International Journal of Phytoremediation最新文献

In the critically polluted Yamuna River, a lifeline for the Delhi-NCR region, the interplay between seasonal contaminant loads and natural phytoremediation remains poorly understood. This study presents the quantification of eight priority pharmaceutical and personal care products (PPCPs) in water with evaluation of the bioaccumulation potential in Eichhornia crassipes along a 22 km area in pre- and post-monsoon. Paracetamol (up to 2866.9 ± 41.60 ng/L) and mefenamic acid (up to 829.5 ± 5.48 ng/L) were the most abundant analytes found in post-monsoon with frequencies of detection (FoD) > 90%. The bioaccumulation assessment was performed in E. crassipes that was naturally abundant in pre-monsoon season but less so in winter, coinciding with a notable rise in PPCP concentrations. The study revealed significant uptake with the assistance of the bioaccumulation factor. The contaminant's retention and distribution in surface water are directly influenced by the seasonal dieback of E. crassipes in river water. Notably, seasonal analysis revealed that pre-monsoon concentrations of carbendazim were significantly higher than post-monsoon levels (p < 0.05). These findings emphasize the regulation of PPCP dynamics in urban rivers by the phytoremediation potential of E. crassipes and highlight the need for integrating natural wetland vegetation into water quality management strategies.

This study offers a detailed case-based evaluation of a laboratory-scale vertical flow constructed wetland (VFCW) system treating aquaculture wastewater characterized by a controlled effluent matrix and carefully managed hydraulic retention times (HRTs). Unlike more generalized constructed wetlands (CWs) applications, our research integrates specific operational parameters including vertical flow design, a 360 L treatment capacity, and a hydraulic loading rate of 8.2 L/d/m² to systematically assess the removal of critical pollutants such as nitrate (N$O_3^{-}$), phosphate (P$O_4^{-3}$), hydrogen sulfide (H₂S), biochemical oxygen demand (BOD), and potassium (K⁺). The significant pollutants reductions achieved N$O_3^{-}$ by 73.9%, P$O_4^{-3}$ by 96.3%, and BOD by over 90% demonstrate the system's high efficacy and validate its practical potential as a climate-resilient, nature-based treatment solution tailored for sustainable small-holder aquaculture systems. Indeed, our work emphasizes the quantification of multi-parameter attenuation under five distinct HRTs conditions during a short-term experimental trial, offering valuable, actionable insights for optimizing VFCW configurations adapted to aquaculture wastewater characteristics. This focused approach, addressing a specific aquaculture effluent matrix with operational conditions tailored to laboratory-scale treatment systems, clearly differentiates our contribution as an incremental yet valuable advancement. Moreover, it provides practical, real-world context insights and design implications for climate-resilient, nature-based wastewater treatment solutions that are well-suited to support sustainable aquaculture practices. We thereby explicitly acknowledge the foundation established by extensive prior research while delineating our study's unique contextual and operational contributions within the constructed wetland domain.

The novelty of this work lies in the development of a sustainable nanomaterial with an exceptionally high surface area and the comprehensive application of advanced nonlinear isotherm and kinetic modeling. Avocado seed nanomaterial (ASNM) was comprehensively characterized, particle size analysis revealed a uniform distribution of 155-160 nm, with BET surface areas of 2963.4 m²/g, confirming microporous character. SEM imaging revealed a rough morphology, while TEM confirmed nanodomains. Several nonlinear isotherm models were employed to evaluate the efficacy of adsorption. Henry, Langmuir, Freundlich, Temkin, Dubinin-Radushkevish, Jovanovic, Harkins-Jura, Frenkel-Halsey-Hill, Elovich, Sips, Toth, Khan, Liu, Jossens, Radke-Prausnitz, Redlich-Peterson, Hill, Baudu, and Fritz-Schlunder isotherms were used to test the equilibrium data. The model parameters were statistically analyzed using error functions, including the Residual Sum of Squares Error, Chi-square, Average Relative Error, Hybrid Fractional Error Function, Marquardt's Percent Standard Deviation, coefficient of determination, adjusted coefficient, and Root Mean Square Error. For isotherm model, Liu had a goodness of fit. Pseudo-first-order, pseudo-second-order, Elovich, Avrami, Weber-Morris, Linear Driving Force, Boyd's external diffusion, and Bangham models were used to examine the kinetic data. The Avrami and Bangham models provided the best fit for the sorption kinetics of phenol. Thermodynamic parameters confirmed that phenol adsorption was endothermic and spontaneous.

