International Journal of Phytoremediation最新文献

Tannery solid waste poses significant environmental challenges owing to its high metal content, especially Cr. Converting this waste into value-added byproduct i.e., biochar offers a sustainable management approach to reducing the waste load on landfill sites and also guarding the nearby fauna, flora and water bodies. This study aimed to develop metal-resistant microbial consortium loaded biochar (MCLB) by inoculating tannery solid waste biochar (BC) with consortium of ten Bacillus and/or five Trichoderma strains and their effect was evaluated on the morphological and biochemical attributes of sunflowers including metals immobilization. The soil amendment with BC at 2% rate improved the shoot height, dry biomass, and chlorophyll content in sunflowers but not in higher doses. However, the application of MCLB even at its highest concentration i.e., 10% dose showed a significant increase in shoot length (61.2%) and dry weight (656.9%) over BC only. The findings of metal bioavailability indicated that the application of MCLB having metal-resistant strains decreased the mobility of Cd, Cr, Cu, Ni, Pb and Zn into the sunflower tissues compared to BC. Moreover, MCLB enhanced the uptake of Fe and Mg which are beneficial to the plant. In addition to that, the results for phenolic and proline content demonstrated a considerable decrease by MCLB indicating less stress response as compared to BC. Therefore, these findings highlight the potential of MCLB as a sustainable soil amendment for improving the growth attributes of oil-yielding sunflower varieties by using tannery solid waste biochar while decreasing the uptake of nonessential metals. By pyrolyzing the tannery solid waste into biochar, this approach contributes to a circular economy and environmental remediation practices.

Remediation of heavy metal pollution is essential for safeguarding ecological integrity and public health. The present work aimed to prepare a novel biochar from Eucalyptus Camaldulensis leaves (EC-biochar) for the effective removal of Cd²⁺ and Pb²⁺ cations, as representative heavy metals, from aqueous solutions. The adsorption performance of Cd²⁺ and Pb²⁺ cations by EC-biochar was assessed by varying different operating parameters (e.g. pH, temperature, EC-biochar dose, adsorption time, and adsorbate concentration). The maximum removal efficiencies of Pb²⁺ (83.8%) and Cd²⁺ (89.6%) ions were achieved at pH 4.5. The pseudo-second order and Langmuir isotherm models satisfactorily predict the adsorption of Pb²⁺ and Cd²⁺ cations onto EC-biochar. The negative values of ΔG° and ΔH° demonstrated that the adsorption process is spontaneously feasible and exothermic. It is also worth pointing out that the regeneration/reuse study revealed that the as-prepared EC-biochar maintained an excellent adsorption performance after five reuse cycles, demonstrating its suitable reusability. These findings demonstrate that the EC-biochar can serve as an inexpensive, effective and recyclable adsorbent for treating heavy metal-laden effluents.

The discharge of wastewater containing toxic pollutants, such as lead [Pb(II)] and cadmium [Cd(II)], into water bodies is one of the most critical challenges nowadays. Apart from this, the daily generation of organic waste like vegetable, fruit, and flower waste in cities is increasing constantly. Therefore, a novel approach was adopted in this study that used flower waste (Tagetes erecta L. marigold) for the metal removal from polluted water with a view to manage flower waste and metal contaminants simultaneously. The characterization of prepared waste of T. erecta flowers and its biosorption capacity for Cd and Pb were investigated through various techniques viz., atomic absorption spectrophotometer (AAS), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), and Fourier transform infrared analysis (FTIR). Experiments for adsorption isotherm were carried out at the room temperature and the performance was determined using Langmuir and Freundlich adsorption models. Equilibrium data was confirmed to follow pseudo second order kinetics. The maximum adsorption capacities of flower waste for Cd(II) and Pb(II) were 52.6 and 21.74 mg g^-1, respectively. The study findings indicated that the optimum pH and time for the most effective elimination were pH 6 and 150 min, respectively, for Pb (80%) and Cd (91.8%).

