scholarly journals Remediation of Cr(VI)-Contaminated Soil by Nano-Zero-Valent Iron in Combination with Biochar or Humic Acid and the Consequences for Plant Performance

Toxics ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 26 ◽  
Author(s):  
Yuhuan Sun ◽  
Fangyuan Zheng ◽  
Wenjie Wang ◽  
Shuwu Zhang ◽  
Fayuan Wang
Keyword(s):  
Humic Acid ◽  
Plant Growth ◽  
Contaminated Soil ◽  
Crop Production ◽  
Agricultural Soils ◽  
Synergistic Effects ◽  
Zero Valent Iron ◽  
Plant Performance ◽  
High Dose ◽  
Nano Zero Valent Iron

Nano-scale zero-valent iron (nZVI) is among the most common nanoparticles widely used for the treatment of various environmental contaminants. However, little is known about the combined effects of nano-zero-valent iron (nZVI) and other soil amendments on soil remediation and plant performance. For the first time, we studied the remediation of Cr(VI)-contaminated soil using bare nZVI (B-nZVI) and starch-supported nZVI (S-nZVI) in combination with either biochar (BC) or humic acid (HA), and the consequent effects on plant growth and Cr accumulation. Both S-nZVI and B-nZVI decreased the contents of Cr(VI) and available Cr in soil, but increased available Fe content, with S-nZVI generally showing more pronounced effects at a higher dose (1000 mg/kg). B-nZVI exerted no inhibition and even stimulation on plant growth, but 1000 mg/kg S-nZVI produced significant phytotoxicity, resulting in decreased plant growth, low chlorophyll content in leaves, and excessive accumulation of Fe in roots. Each nZVI decreased shoot and root Cr concentrations. BC and HA produced synergistic effects with nZVI on Cr(VI) removal from soil, but HA decreased soil pH and increased the availability of Cr and Fe, implying a potential environmental risk. Addition of BC or HA did not alter the effects of either nZVI on plant growth. In conclusion, combined application of 100 mg/kg nZVI and BC could be an ideal strategy for the remediation of soil contaminated with Cr(VI), whereas high-dose S-nZVI and HA are not recommended in the remediation of agricultural soils for crop production or in the phytostabilization of Cr(VI).

scholarly journals Heterogeneous Fenton-Like Catalytic Degradation of 2,4-Dichlorophenoxyacetic Acid by Nano-Scale Zero-Valent Iron Assembled on Magnetite Nanoparticles

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2909 ◽  
Author(s):  
Xiaofan Lv ◽  
Yiyang Ma ◽  
Yangyang Li ◽  
Qi Yang
Keyword(s):  
Hydrogen Peroxide ◽  
Synergistic Effects ◽  
Degradation Process ◽  
Zero Valent Iron ◽  
Dichlorophenoxyacetic Acid ◽  
Heterogeneous Fenton ◽  
Reaction Conditions ◽  
Nano Zero Valent Iron ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Better Than

Fe0@Fe3O4 nanoparticles with dispersibility and stability better than single nano zero-valent iron (nZVI) were synthesized and combined with hydrogen peroxide to constitute a heterogeneous Fenton-like system, which was creatively applied in the degradation of 2,4-dichlorophenoxyacetic acid (2,4-D). The effects of different reaction conditions like pH, hydrogen peroxide concentration, temperature, and catalyst dosage on the removal of 2,4-D were evaluated. The target pollutant was completely removed in 90min; nearly 66% of them could be mineralized, and the main intermediate product was 2,4-dichlorophenol. Synergistic effects between nZVI and Fe3O4 made the 2,4-D degradation efficiency in the Fe0@Fe3O4/H2O2 system greater than in either of them alone. More than a supporter, Fe3O4 could facilitate the degradation process by releasing ferrous and ferric ions from the inner structure. The reduction of 2,4-D was mainly attributed to hydroxyl radicals including surface-bound ∙OH and free ∙OH in solution and was dominated by the former. The possible mechanism of this Fe0@Fe3O4 activated Fenton-like system was proposed.

scholarly journals Effects of Soil Amendments on Heavy Metal Immobilization and Accumulation by Maize Grown in a Multiple-Metal-Contaminated Soil and Their Potential for Safe Crop Production

Toxics ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 102
Author(s):  
Fayuan Wang ◽  
Shuqi Zhang ◽  
Peng Cheng ◽  
Shuwu Zhang ◽  
Yuhuan Sun
Keyword(s):  
Heavy Metal ◽  
Plant Growth ◽  
Contaminated Soil ◽  
Crop Production ◽  
Metal Uptake ◽  
Soil Amendments ◽  
Heavy Metal Uptake ◽  
X Ray ◽  
Metal Immobilization ◽  
Heavy Metal Immobilization

