International Journal of Phytoremediation最新文献

Winter evergreen shrubs play a vital role in mitigating atmospheric particulate matter (PM) and potentially toxic elements (PTEs). This study evaluated PM retention and PTE accumulation in four shrub species from northern Jiangsu. Rhododendron × pulchrum exhibited the greatest PM retention (0.1082 mg/cm²) and the highest accumulation of Cr, Mn, Ni, As, Cd, and Pb in both surface deposits and leaf tissues. PM distribution was dominated by coarse particles (PM_>10, 71.60%), followed by PM_2.5-10 (21.60%) and PM_0.2-2.5 (6.81%), with Buxus megistophylla showing superior capacity for fine particle (PM_0.2-2.5) capture. Photinia × fraseri displayed elevated Hg levels (0.040 mg/kg), whereas Pittosporum tobira accumulated the highest Zn concentrations (36.041 mg/kg). Leaf PM load was strongly and positively correlated with most PTEs (p < 0.01). Notably, Cu and Pb in P. tobira leaves and Pb in B. megistophylla leaves were significantly correlated with the corresponding elements in leaf-associated PM (p < 0.05). These results confirm that PM of different size fractions exhibits distinct selective adsorption patterns for atmospheric PTEs. Overall, R. pulchrum appears to be a promising understory shrub species for greening in PTE-contaminated environments.

The current study prepares a confluence of all arsenic remediation strategies by Eichhornia crassipes (E. crassipes) in various forms along with the current arsenic scenario across the world. Conventionally engineered remediation tools have been discussed and research gaps in finding simple, cost-effective, greener approaches have been emphasized. Outstanding biosorption efficiency and underdeveloped mechanism of complexation with metal and other water contaminants by the living plant and its biomass might be quite fascinating. It can reveal broad scopes of research to extract many outstanding end-use outcomes in water treatment. The study is classified into three major sections, viz. global arsenic impact, existing tools to combat it - their pros and cons - and prospects of E. crassipes in its remediation. Performances in their different forms (living and nonliving) have been critically reviewed. Alongside, arsenic chemistry and distribution are briefly covered and a few proposed mechanisms of its remediation by the plant also have been assessed. Focus was given to sort out management/modifications to improve the efficiency of those established technologies. Understanding the mechanisms of arsenic sequestering in the plant body and its arsenic tolerance might be helpful for genetic engineering and to mimic the behind-the-scene concept at the synthetic level as well.

Typha domingensis is the most abundant species in a petroleum-contaminated area impacted by one of Brazil's largest environmental disasters in 2000. This pioneering study evaluates this species in situ and aims to analyze the anatomical and morphological differences in T. domingensis from the contaminated site compared to a nearby uncontaminated area (control). Morphological, anatomical, and histochemical analyses were performed, along with gas chromatography and fluorescence microscopy, to assess the plant's potential for petroleum uptake. Results indicated that individuals from the contaminated site developed longer leaves, produced phenolic compounds, and formed aerenchyma as adaptive responses to environmental stress, while leaf count remained unchanged, and no evidence of xenobiotic absorption was found. This lack of uptake likely explains the absence of significant growth inhibition or severe anatomical damage. These findings suggest that T. domingensis has successfully adapted to the contaminated environment, possibly using petroleum degradation by-products to enhance its growth. Its anatomical and histochemical adaptations underscore its strong potential as a sustainable phytoremediation tool.

Cadmium (Cd), a highly toxic heavy metal(loid) (HM), poses significant environmental challenges, demanding effective remediation strategies. Ricinus communis L. (castor), recognized for HM accumulation, offers promise for phytoremediation. This study examines the role of nitric oxide (NO), applied as 100 µM sodium nitroprusside (SNP) (NO donor), in mitigating Cd stress (500 µM CdCl₂) in 7-day-old seedlings of contrasting castor genotypes: Western Maruti (WM), Cd-tolerant, and Gujarat Castor Hybrid-2 (GCH-2), Cd-sensitive, for 21 days. Physiological parameters and antioxidant enzyme activity were analyzed under Cd and NO treatments. SNP mitigated Cd toxicity in GCH-2, boosting root length (137.88%), shoot length (83.53%), dry biomass (root-125.95%; stem-169% and leaves-70.14%), chlorophyll content (117.1%), photosynthetic rate (119.28%), stomatal conductance (129.11%) and transpiration rate (167.3%), compared to plants under Cd treatment. SNP treatment increased Cd accumulation in the root and stem of GCH-2 (4.4% and 13.7%) and WM (7.5% and 29.3%), respectively. This study hypothesizes that exogenous application of NO in R. communis reduces the cellular toxicity due to Cd stress, particularly in the sensitive genotype, as well as enhances Cd tolerance and accumulation by modulating growth, photosynthesis, and antioxidant defense. Thus, NO may be a viable candidate for improving phytoremediation in Cd-contaminated soils.

