International Journal of Phytoremediation最新文献

This study investigated two lab-scale CW systems, traditional horizontal flow (HFCW) and baffled horizontal flow (BHFCW), as a treatment process in CWs filled with porous gravel and planted with Typha latifolia. BHFCW achieved average removal efficiencies of 88.65, 86.00, and 84.17% for TSS, BOD₅, and, COD, respectively. Meanwhile, in HFCW, the removal efficiencies for these pollutants were 88.48, 81.07, and 77.89%, respectively. The results demonstrated that BHFCW is a reliable alternative to enhance the treatment performance of nitrogen in CWs compared to HFCW. The BHFCW removals were the best among all units: 76.59, 86.39, and 92.22% for NH₄⁺, NO₃^-, and NO₂^-, respectively. Statistical differences were observed when comparing removal effects between HFCW and BHFCW (p < 0.05). Nevertheless, 84.15% of orthophosphate was successfully removed in HFCW. The introduction of baffles augmented the flow path of wastewater. 14% and one-day reduction in the area and HRT of BHFCW was noted relative to the HFCW respectively. The two types of flow used are suitable for wastewater treatment. This investigation of flow type showed a role in the absorption and retention of pollutants. In addition, the BHFCW could generate interest in a treatment option.

This study aims to elucidate the effect of Torreya grandis peel biochar application on cadmium-contaminated soil and pakchoi (Brassica chinensis L.) growth. A pot experiment was designed involving four distinct biochar/soil ratio treatments: 0 (Control, CK), 1% (T1), 2.5% (T2), and 5% (T3). The results demonstrated that the incorporation of 5% effectively modulated the pH of acidic soil, substantially elevating soil organic matter, and available N, P, K content. Moreover, it augmented the activities of catalase, urease, and acid phosphatase in the soil, concurrently diminishing the Cd content. This treatment reduced the exchangeable and carbonate-bound Cd fractions by 45% while enhancing the iron-manganese oxide-bound, organic matter-bound, and residual Cd fractions by 26%, 29%, and 96%, respectively. Regarding the growth of pakchoi, the 5% biochar application significantly decreased the Cd content in the edible portion by 51%. It significantly enhanced the fresh weight per plant, soluble solids, soluble sugar, soluble protein, and vitamin C content of pakchoi. In conclusion, the application of T. grandis peel biochar is a viable approach for improving the properties of Cd-contaminated soil, passivating Cd fractions, and enhancing the yield and quality of pakchoi. A biochar pyrolysis temperature of 500 °C and a biochar/soil ratio of 5% is recommended.

Pomegranate peel waste in the forms of raw biomass, biochar and activated carbon has been explored as adsorbents in water treatment. This review examined and discussed published works between 2008 and 2024 that focused on the utilization of pomegranate peel waste adsorbents with emphasis on preparation strategies, characterization techniques and applications. The thermal and chemical activation have shown to improve the structural and chemical properties of the resultant adsorbent materials to effectively adsorb various pollutants such as dyes, heavy metals, organics, inorganic nonmetals, and pharmaceuticals from water. The performance was compared and the avenues for future research was highlighted to shed insight into the potential of pomegranate peel adsorbents for environmental protection.

Enzymatic activity is one of the most essential biochemical mechanisms in CWs and plays a significant function in discharging nutrients from organic molecules. This study aimed to consider the activity of soil enzymes in CWs during the phytoremediation of As and to evaluate the interaction between the enzyme activity and As phytoremediation. The treatments (control, 39 mg kg^-1As, 2% nine-rhizobacteria consortium + 39 mg kg^-1As, 0.04% NPKS fertilizer + 39 mg kg^-1As, and 2% nine-rhizobacteria consortium + 0.04% NPKS fertilizer + 39 mg kg^-1As) were studied for assessing different enzymatic activity and plant-microbe interaction during phytoremediation of As in CWs. The activities of various enzymes were significantly higher at rhizosphere sand than at non-rhizosphere sand and leachate. However, enzyme activity was significantly higher in non-rhizosphere sand than in rhizosphere sand in the case of only alkaline phosphatase enzyme. A significant interaction was observed between the activity of enzymes and As phytoremediation which linear correlation coefficients at rhizosphere sand were 0.9812, 0.9484, 0.9271, 0.925, 0.9175, 0.8661, 0.9598, 0.9261, and 0.87 for urease, acid phosphatase, alkaline phosphatase, arylsulphatase, β-glucosidase, dehydrogenase, amylase, catalase, and total enzyme respectively. These enzymatic functions helped in waste breakdown; hence, higher enzymatic activity may boost As phytoremediation in CWs. So, these results of the current investigation will significantly provide knowledge of plant-microbe relationships for the phytoremediation of arsenic in CWs.