Soil amendments have been proposed for immobilizing metallic contaminants, thus reducing their uptake by plants. For the safe production of crops in contaminated soil, there is a need to select suitable amendments that can mitigate heavy metal uptake and enhance crop yield. The present experiment compared the effects of three amendments, hydroxyapatite (HAP), organic manure (OM), and biochar (BC), on plant growth and heavy metal accumulation by maize in an acidic soil contaminated with Cd, Pb, and Zn, and their potential for safe crop production. Toxicity characteristic leaching procedure (TCLP) tests, energy dispersive X-ray spectroscopy (EDS) analysis, and X-ray diffraction (XRD) analysis were used to evaluate the effectiveness and mechanisms of heavy metal immobilization by the amendments. The results showed that shoot and root biomass was significantly increased by HAP and 1% OM, with an order of 1% HAP > 0.1% HAP > 1% OM, but not changed by 0.1% OM and BC (0.1% and 1%). HAP significantly decreased Cd, Pb, and Zn concentrations in both shoots and roots, and the effects were more pronounced at the higher doses. OM decreased the shoot Cd and Pb concentrations and root Zn concentrations, but only 1% OM decreased the shoot Zn and root Pb concentrations. BC decreased the shoot Cd and Pb concentrations, but decreased the shoot Zn and root Pb concentrations only at 1%. HAP decreased the translocation factors (TFs) of Cd, Pb, and Zn (except at the 0.1% dose). OM and BC decreased the TFs of Cd and Zn, respectively, at the 1% dose but showed no significant effects in other cases. Overall, plant P, K, Fe, and Cu nutrition was improved by HAP and 1% OM, but not by 0.1 OM and BC. Soil pH was significantly increased by HAP, 1% OM, and 1% BC, following an order of 1% HAP > 1% OM > 0.1% HAP > 1% BC. The TCLP levels for Cd, Pb, and Zn were significantly reduced by HAP, which can be partly attributed to its liming effects and the formation of sparingly soluble Cd-, Pb-, and Zn-P-containing minerals in the HAP-amended soils. To some extent, all the amendments positively influenced plant and soil traits, but HAP was the optimal one for stabilizing heavy metals, reducing heavy metal uptake, and promoting plant growth in the contaminated soil, suggesting its potential for safe crop production.

The Use of Nano Zero Valent Iron in Remediation of Contaminated Soil and Groundwater

2013 ◽  
Vol 1 (7) ◽  
pp. 152-157
Author(s):  
Maryam Taghizadeh ◽  
Daryoush Yousefi Kebria ◽  
Golamreza Darvishi ◽  
Farshad Golbabaei Kootenaei
Keyword(s):  
Contaminated Soil ◽  
Zero Valent Iron ◽  
Nano Zero Valent Iron

scholarly journals Synergistic and offset effects of fungal species combinations on plant performance

2021 ◽  
Author(s):  
Yoshie Hori ◽  
Hiroaki Fujita ◽  
Kei Hiruma ◽  
Kazuhiko Narisawa ◽  
Hirokazu Toju
Keyword(s):  
Plant Growth ◽  
Synergistic Effects ◽  
Dry Weight ◽  
Fungal Species ◽  
Plant Performance ◽  
Plant Growth Promoting Bacteria ◽  
Microbial Species ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Dual Inoculation

In natural and agricultural ecosystems, survival and growth of plants depend substantially on microbes in the endosphere and rhizosphere. Although numerous studies have reported the presence of plant-growth promoting bacteria and fungi in below-ground biomes, it remains a major challenge to understand how sets of microbial species positively or negatively affect plants' performance. By conducting a series of single- and dual-inoculation experiments of 13 endophytic and soil fungi targeting a Brassicaceae plant species, we here evaluated how microbial effects on plants depend on presence/absence of co-occurring microbes. The comparison of single- and dual-inoculation experiments showed that combinations of the fungal isolates with the highest plant-growth promoting effects in single inoculations did not yield highly positive impacts on plant performance traits (e.g., shoot dry weight). In contrast, pairs of fungi including small/moderate contributions to plants in single-inoculation contexts showed the greatest effects on plants among the 78 fungal pairs examined. These results on the offset and synergistic effects of pairs of microbes suggest that inoculation experiments of single microbial species/isolates can result in the overestimation or underestimation of microbial functions in multi-species contexts. Because keeping single-microbe systems in outdoor conditions is impractical, designing sets of microbes that can maximize performance of crop plants is an important step for the use of microbial functions in sustainable agriculture.

scholarly journals Biochar: a potential soil ameliorant for sustainable land, agriculture and environmental development

2021 ◽  
Author(s):  
Sanat Dwibedi ◽  
VC Pandey ◽  
Donakonda Divyasree
Keyword(s):  
Plant Growth ◽  
Sustainable Agriculture ◽  
Environmental Remediation ◽  
Crop Production ◽  
Synergistic Effects ◽  
Conservation Agriculture ◽  
Chemical Conversion ◽  
Long Term Effects ◽  
Soil Microbial ◽  
Economically Deprived

