Search Results (266)

Phytoremediation is a cost-effective and sustainable method for the remediation of minewaste contaminated with heavy metals such as arsenic (As). However, mine waste soil is often nutrient-limited, especially in nitrogen (N), impairing plant growth and phytoremediation. This study aimed to assess how planting density together with soil amendments, biochar, and an isolated indigenous nitrogen-fixing bacterium (NFB) (Bacillus subtilis) affect the efficacy of phytoremediation by Juncus pauciflorus of an As-contaminated mine waste soil from Bendigo, Victoria. Three plant densities, including 9, 26, and 44 plants/m², were grown in As-contaminated mine waste soil amended with biochar (10% w/w) and B. subtilis (8.1 × 10⁸ CFU/mL) and incubated for 100 days. Plant biomass, plant As uptake, soil As concentration, bacterial abundance (total and NFB using 16S and nifH gene copy numbers, respectively), and total soil N were assessed. Juncus pauciflorus at a higher density (44 plants/m²) promoted the greatest biomass and total As uptake, 70.22 g/m² and 209.53 mg/m², respectively. Plant density significantly influenced the root–shoot partitioning of As. Higher densities increased shoot uptake (BAF_soil→shoot), and TF_root→shoot values remained >1 across all treatments, confirming the active translocation of As to the shoots, suggesting both phytostabilisation and phytoextraction potential by J. pauciflorus. Planting density significantly reduced soil As, ranging from 8000 mg/kg to 9500 mg/kg, compared to the initial concentration (13,032 mg/kg). The abundance of 16S and nifH genes was stable among treatments, ranging from 7 log₁₀ copies/g to 12 log₁₀ copies/g. TN content in soils amended with 44 plants/m² contained the highest TN content at day 33, approximately 7000 mg/kg. This study is the first to report that higher planting density of J. pauciflorus amended with biochar and NFB provides the strongest phytoremediation performance in highly As-contaminated mine soil by enhancing As uptake and accumulation in aboveground biomass. Most importantly, the results show that plant density also regulates the plant’s remediation strategy, shifting J. pauciflorus between phytostabilisation at dense planting and greater phytoextraction at lower density. These findings support the use of native plants in combination with biochar and microbial amendment as a sustainable strategy for remediating As-contaminated mine waste. Full article

Seed biopriming is increasingly recognized as a strategy capable of inducing molecular memory that enhances plant performance under heavy-metal stress. Here, we investigated how biopriming Silene sendtneri seeds with Paraburkholderia phytofirmans PsJN establishes a transcriptional state that predisposes seedlings for improved cadmium (Cd) tolerance. RNA-seq profiling revealed that primed seeds exhibited differential gene expression prior to Cd exposure, with strong upregulation of detoxification enzymes, antioxidant machinery, metal transporters, photosynthetic stabilizers, and osmoprotectant biosynthetic genes. Enrichment of gene ontology categories related to metal ion detoxification, redox homeostasis, phenylpropanoid metabolism, and cell wall organization indicated that biopriming imprints a preparatory transcriptional signature resembling early stress responses. Upon Cd exposure, primed plants displayed enhanced physiological performance, including preserved integrity, elevated antioxidant activity, particularly peroxidases in roots, higher osmolyte accumulation, stabilized micronutrient levels, and substantially increased Cd uptake and sequestration. These coordinated responses demonstrate that biopriming induces a sustained molecular memory that accelerates and strengthens downstream defense activation. These findings demonstrate that PGPR-based biopriming establishes a stable transcriptomic memory in seeds that enhances cadmium tolerance, metal sequestration, and stress resilience, highlighting its potential for improving hyperaccumulator performance in phytoremediation and stress adaptation strategies. Full article

Soil co-contamination with cadmium (Cd) and zinc (Zn) poses serious threats to environmental safety and public health. This study investigates the enhancement effect and underlying mechanism of the biodegradable chelator Ethylenediamine-N,N′-disuccinic acid (EDDS) on phytoremediation of Cd-Zn contaminated soil using Sedum lineare. The results demonstrate that EDDS application (3.65 g·L⁻¹) effectively alleviated metal-induced phytotoxicity by enhancing chlorophyll synthesis, activating antioxidant enzymes (catalase and dismutase), regulating S-nitrosoglutathione reductase activity, and promoting leaf protein synthesis, thereby improving photosynthetic performance and cellular integrity. The combined treatment significantly increased the bioavailability of Cd and Zn in soil, promoted their transformation into exchangeable fraction, and resulted in removal rates of 30.8% and 28.9%, respectively. EDDS also modified the interaction patterns between heavy metals and essential nutrients, particularly the competitive relationships through selective chelation between Cd/Zn and Fe/Mn during plant uptake. Soil health was substantially improved, as evidenced by reduced electrical conductivity, enhanced cation exchange capacity, and enriched beneficial microbial communities including Sphingomonadaceae. Based on the observed ion antagonism during metal uptake and translocation, this study proposes a novel “Nutrient Regulation Assisted Remediation” strategy to optimize heavy metal accumulation and improve remediation efficiency through rhizosphere nutrient management. These findings confirm the EDDS–S. lineare system as an efficient and sustainable solution for remediation of Cd–Zn co-contaminated soils. Full article