A hazardous triphenylmethane dye, Crystal Violet, was effectively removed from its aqueous solution using a waste material-Hen Feather-as biosorbent. The Crystal Violet-Hen Feather adsorption system gives promising results and has not been studied previously. By removing a highly toxic dye, using a ubiquitous biowaste material this research provides dual advantages. The influence of contact time, adsorbent dosage, dye concentration, and solution pH on the uptake of Crystal Violet by Hen Feathers was systematically investigated. Six adsorption isotherm models, namely the Freundlich, Langmuir, Temkin, Dubinin-Radushkevich, Halsey, and Jovanovic models, were studied for the adsorption of Crystal Violet over Hen Feather and various physicochemical parameters were derived. Langmuir isotherm data were exploited to obtain thermodynamic variables. Negative values for ΔH° were recorded as -15.15 to -17.01 kJ·mol^-1, and negative ΔG° values of -23.34 to 25.94 kJ·mol^-1 confirmed the adsorption process was exothermic and spontaneous. It was determined that a pseudo-second-order kinetic model is applicable to the present adsorption system at all three tested temperatures. It was established that Hen Feather possesses a very strong affinity for Crystal Violet and works as an excellent scavenger through physisorption.

Emergent macrophytes effectively control eutrophication in constructed floating wetlands (CFW). However, tropical species from South America are underutilized. This study evaluates five emergent macrophytes-Alternanthera philoxeroides, Ludwigia leptocarpa, Polygonum ferrugineum, Typha domingensis, and Urochloa mutica-for their ability to control eutrophication and inhibit cyanobacterial growth, compared to the well-studied floating Pontederia crassipes. Phytoremediation experiments in 50 L mesocosms with high soluble reactive phosphorus (SRP) concentrations (400 µg L-1) showed that while P. crassipes reduced SRP by 76% in 14 days, compared to the control without macrophytes; other macrophytes reduced SRP by over 91%, except for T. domingensis at 40%. NH4+ and NO3- removal rates for P. crassipes were 90% and 47%, respectively, matching the performance of the tested macrophytes. Root exudates of A. philoxeroides, L. leptocarpa, and P. ferrugineum inhibited the growth of the cyanobacterium Microcystis aeruginosa, with no Chl-a detected after 7 days. Thus, three emergent macrophytes outperformed P. crassipes in nutrient removal and showed allelopathic potential against cyanobacteria. Utilizing local emergent macrophytes in CFW systems presents a valuable and sustainable approach to mitigating eutrophication and its consequences on aquatic environments such as cyanobacteria blooms.

The application of engineered humic Fe/Zn complexes in remediating lead (Pb) biotoxicity, as well as their impact on CO₂ efflux, soil carbon distribution, and spinach growth, remains unexplored. This study revealed the impact of engineered Fe- and Zn-enriched humate complexes on Pb immobilization, geochemical fractionation, and translocation in a spinach crop, and the effects on soil biochemical health and CO₂-C efflux from tillage and no-tillage Pb-contaminated soils in closed chambers. Advanced statistical models like PLS-PM were employed to determine the direct and total effects of the applied amendments under different tillage regimes. Results demonstrated that Zn- and Fe-humate applications decreased Pb contents by 48% and 72% in tillage soil, while under no-tillage soil Pb concentration was reduced by 35%; 8.7 mg kg^-1 (Zn-humate) vs 33%; 5.9 mg kg^-1 (Fe-humate) compared to respective controls. Soil C distribution showed dramatically varying trends in tilled and no-tilled soils. Soil extracellular enzyme activity was enhanced under both tillage and no-tillage operations with Zn- and Fe-humate complexes. Human-associated health risk was reduced by 3-fold by the application of Fe-humate, and it was 2-fold with Zn-humate. Overall, findings revealed that the tillage-driven application of Fe/Zn humate complexes significantly enhanced spinach growth, reducing Pb bioavailability, highlighting their potential for sustainable soil management in contaminated farmlands.

