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Bioaugmentation and biostimulation effects on PAH dissipation and soil ecotoxicity under controlled conditions 总被引：2，自引：0，他引：2
The degradation of spiked anthracene (ANT), pyrene (PYR) and benzo[a]pyrene (B[a]P) in soil (3000 mg ∑ 3 PAHs kg−1 dry soil) was studied in aerobically incubated microcosms for 120 d. The applied treatments aimed at enhancing PAH removal from the heavily contaminated soils are: (i) bioaugmentation by adding aged PAH-contaminated soil (ACS) containing activated indigenous degraders; and (ii) combined bioaugmentation/biostimulation by incorporating sewage sludge compost (SSC) and decaying rice straw (DRS). The adopted treatments produced higher PAH dissipation rates than those observed in unamended PAH-spiked soils, especially for ANT and PYR in the presence of DRS or ACS (>96%). However, B[a]P was the most recalcitrant hydrocarbon to biodegradation. Extracellular enzyme investigation revealed the existence of ligninolytic activities in all soil treatments, including control but no relationship could be found with PAH dissipation. The ecotoxicological assessment indicated that regardless of applied treatment, PAH-spiked soils were chronically lethal to ostracod Heterocypris incongruens and confirmed the sensitivity of the microcrustacean to the concomitant presence of these three hydrocarbons. Lettuce root elongation inhibition was correlated with PAH level but the presence of SSC conferred a strong phytotoxic capacity to PAH-spiked soils. DRS amendment may constitute a cost-effective alternative for hydrocarbon bioremediation as it has impacted positively on soil microbial activity and enhanced PAH removal with no apparent changes in soil physico-chemical properties. 相似文献
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Analysis for sixteen types of Polycyclic Aromatic hydrocarbons (PAHs)from samples of raw and treated wastewater, sediments, sludge andplants growing along treated wastewater way was performed inOctober 1997. The collection sites represent two wastewatertreatment plants (WWTP) receiving different types of wastewaterand one site from disposal of raw wastewater in the city ofKarak in southern Jordan.Wastewater treatment efficiency showed removal of PAHs throughsettling tanks and adsorption on sediments after treatment. Theremoval percentage ranged from 44–100% for individual PAH.PAHs were widely distributed at various levels in rawwastewater, treated wastewater, sludge, sediments and plants.The highest concentration was observed in sludge and the lowestin plants. There was a variation in PAHs concentration betweenthe three investigated sites which was attributed to theefficiency of treatment, period of contact with the wastewater,and the nature of activities. The WWTPs were capable or reducingPAHs contamination in water, up to 40% of the total PAHs byadsorption on sludge and sediments. 相似文献
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Heiba Helmi I. Al-Easa Hala S. Rizk Abdel-Fattah M. 《Plant foods for human nutrition (Dordrecht, Netherlands)》1997,51(1):27-34
Fatty acid compositions of twelve algal species from two different classes were determined. Three Chlorophyta species (Acetabularia calyculus, Cladophora sericoides and Dictyosphaeria cavernosa) and nine Phaeophyta species (Colpomenia sinuosa, Cystoseria trinodis, Dictyota cervicornis, Hormophysa triquetra, Padina gymnospora, Sargassum binderi, S. boveanum, S. denticulatum and S. heteromorpha) were investigated. Thirty-four fatty acids were identified. Myristic, palmitic, oleic, linoleic, eicosodienic and lignoceric acids were predominant in all examined algal species. Branched saturated fatty acids were also found in all investigated species except Cladophora serricoides. 相似文献
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Tomato plants are severely infested with Aphis gossypii in all over the world. The present investigation aims at evaluating effects of tomato leaf biochemical components as well as leaflet surface physical features on the susceptibility of five tomato cultivars (Alissa, GS, Logan, Super Strain B and Andos). Results clearly indicated significant differences among the five tested tomato cultivars according to their susceptibility to A. gossypii infestation. In addition, the cultivars Logan and Andos are the most susceptible, while Super Strain B and Alissa cultivars showed moderate resistance. The GS cultivar, finally, was the most resistant one. Photosynthetic pigments, biochemical components and antioxidant defense enzymes activity were negatively affected by infestation. Moreover, the density and length of leaflet non-glandular trichomes negatively effect on the population density of A. gossypii, while this was not the case with glandular trichomes. From these results, the susceptibility of tomato cultivars on the basis of these results in the integrated aphids management programs. 相似文献
