International Journal of Phytoremediation最新文献

Water scarcity and pollution are major environmental problems in developing countries. To tackle these issues, it is crucial to develop sustainable and innovative waste water treatment methods. Constructed wetlands (CW) are efficient and eco-friendly waste water treatment systems, valued for their low cost, energy efficiency, and easy maintenance. The current study aimed to evaluate the potential of Canna indica and Colocasia esculenta plant species, along with Styrofoam and crushed plastic as amendments to filtration media (large gravel, small gravel, loamy soil, and sand), in treating waste water. We constructed four wetland units, each with four treatments, and monitored their performance by measuring pH, electrical conductivity (EC), total dissolved solids (TDS), total suspended solids (TSS), biological oxygen demand (BOD), chemical oxygen demand (COD), nitrate nitrogen (NO₃-N), phosphate (PO₄^3-), lead (Pb), cadmium (Cd), and Escherichia coli (E. coli). The pH of waste water in treatment T4 (filtration media with crushed plastic and styrofoam planted with C. indica and C. esculenta) of Unit 4 reached 8.1, which was the highest observed and played a key role in breaking down organic substances in the waste water. Results showed that unit 4 led to the best improvement in plant growth. T4 treatment of unit 4 produced the highest root fresh biomass (197 g for Ci and 1126 g for Ce) and shoot fresh biomass (607 g for Ci and 458 g for Ce). The increased root volume of both plant species provided microbial films and helped to reduce BOD by 92.7% and COD by 83.1%. T4 treatment of unit 4 turned out to be the most effective, achieving significant reductions in various waste water quality parameters. For instance, levels of NO₃-N dropped by 100%, PO₄^3- by 77%, EC by 77%, TDS by 92%, TSS by 50%, Pb by 77%, Cd by 100%, and E. coli by 99.1%. These findings confirm that our developed CWs are an effective, economical, and environment friendly solution for waste water treatment, particularly in developing countries facing water scarcity.

This study investigated the combined effect of Bacillus megaterium (B) and humic acid activator (HA) on enhancing ryegrass phytoremediation of Cd-contaminated phosphate soil. A pot experiment compared four treatments: control (CK), B alone, HA alone, and combined B + HA. Results showed that the B + HA treatment most effectively improved the soil microenvironment, reducing pH by 0.83 units and increasing available phosphorus by 45.74% compared to CK. This combination also notably promoted ryegrass growth, increasing above-ground and root dry weight by 47.31% and 58.33%, respectively, while increased plant height and chlorophyll content. Regarding Cd remediation, B + HA increased available Cd in rhizosphere soil by 61.90% and enhanced above-ground Cd accumulation by 21.18% compared to CK. Two-way ANOVA confirmed significant interactive effects between B and HA on Cd accumulation, soil pH, and phosphorus availability. The combined treatment also increased the bioaccumulation factor and transportation factor of Cd. The study demonstrates that B. megaterium and HA act complementarily to improve soil conditions, promote plant growth, and enhance Cd phytoextraction efficiency in ryegrass.

Chromium is a widespread environmental contaminant, with its hexavalent form [Cr(VI)] recognized as highly toxic due to its solubility, mobility, and bioavailability. Cr absorption and intracellular redox reactions in plant systems generate free radicals that interfere with vital phytochemical processes. Oxidative stress, driven by excessive reactive oxygen species (ROS) production, causes DNA damage, chromosomal abnormalities, impaired seed germination, stunted seedling growth, disruption of photosynthesis and nutrient uptake. Genotoxic and mutagenic impacts include chromosomal aberrations, micronuclei formation, and epigenetic alterations. Plants counteract these effects through antioxidative defense systems that involve both non-enzymatic and enzymatic antioxidants. Microorganisms also contribute to detoxification by biosorption, bioaccumulation, redox transformations, and secretion of extracellular polymeric substances. It facilitates the toxicity reduction of Cr by converting Cr(VI) to Cr(III). An integrated remediation strategy involving plant antioxidative defenses and microbial interactions offers a sustainable approach for the restoration of Cr-contaminated ecosystems. This review is a synthetic conceptualization of current knowledge on the molecular and genotoxic impacts of Cr in plants, highlighting plant-microbe interactions, ROS-mediated responses, and eco-friendly remediation strategies. It emphasizes the need for advancing phytoremediation and microbial biotechnology, along with emerging genomic and omics-based approaches, to mitigate Cr-induced stress and safeguard agricultural productivity and ecosystem health.

