Effectiveness of Various Small‐Scale Constructed Wetland Designs for the Removal of Iron and Zinc from Acid Mine Drainage under Field Conditions

A system of planted and unplanted small‐scale subsurface flow (SSF) and surface flow (SF) constructed wetlands together with hydroponic systems (HP) were installed to compare the removal efficiencies of Fe and Zn from acid mine drainage (AMD) under long‐term field conditions. Maximum removal of 94–97 % (116–142 mg/m² d) for Fe and 69–77 % (6.2–7.9 mg/m² d) for Zn was calculated for the planted soil systems. The planted SSF was most sensitive to heavy rain fall. Short‐term increases of the metal concentration in the outflows, short‐term breakdowns of the Fe removal and continual long‐term breakdowns of the Zn removal were observed. In contrast to Zn removal, all wetland types are applicable for Fe removal with maximum removal in the range of 60–98 %. Most of the removed Fe and Zn was transformed and deposited inside the soil bed. The amount absorbed by the plants (0.03 to 0.3 %) and gravel‐associated soil beds (0.03 to 1.7 %) of the total input were low for both metals. The response of the planted SSF to rainfall suggests a remobilization of metals accumulated inside the rhizosphere and the importance of buffering effects of the surface water layers of SF systems. The importance of plants for metal removal was shown.     

Impact of Zinc Oxide Nanoparticles on Pomegranate Growth under In Vitro Conditions

Russian Journal of Plant Physiology - Nanotechnology is a promising tool to achieve great advancements in the global agricultural systems and food production. The widespread application of...     

Stimulation of Peanut Seedling Development and Growth by Zero-Valent Iron Nanoparticles at Low Concentrations

Because of its strong pollutant degradation ability, nanoscale zerovalent iron (NZVI) has been introduced to soils and groundwater for remediation purposes, but its impacts on plants are still not very clear. In this work, the effects of low concentration (10–320 μmol/L) NZVI particles on seed germination and growth of peanut plants were evaluated. The exposure of peanut seeds to NZVI at all the tested concentrations altered the seed germination activity, especially the development of seedlings. In comparison with the deionized water treated controls (CK), all of the NZVI treatments had significantly larger average lengths. Further investigations with transmission electron microscopy (TEM) and thermogravimetric analysis (TGA) suggested that NZVI particles may penetrate the peanut seed coats to increase the water uptake to stimulate seed germination. The growth experiments showed that although NZVI at a relatively high concentration (320μmol/L) showed phytotoxicity to the peanut plants, the lower concentrations of NZVI particles stimulated the growth and root development of the plants. At certain concentrations (e.g., 40 and 80 μmol/L), the NZVI treated samples were even better than the ethylenediaminetetraacetate-iron (EDTA-Fe) solution, a commonly used iron nutrient solution, in stimulating the plant growth. This positive effect was probably due to the uptake of NZVI by the plants, as indicated in the TEM analyses. Because low concentrations of NZVI particles stimulated both the seedling development and growth of peanut, they might be used to benefit the growth of peanuts in large-scale agricultural settings.     

Fixed-Bed Studies on Removal of Arsenic from Simulated Aqueous Solutions Using Chitosan Nanoparticles

Arsenic is a toxic element and may be found in natural as well as in industrial water; therefore, before using water for drinking purpose, its proper treatment is required. Thus, the aim of this work was to evaluate the potential of chitosan nanoparticles, in a continuous-flow method, for the removal of arsenic (III) and (V) from aqueous solutions. All experiments were conducted in fixed-bed columns. Experiments were carried out as a function of varying liquid flow rate (0.3–1.0 ml/min), initial metal concentration (0.5–1.5 mg/L), and bed height (3–9 cm) of adsorbent. The total adsorbed quantity, equilibrium uptake, and total percentage removal of arsenic ions were determined by evaluating the breakthrough curves obtained at different flow rates, initial concentrations, and bed heights. The results showed that the column performed well at the lowest flow rate. Also, column bed capacity and exhaustion time were found to increase with increasing bed height. When initial metal ion concentration was increased from 0.5 to 1.5 mg/L, the corresponding adsorption bed capacity decreased from 0.076 to 0.028 mg/g. The bed depth service time model (BDST) model was used to analyze the experimental data and the model parameters were evaluated. The calculated values of N _o and K _a were found to be 19.28 × 10^?2 mg/L and 0.662 L/mg·min, respectively. Good agreement was found between the experimental breakthrough curves and the model predictions.     

