International Journal of Phytoremediation最新文献

This research examines the composition of macro and trace elements in wild plants that thrive along two riverbanks, with an emphasis on their capacity for bioaccumulation, potential for phytoremediation, and contributions to nutrition. Nutritional assessment showed that these plants contribute on average 7% of the recommended dietary allowance (RDA) for K, 3.8% for P, while trace elements contribute on average to the RDA as follows: Fe (51.9% for male and 23.2% for female) > Ni (26%) > Cu (19.1%) > Zn (5.4% for male and 7.5% for female). Bioaccumulation revealed that Amaranthus retroflexus and Cuscuta campestris clustered together as efficient accumulators. Cadmium and Pb were identified as the primary contributors to the elevated hazard index, indicating that they are the trace elements of greatest concern regarding non-carcinogenic health risks in this study. This case study examines 17 plant species, offering new insights into their dual functions as bioindicators and sources of nutrition. It establishes a foundational benchmark for phytoremediation strategies in similar ecosystems affected by human activities. This study uniquely highlights the nutritional potential and health risks associated with the consumption of wild plants. The findings emphasize the significant role of wild plants in meeting dietary needs for elements such as Fe, Ni, Cu, and Zn while also addressing the potential human health risks, their capacity for bioaccumulation, and potential for phytoremediation.

Industrial hemp offers several advantages for phytomanaging metal(loid)-contaminated soils as it can provide valuable biomass notably for bioenergy while accumulating some metals (i.e., Cd and Zn) in its shoots. In a previous pot study humic/fulvic acids (HFA) incorporated into the soil with arbuscular mycorrhizal fungi (AMF) enhanced hemp growth. This study assessed the biostimulant effect of HFA, alone or paired with AMF (HFAxAMF), on the shoot yield and shoot Cd, Pb and Zn uptakes in a 2-year field trial in view of producing clean, renewable liquid biofuels. The trial (0.07 ha) was carried out at a contaminated agricultural field in a randomized split-plot design (nine blocks). Cannabis sativa L. was sown at a density of 173 000 plants ha^-1. Effects of HFA and HFAxAMF treatments on the behavior of metals and plants were compared to an unamended one. Hemp produced on average 10.7 (year 1)-14.5 (year 2) t DW ha^-1 despite a severe drought in year 1. Neither HFA nor HFAxAMF treatments enhanced shoot yield. Shoot Cd, Pb and Zn uptakes reached 9.9, 230, and 869 g ha^-1year^-1, respectively. In year 2, shoot Cd uptake improved under all treatments and the 0.01 M Ca(NO₃)₂-extractable soil Cd, Pb and Zn concentrations at harvest decreased by 95, 79 and 96%, respectively. Hemp was a relevant plant species for phytomanaging this metal-contaminated soil under current climatic constraints. The potential bioethanol yield was estimated in the 3851-6481 L ha^-1 range. Overall, hemp can simultaneously reduce soil metal availability while producing a biomass convertible into liquid biofuels. This highlights its strong potential as a dual-purpose crop for sustainable and progressive phytoremediation and renewable energy production.

Although biochar is widely used for the remediation of potentially toxic elements (PTEs), comparative evaluations of biochar (BC) and its nanoform (nanobiochar, NB) for soil-based phytostabilization remain limited. This study assessed the efficiency of BC and NB (applied at 2.5%, 5%, and 10% w/w) in immobilizing cadmium (Cd) and lead (Pb) in contaminated soils using maize (Zea mays L.) as a test crop in a completely randomized design. Both amendments significantly improved soil physicochemical properties, with NB 10% producing the greatest increase in organic matter (from 0.85% to 1.80%) and cation exchange capacity (from 9.8 to 18.4 cmol/kg). Compared with the unamended control, NB 10% reduced bioavailable Cd and Pb fractions by 76.1% and 83.7%, respectively, while increasing pseudo-residual metal forms. Maize germination increased from 64% in the control to 88% under NB 10%, and root growth inhibition decreased by 62%, indicating reduced metal phytotoxicity. Shoot and root Cd and Pb concentrations declined by more than 50%, resulting in markedly lower bioaccumulation and translocation factors. The highest phytostabilization efficiency (90% for Cd, 94% for Pb) and pseudo-residual fractions (90.7% Cd, 94.1% Pb) were recorded in NB 10%-amended soil. Overall, NB outperformed conventional BC due to its greater surface reactivity, porosity, and functional properties, demonstrating strong potential for sustainable stabilization of PTE-contaminated soils. These results demonstrate that NB can serve as an efficient and sustainable soil amendment for reducing metal bioavailability and ensuring safer crop production in contaminated agricultural soils.

