Wyniki wyszukiwania - Biblioteka Nauki

1

Do application rates of wastewater sewage sludge affect the removal of PAHs from alkaline saline soil?

100%

Fernandez-Luqueno F. , Mendoza-Cristino R. , Dendooven L.

Polish Journal of Environmental Studies

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2016

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tom 25

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nr 6

EN

The application of wastewater sludge to an alkaline saline soil of Texcoco accelerated removal of polycyclic aromatic hydrocarbons (PAHs), but not always. As part of a study into factors that might affect dissipation of PAHs from soil, the effect of different application rates (0, 3, 9, 18, and 36 tons dry sludge ha-1) of wastewater sludge on removal of phenanthrene and anthracene was studied in an alkaline saline soil with pH 9.7 and electrolytic conductivity (EC) of 7.6 dS m-1. The dynamics of phenanthrene, anthracene, ammonium, nitrite, nitrate, and CO2 were monitored for 56 days. Application of wastewater increased the removal rate of the PAHs independent of the concentration applied, and between 70 and 79% of the phenanthrene and 69 and 79% of the anthracene was removed after 56 days. Spiking soil with PAHs increased emissions of CO2 while applying sludge further increased it. It was found that the removal of PAHs was initially low as the amount of phenanthrene and anthracene decreased after only 14 days. The addition of wastewater sludge increased the removal of phenanthrene and anthracene, but the effect was independent of the application rate or the PAHs studied. Spiking soil with PAHs increased emissions of CO2 and reduced the amount of NH4+ and NO3- in soil.

2

Dissipation of phenanthrene and anthracene from soil with increasing salt content amended with wastewater sludge

88%

Fernandez-Luqueno F. , Cabrera-Lazaro G. , Corlay-Chee L. , Lopez-Valdez F. , Dendooven L.

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tom 26

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nr 1

EN

The removal of PAHs was stimulated by wastewater sludge in an alkaline saline soil of the former Lake Texcoco, but not always to the same extent. We investigated how a varying electrolytic conductivity (EC) affected the removal of phenanthrene (PHEN) and anthracene (ANTHR) from wastewater sludge-amended soils. Soil with EC 6, 30, 80, and 146 dS m⁻¹ was contaminated with PHEN and ANTHR and amended with or without wastewater sludge, while emissions of CO₂ and concentrations of ammonium, nitrite, and nitrate were monitored. A decrement on the concentrations of PHEN and ANTHR was observed and was faster in soil with EC 6 dS m⁻¹ than in soil with EC 30 dS m⁻¹ and 80 dS m⁻¹, and was slower than in soil with EC 146 dS m⁻¹. Adding wastewater sludge to soil reduced the concentration of PHEN and ANTHR in soil after 56 days. Spiking soil with PAHs or amending it with wastewater sludge increased the CO₂ emission rate, but decreased at higher EC. The concentration of NO₃⁻ decreased when soil was spiked with PAHs and amended with sludge, except in soil with EC 146 dS m⁻¹. It was found that the removal of PAHs was not inhibited by salt content and a principal component analysis indicated that none of the measured soil characteristics, i.e., pH, EC, particle size distribution, water-holding capacity, or organic C content predicted the removal of ANTHR or PHEN from contaminated soil. The application of wastewater sludge increased the dissipation of PHEN and ANTHR after 56 days.

3

Heavy metals in mine-tailing soil mixtures cultivated with Ricinus communis L.

75%

Gonzalez-Terreros E. , Ruiz-Valiviezo V. M. , Galvan-Valazquez A. , Franco-Hernandez M. O. , Luna-Guido M. , Dendooven L.

Polish Journal of Environmental Studies

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2018

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tom 27

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nr 5

EN

Ricinus communis L. was found to vegetate mine tailings with high concentrations of Al (4,456 mg kg⁻¹), As (3,473 mg kg⁻¹), Cd (120 mg kg⁻¹), Cr (14 mg kg⁻¹), Cu (1,147 mg kg⁻¹), and Pb (910 mg kg⁻¹). We investigated how this plant responded to increased heavy metal concentrations by mixing mine tailing at 0%, 50%, 70%, and 100% with soil at 100%, 50%, 30%, and 0%, while metal concentrations in the rhizosphere, roots, and aboveground parts of R. communis were monitored. Ricinus communis shoots were 19% smaller and roots 8% in soil mixed with an equal amount of mine tailings compared to plants cultivated in soil and 33% and 54%, respectively, when cultivated in mine tailings. The ratio of As, Cd, Cu, and Pb in the aboveground plant parts to the concentration in soil remained <0.12, while that of the roots <0.25. The As concentration was 35% lower in the bulk soil than in the rhizosphere. We found that R. communis growth was inhibited strongly when cultivated in mine tailings, but less so when mixed with soil, and metals did not accumulate in the roots and aboveground plant parts. These characteristics make R. communis ideal to vegetate metal-contaminated soil, thereby reducing the environmental hazards of mine tailings.

4

Micro-morphology of common bean (Phaseolus vulgaris L.) nodules undergoing senescence

75%

Fernandez-Luqueno F. , Dendooven L. , Munive A. , Corlay-Chee L. , Serrano-Covarrubias L. M. , Espinosa-Victoria D.

Acta Physiologiae Plantarum

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2008

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tom 30

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nr 4

EN

We studied morphological changes over time by nodules formed on the root system of the common bean (Phaseolus vulgaris L.). Two cultivars, Bayomex and Cacahuate 72 with growth habit Type I and the Rhizobium etli strain CE-3 were used. The results showed the collapse of the infected zone, degradation of the cell walls and membranes, changes in the number and distribution of the starch granules, appearance of protein granules, and disintegration of the central tissue of the nodule with ageing. Additionally, we describe the influence of time on the progress of the nodular senescence.

5

Relationship between sucrose accumulation and activities of sucrose-phosphatase, sucrose synthase, nautral invertase and soluble acid invertase in micropropagated sugarcane plants

75%

Gutierrez-Miceli F. A. , Rodriguez-Mendiola M. A. , Ochoa-Alejo N. , Mendez-Salas R. , Dendooven L. , Arias-Castro C.

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tom 24

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nr 4