Bisphenol A (BPA), a widespread industrial chemical, significantly inhibits root elongation, reducing it by 2%, 32%, and 64% at concentrations of 10, 20, 30, and 40 µM, respectively. This study delves into the interplay between ethylene and auxin in mediating BPA-induced primary root growth inhibition in Arabidopsis thaliana. Furthermore, ethylene modulates BPA sensitivity, as evidenced by reduced inhibition in ethylene-insensitive mutants (etr1-1, etr1-3, ein2-1) and heightened sensitivity in ethylene-overproducing lines (eto1-1, ctr1-1). Ethylene biosynthesis inhibitors (AVG, CoCl2) significantly decreased BPA-induced root inhibition. Treated plants showed increased expression of ethylene biosynthetic genes (ACS2, ACS6, ACS8, ACO1, ACO2). Auxin involvement was evident as aux1-7 mutants showed reduced sensitivity, and NPA (an auxin transport inhibitor) improved root growth. BPA and ACC treatments elevated DR5 and EBS activity, indicating enhanced ethylene and auxin signaling. AVG or NPA effects on DR5 activity under BPA stress revealed that ethylene modulates auxin accumulation and distribution. The study suggests that ethylene regulates BPA-mediated root inhibition by influencing AUX1 expression and auxin distribution, offering new insights into the interaction between ethylene, auxin, and BPA in plant growth.

Herein, a walnut shell as a biosorbent was applied to remove petroleum compounds from the water medium. The characterization analyses of the walnut shells showed the macro-mesopore structure of the walnut shells, a specific surface area of 26 m²/g, and the presence of various functional groups (-OH, -COOH, -C = O). The CCD design showed that the walnut shell can remove 84.43% of petroleum compounds at pH = 3 (the optimum pH), adsorbent dosage: 2 g/L, and initial concentration of petroleum compounds: 550 mg/L. The study of kinetics and adsorption equilibrium indicated matching the experimental data with the pseudo-second-order kinetic model and Freundlich equilibrium isotherm, respectively. The maximum adsorption ability of walnut shell was 3038.29 mg/g at 45 °C. The ability to regenerate and reuse the walnut shell was investigated in 6 cycles, and the results showed a 21% decrease in adsorption ability after 6 cycles. The obtained data showed that the walnut shells could be a promising adsorbent with high adsorption ability toward petroleum components. Also, the walnut shell is a regenerable adsorbent, low-cost, and environmentally friendly, and can be effective in successive cycles. Therefore, this biosorbent can have a superb influence on wastewater treatment technology and possible applications at an industrial scale.

Synthetic dyes are a major source of environmental pollution. In this regard, biosorption is an important treatment method for the removal and detoxification of synthetic dyes from aqueous solutions. Accordingly, the present study was conducted to investigate the potential of Robinia pseudoacacia L. biosorbent (RPF) in the removal of crystal violet (CV) dye from aqueous solutions. To this end, biosorption parameters, including zero charge point, pH, initial dye concentration, biosorbent dose, stirring speed, and temperature, were investigated. Variations in the treated and untreated biosorbent surfaces were characterized using FTIR spectroscopy. The results showed that the RPF biosorbent removed 77% of CV under optimal conditions: pH of 6, initial dye concentration of 10 mg/L, biosorbent dose of 1 g, contact time of 30 min, stirring speed of 150 rpm, and temperature of 298 K. The Dubinin-Radushkevich isotherm (R²= 0.976) and pseudo-second-order kinetic (R² = 0.995) models were well fitted according to isotherm and kinetic studies. Thermodynamic studies revealed that the process was endothermic according to the ΔG values. Moreover, the phytotoxicity of treated CV solutions was significantly reduced. Thus, the RPF biosorbent was determined to be a low-cost, sustainable, and ecofriendly material for the removal and detoxification of synthetic dyes from aqueous solutions.