Biochar or pyrogenic carbon, obtained from thermo-chemical conversion of biomass in an anaerobic or oxygen limited environment has been in use in agriculture since long back to Neolithic era. Its unique soil ameliorating properties, render it suitable for environmental remediation as well as sustainable crop production. It improves soil physicochemical properties and plant nutrient availability, facilitates biodiversity, and reduces emission of greenhouse gases, thereby subsiding global warming. Application of biochar reduces soil erosion, improves soil hydrological properties, and soil microbial dynamics. It has synergistic effects on plant growth, disease-pest resistance, and crop yield per unit area and time. Due to its soil ameliorative effects, and soil and water conserving ability, it can very well be used in organic farming, pemaculture, dryland farming, conservation agriculture, and land remediation. Cheaper production cost, simple and easy pyrolytic technologies, easy availability of feedstock and bio-wastes in many developing countries and its long-term effects in soil not only build up soil carbon pool but also help support small and marginal farmers in resource-rich but economically deprived countries for sustainable agriculture and environment. In this review, efforts have been made to elucidate various methods of biochar synthesis, its characteristics and effects on soil properties, and plant growth and development, its role in sustainable agriculture and remediation of the environment.

scholarly journals Effects of Co-Contamination of Microplastics and Cd on Plant Growth and Cd Accumulation

Toxics ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 36 ◽  
Author(s):  
Fayuan Wang ◽  
Xiaoqing Zhang ◽  
Shuqi Zhang ◽  
Shuwu Zhang ◽  
Catharine A. Adams ◽  
...  
Keyword(s):  
Plant Growth ◽  
Soil Ph ◽  
Terrestrial Ecosystems ◽  
Ecological Impacts ◽  
Plant Performance ◽  
Plant Tissues ◽  
High Dose ◽  
Cd Uptake ◽  
Cd Accumulation ◽  
Maize Plants

Microplastics (MPs) occur widely in terrestrial ecosystems. However, information on the interaction of MPs with metals in terrestrial ecosystems is lacking in the literature. The present study investigated the effects of two types of MPs (high-density polyethylene (HDPE) and polystyrene (PS)) with different dosages (i.e., 0, 0.1%, 1%, and 10%) on the uptake and effects of Cd in maize plants grown in an agricultural soil. Results showed that addition of Cd at a 5 mg/kg caused inhibited plant growth and resulted in high Cd accumulation in plant tissues. Polyethylene alone showed no significant phytotoxic effects, but a high-dose of HDPE (10%) amplified Cd phytotoxicity. Polystyrene negatively affected maize growth and phytoxicity further increased in the presence of Cd. Both HDPE and PS caused soil diethylenetriaminepentaacetic acid (DTPA)-extractable Cd concentrations to increase but did not significantly affect Cd uptake into plant tissues. In the soil without Cd addition, HDPE decreased soil pH, while PS did not significantly alter soil pH. However, in the soil spiked with Cd, both HDPE and PS increased pH. Overall, impacts on plant growth and Cd accumulation varied with MP type and dose, and PS induced substantial phytotoxicity. In conclusion, co-occurring MPs can change Cd bioavailability, plant performance, and soil traits. Our findings highlight the ecological impacts that could occur from the release of MPs into soil.

scholarly journals Effects of growth regulators on the quality of tomato fruits

2020 ◽  
pp. 54-57
Author(s):  
Ah. A. Suliman ◽  
A. G. Abramov ◽  
A. A. Shalamova
Keyword(s):  
Humic Acid ◽  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Dry Weight ◽  
Fruit Weight ◽  
Plant Performance ◽  
Naphthalene Acetic Acid ◽  
Tomato Plants ◽  
Active Substances

Relevance and methods. This study aimed to improve fruit set and plant performance to increase tomato productivity by studying the effect of plant growth regulators on tomato plants. A specific experiment has been carried out to study the effect of plant growth regulators Hemo bles active substances (850 g/kg) Humic Acid with applied doses (250, 500 and 700 ppm) and Magictone active substances (5-12.5 g/kg) naphthalene acetic acid and naphthalene acetamide with applied doses (250, 500 and 700 ppm) on growth and physiological characteristics of tomato plants (Big Beef F1). The experimental design was a Complete Randomized Blocks Design. Both Hemo bles and Magictone were applied three times (spraying on plants at 30 DAP, spraying on plants at 60 DAP and spraying on plants 90 DAP).Results. The obtained results showed that, Applying Humic Acid “Ener-850” had the highest significant fruit weight (137 g) during the two seasons. Also using “Magictone” had the highest significant Flowers number (48.1), Fruits Number (35.1), Flower Clusters number in the plant (13.6) and Fruits Number (54.6. while (Humic Acid) improved tomato fruit’s quality during improve Dry weight (75.1 g) of Arial parts, Ascorbic Acid, level of Vitamin C and Carotenoids contents (4.82 mg 100 g-1). The results were analyzed using one-way analysis of variance (ANOVA) followed by Tukey’s HSD test with α = 0.05 with the help of MINITAB (v. 19.0) program.

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