The present study investigates the potential of poplar (Populus spp.) biomass from phytoremediation plantations as a feedstock for downdraft fixed bed gasification. The biomass was characterized in terms of moisture, ash content, elemental composition (C, H, N, O), and calorific values (HHV and LHV), confirming its suitability for thermochemical conversion. Gasification tests yielded a volumetric syngas production of 1.79 Nm³ kg⁻¹ biomass with an average composition of H₂ 14.58 vol%, CO 16.68 vol%, and CH₄ 4.74 vol%, demonstrating energy content appropriate for both thermal and chemical applications. Alkali and alkaline earth metals (AAEM), particularly Ca (273 mg kg⁻¹) and Mg (731 mg kg⁻¹), naturally present enhanced tar reforming and promoted reactive gas formation, whereas heavy metals such as Cd (0.27 mg kg⁻¹), Pb (0.02 mg kg⁻¹), and Bi (0.01 mg kg⁻¹) were detected only in trace amounts, posing minimal environmental risk. The results indicate that poplar pruning residues from phytoremediation sites can be a renewable and sustainable energy resource, transforming a waste stream into a process input. In this perspective, the integration of soil remediation with syngas production constitutes a tangible model of circular economy, based on the efficient use of resources through the synergy between environmental remediation and the valorization and sustainable management of marginal biomass—i.e., pruning residues—generating environmental, energetic, and economic benefits along the entire value chain. Full article

Enteric viruses in wastewater remain a persistent public health threat. Conventional treatments often achieve only modest viral log₁₀ reductions and can generate toxic disinfection byproducts, but high-energy advanced processes are often unaffordable. Antiviral phytoremediation, which involves virus removal mediated by plants and their rhizosphere microbiota, offers a low-cost, low-energy alternative; however, it has scarcely been studied. A bibliometric analysis of ~23,000 wastewater treatment studies (1976–2025) identified only 30 virus-targeted records within plant-based treatment branches, representing ~0.13% of the total corpus. This critical review structures antiviral phytoremediation into a four-barrier framework: (i) sorption/filtration, (ii) rhizosphere-mediated inactivation, (iii) plant internalization, and (iv) intracellular degradation. Pilot and full-scale studies provide strong support for the first two barriers, whereas evidence for internalization and intracellular degradation is limited, mainly laboratory-based, and often inferred from molecular rather than infectivity assays. Standalone constructed wetlands typically achieve ~1–3 log₁₀ virus reductions, but hybrid configurations that combine wetlands with complementary processes achieve ~3–7 log₁₀ reductions, with performance varying between enveloped and non-enveloped viruses and across climates. This review distills design principles for cost-effective hybrid systems and identifies methodological and governance priorities, positioning rigorously designed phytoremediation as a scalable part of climate- and pandemic-resilient wastewater infrastructure. Full article

Heavy metal contamination of agricultural soils represents a critical environmental and agronomic challenge, particularly in regions exposed to intensive land use and transport-related emissions. This study presents a detailed assessment of soil contamination in the Dargov cadastral area (Eastern Slovakia), where elevated concentrations of Cu, Zn, Pb, Ni, As, Cd, and Cr were detected through multi-depth sampling near the I/19 first-class road. Analytical results confirmed exceedances of Slovak regulatory thresholds (Decree No. 59/2013), with persistent contamination observed even in the deepest sampling interval (20–40 cm), indicating vertical migration and long-term accumulation. Concentrations of Pb (85–210 mg·kg⁻¹), Cd (2.1–5.4 mg·kg⁻¹), Zn (120–340 mg·kg⁻¹), and Ni (45–95 mg·kg⁻¹) exceeded Slovak regulatory thresholds. The highest values were consistently detected in the 0–10 cm layer and within 3 m of the I/19 road, with a gradual decline at greater depths and distances. Nevertheless, Cd and Ni remained above permissible limits even in the deepest sampling interval (20–40 cm), confirming vertical migration and long-term persistence of contamination. The spatial distribution of contaminants suggests a dominant influence of road traffic, with implications for crop safety, soil fertility, and rural land management. Based on the findings, the study proposes context-sensitive remediation strategies, including phytoremediation and chemical immobilization, and emphasizes the need for integrated monitoring systems and land-use planning to mitigate risks. The case study contributes to the broader discourse on sustainable soil management in Central European agricultural landscapes affected by diffuse pollution. Full article