This study investigates the potential of Citrus paradisi peel (CP) as biosorbent for the elimination of Rhodamine B (RhD B) from wastewater. The study used FTIR, SEM and EDX to determine the structure of CP. It was shown that 1.4 and 2.0 g were the optimal biosorbent doses for plain and treated peels, respectively. A number of factors were optimized in order to examine the sorbent efficiency for Rhodamine-B dye. Simple and acid-modified biosorbents were employed in batch mode processing to remove hazardous basic dyes such as rhodamine-B. Adsorption equilibrium was achieved within 60 min, and treated grapefruit peels (TTCP) were found to be more effective than untreated grapefruit peels (UCP). Kinetic studies outcomes showed that the pseudo-second-order kinetics form fit more with an R2 of ≥ 0.916 and ≥ 0.932 for UCP and TTCP respectively. The adsorption isotherm of Langmuir was used to describe equilibrium for TTCP, with highest sorption ability of 321.507 µg/g. The study also discovered that 1 M HCl and NaOH may be used to regenerate CP, with recovery rates of RhD B reaching up to 98% and 85%, respectively indicating CP is a potential biosorbent for removing RhD B from aqueous solutions.

In Mexico, oil spills are primarily caused by fuel theft. These incidents have led to the degradation of agricultural soils, with adverse effects on the environment, human health, and the economic development of affected regions. Consequently, biotechnological decontamination techniques have emerged as a promising solution for the restoration of these sites. This study aimed to evaluate the phytoremediation of diesel-contaminated agricultural soils using Gypsophila paniculata and spent Pleurotus spp. substrate as a biostimulant. Additionally, the potential genetic and cellular damage caused by the contaminants present in the soil was assessed before and after the application of biological decontamination treatments. The greenhouse experiment lasted 50 days. Morphological variables of the plants and the total petroleum hydrocarbons (TPH) (mg/kg) were measured, alongside soil toxicity, which was assessed by evaluating the mitotic index (%) and micronucleus frequency (%) in Vicia faba cells. Plants grown with the biostimulant exhibited enhanced morphological characteristics, while the bioremediation treatments achieved diesel removal rates ranging from 29.4% to 46.1%. However, potential genotoxic and cytotoxic effects were observed across all treatments.

Miscanthus × giganteus was tested for textile dye removal. Sorption of Direct Blue 78 was achieved slowly by the leaf (63% after 24 h), while sorption of Basic Red 18 was fast by the stem (96% in an hour). Lignocellulose (24.62% in leaf, 41.34% in fresh and 48.05% in old stem) was responsible for the interaction. FTIR spectra and SEM images of native material and with sorbed dye were similar. Negligible quantities of peroxidases (2 μg/g in old stem) pointed to physical forces underlying sorption. pHpzc for stem-BR18 pair was 5.90 and maximum sorption could be achieved in pH interval 4-9. Desorption and repeated sorption defined maximal binding capacity of 20.8 mg BR18/g of stem. BR18 could be desorbed by only 23% with 0.1 M HCl. Small quantities of zinc (0.71-1.13%), copper (0.74-1.43%) and silicon (0.12-0.28%) were detected without significant difference between samples, as well as chlorine (0.24%) in the sample after desorption and in the sample with sorbed 20.8 mg/g BR18. We propose a more thorough investigation of M. × giganteus as a sorbent of a wider pallet of dyes, as it exerts a potential for such purpose.

This study presents an eco-friendly approach for the green synthesis of manganese oxide nanoparticles (MnONPs) using Triticum monococcum (T. monococcum) (einkorn wheat) seed extract as a reducing and stabilizing agent. The synthesized MnONPs were characterized by UV-Vis, XRD, FTIR, SEM-EDX, BET, and zeta potential analyses, which confirmed their crystalline nature, spherical morphology, and mesoporous structure with a surface area of 41.50 m²/g. Photocatalytic experiments showed significant degradation of Rhodamine B dye, with an efficiency of 98.50% under UV light and the synergistic influence of H₂O₂. The antimicrobial activity of MnONPs was used through the disk diffusion method to observe the sensitivity of Gram-positive and Gram-negative bacterial strains and MnONPs inhibited the growth of Escherichia coli, and Staphylococcus aureus (MRSA and MSSA) bacteria. Antioxidant evaluations showed that MnONPs exhibited improved total oxidant and antioxidant status compared to T. monococcum extract, suggesting superior mitigation of oxidative stress. These results indicate that MnONPs synthesized via this green method are promising materials for environmental remediation and biomedical applications, particularly in oxidative stress management.