Industrial hemp (Cannabis sativa L.) is an effective crop for the phytomanagement of lands contaminated with trace metals, demonstrating tolerance to metal toxicity without significant impacts on its value-chain. However, the effects of metal contamination on hemp flowers remain understudied, limiting the assessment of the valorization potential for this valuable plant part. In a greenhouse experiment, we evaluated flower production, cannabinoid content and metal accumulation in hemp grown on a soil contaminated with Cd, Pb and Zn (pseudo-total concentrations: 13.0, 664 and 1048 mg kg^-1, respectively). Our results suggest a limited capacity for phytoextraction, with low removal rates for all three metals. Still, hemp flowers presented favorable features that support valorization potential. Both flower biomass and the synthesis of cannabidiol and tetrahydrocannabinol were comparable to plants grown under reference conditions. Notably, inflorescences exhibited the lowest accumulation of Cd and Pb among all plant tissues. Concentrations for these elements were 0.45 and 1.1 mg kg^-1 respectively, remaining below most commercial limits for herbal drug products. These findings demonstrate that hemp flowers can be safely produced on metal-contaminated soils, reinforcing the suitability of hemp as a robust and versatile crop for the phytomanagement of legacy metal pollution.

Heavy metals contamination poses a persistent threat to ecosystems and human health due to its toxicity, non-biodegradability, and tendency to bioaccumulate. This review systematically evaluates recent advances in phytoremediation as a sustainable strategy for mitigating heavy metals pollution, with a specific focus on underlying mechanisms, technological innovations, and field-scale applicability. The scope of the review encompasses major phytoremediation approaches, including phytoextraction, phytostabilization, phytovolatilization, phytodegradation, and rhizofiltration, alongside detailed analyses of plant-metals interactions, uptake and translocation pathways, and metal sequestration processes. Key findings highlight the critical role of plant-associated microorganisms, genetic engineering, and transgenic plants in improving metal tolerance, accumulation efficiency, and remediation rates. Evidence from recent field studies demonstrates that integrated phytoremediation systems can significantly enhance remediation performance when compared to single-approach strategies, although challenges related to metal bioavailability, site specificity, and long remediation timelines persist. Emerging developments such as nanophytoremediation and combined phytotechnological frameworks have been identified as promising solutions to overcome current limitations. Overall, this review provides new insights into the integration of biological, technological, and policy-driven approaches required to advance phytoremediation from experimental applications to large-scale environmental management.

The application of zinc oxide nanoparticles (ZnONPs) often affects the cadmium (Cd) uptake by plants; however, the relative efficiencies of different ZnONP application methods on Cd and zinc (Zn) uptake by plants need to be studied. The current study compared the efficiency of three ZnONP application methods [soil, foliar, and soil + foliar (S + F)] in terms of wheat plant growth and Cd/Zn uptake. The methods of ZnONP application caused significant variations in plant growth, photosynthetic pigments, oxidative stress, Zn and Cd uptake. The combined S + F method of ZnONP application was more effective in enhancing growth, Zn concentration and reducing Cd content in grains as compared to other methods. The S + F method increased the grain yield by 148.9% and Zn contents in grains by 72.8% compared to the control. Combined S + F application method reduced Cd concentrations in shoots, roots and grains by 12.7%, 20%, and 37.7%, respectively, compared to soil application method. Furthermore, compared to foliar application method, this decrease was 15.3%, 16.6%, and 31% for shoots, roots, and grains, respectively. Our results demonstrate that the S + F application of ZnONPs is more effective at reducing grain Cd contents in wheat, enhancing Zn biofortification for the nano-enabled production of safer food crops.

p,p'-DDE (2,2-bis(chlorophenyl)-1,1-dichloroethylene), a degradation product of p,p'-DDT (2,2-bis(chlorophenyl)-1,1,1-trichloroethane), persists in the environment due to its historical use. Cucurbita pepo spp. pepo is known for its ability to accumulate p,p'-DDE from the soil; however, the uptake mechanism remains poorly understood. Furthermore, moss species are also capable of retaining chlorinated organic compounds, which makes them valuable bioindicators for environmental research. This study assessed the effect of moss (Selaginella kraussiana) amendment on the accumulation and translocation of p,p'-DDE in the roots, shoots, and xylem sap of Cucurbita pepo ssp. pepo grown in two soils with different levels of contamination. Plants were cultivated in pots that were with or without S. kraussiana, using two soils containing 2,180-2,490 ng/g and 1,710-1,870 ng/g residual p,p'-DDE. The average p,p'-DDE concentrations in xylem sap decreased by more than 60% in moss-amended plants compared to control groups. Additionally, moss amendment reduced root and shoot p,p'-DDE concentrations by approximately 70% and 55%, respectively, compared to control groups. These findings suggest that moss amendments may reduce p,p'-DDE bioaccumulation in crops by altering contaminant bioavailability in the rhizosphere, offering a promising approach to promote food safety and minimize POP transfer through the food chain.