Contamination of agricultural soils with heavy metals, such as zinc (Zn), copper (Cu) and lead (Pb), is a major problem for food safety and environmental sustainability. The present study aimed to evaluate the efficiency of phytoremediation induced with Brassica juncea (Indian mustard) and ethylenediaminetetraacetic acid (EDTA) in reducing the content of heavy metals in contaminated soils. The experiment was carried out in a greenhouse, using soil polluted with Zn, Cu and Pb, to which different treatments were applied, using: the biological method (Indian mustard only), the chemical method (EDTA in three concentrations: 0.5–1.0–2.0 mmol·kg⁻¹) and the mixed method (Indian mustard and EDTA in three concentrations: 0.5–1.0–2.0 mmol·kg⁻¹). The determinations included the analysis of the residual metal content by atomic absorption spectroscopy, as well as the evaluation of the physiological parameters of the plants (biomass, chlorophyll content in leaves, humidity, height). The results of unifactorial and bifactorial ANOVA revealed highly significant differences (p < 0.001) between the treatments and the types of metals, confirming the synergistic interaction between the chelation and phytoextraction processes. The combined treatments Indian mustard and EDTA in concentrations of 1.0 mmol·kg⁻¹ and 2.0 mmol·kg⁻¹, ensured the highest decontamination efficiency, with reductions of 51.5% for Zn, 36.3% for Pb and 27.5% for Cu. In conclusion, the mixed method represents a viable, ecological and reproducible strategy for the remediation of soils contaminated with heavy metals. Full article

The contamination of water with toxic metals, such as copper, poses significant environmental and public health challenges, necessitating sustainable treatment solutions. This study investigates the phytoremediation potential of Epipremnum aureum for the removal of Cu(II) from aqueous solutions under both static and dynamic conditions. Batch experiments were conducted using initial copper concentrations of 5, 10, 15, and 20 mg L⁻¹, while a prototype vertical flow system (“green wall”) was implemented for continuous flow studies at 10 mg L⁻¹. Copper removal efficiency, plant morphology, and kinetic behavior were monitored over four weeks. ATR-FTIR, SEM-EDX, and X-ray diffraction analyses were performed to elucidate the sorption mechanism. Results demonstrated that E. aureum tolerates copper concentrations up to 10 mg L⁻¹ without significant morphological damage, achieving up to 70% removal in continuous flow, with sorption occurring via a combination of surface adsorption to oxygenated functional groups and intracellular absorption. At higher concentrations (≥15 mg L⁻¹), plants exhibited severe stress and necrosis, limiting their remediation capacity. The findings indicate that E. aureum is effective for moderate copper contamination and provide mechanistic insights into its metal uptake processes, highlighting its suitability for integration into sustainable water treatment systems. This work contributes to the development of eco-friendly, plant-based strategies for toxic metal remediation, supporting advances in chemical and hybrid technologies for safe water management. Full article

Lead (Pb) pollution in wastewater is an immense problem for public health and the environment because it persists in the water bodies for a long period of time. Over the past years, many different techniques of Pb remediation have been discovered to eliminate Pb pollution. This systematic review analyzed the major findings of Pb removal from wastewater using microbial biosorption, agro-waste- and fruit peel-based adsorbents, plant-assisted phytoremediation, engineered biochars, clay and natural minerals, and nanomaterials. Each of these methods is critically reviewed in terms of removal efficiency, limitations, cost-effectiveness, how it works, how well it eliminates the problem, environmental compatibility, regeneration potential, and scalability, as supported by recent experimental and case studies. This review provides a comprehensive comparison of all the remediation methods in one framework. It also shows the potential of the integrated and hybrid systems, a combination of biological and high-technology material-based strategies, to reach high-performance Pb remediation in the long run. Therefore, the study aims to assist policymakers, environmental engineers, and researchers who are interested in finding a sustainable solution to Pb contamination by providing a comparative overview of the existing and recently developed remediation methods. Full article