Colorimetric Sensor of Cobalt Ions in Aqueous Solution Using Gold Nanoparticles Modified with Glycyrrhizic Acid

Plasmonics - The present work describes simple and green method for the preparation of gold nanoparticles (AuNPs) in aqueous medium under ambient condition and their use in colorimetric detection...     

Turnover of Phospholipids in Bacillus cereus under Various Growth Conditions

As a search for natural antioxidants from plant materials, strong antioxidative activity was observed in leaf waxes extracted from Eucalyptus species. A novel type of antioxidant was isolated from the leaf wax of Eucalyptus globulus and identified as n-tritriacontan-16,18-dione. Antioxidative activities were determined by different methods; a thiocyanate method, a thiobarbituric acid method, a total carbonyl value method and a weighing test. The anti-oxidant showed remarkable antioxidative activity in a water/alcohol system and was more effective than α-tocopherol and BHA; however, it has no antioxidative activity in an oil system.     

Comparison of PCR versus Culture for Detection of Mycobacterium bovis after Experimental Inoculation of Various Matrices Held under Environmental Conditions for Extended Periods

The purpose of this study was to compare the performance of a molecular detection technique (nested PCR) with that of mycobacterial culture in the detection of Mycobacterium bovis DNA in a set of 687 samples of experimentally inoculated environmental substrates (hay, soil, corn, water) exposed to natural weather conditions in Michigan. Four replicates of each substrate were used; half were autoclaved for sterilization, all were inoculated with 50,000 CFU of M. bovis isolated from Michigan livestock, and all were placed in outdoor enclosures, with half under shade and the other half exposed to direct sunlight. Samples were tested for the presence of M. bovis during one 12-month period, with monthly sample testing and during three 12-week periods (winter, spring, summer) with weekly sample testing. Samples were subjected to mycobacterial culture for isolation of M. bovis and a nested PCR with two primer sets targeting IS6110 to detect M. bovis DNA. In 128 samples tested during the 12-month period, M. bovis was not detectable by culture after 2 months but M. bovis DNA was detectable by PCR for at least 7 months. Of the 559 samples tested during the 12-week periods, PCR detected M. bovis DNA for up to 88 days in all of the sample types. There were no significant differences in the detection of M. bovis between shade and sun samples or between sterile and unsterilized samples, regardless of the detection method (PCR or culture). For use in epidemiologic investigations, the PCR assay was more rapid than mycobacterial culture, was not hindered by contaminating organisms, and detected M. bovis DNA in environment samples much longer after initial contamination than mycobacterial culture did.     

Response of Contrasting Rice Genotypes to Zinc Sources under Saline Conditions

Abiotic stresses are among the major limiting factors for plant growth and crop productivity. Among these, salinity is one of the major risk factors for plant growth and development in arid to semi-arid regions. Cultivation of salt tolerant crop genotypes is one of the imperative approaches to meet the food demand for increasing population. The current experiment was carried out to access the performance of different rice genotypes under salinity stress and Zinc (Zn) sources. Four rice genotypes were grown in a pot experiment and were exposed to salinity stress (7 dS m⁻¹), and Zn (15 mg kg⁻¹ soil) was applied from two sources, ZnSO₄ and Zn-EDTA. A control of both salinity and Zn was kept for comparison. Results showed that based on the biomass accumulation and K⁺/Na⁺ ratio, KSK-133 and BAS-198 emerged as salt tolerant and salt sensitive, respectively. Similarly, based on the Zn concentration, BAS-2000 was reported as Zn-in-efficient while IR-6 was a Zn-efficient genotype. Our results also revealed that plant growth, relative water content (RWC), physiological attributes including chlorophyll contents, ionic concentrations in straw and grains of all rice genotypes were decreased under salinity stress. However, salt tolerant and Zn-in-efficient rice genotypes showed significantly higher shoot K⁺ and Zn concentrations under saline conditions. Zinc application significantly alleviates the harmful effects of salinity by improving morpho-physiological attributes and enhancing antioxidant enzyme activities, and the uptake of K and Zn. The beneficial effect of Zn was more pronounced in salt-tolerant and Zn in-efficient rice genotypes as compared with salt-sensitive and Zn-efficient genotypes. In sum, our results confirmed that Zn application increased overall plant’s performance under saline conditions, particularly in Zn in-efficient and tolerant genotypes as compared with salt-sensitive and Zn efficient rice genotypes.     