The use of organic and inorganic amendments like stilbite-zeolite (SZ) and nano-biochar (NBC) in phytoremediation holds immense promise, long-term stability, and its effectiveness necessitate comprehensive research. This study aimed to evaluate their potential in mitigating heavy metal contamination in soil and plants. Our results shows that SZ and NBC treatments significantly impacted heavy metal levels, notably reducing arsenic (As), nickel (Ni), lead (Pb), cadmium (Cd), and mercury (Hg) accumulation in plant tissues. The treatments exhibited varying degrees of effectiveness in reducing heavy metal levels. Notably, SZ₂ treatment decreased As and Pb levels by 33.33% and 20%, respectively, while NBC₃ achieved even greater reductions, lowering As by 53.33% and Pb by 30%. Moreover, SZ₂, SZ₅, and NBC₃ treatments halved Cd levels, showcasing their potential in mitigating heavy metal contamination in rice. However Hg levels remained largely unaffected, except for NBC₁, which unexpectedly doubled its concentration. In soil, SZ₂ treatment significantly reduced metal concentrations, particularly Cd (66.8% reduction) and Hg (70.7% reduction). Conversely, SZ₃ and SZ₇ treatments increased metal concentrations, suggesting that certain zeolite applications might enhance metal bioavailability. NBC treatments showed varying effectiveness, with NBC₃ being the most effective, substantially reducing As, Pb, and Cd levels.

In this study, rice plants were co-exposed to selenium (Se) and silica (Si) under arsenic (As) stress to evaluate As accumulation in rice grains, associated cancer risk, and its impact on the types and numbers of grain metabolites. A total of 58 metabolites were identified, of which, 19 belong to sugars, and drastically altered during different treatments. Arsenic exposure significantly reduced monosaccharides, i.e., D-glucose (83%) >D-galactose (60%) >D-fructose (57%) >D-ribose (29%) but increased that monosaccharide units which have antioxidant properties (i.e. α-D-glucopyranoside and melibiose). However, the levels of D-galactose, fructose, and ribose were significantly increased during co-supplementation of selenite (Se^IV) and Si under As stress. Other groups of rice grain metabolites, like sugar alcohols, organic acids, polyphenols, carboxylic acids, fatty acids, and phytosterols, were also significantly altered by As exposure and increased in grains of Se^IV and Si supplemented rice compared to alone As exposure. In brief, rice growing in As-affected areas may have a low level of different metabolites. However, supplementation by selenite (Se^IV) with Si not only increased metabolites and amylose/amylopectin ratio but also reduced ∼90% of As accumulation in grains. Thus, the use of Se^IV with Si might be advantageous for the locals to provide a healthy diet of rice and limit As-induced cancer risk up to 10-fold.

This study comprehensively assessed the physiological adaptations of Cymbopogon nardus (citronella) exposed to varying concentrations (25-100 mg.kg^-1) of cadmium (Cd) and chromium (Cr). The phytoremediation potential was also evaluated over a 60d greenhouse experiment with triplicate replication, where Cd and Cr were introduced as cadmium chloride (CdCl₂) and potassium dichromate (K₂Cr₂O₇), respectively. While elevated metal concentrations adversely affected plant growth and chlorophyll content, C. nardus exhibited remarkable tolerance. This was evidenced by the upregulation of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidise (APX), alongside increases in reduced glutathione (GSH) and proline, effectively mitigating oxidative stress. However, high-intensity metal exposure eventually overwhelmed these systems, leading to reactive oxygen species (ROS) accumulation and oxidative damage. Notably, Western blot analysis revealed that Cr distinctly induced a greater reduction in ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity compared to Cd, highlighting nuanced physiological responses to different metals. The plant demonstrated substantial phytoremediation capacity, achieving bio-concentration factors (BCF) of 0.25 for Cd and 0.28 for Cr at 100 mg.kg^-1, and effectively removing 75.1% of Cd and 72.1% of Cr from contaminated soil. The novelty of this study lies in its comprehensive analysis of physiological adaptations and phytoremediation capabilities of C. nardus under both Cd and Cr stress, revealing its potential as a robust phytoremediator. The observed differential impact on Rubisco activity and efficient metal removal capacity underscore the plant's suitability for remediating soils contaminated with these prevalent heavy metals.