Heavy metal (HM) contamination threatens environmental sustainability, food safety, and agricultural productivity worldwide. HM toxicity adversely affects plant growth, reducing germination rates by 20–50%, impairing seedling establishment, and inhibiting shoot and root development by 30–60% in various crops. HM disrupts key physiological processes, including photosynthesis, stomatal regulation, membrane integrity, nutrient uptake, and enzymatic and nonenzymatic antioxidant activities. These disruptions largely result from oxidative stress, caused by the excessive accumulation of reactive oxygen species, which damage cellular components. To counteract HM toxicity, plants deploy a complex defense network involving antioxidant enzymes, metal chelation by phytochelatins and metallothioneins, vacuolar sequestration, and symbiotic interactions with arbuscular mycorrhizal fungi, which can retain 40–70% of metals in roots and reduce translocation to shoots. At the molecular level, MAPK (Mitogen-Activated Protein Kinase) signaling pathways, transcription factors (e.g., WRKY, MYB, bZIP, and NAC), and phytohormonal crosstalk regulate the expression of stress-responsive genes expression to enhance HM stress tolerance. Advances in nanotechnology offer promising strategies for the remediation of HM-contaminated soils and water sources (HM remediation); engineered and biogenic nanoparticles (e.g., ZnO, Fe₃O₄) improve metal immobilization, reduce bioavailability, and enhance plant growth by 15–35% under HM stresses, although excessive doses may induce phytotoxicity. Future applications of nanotechnology in HM remediation should consider nanoparticle transformation (e.g., dissolution and agglomeration) and environmentally relevant concentrations to ensure efficacy and minimize phytotoxicity. Integrating phytoremediation with nanoparticle-enabled strategies provides a sustainable approach for HM remediation. This review emphasizes the need for a multidisciplinary framework linking plant science, biotechnology, and nanoscience to advance HM remediation and safeguard agricultural productivity. Full article

The increasing presence of microplastics (MPs) in terrestrial ecosystems, particularly when combined with organic pollutants and heavy metals, presents a considerable environmental challenge. This review examines the intricate interactions between MPs, co-contaminants (both organic and inorganic), and plants involved in phytoremediation processes. A literature search was performed across the databases Scopus, ScienceDirect, and Google Scholar, covering the timeframe from 2015 to 2025. The studies selected specifically addressed the synergistic and antagonistic effects of microplastics in conjunction with heavy metals or organic pollutants (such as PAHs and pesticides) within plant–soil systems. The findings reveal that MPs influence pollutant mobility, bioavailability, and toxicity through adsorption and desorption mechanisms, leading to varied implications for plant growth, microbial communities, and contaminant uptake. Depending on the physicochemical characteristics of MPs and co-pollutants, the effects can range from increased phytotoxicity to diminished contaminant accumulation in plants. Additionally, physiological and molecular disruptions, including oxidative stress, hormonal imbalances, and impaired enzymatic activity, were frequently noted in co-contamination scenarios. Recent developments, such as the creation of genetically modified hyperaccumulator plants and the use of nanotechnology and microbial consortia, demonstrate potential to enhance phytoremediation efficiency in complex polluted soils. This review underscores the pressing need for integrated, multidisciplinary strategies to overcome the limitations of existing phytoremediation methods in co-contaminated environments. Future research should focus on standardized methodologies, a mechanistic understanding, and the safe implementation of emerging biotechnologies for sustainable soil remediation. Full article

The sustainable management of dredged sediments contaminated with heavy metals represents a major environmental challenge. This study evaluated the phytoremediation potential of hemp (Cannabis sativa L.) and sorghum (Sorghum bicolor L.) cultivated in metal-enriched sediment from the Bega Canal (Cu = 204 mg kg⁻¹, Pb = 171 mg kg⁻¹, Cr = 281 mg kg⁻¹, Ni = 56 mg kg⁻¹, Cd = 6.8 mg kg⁻¹) and examined the effects of glutamic (GA) and tartaric (TA) acids (20 mmol kg⁻¹) on sediment properties and metal uptake. Pot experiments under natural conditions (n = 3, 6–8 weeks) showed that GA treatment resulted in cation exchange capacity (CEC) values ranging from 31.0 to 58.5 cmolc kg⁻¹, which were lower than in the initial sediment (60.7 cmolc kg⁻¹) but still higher than in the corresponding controls and TA treatments. GA also increased electrical conductivity from 435 to 1189 µS cm⁻¹, which may indicate enhanced ion mobility and be consistent with redox-related processes, whereas TA maintained near-neutral pH (8.0–8.2) and caused only minor changes in CEC and EC, preserving overall structural stability. Hemp produced up to 40% more biomass than sorghum and allocated a relatively larger share of Cu, Pb and Cd to shoots, whereas sorghum retained up to 80% of total Cr and Ni in roots. Bioaccumulation factors ranged from 4.3 for Cu in hemp (GA) to 20.8 for Cu in sorghum (GA), while translocation factors remained <1.0 in both species, indicating that root-based phytostabilization was the dominant mechanism. The results demonstrate that combining low-molecular-weight organic acids with energy crops can effectively enhance metal mobility and plant uptake, offering a viable route for sediment remediation and biomass valorization within circular economy strategies. Full article