Effect of Dermorphin Analogs on Thermoregulation of Rats under Various Thermal Conditions

We studied the influence of dermorphin (dermorphin) analogs with stereochemical modification of the amino acid residue proline in position 6 (Pro6), Tyr-D-Ala-Phe-Gly-Tyr-Hyp-Ser-NH₂, Tyr-D-Ala-Phe-Gly-Tyr-[D-Pro]-Ser-NH₂, Tyr-D-Ala-Phe-Gly-Tyr-[dehydro-Pro]-Ser-NH₂, and Tyr-D-Ala-Phe-Gly-Tyr-[D-dehydro-Pro]-Ser-NH₂, after their intraperitoneal injection at 0.5 mg/kg dose in the cold (4–7°C), thermoneutral (27–28°C), and hot (31–33°C) environment. Stereochemical modifications of amino acid residue Pro6 proved to induce specific changes in the thermoregulatory effect of the peptide. Substitution of DPro6 for Pro6 has the most dramatic consequences: it considerably attenuates the thermoregulatory effect of dermorphin in the cold environment, cancels it in the hot environment, and inverts the dermorphin-specific thermoregulatory response in thermoneutral conditions. The data obtained indicate the important role of Pro6 residue in realization of this physiological activity of dermorphins.     

Functional Body Capacities under the Conditions of Various Concentrations of Carbon Dioxide and Oxygen

We determined a permissible ratio between carbon dioxide and oxygen concentrations during accidental situations. The experiments (n = 138, 10 h each) on the effect of various concentrations of carbon dioxide and oxygen in the inhaled air were conducted on male volunteers aged 20–40 years subjected to a special medical examination. All experiments were divided into five series: hypercapnia + normoxia, hypercapnia + hyperoxia, hypercapnia + hypoxia, normocapnia + hypoxia, and ambient air (control). The results showed that functional capacities of the body are less impaired under the conditions of hypercapnia combined with hyperoxia. Thus, in accidental situations associated with rapid accumulation of carbon dioxide in the atmosphere of airtight chambers, a synchronous increase in pO₂ to 220–230 torr can provide for the highest work capacity.     

Assessing the Potential Role of Zinc Oxide Nanoparticles for Mitigating Cadmium Toxicity in Capsicum annuum L. Under In Vitro Conditions

Journal of Plant Growth Regulation - The application of metal and metal-oxide nanoparticles (NPs) in agriculture to mitigate the abiotic environmental stress factors and pollutants has gained...     

Aluminum, Iron, and Zinc Ions Promote Aggregation of Physiological Concentrations of β-Amyloid Peptide

Abstract: Mechanisms of non-NMDA receptor-mediated excitotoxicity were studied in embryonic rat hippocampal cultures using kainic acid (KA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) as agonists. Under basal culture conditions, overnight treatment with AMPA resulted in negligible excitotoxicity as assessed by phase-contrast microscopy and measurement of lactate dehydrogenase (LDH) release. In contrast, similar treatment with KA resulted in marked excitotoxic morphologic changes and release of LDH. Cotreatment of cultures with AMPA but not NMDA effectively blocked KA toxicity, suggesting that AMPA-induced rapid desensitization of the AMPA/KA receptor could account for the lack of prominent direct toxicity as well as AMPA's ability to block KA toxicity. To test this hypothesis, cultures were briefly pretreated with 10 μ M cyclothiazide, a drug reported to block desensitization of the AMPA/KA receptor, and then exposed overnight to cyclothiazide plus AMPA and/or KA. Cyclothiazide-treated cultures were now vulnerable to AMPA as well as KA; moreover, AMPA was unable to block KA toxicity completely, suggesting that cyclothiazide impaired AMPA/KA receptor desensitization. These and related studies suggest that a regulatory site may exist on the AMPA/KA receptor that modulates non-NMDA receptor-mediated excitotoxicity.     

Production of Fungal Biomass Immobilized Loofa Sponge (FBILS)-discs for the Removal of Heavy Metal Ions and Chlorinated Compounds from Aqueous Solution

A white rot basidiomycete, Phanerochaete chrysosporium, was immobilized on loofa sponge (FBILS) discs. It removed ca. 37 and 71 mg Cd (II) g⁻¹ from 50 and 200 mg l⁻¹ aqueous solutions and up to 89% of 4-chloroanisole from a 10 mg l⁻¹ aqueous solution. FBILS are physically strong and chemically recalcitrant, resisting temperature, mechanical agitation, and variations in pH without alteration to shape, structure or texture.