The increasing discharge of synthetic dyes into aquatic environments has raised serious environmental concerns, prompting the need for sustainable and cost-effective treatment solutions. Herein, a sustainable biocomposite of sulfonated lignocellulosic biomass (banana peel, Musa spp.)/chitosan polymer composite (CTS/SBP) was produced to be an efficient adsorbent for the removal of crystal violet (CV) dye from water systems. The physicochemical properties of CTS/SBP were investigated by the use of several techniques, including CHNS-O, FTIR, BET, pH_pzc, XRD, EDX, and FESEM measurements. When optimizing the adsorption performance of CTS/SBP, the Box-Behnken Design (BBD) was adopted, considering several elements, including the dosage of CTS/SBP (0.03-0.09 g), the pH (4-10), and the duration (10-70 min). In terms of the experimental data of CV adsorption by CTS/SBP, the Freundlich isotherm and pseudo-first-order models are in good agreement with the obtained results. The negative values of Gibbs free energy (ΔG° = -4.919 to -6.964 kJ/mol) confirm the spontaneity of the CV dye adsorption. Furthermore, the positive enthalpy (ΔH° = 15.403 kJ/mol) and entropy (ΔS° = 0.0681 kJ/molK) changes indicate an endothermic process accompanied by an increase in disorder at the solid-liquid interface. The adsorption of CV dye by CTS/SBP is identified as physisorption, based on its conformity to the pseudo-first-order kinetic model and a Dubinin-Radushkevich adsorption energy of 1.112 kJ/mol, a value characteristic of physical adsorption processes. The adsorption capacity of CTS/SBP was measured to be 667.68 mg/g. One of the primary reasons for the significant adsorption of CV onto CTS/SBP is the presence of electrostatic interaction between the CTS/SBP's acidic groups and the CV's positive group. The obtained data illustrate a sustainable, environmentally friendly, and green method to produce effective adsorbents, opening the door for the development of adsorbents produced from renewable resources as a viable substitute for the removal of cationic dyes from polluted water.

Indoor formaldehyde primarily originates from building materials, furniture, artificial boards, and various adhesive coatings. Phytoremediation is a green and environmentally friendly method for removing formaldehyde. The existing researches on the removing formaldehyde by plants lacked exploration of Dieffenbachia maculata, which had a purification rate of formaldehyde of 43.7%. This study subjected the roots, stems and leaves of D. maculata to time-gradient treatments with formaldehyde isotopic solutions. The metabolites for assimilating formaldehyde in the roots, stems and leaves parts of D. maculata were determined. The metabolic pathways of formaldehyde in each part of D. maculata were analyzed, and the metabolic pathway diagrams were drawn. The experimental results revealed that under the treatment of time gradients of formaldehyde isotope solution, the metabolites involved in formaldehyde detoxification in different parts of D. maculata included formic acid, bicarbonate ion, formic acid, citric acid, glycine, asparagine, glutamine, glutamic acid, fructosamine, and gluconic acid. The glyoxylate acid cycle and the tricarboxylic acid (TCA) cycle worked in concert in the process of decontaminating formaldehyde, and the Calvin cycle played a role in the formaldehyde decontamination in the stems and leaves of D. maculata, while gluconeogenesis was involved in the formaldehyde decontamination in the roots of D. maculata.

Microplastics from personal care products and heavy metals (HMs) in wastewater pose significant threats to crop health in peri-urban agricultural areas. This study evaluates the interactive effects of contaminated wastewater with Cd, Hg, Pb and polyethylene microplastics (MPs) from exfoliating personal care products on Capsicum annuum. Plant growth parameters (e.g.,height, biomass, leaf number) were reduced with increasing wastewater and MPs levels, and the observed reduction rates were 71-82%. at SWW (100%) + MPs (5 g/L), accompanied by 51-72% loss in photosynthetic pigments (chlorophyll a, b, and carotenoids) and 74-85% decrease in soluble proteins compared to the control. Oxidative stress markers such as MDA increased by 124-150% and H₂O₂ by 180-230%, at SWW 100% + MPs (5 g/L) compared to the control. Antioxidant enzyme activities amplified at moderate stress levels (SWW 50%) before declining by 18-20% at higher levels (compared to peak activity), indicating failure to acclimate. Mechanistically, HMs accretion was root-dominant and significantly increased in levels in high stress conditions, with increased HMs uptake facilitated by MPs ranging 11-23% (low MPs: 11-15%, high MPs: 18-23%) at high stress conditions. These findings underscore the need for MPs removal from wastewater to mitigate phytotoxicity and enhance crop safety in contaminated agroecosystems.