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Effects of the water-soluble fraction of the mixture fuel oil/diesel on the microalgae Dunaliella tertiolecta through growth Texto completo
2020
Salinas-Whittaker, Soledad | Gómez-Gutiérrez, Claudia M. | Cordero-Esquivel, Beatriz | Luque, Priscy A. | Guerra-Rivas, Graciela
There is evidence that water-soluble fraction (WSF) from fuel oil/diesel mixture affects marine microbiota. In order to establish a sequence of WSF effects during microalgal growth, this work aimed to monitor Dunaliella tertiolecta exposed to WSF during 15 days. Three different pigments (chlorophyll a, lutein, and β-carotene) and four metabolites (protein, lipids, fatty acids, and phenols) were studied, and FTIR spectroscopy was used to determine the biomolecular transitions of lipids and their accumulation. The results show that D. tertiolecta triggered a physiological and biochemical response with changes in growth rate, pigments, phenols, lipids, and proteins of the microalga, although fatty acid profile was unaltered. For all the biochemical parameters altered, there were significant differences with the controls. At the end of the assay, exposed D. tertiolecta showed similar values with the control on all the compounds analyzed, except lipids. FTIR absorbance showed an increase in unsaturated acyl chains within the exposed microalgae, giving support for a possible uptake of hydrocarbons from WSF. Variation in pigments and phenol contents is presented as an integrated antioxidant response to the stress imposed by WSF. Overall, this research provides information about the effects of WSF on D. tertiolecta, and the ability of this microalga to recover after long-term exposure to the water-soluble fraction of fuel oil/diesel.
Mostrar más [+] Menos [-]Contamination of Soil with Diesel Oil, Application of Sewage Sludge and Content of Macroelements in Oats Texto completo
2020
Wyszkowski, Mirosław | Wyszkowska, Jadwiga | Borowik, Agata | Kordala, Natalia
The aim of the study was to determine the effect of soil contamination with diesel oil (0, 5, 10 and 15 mL/kg d.m. of soil) on the macroelement content (nitrogen, phosphorus, potassium, sodium, magnesium and calcium) in the above-ground parts of oats (Avena sativa L.). A remediation effect of sludge as a substance which reduces the negative impact of this petroleum product on its element content in oats was also evaluated. Sewage sludge was applied in doses 0, 4, 8 and 12 g/kg of soil. The macroelement content in the above-ground parts of oats depended on the soil contamination with diesel oil and on the addition of sewage sludge to the soil. Soil contamination with diesel oil caused significant changes in the content of all macroelements in the above-ground biomass of oats. Increasing doses of the petroleum product in the series without sewage sludge decreased the content of all macroelements, except phosphorus and calcium. The highest effect was observed for the content of sodium in oats. The addition of sewage sludge to the soil alleviated the negative impact of diesel oil on the chemical composition of the plants. The application of sewage sludge to soil resulted in an increase in average content of nitrogen, sodium and magnesium (as opposed to phosphorus and partly calcium) in the above-ground parts of oats, compared to the series without sewage sludge.
Mostrar más [+] Menos [-]Removal Kinetics of Heavy Metals and Nutrients from Stormwater by Different Filter Materials Texto completo
2020
Reddy, Krishna R. | Dastgheibi, Sara | Cameselle, Claudio
During storm events, contaminants and sediments from roadways, curbside, parking lots, and lawns in urban environments are mobilized and transported by the stormwater runoff. These contaminants are finally discharged in waterbodies, such as rivers and lakes, with adverse effects on public health and ecosystems. Several studies have reported high levels of heavy metals and nutrients in urban stormwater runoff. Best management practices such as sedimentation and bioretention are not practical in urban environments due to the lack of adequate space; however, filtration systems, such as an in-ground permeable filter system, are being developed because they are practical and feasible. Four different filter materials (calcite, zeolite, sand, and iron filings) were effective in removing individual contaminants (Cd, Cu, Ni, Cr, Zn, nitrate, and phosphate) in tests at 24 h. The present investigation assessed the removal kinetics of contaminants from a simulated stormwater consisting of multiple heavy metals and nutrients by the four filter materials. Batch experiments were conducted to evaluate the removal kinetics of co-existing heavy metals and nutrients from the simulated stormwater. The rate of contaminant removal and overall removal efficiency was found to be dependent on the filter material and contaminant nature, as well as the induced pH changes caused by the filter media. The zero-order kinetic model best described the removal rate of Cu and Ni by sand. The first-order kinetic model was only applicable for nitrate removal by iron filings, and the second-order kinetic model described the removal rates of other contaminants and filter media combinations.
