International Journal of Phytoremediation最新文献

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.

A field investigation was conducted in 5 lead-zinc mining areas in Guangxi to screen plant species suitable for remediating soil contaminated with potentially toxic elements (PTEs) in the karst region. Samples from 57 dominant plant species, along with their rhizosphere soils, were collected for analysis. The results suggested that Vitex negundo and Ixeris chinensis exhibited high translocation abilities for Cd, Pb, and Zn, with V. negundo showing translocation factor (TF) values of 3.43, 5.01, and 6.01, respectively, and I. chinensis showing TF values of 3.41, 5.69, and 4.80, respectively. The Cd bioconcentration factor (BCF) values of Artemisia indica and Erechtites valerianifolius were 5.43 and 4.61, respectively. Achyranthes bidentata exhibited a high ability for Zn accumulation, with a BCF value of 2.76 for Zn. V. negundo, I. chinensis, A. indica, E. valerianifolius and A. bidentata are potential candidates for soil remediation in areas affected by lead-zinc mining in karst regions. Miscanthus floridius, Clinopodium chinense, and Eleocharis dulcis primarily stored Cd, Pb, and Zn in their roots, with TF values below 0.30 and BCF values below 0.10. It is thereby concluded that these 8 plants can be used in vegetation restoration in lead-zinc mining areas in the karst region.

The arsenic hyperaccumulator Pteris vittata is a prime candidate for phytoremediating globally concerning soil arsenic pollution, however, the mechanism by which arsenic-transforming bacteria enhance its efficiency remains unelucidated. This study used a rhizobag soil culture method to compare the impacts of arsenic-oxidizing (Agrobacterium sp.) and -reducing bacterial (Delftia sp.) strains on arsenic absorption, transformation, and root exudation in P. vittata. The results showed that inoculation of the two microorganisms boosts P. vittata's arsenic uptake: frond and root arsenic contents are 1.57-2.87 and 1.22-2.09 times that of the non-inoculated group, and arsenate-reducing bacteria exert a more significant effect. Arsenic-reducing bacteria raised As(III) proportions in the fern and soil, while arsenic-oxidizing bacteria increased As(V) in the fern. Microbial inoculation also promoted root secretion of oxalic, malic, and acetic acids, more significantly at 5 d than 30 d. In conclusion, exogenous microorganisms improve the fern's arsenic absorption and soil remediation efficiency, offering a microbial strategy for optimizing arsenic phytoremediation.

This study presents a paper-based plasmonic detection mechanism that relies on a distinct colorimetric change in silver nanoparticles (AgNPs), triggered by aggregation-induced plasmonic shifts. Spherical AgNPs are synthesized using the stem bark extract of Ceriops decandra (C. decandra), which serves as both a reducing and capping agent. The extract's strong reducing properties and high affinity for Ag(I) ions enable the formation of a highly selective Cr(III) sensor. The aggregation-based sensing mechanism and its sensitivity and selectivity have been systematically validated using UV-Vis spectroscopy, SERS, FESEM, TEM, and DLS analyses. The optimized sensor exhibits a linear response to Cr(III) concentrations from 0.1 to 20 nM, achieving a detection limit of 0.1 nM with a regression coefficient (R²) of 0.9832. Kinetic and thermodynamic studies further elucidate the sensor's performance and specificity. Overall, this label-free plasmonic sensing method provides a reliable, portable, and efficient solution for on-site detection of Cr(III) in real-world aquatic samples.

Air pollution has emerged as a serious global issue driven by rapid urbanization and industrialization. This study aims to evaluate the air quality of Lucknow, a fast-growing city in North India, using lichen Pyxine cocoes (Sw.) Nyl. Lichen specimens collected from the relatively unpolluted area of Malihabad were transplanted for 30 days at 10 sites in Lucknow City with varying traffic volumes. The concentrations of potentially toxic elements (Fe, Al, Mn, Zn, Cu, Pb, Ni, Cr, Co, and Cd) were determined using an ICP-MS, while PAHs were examined through HPLC. Additionally, the physiological status of the lichen specimen was assessed by analyzing chlorophyll content, chlorophyll degradation, and photosynthetic efficiency (F_v/F_m). A total of 15 PAHs were detected in the transplanted lichens with molecular weights varying from 0.006-6.265 μg g^-1 (low), 0.001-17.027 μg g^-1 (medium), and 3.957-20.862 μg g^-1 (high). In contrast, significantly increased amounts of potentially toxic elements such as iron (4.42-5.38 μg L^-1), aluminum (3.52-4.38 μg L^-1), manganese (99.42-136.35 μg g^-1), and zinc (77.67-83.82 μg g^-1) were detected in sites Alambagh Chauraha, IT crossing and Polytechnic Chauraha. In all the specimens, chlorophyll a (5.17 μg L^-1), chlorophyll b (2.21 μg L^-1), and total chlorophyll (7.38 μg L^-1) were significantly decreased and degraded (0.53 μg g^-1). The results once again demonstrate that transplanted P. cocoes as a sensitive and reliable bioindicator of PAHs and potentially toxic elements induced air pollution in Lucknow City.

Phytoremediation using halophytes provides a sustainable, low-cost method for removing heavy metals from saline-contaminated water. However, the influence of pH on cadmium (Cd) uptake is unclear. This study investigates the combined effects of pH and salinity on Cd uptake and phytoremediation efficiency in the halophyte Atriplex halimus L. A hydroponic experiment was conducted with three pH levels (5.5, 7.0, and 8.5) and two irrigation types (tap and saline water at 20 dS m^-1), using 40 µg Cd L^-1. Results showed that saline irrigation enhanced plant growth, root development, and Cd accumulation, especially under acidic conditions. The highest Cd removal (39.1%), shoot Cd uptake (10.53 μg plant^-1), bioconcentration factor (4.88), and translocation factor (1.18) were observed under saline-acidic conditions, indicating enhanced Cd uptake and efficient translocation to shoots. In contrast, alkaline pH reduced Cd uptake, likely due to decreased exudation of low molecular weight organic acids (citrate, malate, oxalate). Physiological responses, including increased proline and reduced chlorophyll, reflected stress induced by Cd and salinity effects. These findings highlight the importance of pH and root exudates in enhancing halophyte-based phytoremediation and support the use of A. halimus in treating saline wastewater and reclaiming marginal water resources.