The application of Ricinus communis L. on remediation of heavy metal-polluted soil shows significant potential due to its advantages of large biomass, high resistance to heavy metals and high economic value, etc. To further enhance phytoremediation efficiency, eight plant growth-promoting endophytic bacteria (TR4, TR8, TR16, TR18, TR21, YL1, YS3 and YS5) were used to investigate the effect of inoculation on R. communis growth and Cu/Cd accumulation. The results showed that inoculation of strain TR16, TR18, TR21, YS3, and YS5 significantly increased plant biomass by 20.0%-39.9%. Except for strain YL1 and TR4, other six strains increased Cu and Cd concentration in plant tissues to varying degrees, as well as total metals uptake. Total uptake of Cu and Cd were enhanced by 15.8%-71.8% and 20.8%-85.4%, respectively. TR16, TR18 and TR21 treatments got the greatest improvement. Inoculation of endophytic bacteria also promoted the absorption of P, Fe, and Mg by plants. Consequently, inoculating TR16, TR18, TR21 and YS3 effectively boosted the phytoextraction efficiency of Cu/Cd by increasing plant biomass, and enhanced heavy metal concentration in different R. communis tissues. These findings provided basis for strengthening R. communis phytoremediation efficiency in Cu/Cd-contaminated soil using plant growth-promoting endophytic bacteria.

Soil pollution due to heavy metals and petroleum hydrocarbons (PHCs), has become an alarming issue worldwide. Micronutrients, especially Zinc (Zn), have shown enormous capacity to improve growth and oxidative stress tolerance of plants under co-stressed conditions. The current study evaluated the capability of zinc to reduce Chromium (Cr) uptake in Tagetes erecta L exposed to PHCs toxicity. The pot experiment was carried out using soil amended with chromium (150 mg kg^-1) and PHCs (2 g crude oil/kg soil). Results demonstrated that Cr and PHCs stress significantly reduced growth metrics and photosynthetic pigments but substantially increased the contents of antioxidant enzymes, phenols, flavonoids, proline, malondialdehyde (MDA), and hydrogen peroxide (H₂O₂) contents in T. erecta. However, zinc application at various doses (3, 6, 12 mg kg^-1) ameliorated the toxicity of PHCs and Cr in T erecta. Specifically, Zn3 (12 mg kg^-1) treatment increased shoot weight, total chlorophyll, antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD), by 17.2, 18.3, 56, 49, and 67%, respectively in T. erecta under Cr + PHCs treatment. Additionally, the Zn3 application lowered MDA, H₂O₂, and Cr uptake in root and shoot by 23.5, 31.9, 36 and 42% respectively in T. erect subjected to Cr + PHCs stress.

This pot experiment elucidated the dynamic effects of continuous grafting on cadmium (Cd) accumulation in tomato plants, investigating its impact on Cd distribution, accumulation characteristics, and generational responses. The results demonstrated that continuous grafting significantly reduced both biomass and antioxidant enzyme activities in tomato scions. Specifically, compared to non-grafted controls, the root biomass of secondary and tertiary grafted plants decreased by 40.21% and 40.38%, respectively. Concurrently, a reduction in DNA methylation levels was observed across cuttings and grafted generations. Demethylation emerged as the predominant pattern in seedlings, while hypermethylation was notably present in the progeny of tertiary grafted plants. Although the Cd content in the cuttings themselves was not significantly altered, continuous grafting markedly increased Cd accumulation within various tissues of the subsequent grafted generation plants. Furthermore, it contributed to a reduction in Cd bioavailability in the soil. In summary, continuous grafting suppressed the growth of the grafted cuttings but paradoxically enhanced both growth and Cd uptake capacity in their progeny. This study provides a theoretical foundation for employing grafting techniques to modulate crop physiological responses to Cd-contaminated soil. Subsequent research incorporating transcriptomic analysis is recommended to elucidate the molecular mechanisms underlying these transgenerational effects.