Mostrar más [+] Menos [-]Diesel Impacts on Functional Bacterial Groups and Collembolans During Phytoremediation in a Mesocosm System Texto completo
2020
Guerrero-Chávez, Ana Carolina | Alarcón, Alejandro | Ferrera-Cerrato, Ronald | Díaz-Aguilar, Irma | Mendoza-López, Ma Remedios | Rios-Galicia, Bibiana | Arteaga-Garibay, Ramón Ignacio | Larsen, John
Phytoremediation of contaminated soils relies on the ability of plants to stimulate microbial rhizosphere diversity, by releasing root exudates. This work assessed the impact of diesel contamination on soil populations of culturable bacterial groups (fast growing, N₂-fixing, phosphate (P) solubilizing, and lipolytic bacteria), and collembolans under mesocosm conditions with and without the influence Medicago sativa. We set up six treatments sampled initially within 24 h and examined at 4, 8, and 12 months. Bacterial groups were isolated and identified with 16S rRNA sequencing, while collembolans were classified using taxonomic keys. The populations of P-solubilizing and fast-growing bacteria were stimulated after 4 months in the polluted treatments in absence of M. sativa. On the M. sativa treatments, P-solubilizing and lipolytic bacteria increased after 8 months. Stenotrophomonas and Achromobacter were the most predominant bacterial genera. Collembolans mainly belonging to Poduromorpha and Entomobryomorpha orders, were observed in contaminated treatments on the 12th month, while in the uncontaminated control were found at the 4th month. Hydrocarbon degradation was higher than 80% in all treatments after 12 months. Diesel contamination and soil management reduced significantly the collembolan abundance; these organisms may be considered as biological indicators of soil quality and recovery after an event of diesel contamination.
Mostrar más [+] Menos [-]Adsorption, degradation, and mineralization of emerging pollutants (pharmaceuticals and agrochemicals) by nanostructures: a comprehensive review Texto completo
2020
Jain, Monika | Mudhoo, Ackmez | Ramasamy, Deepika Lakshmi | Najafi, Mahsa | ʻUs̲mān, Muḥammad | Zhu, Runliang | Kumar, Gopalakrishnan | Shobana, Sutha | Garg, V. K. (Vinod Kumar) | Sillanpää, Mika
This review discusses a fresh pool of research findings reported on the multiple roles played by metal-based, magnetic, graphene-type, chitosan-derived, and sonicated nanoparticles in the treatment of pharmaceutical- and agrochemical-contaminated waters. Some main points from this review are as follows: (i) there is an extensive number of nanoparticles with diverse physicochemical and morphological properties which have been synthesized and then assessed in their respective roles in the degradation and mineralization of many pharmaceuticals and agrochemicals, (ii) the exceptional removal efficiencies of graphene-based nanomaterials for different pharmaceuticals and agrochemicals molecules support arguably well a high potential of these nanomaterials for futuristic applications in remediating water pollution issues, (iii) the need for specific surface modifications and functionalization of parent nanostructures and the design of economically feasible production methods of such tunable nanomaterials tend to hinder their widespread applicability at this stage, (iv) supplementary research is also required to comprehensively elucidate the life cycle ecotoxicity characteristics and behaviors of each type of engineered nanostructures seeded for remediation of pharmaceuticals and agrochemicals in real contaminated media, and last but not the least, (v) real wastewaters are extremely complex in composition due to the mix of inorganic and organic species in different concentrations, and the presence of such mixed species have different radical scavenging effects on the sonocatalytic degradation and mineralization of pharmaceuticals and agrochemicals. Moreover, the formulation of viable full-scale implementation strategies and reactor configurations which can use multifunctional nanostructures for the effective remediation of pharmaceuticals and agrochemicals remains a major area of further research.