The plant species used in constructed wetlands are mainly aquatic herbaceous, most of which tend to die during winter in subtropical areas. At present, very few studies have examined the performance of woody plants in constructed wetlands. In order to increase plant diversity and improve purification ability of vertical-flow constructed wetland during winter, 10 woody plant species were tested by establishing the microcosms simulating vertical-flow constructed wetlands. Their applicability was integrally evaluated, on basis of their adaptability, rhizospheric enzyme activity, and rhizospheric microbial diversity. The results showed that (1) seven woody plant species, Adina rubella, Salix rosthornii, Callicarpa dichotoma, Nerium oleander, Hibiscus mutabilis, Ligustrum obtusifolium, and Ligustrum lucidum could survive in the simulated vertical-flow constructed wetland; (2) N. oleander and C. dichotoma had higher nitrogen (N) and phosphorous (P) absorption capacity; (3) according to the integral evaluation, N. oleander, C. dichotoma, and S. rosthornii have excellent applicability for vertical-flow constructed wetland; A. rubella and H. mutabilis have moderate applicability; L. obtusifolium and L. lucidum have poor applicability; Ligustrum. japonicum "Howardii", Pittosporum. tobira and Distylium. buxifolium, were not applicable to vertical-flow constructed wetland. N. oleander, C. dichotoma, and S. rosthornii are recommended for application in vertical-flow constructed wetland.

Modeling and predicting heavy metal uptake by plants using organic amendments helps reduce metal concentrations in contaminated soils. This study examined the effects of 1% and 2% (W/W) biochar and urban waste compost on the growth and cadmium (Cd) and lead (Pb) uptake by Bromus tomentellus in contaminated soil. The highest plant height (34.0 cm) and biomass (30.0 g) occurred with 2% biochar, compared to 16.0 cm and 9.0 g in control. For Pb, the maximum bioconcentration factor (BCF) was 2.25 with 1% compost, and the highest translocation factor (TF) was 1.4 with 2% biochar. For Cd, both max BCF (3.40) and TF (1.4) were seen at 1% biochar. Metal uptake and transfer significantly correlated with biomass and soil factors such as fertility (N, P, and K), pH, sodium adsorption ratio (SAR), and organic matter (OM) (Mantel test: p = 0.1, r = 0.4). The Group Method of Data Handling (GMDH) model, with high accuracy (R² = 0.998), showed compost caused an initial rise then decline in Cd uptake, while biochar had the opposite effect. Pb uptake increased with compost up to 1.052%, peaking at 763.7 ppm, then decreased. The GMDH model can optimize biochar or compost levels to enhance metal uptake by plants in polluted soils.

Constructed wetlands (CWs) offer an eco-friendly wastewater treatment technology which can provide a low-cost alternative to "raw wastewater discharge" which although is increasingly becoming unsustainable, remains the most common practice for urban housing colonies in India. This study demonstrates that despite being a semi-engineered system CWs can provide consistent removal efficiency while treating "grey water", which constitutes the major fraction of the total wastewater generated in an urban housing colony. The lack of field-scale performance data for CWs has kept builders, practicing engineers, and policy makers thus far unconvinced about their true potential beyond scientific publications. The work presented here provides comparative assessment of phytoremediation potential of two macrophytes Canna indica and Ageratum conyzoides while treating grey water emanating from a nearby urban housing colony. How the relative positioning of these macrophytes, upstream or downstream of each other, can influence the wastewater treatment efficiency was also evaluated. Higher removal efficiencies were observed for inorganic nitrogen (43.4%) and phosphate (45.68%) for CWs vegetated with Canna indica while higher sulfate removal efficiency (63.5%) was observed for CWs vegetated with Ageratum conyzoides. For chemical oxygen demand (COD) and total suspended solids (TSSs), removal efficiencies remained consistently above 65% and 80%, respectively.