenic （As）, cadmium （Cd） and lead （Pb） were studied. The results showed that the shoot biomass of giant reed was enhanced by 24.8% and 15.0%, while superoxide mutase and catalase activities slightly varied when adding 5.0 mmol/kg CA and 2.5 mol/kg EDTA to soil as compared to the control, respectively. The concentrations of As, Cd and Pb in shoots were remarkably increased by the addition of 2.5 mmol/kg AA and CA, 5.0 mmol/kg EDTA, and 4.0 g/kg sepiolite as compared to the control. The accumulations of As and Cd were also significantly enhanced in the above condition, while the shoot Pb accumulation was noticeably enhanced by amending with 4.0 g/kg sepiolite and 8.0 g/kg phosphogysum, respectively. The results suggested that AA, CA and sepiolite could be used as optimum soil amendments for giant reed remediation system.
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.