Mostrar más [+] Menos [-]One-Stage Adsorption Treatment of Liquid Radioactive Wastes with Complex Radionuclide Composition Texto completo
2020
Ivanets, Andrei | Kitikova, Natalja | Shashkova, Irina | Radkevich, Artsiom | Stepanchuk, Tatiana | Maslova, Marina | Mudruk, Natalya
The development of new materials and technologies for effective treatment of liquid radioactive waste is an urgent task. In present work, the novel Ti-Ca-Mg phosphate sorbents were developed. Sorbents were characterized by X-ray diffraction (XRD), Fourier transmittance infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and N₂ adsorption-desorption techniques. The influence of the chemical composition of mixed Ca-Mg-Ti phosphate sorbents and solution pH and the nature of the radionuclide on the sorption efficiency of ¹³⁷Cs, ⁸⁵Sr, and ⁶⁰Co radionuclides were determined. The obtained materials demonstrated excellent affinity towards ¹³⁷Cs, ⁸⁵Sr, and ⁶⁰Co radionuclides (Kd reached up to 10⁵ mL g⁻¹). For all Ti-Ca-Mg phosphates, an increase in the sorption efficiency of ¹³⁷Cs with an increase in the titanium content was observed. It was shown that the samples of Ti-Ca-Mg phosphates containing of 33–60 wt% titanium effectively removed ¹³⁷Cs, ⁹⁰Sr, and ⁶⁰Co radionuclides at pH 8.0–11.0. The prepared Ti-Ca-Mg phosphate sorbents are promising for one-stage treatment of aqueous solutions of complex composition from ¹³⁷Cs, ⁸⁵Sr, and ⁶⁰Co radionuclides and could be used for development of advanced technology for liquid radioactive waste treatment.
Mostrar más [+] Menos [-]Identifying environmental pollution recorded in street dust using the magnetic method: a case study from central eastern China Texto completo
2020
Zhao, Guoyong | Zhang, Ronglei | Han, Yan | Lü, Bin | Meng, Yuanhang | Wang, Shijie | Wang, Ningning
Urban street dust constitutes important intermediate products for the transmission of solid organic and inorganic pollutants in the urban environment. In this study, 133 street dust samples were collected from Xinyang to explore their magnetic characteristics, spatial distribution, and environmental implications using magnetic measurements. The results are as follows. (1) There were ferrimagnetic, antiferrimagnetic, and paramagnetic (e.g., lepidocrocite) minerals in the dust. Among these, the dominant magnetic carriers were ferrimagnetic minerals. Furthermore, magnetite was a first-order ferrimagnetic carrier. (2) The magnetic domains of the dust were pseudo single-domain to multi-domain. (3) The magnetic concentration (χ and SIRM) of dust were 2.6 and 4.1 times higher than those of background samples that were not polluted by urban and anthropogenic activities, respectively. Therefore, we conclude that the dust consisted of high concentration of ferrimagnetic minerals and coarse magnetic particles. (4) The magnetic distribution was spatially different. The industrial area, which was the most polluted sampling area, had the highest magnetic concentration and the coarsest magnetic particles. This was attributable to industrial emissions, fossil fuel combustion, and exhaust emissions from heavy-laden trucks. Residential and commercial areas, which were the second most polluted areas, had higher concentration and coarser particles. This was primarily due to the high population density and traffic activities of mini-cars (i.e., high flux and exhaust emissions). Hence, the conclusion is that the magnetic characteristics, spatial distribution, and the sources of dust are dictated by anthropogenic activities. Our results indicate that the magnetic method is a highly effective tool to monitor urban environmental pollution.
