International Journal of Phytoremediation最新文献

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.

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.

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.

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.

BTEX compounds (Benzene, Toluene, Ethylbenzene, and Xylene) are hazardous indoor air pollutants known for their carcinogenic properties and adverse effects on respiratory health. This systematic review, conducted in accordance with PRISMA guidelines, investigates the potential of indoor plants to reduce or remove BTEX from indoor air. A comprehensive search across Scopus, PubMed, and Web of Science yielded 687 articles, with 43 studies meeting inclusion criteria after rigorous screening. The findings indicate that removal efficiencies vary widely, ranging from -25% to 100%, with phytoremediation (82.4%) and microbial degradation (17.5%) identified as the primary removal mechanisms. Commonly studied species included Ficus benjamina, Zamioculcas zamiifolia, and Aglaonema brevispathum. However, practical application remains constrained by the limited effect size per plant, often necessitating large quantities for meaningful pollutant reduction. While indoor plants offer a natural, sustainable, and cost-effective approach to improving indoor air quality, challenges related to cost, maintenance, and scalability must be addressed. Future research should prioritize cost-benefit analyses, pollutant-specific plant selection, and standardized experimental metrics such as mg/h/m² to facilitate real-world implementation.

Microalgal biomass represents a renewable and carbon-neutral resource to produce biofuels and value-added biochemicals. In this study, both raw and lipid-extracted Nitzschia laevis biomass were subjected to hydrothermal carbonization (HTC) in a batch-type SS-316 autoclave reactor (100 mL) to investigate the dual valorization potential of the resulting hydrochar and process water. HTC was conducted at 180-260 °C for 30-60 min using a biomass-to-water ratio of 0.2 (w/v). The operating conditions of 260 °C and 60 min produced the highest carbon efficiency (46.3 wt%) and hydrochar yield (35.9 wt%), while the maximum higher heating value reached 2.95 MJ kg^-1. The process water contained up to 1075 mg C L^-1 total organic carbon and was enriched with acetic acid, formic acid, and furfurals, reflecting extensive hydrolysis and reformation reactions of carbohydrate and protein fractions. Although the high silica and ash contents of Nitzschia laevis limit its suitability as a direct solid fuel, the hydrochars exhibited enhanced porosity and diverse surface functionalities, indicating potential applications in adsorption, catalysis, and soil improvement. Overall, this study establishes a comprehensive framework for microalgal biomass valorization, demonstrating that simultaneous recovery of hydrochar and biochemical-rich process water through HTC can support next-generation, circular, and sustainable microalgae-based biorefineries.

Photocatalytic degradation of organic pollutants on biogenically synthesized nanocatalysts is a pragmatic approach. In this regard, the use of gallic acid (GA) as a capping and reducing agent is scarcely studied. Therefore, the synthesis of GA capped g-ZnO NPs, g-CuO NPs, and g-ZnO-CuO NCs is reported here for the photocatalytic and antioxidant applications. The synthesized samples were thoroughly characterized by PXRD, FTIR, SEM, EDX, ZP, and UV-Visible spectroscopy, confirming the reduction and formation of nanomaterials. Due to the visible light-responsive energy band gaps (2.68-3.14 eV), the photocatalytic activity of the g-ZnO NPs, g-CuO NPs, and g-ZnO-CuO NCs was evaluated for the photodegradation of azo dyes, i.e., methylene blue (MB) and crystal violet (CV). On comparison of pristine g-ZnO NPs and g-CuO NPs, the g-g-ZnO-CuO NCs showed the best photocatalytic activity by degrading CV (91%) and MB (90%) with rate constant values of 2.43 × 10^-2min^-1 and 2.35 × 10^-2min^-1, respectively. Due to potent antioxidant GA capping, the antioxidant activity of synthesized NPs and NCs was also evaluated by DPPH assay, FRAP assay, and TPC assay. Based on experimental findings, the synthesized g-ZnO-CuO NCs have been proposed as a reliable material for a sustainable and efficient solution to tackle water contamination.

Lead (Pb) contamination in soil presents a major threat to plant health and ecosystem integrity, particularly in urban areas with ornamental plants. Arbuscular mycorrhizal fungi (AMF) mitigates heavy metal toxicity, but comparative data across ornamental species are limited. This study investigated Rhizophagus irregularis effects on Pb uptake and physiological traits in ornamental cabbage (Brassica oleracea) and gladiolus (Gladiolus grandiflorus) under five Pb levels (0-200 mg Pb/kg soil) in a greenhouse using a factorial experimental design. Results showed that AMF reduced Pb translocation from roots to shoots in both species. At 200 mg/kg Pb, root Pb concentrations decreased from 67.8 ± 3.2 mg/kg to 54.6 ± 2.9 mg/kg in ornamental cabbage, and from 63.2 ± 3.0 mg/kg to 51.7 ± 2.8 mg/kg in gladiolus due to AMF inoculation. Chlorophyll content and shoot biomass also declined less severely in AMF-treated plants. Notably, gladiolus plants exhibited higher AMF colonization (70.2% at 0 mg/kg Pb) and maintained greater stability in growth and chlorophyll content than ornamental cabbage, indicating a species-specific variation in symbiotic efficiency and Pb stress tolerance. These results highlight species-specific benefits of AMF under Pb stress and underscore the potential of integrating diverse ornamental and crop species in phytoremediation strategies based on their symbiotic compatibility.

This research focused on applying three microalgae Chlorella vulgaris, Chlorella sorokiniana, and local strain Haematococcus pluvialis for wastewater remediation at high temperature, assessing their efficiency in reducing nitrogen (NH₄⁺ and NO₃^-), phosphorus (PO₄^-3) and soluble chemical oxygen demand (COD). The growth rates, proximate and fatty acid (FA) compositions of microalgae were also investigated. Initially, microalgae were cultured in BG-11 medium in 250-mL Erlenmeyer's for 10 days, then scaled up to 1-L Erlenmeyer's for another 10 days, and finally to 5-L plastic vessels for another 15 days. For wastewater treatment (WWT), microalgae were cultivated in rectangular, bench-scale plastic containers (15 L) for 14 days at 35 °C. Growth performance did not change for the first 10 days; however, C. vulgaris and H. pluvialis showed significantly higher growth, compared to C. sorokiniana at the end of the experiment in BG-11 medium. Regarding WWT, C. vulgaris and H. pluvialis showed significantly higher growth performance than C. sorokiniana at the end of the14-day experiment. H. pluvialis showed the highest PO₄^-3 removal rate (96.53%). However, no significant difference was observed in NH₄⁺ removal, which was over 90% for all species. On the other hand, C. vulgaris and H. pluvialis showed significantly higher removal for NO₃^- (92.07% and 92.17%) and for COD (88.44 and 87.55%), respectively, compared to C. sorokiniana. Regarding FA composition of microalgae before WWT, C. sorokiniana and H. pluvialis were dominated by saturated fatty acids (SFA) (39.4 and 50.1%, respectively), while monounsaturated fatty acids (MUFA) were the most abundant ones in C. vulgaris (35.1%). After WWT, SFAs significantly increased in C. vulgaris (95.5%-increment) while they were significantly decreased (17.9%-decrement) in H. pluvialis, and did not change in C. sorokiniana. The findings suggest that all strains, specially C. vulgaris and H. pluvialis, have remarkable capabilities for nutrient absorption at high temperatures, which makes these strains suitable for arid regions.