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ABSTRACT: Avian influenza virus can be divided into two groups, highly pathogenic avian influenza virus (HPAI) and low pathogenic avian influenza virus (LPAI) based on their difference in virulence. To investigate if the difference in clinical outcome between LPAI and HPAI in chickens is due to immunological host responses in the lung within the first 24 hours post infection (hpi), chickens were infected with LPAI or HPAI of subtype H7N1. Virus was found in the caudal and cranial part of the lung. With LPAI, virus was localised around the intrapulmonary bronchus and secondary bronchi. In sharp contrast, HPAI was detected throughout the whole lung. However, based on viral RNA levels, no quantitative difference was observed between LPAI and HPAI infected birds. In infected areas of the lungs, an influx of CD8α+ cells as well as KUL01+ macrophages and dendritic cells (DC) occurred as fast as 8 hpi in both infected groups. No major difference between LPAI and HPAI infected birds in the induction of cytokines and interferons at mRNA level in lung tissue was found.In conclusion, the differences in lethality for chickens infected with LPAI or HPAI could be ascribed to difference in location of the virus. However similar amounts of viral RNA, similar cytokine mRNA levels, and similar influxes of CD8α+ and KUL01+ macrophages and DC were found between HPAI and LPAI in the lungs. A cytokine storm at mRNA level as described for mammals was not observed in the lungs of HPAI infected birds within 24 hpi. 相似文献
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Fethia Ayari Saoussen Benzarti Helmi Hamdi Naceur Jedidi Neji Gharbi Ridha Kossai 《Compost science & utilization》2013,21(3):145-151
A field study was carried out to evaluate long-term heavy metal (HM) accumulation in the top 20 cm of a Tunisian clayey loam soil amended for (four years) with municipal solid waste compost (MSWC) at three levels (0, 40 and 80 t ha?1 year?1). HM uptake and translocation within wheat plants grown on these soils were also investigated. Compared to untreated soils, MSWC-amended soils showed significant increases in the content of all measured HM (Cd, Cr, Cu, Ni, Pb and Zn) in the last three years, especially for the 80 t ha?1 year?1 MSWC-amended plots. Wheat plants grown on MSWC-amended soils showed a general increase in metal uptake and translocation, especially for Cr and Ni. This HM uptake was about three fold greater for treatment 80 t h?1 as compared to plots amended at a rate of 40 t h?1. At times, the diluting effect resulting from enhanced growth rates of the plants with compost application resulted in lower concentrations in the plants grown (grain part) on treated plots. On the other hand, Cr and Ni were less mobile in the aerial part of wheat plants and were accumulated essentially in root tissues. Plant/soil transfer coefficients for MSWC-amended treatments were higher than threshold range reported in the literature, indicating that there was an important load/transfer of HM ions from soils to wheat plants. 相似文献
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The solubility and the enthalpy of dicarboxylic acids have been determined in water at intervals between 278.5 and 543.5 K. At 298.15 K, the values derived were: Δsol H m (m?=?1.33 mol kg?1)?=?29.80 kJ mol?1for oxalic acid; Δsol H m (m?=?16.03 mol kg?1)?=?12.82 kJ mol?1 for malonic acid; Δsol H m (m?=?0.75 mol kg?1)?=?28.20 kJ mol?1 for succinic acid; Δsol H m (m?=?8.77 mol kg?1)?=?48.01 kJ mol?1 and Δsol H m (m?=?0.17 mol kg?1)?=?40.30 kJ mol?1 for glutaric and adipic acid respectively. The solubility value exhibits a prominent odd–even effect with respect to terms with even number of carbon atoms with the odd carbon numbers showing much higher solubility. Observations made in the atmospheres suggest that this odd–even effect may have implications for the relative abundance of these acids in aerosols. 相似文献
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