Mostrar más [+] Menos [-]Acute toxicity of fluazinam to aquatic organisms and its bioaccumulation in Brachydanio rerio Texto completo
2020
Wu, Wenzhu | Kong, Deyang | Zhang, Weidong | Bu, Yuanqing | Li, Juying | Shan, Zhengjun
Fluazinam (FZN) is a dinitroaniline fungicide. To evaluate the environmental risk of FZN in aquatic environments and ascertain the potential danger to typical aquatic organisms in China, the acute toxicity of FZN to representative aquatic organisms, including Brachydanio rerio, Chlorella vulgaris Beij., Daphnia magna Straus, and Xenopus laevis, was measured, and its bioaccumulation properties in Brachydanio rerio were further investigated. The results showed that the acute toxicity of FZN to Brachydanio rerio and Xenopus laevis is extremely high, and the bioaccumulation factor BCF₈d of FZN in Brachydanio rerio ranges between 2287 and 3570, implying that it has high bioaccumulation properties. FZN poses a strong environmental risk for aquatic organisms and possesses great bioaccumulation properties, which may cause pollution to aquatic environments.
Mostrar más [+] Menos [-]Assessment of background levels and pollution sources for arsenic and fluoride in the phreatic and confined groundwater of Xi’an city, Shaanxi, China Texto completo
2020
Gao, Yanyan | Qian, Hui | Wang, Haike | Chen, Jie | Ren, Wenhao | Yang, Faxuan
The presence of arsenic and fluoride in groundwater and their impacts on human health have been reported in many countries worldwide, but little information is available on As or F⁻ contamination in Xi’an city. This study highlights the distribution and sources of As and F⁻ anomalies in different aquifers of Xi’an city, based on the assessment of natural background levels (NBLs) and threshold values (TVs). Groundwater samples collected from phreatic and confined aquifers were analyzed to evaluate NBLs and TVs, using median + 2MAD, Tukey inner fence (TIF), and percentile-based methods. Results showed that NBLs and TVs of As and F⁻ in the phreatic aquifer were lower than those in the confined aquifer, indicating importance of the geological effects on the enrichment of arsenic and fluoride in the confined aquifer. Combined with hydrogeochemical methods, the distributions of As and F⁻ anomalies show that high concentrations of As in both aquifers and F⁻ in the confined aquifer can be attributed to the upward flow of geothermal water through faults and ground fissures, while high concentrations of F⁻ in the phreatic aquifer may be greatly influenced by contaminated rivers. Although geological structures such as faults and ground fissures contribute to the high concentrations of potentially toxic elements, anthropogenic activities cannot be ignored because over exploitation of groundwater accelerates the development of ground fissures and results in the upward flow and mixing of geothermal water with groundwater in the upper aquifers.
Mostrar más [+] Menos [-]Ameliorative effect of kefir against γ-irradiation induced liver injury in male rats: impact on oxidative stress and inflammation Texto completo
2020
Ali, Ola Sayed M. | Amin, Nour El-Din | Abdel Fattah, Salma M. | Abd El-Rahman, Omnia
Ionizing radiation is a double-edged sword because of its benefits and risks to human health. Therefore, protecting human organs from harmful effects of radiation is an important concern of researchers. Kefir, as a good source of probiotics, received growing interest in protective medicine owing to its antioxidant, anti-inflammatory, and immunomodulatory properties. Thus, this study was planned to investigate the protective role of kefir against γ-radiation-induced hepatotoxicity. Thirty-two male rats were distributed in four groups: (I) control, (II) received Kefir orally (5 ml/kg body weight) for 28 days, (III) exposed to whole body γ-irradiation (6.5 Gy) to induce hepatotoxicity, and (IV) was pretreated with kefir for 21 days then exposed to γ-irradiation followed by 7 days of kefir treatment. At the end of the experiment, complete blood picture (CBC), liver function, and lipid profile were estimated. Furthermore, levels of lipid peroxidation, nitric oxide content, and endogenous antioxidants, in addition to concentrations of copper, iron, and calcium were measured in liver tissue. Furthermore, monocyte chemoattractant protein-1 (MCP-1) and relative gene expression of nuclear factor kappa (NF-κB) were assessed. The results revealed that oral administration of kefir significantly reduced the radiation-induced hepatic histological alterations, hepatic function impairment, and dyslipidemia. Moreover, kefir notably ameliorated the state of oxidative stress and appeared to inhibit the induced inflammation. This study provides a possible counteracting role of kefir against hepatotoxicity induced γ-radiation. This can focus the benefit of kefir application as a prophylactic treatment to limit hepatic inflammation during radiotherapy.
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