Water contamination by heavy metals threatens human and environmental health. This study evaluated Pistia stratiotes L. and Lemna minor L. for remediation of cadmium (Cd), chromium (Cr VI), and lead (Pb) applied at the rate of 0, 5, 10, and 20 mg L^-1 under varying pH (6-8) and electrical conductivity (EC; 1,450 and 2,150 µS cm^-1) in Hoagland solution. Higher moisture content was observed at neutral pH in Lemna minor L (98.1%) and Pistia stratiotes L. (96.8%) which were decreased with increasing EC and acidic pH. P. stratiotes sustained comparatively higher moisture between pH 6-8, proving its adaptability to pH stress. Heavy metal stress significantly decreased growth of both aquatic macrophytes. Higher growth (75% and 54.5%), tolerance index (41.9% and 62.1%), and plant growth rate (0.16 and 0.07) were recorded in L. minor and P. stratiotes respectively, at neutral pH. However, acidic pH and increasing heavy metal content adversely affected mentioned parameters. The potential of macrophytes for heavy metal absorption/uptake significantly varied between the species depending upon pH and EC. The P. stratiotes absorbed higher Cr (1,614 mg kg^-1), Pb (1,469 mg kg^-1), and Cd (487 mg kg^-1) at pH 6-7, while L. minor showed higher accumulation (1,644 mg Cr kg^-1, 617 mg Cd kg^-1 and 593 mg Pb kg^-1) under salinity stress. Both species showed hyper-accumulation having a bio concentration factor (BCF) > 1,000) of Cd, Cr, and Pb under acidic pH and elevated EC. The P. stratiotes exhibited greater overall adaptability across pH conditions while L. minor performed better under saline environments. Therefore, Pistia stratiotes is recommended for remediation of metal-contaminated waters across variable pH regimes, whereas Lemna minor is better suited for saline and alkaline environments.

Hexavalent chromium, Cr(VI), is a highly toxic heavy metal that disrupts metabolic processes and threatens aquatic ecosystems. Cyanoremediation using metabolically active cyanobacteria for heavy-metal sequestration and detoxification is a sustainable, eco-friendly remediation approach. The present study evaluated the Cr(VI) removal efficiency and physiological responses of an indigenously isolated freshwater cyanobacterium, Oscillatoria pseudogeminata, under different Cr(VI) concentrations (2, 5, 7, and 10 ppm). Growth performance, photosynthetic pigments, oxidative stress markers, antioxidant responses, and chromium uptake were assessed to determine cellular responses to metal stress. Increasing Cr(VI) concentrations caused a concentration-dependent decline in growth, biomass accumulation, and pigment content, indicating impairment of photosynthetic and metabolic processes. In contrast, oxidative stress indicators and antioxidant defense responses, including malondialdehyde accumulation, superoxide dismutase activity, and proline content, were significantly elevated at lower Cr(VI) levels (2 and 5 ppm), reflecting activation of cellular defense mechanisms. These responses declined at higher concentrations, suggesting enzyme inhibition and severe metal-induced oxidative damage. Scanning electron microscopy revealed morphological alterations in treated filaments, while atomic absorption spectroscopy confirmed significant Cr(VI) absorption by the cyanobacteria, with removal efficiencies ranging from 48 to 60%. Overall, Oscillatoria pseudogeminata demonstrates notable chromium tolerance and biosorption capacity, highlighting its remediation potential for treating chromium-contaminated water.

Water scarcity and pollution are major environmental problems in developing countries. To tackle these issues, it is crucial to develop sustainable and innovative waste water treatment methods. Constructed wetlands (CW) are efficient and eco-friendly waste water treatment systems, valued for their low cost, energy efficiency, and easy maintenance. The current study aimed to evaluate the potential of Canna indica and Colocasia esculenta plant species, along with Styrofoam and crushed plastic as amendments to filtration media (large gravel, small gravel, loamy soil, and sand), in treating waste water. We constructed four wetland units, each with four treatments, and monitored their performance by measuring pH, electrical conductivity (EC), total dissolved solids (TDS), total suspended solids (TSS), biological oxygen demand (BOD), chemical oxygen demand (COD), nitrate nitrogen (NO₃-N), phosphate (PO₄^3-), lead (Pb), cadmium (Cd), and Escherichia coli (E. coli). The pH of waste water in treatment T4 (filtration media with crushed plastic and styrofoam planted with C. indica and C. esculenta) of Unit 4 reached 8.1, which was the highest observed and played a key role in breaking down organic substances in the waste water. Results showed that unit 4 led to the best improvement in plant growth. T4 treatment of unit 4 produced the highest root fresh biomass (197 g for Ci and 1126 g for Ce) and shoot fresh biomass (607 g for Ci and 458 g for Ce). The increased root volume of both plant species provided microbial films and helped to reduce BOD by 92.7% and COD by 83.1%. T4 treatment of unit 4 turned out to be the most effective, achieving significant reductions in various waste water quality parameters. For instance, levels of NO₃-N dropped by 100%, PO₄^3- by 77%, EC by 77%, TDS by 92%, TSS by 50%, Pb by 77%, Cd by 100%, and E. coli by 99.1%. These findings confirm that our developed CWs are an effective, economical, and environment friendly solution for waste water treatment, particularly in developing countries facing water scarcity.