Multitiered duckweed bioreactors have been developed but have limitations due to the weight of the water column. It was hypothesized that fog-o-ponic growth systems can enable space efficient duckweed culturing by facilitating stacked cultivation systems with multiple thin layers of duckweed, in the absence of a heavy water column. In this study, the growth was assessed of Lemna minor suspended on a fabric textile under a nutrient-rich medium provided as a fog. The best growth of L. minor was a relative growth rate (RGR) of 0.24 d^-1 with a maximum quantum efficiency (Fv/Fm) and light-adapted quantum yield (Y(II)) of around 0.8 and 0.5, respectively, which are values comparable to those achieved on traditional liquid medium under otherwise similar conditions. These results reveal that L. minor not only survives under fog-o-ponics culture conditions, but it thrives both in short and longer trials. Consistent with good growth, removal of nutrients by L. minor was considerably (e.g.,500 mg total nitrogen (TN) m^-2day^-1) under fog-o-ponics conditions. It is concluded the innovative way of duckweed culturing comprises a promising, multi-stacked, high capacity, phytoremediation system.

Cadmium (Cd) is a highly toxic heavy metal that poses a serious threat to rice (Oryza sativa L.) productivity and food safety. γ-aminobutyric acid (GABA) is known to promote rice growth and reduce Cd uptake, but mechanism of its role in alleviating Cd toxicity in rice remains unclear. In this study, we examined the effects of GABA (0.25 mmol L^-1) on biomass accumulation, Cd distribution, and gene expression in rice under Cd stress (1 mg L^-1) with three biological replicates. GABA application increased root and shoot biomass of rice (Duncan's multiple range test) while reducing Cd content in both tissues (Student's t-test). Compared with Cd treatment, GABA increased root and shoot biomass by 47.22% and 23.72%, respectively, and decreased root and shoot Cd contents by 6.56% and 39.16%, respectively. GABA also altered Cd partitioning by promoting its redistribution to soluble and organelle/membrane fractions in roots and shoots. Transcriptome profiling revealed differentially expressed genes (DEGs, fold-change thresholds ≥ 1.5 and false discovery rate < 0.05) involved in photosynthesis, glutathione metabolism, and light-responsive pathways under Cd stress. A total of 1570, 1233, and 232 DEGs were identified in control vs Cd treatment, control vs GABA treatment, and Cd treatment vs GABA treatment, respectively. GABA modulated DEGs associated with the stress response, ion transport, and secondary metabolism. RT-qPCR validation of four key DEGs, ferritin 1 (Fer1), glutathione S-transferase 6 (GSTU6), cytochrome P450 709B2-like (CYP709B2), and ent-sandaracoparadiene 3-hydroxylase-like (CYP701A8), confirmed the transcriptomic trends. These findings suggest that GABA alleviates Cd toxicity in rice by promoting growth, regulating Cd distribution, and modulating stress-responsive gene expression, offering new insights into GABA-mediated heavy metal tolerance.

Heavy metal contamination of agricultural soils, particularly by zinc (Zn) and cadmium (Cd), threatens food security and ecosystem health. This study evaluated the in situ phytoremediation potential of Ricinus communis L. in Zn- and Cd-contaminated field soils amended with citric acid (CA), spent mushroom substrate (SMS), and their combination (CA+SMS). Across contamination levels, SMS and CA+SMS significantly increased total biomass to 164.70 ± 5.61 and 162.80 ± 4.11 g per plant, respectively, compared with 77.38 ± 3.40 g in the unamended control (one-way ANOVA with Tukey's HSD, p < 0.05). Accordingly, total Zn extraction increased by 114.86% (SMS) and 104.89% (CA+SMS), while total Cd extraction increased by 112.80% and 99.22%, respectively (p < 0.05). Cd bioconcentration factors (BCF) remained > 1 across all treatments, whereas Zn BCF remained < 0.33. At high contamination, CA+SMS enhanced soil enzyme activities (urease and catalase (CAT)), with CAT reaching 1.98 ± 0.01 mL 0.1 mol L^-1 KMnO₄ g^-1 h^-1). SMS maintained seed oil content (∼ 55.71 ± 1.78%). Overall, R. communis is a high-biomass, metal-tolerant candidate for field phytoremediation, and CA+SMS is a practical, low-cost strategy that enhances plant uptake while promoting metal sequestration into less labile reducible/oxidizable/residual fractions relative to exchangeable/carbonate-bound pools.

Significant environmental damage to aquatic ecosystems is caused by heavy metals, and the situation necessitates strategies against the contaminants. The present study was intended to explore Salvinia molesta's potential for the phytoremediation of contaminating water to remove three metals: chromium (Cr), nickel (Ni), and cadmium (Cd), with an emphasis on the influence of chemical amendments, ethylene diamine disuccinic acid (EDDS) and sodium dodecyl sulfate (SDS), applied independently. Plants were treated for a period of 60 days with single and combined metal solutions supplemented with EDDS (0.05-0.2%) and SDS (0.5-2%), and responses were measured through morphological factors and biochemical indicators, including bioaccumulation factor (BAF) with translocation factor (TF) used cautiously due to the floating habit of S. molesta. It was observed that S. molesta was capable of substantial heavy metal accumulation, with the highest accumulation recorded under EDDS amended and SDS amended treatments at elevated metal concentrations. EDDS treatments primarily enhanced metal bioavailability and uptake while maintaining plant growth and physiological stability under moderate metal stress, whereas SDS treatments, particularly at higher concentrations, resulted in increased metal accumulation accompanied by reductions in biomass, chlorophyll content and protein levels, indicating stress driven accumulation linked to altered membrane permeability. The application of EDDS or SDS resulted in higher metal uptake compared to untreated controls, with BAF values reaching 3.8 for Cr, 4.2 for Ni, and 3.5 for Cd; however, maximum accumulation under SDS treatments did not consistently correspond to biologically sustainable phytoremediation performance. Statistical analysis showed significant differences (p < 0.05) between treatments and control in metal bioavailability following amendment application, highlighting a dose-dependent tradeoff between metal uptake efficiency and plant health. This study represents the first integrated evaluation of EDDS and SDS under multi-metal (Cr-Ni-Cd) conditions in S. molesta, addressing a major gap in chemical-assisted phytoremediation research. Future work should be aimed at determining the optimum concentrations of these chemical amendments to facilitate the scale-up of phytoremediation projects.