Substrate amendment is a promising strategy to enhance phytoremediation in degraded coastal wetlands, yet the selection of optimal materials and their incorporation ratios remains challenging. This study systematically investigated the effects of five amendments, viz., manganese sand, maifan stone, bentonite, iron–carbon (Fe-C), and vermiculite, across an incorporation ratio gradient (5–40%) on the growth of the mangrove, Kandelia obovata, and the physicochemical properties of coastal wetland substrate. Results demonstrated material-specific and dose-dependent responses. Four amendments (vermiculite, Fe-C, manganese sand, and maifan stone) promoted Kandelia obovata growth to varying degrees, while bentonite exhibited significant inhibition. All amendments ensured the physical stability of the substrate. Nutrient removal efficiency followed the order: Fe-C > vermiculite > maifan stone > manganese sand, with 10% Fe-C showing the highest comprehensive nutrient removal. Conversely, bentonite functioned as a nutrient enrichment agent. The amendments differentially influenced redox potential, CO₂ emissions, and electrical conductivity, yet all maintained a stable substrate pH. A comprehensive evaluation considering plant growth, nutrient removal, and CO₂ sequestration identified maifan stone as the optimal amendment, with the 40% incorporation ratio delivering the most favorable integrated performance. This study provides critical, ratio-specific guidance for selecting and applying substrate amendments in coastal wetland restoration. This study provides critical, ratio-specific guidance for selecting and applying environmentally sustainable amendments, supporting the development of nature-based solutions for long-term coastal wetland restoration. Full article

Nickel contamination poses a serious risk to ecosystems and human health. Phytoremediation provides a sustainable solution. This study evaluates the ability of Helinathus annuus L. to tolerate and accumulate nickel under simulated Mediterranean and semi-arid conditions, representing a short-term contamination event with nickel-enriched irrigation. Laboratory experiments assessed growth, tolerance, and Ni distribution within plant tissues. Results showed that Ni uptake increased with concentration, mainly in roots, while translocation to aerial parts remained limited. The bioconcentration factors ranged from 1.32 to 2.55, and the translocation factors from 0.46 to 0.60, indicating efficient uptake but restricted metal mobility. Higher water availability enhanced Ni absorption, suggesting that soil moisture facilitates metal transport and root activity. Helinathus annuus L. demonstrated good tolerance at moderate Ni levels but reduced growth and accumulation efficiency at higher concentrations, confirming its potential for phytostabilization in Mediterranean soils affected by metal contamination. Full article

The use of mercury in industry causes its continuous increase in nature. A pro-ecological technology that can reduce mercury levels in aquatic environments is phytoremediation using the plant Salvinia natans. The study aimed to determine the maximum mercury concentration for effective phytoremediation using Salvinia natans. The study aimed to determine the threshold for effective phytoremediation using Salvinia natans. A Microtox screening test was performed for concentrations ranging from 0.15 to 0.50 mg Hg·L⁻¹. For the same concentrations, the effect of contamination on the physiological condition of the plant was tested by observing changes in the presence of chlorosis and necrosis. Analysis of enzymatic activity using the API ZYM test for plants exposed to mercury did not show any significant changes. The phytoremediation process produces a significant amount of spent phytoremediation biomass containing large amounts of mercury. Sustainable management in the form of a mixture with soil substrate, uncontaminated with mercury, was proposed. Microtox toxicity analysis of water extracts from soil containing biomass, with a final mercury content in the substrate of 1 mg Hg·kg⁻¹ of soil, showed no toxicity to the environment. However, microbiological analysis of the same soil substrate showed changes in the total number of bacteria, actinomycetes, fungi, moulds, and yeasts compared to the control samples. Full article