This study investigated the combined effect of Bacillus megaterium (B) and humic acid activator (HA) on enhancing ryegrass phytoremediation of Cd-contaminated phosphate soil. A pot experiment compared four treatments: control (CK), B alone, HA alone, and combined B + HA. Results showed that the B + HA treatment most effectively improved the soil microenvironment, reducing pH by 0.83 units and increasing available phosphorus by 45.74% compared to CK. This combination also notably promoted ryegrass growth, increasing above-ground and root dry weight by 47.31% and 58.33%, respectively, while increased plant height and chlorophyll content. Regarding Cd remediation, B + HA increased available Cd in rhizosphere soil by 61.90% and enhanced above-ground Cd accumulation by 21.18% compared to CK. Two-way ANOVA confirmed significant interactive effects between B and HA on Cd accumulation, soil pH, and phosphorus availability. The combined treatment also increased the bioaccumulation factor and transportation factor of Cd. The study demonstrates that B. megaterium and HA act complementarily to improve soil conditions, promote plant growth, and enhance Cd phytoextraction efficiency in ryegrass.

Chromium is a widespread environmental contaminant, with its hexavalent form [Cr(VI)] recognized as highly toxic due to its solubility, mobility, and bioavailability. Cr absorption and intracellular redox reactions in plant systems generate free radicals that interfere with vital phytochemical processes. Oxidative stress, driven by excessive reactive oxygen species (ROS) production, causes DNA damage, chromosomal abnormalities, impaired seed germination, stunted seedling growth, disruption of photosynthesis and nutrient uptake. Genotoxic and mutagenic impacts include chromosomal aberrations, micronuclei formation, and epigenetic alterations. Plants counteract these effects through antioxidative defense systems that involve both non-enzymatic and enzymatic antioxidants. Microorganisms also contribute to detoxification by biosorption, bioaccumulation, redox transformations, and secretion of extracellular polymeric substances. It facilitates the toxicity reduction of Cr by converting Cr(VI) to Cr(III). An integrated remediation strategy involving plant antioxidative defenses and microbial interactions offers a sustainable approach for the restoration of Cr-contaminated ecosystems. This review is a synthetic conceptualization of current knowledge on the molecular and genotoxic impacts of Cr in plants, highlighting plant-microbe interactions, ROS-mediated responses, and eco-friendly remediation strategies. It emphasizes the need for advancing phytoremediation and microbial biotechnology, along with emerging genomic and omics-based approaches, to mitigate Cr-induced stress and safeguard agricultural productivity and ecosystem health.

Industrial hemp (Cannabis sativa L.) is an effective crop for the phytomanagement of lands contaminated with trace metals, demonstrating tolerance to metal toxicity without significant impacts on its value-chain. However, the effects of metal contamination on hemp flowers remain understudied, limiting the assessment of the valorization potential for this valuable plant part. In a greenhouse experiment, we evaluated flower production, cannabinoid content and metal accumulation in hemp grown on a soil contaminated with Cd, Pb and Zn (pseudo-total concentrations: 13.0, 664 and 1048 mg kg^-1, respectively). Our results suggest a limited capacity for phytoextraction, with low removal rates for all three metals. Still, hemp flowers presented favorable features that support valorization potential. Both flower biomass and the synthesis of cannabidiol and tetrahydrocannabinol were comparable to plants grown under reference conditions. Notably, inflorescences exhibited the lowest accumulation of Cd and Pb among all plant tissues. Concentrations for these elements were 0.45 and 1.1 mg kg^-1 respectively, remaining below most commercial limits for herbal drug products. These findings demonstrate that hemp flowers can be safely produced on metal-contaminated soils, reinforcing the suitability of hemp as a robust and versatile crop for the phytomanagement of legacy metal pollution.

Heavy metals contamination poses a persistent threat to ecosystems and human health due to its toxicity, non-biodegradability, and tendency to bioaccumulate. This review systematically evaluates recent advances in phytoremediation as a sustainable strategy for mitigating heavy metals pollution, with a specific focus on underlying mechanisms, technological innovations, and field-scale applicability. The scope of the review encompasses major phytoremediation approaches, including phytoextraction, phytostabilization, phytovolatilization, phytodegradation, and rhizofiltration, alongside detailed analyses of plant-metals interactions, uptake and translocation pathways, and metal sequestration processes. Key findings highlight the critical role of plant-associated microorganisms, genetic engineering, and transgenic plants in improving metal tolerance, accumulation efficiency, and remediation rates. Evidence from recent field studies demonstrates that integrated phytoremediation systems can significantly enhance remediation performance when compared to single-approach strategies, although challenges related to metal bioavailability, site specificity, and long remediation timelines persist. Emerging developments such as nanophytoremediation and combined phytotechnological frameworks have been identified as promising solutions to overcome current limitations. Overall, this review provides new insights into the integration of biological, technological, and policy-driven approaches required to advance phytoremediation from experimental applications to large-scale environmental management.