Nanoparticle-based soil amendments represent a promising strategy to improve plant growth and phytostabilization in contaminated soils. This study investigated the efficacy of nano-sized stilbite-zeolite (NSZ) and nanoblack-carbon (NBC) on durum-wheat (Triticum turgidum L.). This study was conducted to evaluate the effects of NSZ particle size (0.2 mm, 0.1 mm, <0.05 mm), NSZ application rate (0%, 4%, 8% w/w), and NBC application rate (0%, 4%, 8% w/w). The co-application of fine-particle NSZ (<0.05 mm) and NBC, each at 8% (w/w), yielded the most significant improvements. This optimal treatment enhanced soil-health, increasing CEC by 20.04% and available-phosphorus by over 300% compared to the control. Grain yield increased from 1,057 kg ha^-1 in the control to 2,544 kg ha^-1, representing a 140.5% improvement. The number of grains per spike increased from 22.33 to 34.3, while the amendments effectively reduced heavy metal uptake. Specific treatments, such as NSZ at 4% (w/w) (NSZ₂), significantly reduced Cd and Hg concentrations in grain by 69.7% and 69.1%, respectively, compared to the control. The NBC treatment at 8% (w/w) (NBC₂) reduced As and Pb levels by 55.8% and 42.1%. These reductions confirm successful immobilization of metals in the soil and restricted translocation to edible grains.

This study presents the synthesis and evaluation of a novel bio-based nanocomposite, Nitzs-Si@nMs, derived from Nitzschia sp. diatom biomass functionalized with a silica matrix and magnetite (Fe₃O₄) nanoparticles. The composite was fabricated through a facile room-temperature method and comprehensively characterized using FTIR, XRD, SEM-EDX, XRF, and particle size analysis. Nitzs-Si@nMs demonstrated outstanding adsorption performance for Cd(II), Cu(II), and Pb(II) ions in single, binary, and multicomponent systems. Under optimal conditions (pH 5.0, 120 min contact time, and 300 mg L^-1 initial concentration), removal efficiencies exceeded 99%. Adsorption followed pseudo-second-order kinetics and conformed to the Langmuir isotherm, indicating monolayer chemisorption. Maximum adsorption capacities were 1.0204 mmol g^-1 for Cu(II), 0.7299 mmol g^-1 for Cd(II), and 0.5587 mmol g^-1 for Pb(II). Competitive studies revealed a strong selectivity for Cu(II), attributed to its smaller hydrated radius and high affinity for Fe-O coordination sites introduced by magnetite. The composite exhibited robust chemical stability in acidic environments (84% Si retention after 96 h at pH 1.35) and retained over 80% of its adsorption capacity across four regeneration cycles using 0.1 M HCl. Compared to conventional bio-adsorbents, Nitzs-Si@nMs achieved superior adsorption capacities and operational advantages, including facile magnetic separation and reusability.

Lignocellulosic materials, such as bamboo leaves and their acid-treated forms, were used as adsorbents to remove the azo dye Crystal Violet (CV) from the aqueous systems. Scanning electron microscopy, nuclear magnetic resonance spectroscopy, Fourier-transform infrared spectroscopy, and Brunauer-Emmett-Teller (BET) specific surface area analysis were employed to characterize the adsorbents. Each experiment aimed to ascertain the effects of different physical variables. Several kinetic models have been applied to fit the kinetic data, of which the pseudo-2nd-order kinetics is the best fit. CV removal (%) is achieved at roughly 97%. PBL has a higher q_max (166 mg/g at 298 K) than other adsorbents. The Langmuir model is more accurate than the Freundlich and Temkin models. The q_max (Langmuir) data order is significantly increased, i.e., PBL > SBL > BL. The thermodynamic parameters reflect disorder, spontaneity, and a heat-absorbing nature. The investigational data have been examined successfully using a genetic algorithm (GA) and multiple polynomial regression (MPR). The adsorbent's performance in actual industrial effluents (including reductions in COD, BOD, TDS, turbidity, and color) demonstrates its economic feasibility compared with commercial activated carbon, thereby enhancing the practical relevance of the study.