International Journal of Phytoremediation最新文献

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.

Phytoremediation is an emerging technology that is claimed effective in reclaiming contaminated sites. This study investigates the ability of Sporobolus pyramidalis and Sacciolepis africana grasses to bioaccumulate copper, cadmium, chromium and lead in field studies using Challawa-contaminated soil (CCS). The presence of important phenolic acids and their derivatives was detected in both S. pyramidalis and S. africana respectively using Liquid chromatography mass spectrometry (LC-MS). The relative growth rate (RGR) of both plant species were significantly (p ˂ 0.05) lower than the control, with S. africana having a better tolerance ability to heavy metals toxicity than S. pyramidalis with RGR indices of 0.0109 ± 0.00 day^-1 and 0.0077 ± 0.00 day^-1 respectively. Moreover, both species had significant reductions (p ˂ 0.05) in their chlorophyll concentrations, with S. africana being more affected. The bioaccumulation studies revealed that, S. africana accumulated substantial amount of Cr in shoots than in roots, having translocation factor (TF) above the critical value (1.0). However, S. pyramidalis accumulated substantial amount of Cd and Pb in shoots than in roots, having TF greater than the critical value (1.0). This study demonstrated that both S. africana and S. pyramidalis are efficient hyperaccumulators that can be applied for phytoextraction of Cr and Cd, Pb respectively.

Heat stress and soil arsenic (As) contamination are resulting in severe decline in crop production around the world. The present experiment aimed to assess physiological and biochemical changes induced by the combination of As and heat stress in quinoa. Plants were grown in pots with different concentrations of As (0, 10, 20, and 30 mg kg^-1), either at ambient temperature (30/12 °C day/night) or 5 °C higher than ambient temperature. The combination of heat stress with As (30 mg kg^-1 soil) resulted in the highest decrease in shoot/root dry weight (84.1/79.1%), stomatal conductance (84.5%), and leaf relative water contents (75.6%). Heat stress also increased As accumulation in plants, and plants treated with As level of 30 mg As kg^-1, with or without heat stress failed to reach maturity. Over expression of antioxidant enzymes partly neutralized the oxidative stress in quinoa caused by As and heat stress. Accumulation of As in quinoa plant parts was in the order of root > shoot > grains. Human health risks posed by the contaminated quinoa grains were increased under the combination of As and heat stress. Hence, cultivation of quinoa genotype Puno is not suitable under high temperatures and contaminated soils with higher As levels.

Nitrogenous fertilizer (N fertilizer) is crucial to the quality of mulberry leaves. This study evaluated the influences of 4 N fertilizers on the chemical properties of paddy soil, mulberry growth, leaf quality and Cd distribution in mulberry. The results showed the soil pH was reduced with the increasing concentrations of NH₄Cl and (NH₄)₂SO₄. The soil pH for NH₄Cl and (NH₄)₂SO₄ treatments were 4.60 and 4.62 at 300 mg N/kg soil, 21.10% and 20.75% lower than that of the control, respectively. CO(NH₂)₂ increased soil organic matter (OM) and the 4 N fertilizers all increased the Cd phytoavailability with (NH₄)₂SO₄>NH₄Cl > CO(NH₂)₂>NaNO₃. (NH₄)₂SO₄ and CO(NH₂)₂ improved leaf production, total mulberry biomass and the total sugar in leaf. CO(NH₂)₂, NH₄Cl and NaNO₃ increased the crude protein content and (NH₄)₂SO₄ increased the chlorophyll content (8.10%∼20.20%). (NH₄)₂SO₄ and NH₄Cl increased the Cd concentration in leaf, stem and root. CO(NH₂)₂ increased Cd concentration in leaf and stem. All 4 N fertilizers decreased the percentage content of Cd in roots (1.80%∼37.74%) and increased it in stems (3.90%∼263.81%) and leaves (24.09%∼236.18%). The leaves from the CO(NH₂)₂ and NaNO₃ treatments met the hygienical standard for feeds. CO(NH₂)₂ and NaNO₃ could be recommended to safely utilize the Cd polluted acidic paddy soils.

Contamination of agricultural soils with cadmium (Cd) and lead (Pb) poses significant risks to forage production and food chain safety in arid and semi-arid regions. Kochia (Kochia scoparia L.) is a fast-growing, stress-tolerant forage species with potential for phytoremediation. This study evaluated the biochemical, uptake, and translocation responses of kochia roots to soil contaminated with Cd or Pb at concentrations of 25-800 mg kg^-1. Key parameters assessed included non-enzymatic antioxidants (e.g., phenols, flavonoids, proline, glycine betaine), enzymatic activities (catalase, peroxidase, superoxide dismutase, ascorbate peroxidase), hydrogen peroxide content, osmolyte accumulation (water-soluble carbohydrates and proteins), and metal bioconcentration factor (BCF), biological accumulation coefficient (BAC), translocation factor (TF), and translocation efficiency (TE %). Results demonstrated that kochia accumulated substantial Cd and Pb in roots, with maximum root concentrations correlating positively with soil levels (polynomial relationships; R² > 0.95). Cd exhibited high root-to-shoot translocation (TF up to 1.5 at 800 mg kg^-1; TE % up to 60%), while Pb was predominantly sequestered in roots (TF < 0.5; TE % < 30%). Cd induced stronger oxidative stress, evidenced by greater elevations in hydrogen peroxide (up to 115.2% increase at 800 mg kg^-1), antioxidant enzymes (e.g., ascorbate peroxidase increased 79.3% at 800 mg kg^-1), and osmoprotectants (e.g., proline 33.9%, glycine betaine 66.9%) compared to Pb (proline 27%, glycine betaine 50.1%). Biomass declined more severely under Cd (shoot dry weight reduced 83.4% at 800 mg kg^-1) than Pb (67.6%). BCF and BAC were highest at 25 mg kg^-1 (BCF > 4 for both metals) and decreased with concentration. These findings position kochia as an effective Cd phytoremediator due to high translocation, but highlight food chain risks from shoot Cd accumulation when used as forage, necessitating strict biomass management in contaminated sites.

Phytoremediation and soil washing are effective methods for the remediation of arsenic-contaminated soil. In this study, citric acid solution was utilized as a soil leaching agent for in-situ leaching of arsenic-contaminated soil via drip irrigation, aiming to explore the migration and distribution of arsenic in the soil. Hydroponic experiments were conducted to investigate the influence of citric acid on plant absorption and translocation of arsenic. Finally, intercropping of Brassica rapa L. ssp. chinensis and Zea mays L. was carried out under drip irrigation, to explore the effectiveness of citric acid as a soil leaching agent in phytoremediation of arsenic-contaminated soil. The results indicated that after drip irrigation with citric acid solution, the arsenic in the soil undergoes directional migration and exhibits differentiated distribution. Citric acid significantly affected the absorption and transport of arsenic in Brassica rapa L. ssp. chinensis and Zea mays L. Notably, the lowest arsenic content in Brassica rapa L. ssp. chinensis was observed at a citric acid concentration of 2 mmol·L^-1. After drip irrigation with 2 mmol·L^-1 citric acid solution, the arsenic content in Zea mays L. (remediation plant) increased by 23.34%, while the arsenic content in Brassica rapa L. ssp. chinensis decreased by 10.70%. As a soil leaching agent, citric acid effectively enhanced the phytoremediation of arsenic-contaminated soil.