خيارات البحث
النتائج 2451 - 2460 من 4,044
Bio- and toxic elements in edible wild mushrooms from two regions of potentially different environmental conditions in eastern Poland النص الكامل
2016
Brzezicha-Cirocka, Justyna | Mędyk, Małgorzata | Falandysz, Jerzy | Szefer, Piotr
In the present study, the composition of bio-elements (K, Na, Mg, Ca, Fe, Cu, Zn) and toxic elements (Ag, Cd) in seven edible mushrooms from the rural and woodland region of Morąg (north-eastern Poland) and the rural and industrial region of the Tarnobrzeska Upland (south-eastern Poland) were investigated using a validated method. The species examined were Boletus edulis, Cantharellus cibarius, Leccinum aurantiacum, Leccinum versipelle, Lycoperdon perlatum, Suillus luteus, and Xerocomus subtomentosus. Final determination was carried out by flame atomic absorption spectroscopy (FAAS) after microwave-assisted decomposition of sample matrices with solutions of concentrated nitric acid in the pressurized polytetrafluoroethylene vessels. The contents of the alkali elements and alkali earth elements were determined in the species surveyed. The alkali elements, earth alkali elements, and transition metals (Ag, Cu, Zn, Fe, and Mn) were at typical concentrations as was determined for the same or similar species elsewhere in Poland and Europe. The results may suggest a lack of local and regional emissions of those metallic elements from industrialization of some sites in the Tarnobrzeska Plain. Cadmium was at elevated concentrations in L. versipelle from the Tarnobrzeska Plain but the reason—pollution or geogenic source—was unknown, while it was at typical concentrations in other species.
اظهر المزيد [+] اقل [-]Response of wine grape growth, development and the transfer of copper, lead, and cadmium in soil-fruit system to sludge compost amendment النص الكامل
2016
Liu, Hong-tao | Wang, Yan-wen | Huang, Wei-dong | Lei, Mei
Sludge is an organic waste after domestic sewage being treated and contains phytonutrients and organic matter. In this study, recycling of sludge compost (SC) and its compound fertilizer (SCF) to wine grape resulted in improvement in vegetative growth, reproductive development of wine grape, and potential wine quality of grape fruit. The amounts of Cu, Pb, and Cd in grape fruit were significantly higher in response to sludge amendment than in the control, but were all below the permissible limits for agricultural product. The contents of Cu and Pb in sludge-amended soil decreased with increasing soil depth, but Cd content increased with soil depth. Ongoing monitoring of on mobility of Cd downward is proposed with sludge recycling to wine grape soil.
اظهر المزيد [+] اقل [-]Isolation and characterization of Sphingomonas sp. Y2 capable of high-efficiency degradation of nonylphenol polyethoxylates in wastewater النص الكامل
2016
Bai, Naling | Wang, Sheng | Abuduaini, Rexiding | Zhu, Xufen | Zhao, Yuhua
Nonylphenol polyethoxylates (NPEOs), although banned for decades, are still widely used in manufactories and thus affect human lives. In this study, a highly efficient NPEO-degrading bacterium, Sphingomonas sp. Y2, was isolated from sewage sludge by enrichment culture. Strain Y2 ensured the complete removal of NPEO in 48 h and degraded 99.2 % NPEO (1,000 mg L⁻¹) within 30 h at a specific growth rate of 0.73 h⁻¹ in minimum salt medium. To date, this degradation efficiency is the highest reported for NPEO metabolism by a pure bacterium under this condition. Furthermore, the application of this bacterium to wastewater treatment demonstrated that it metabolized 98.5 % NPEO (1,000 mg L⁻¹) within 5 days with a specific growth rate of 2.03 day⁻¹. The degradation intermediates, identified as nonylphenol, short-chain NPEOs and short-chain nonylphenol polyethoxycarboxylates by high-performance liquid chromatography and gas chromatography-mass spectrometry, indicated the sequential exo-cleavage of the EO chain. Additionally, the enzymes involved in the biodegradation were inducible rather than constitutive. Considering that strain Y2 exhibits prominent biodegradation advantages in industrial wastewater treatment, it might serve as a promising potential candidate for in situ bioremediation of contamination by NPEOs and other structurally similar compounds.
اظهر المزيد [+] اقل [-]Attenuation of phenanthrene and pyrene adsorption by sewage sludge-derived biochar in biochar-amended soils النص الكامل
2016
Zielińska, Anna | Oleszczuk, Patryk
The aim of this study was to evaluate the effect of soils on the sorption of phenanthrene (PHE) and pyrene (PYR) by sewage sludge-derived biochars (SS-derived biochars). The SS-derived biochars were added to soils with varying properties as well as with a different degree and source of polycyclic aromatic hydrocarbons (PAHs) contamination. The biochars (BCs) were produced from sewage sludge during pyrolysis at temperatures of 500 °C (BC500) and 700 °C (BC700). The addition of biochars to the soils (5 %, w/w) increased the sorption of PHE from 8.3 to 20.3 % and PYR from 14.5 to 31.7 % by amended soil. BC700 biochar was characterized by better sorption capacity than BC500 biochar. Nevertheless, the presence of soil reduces the effectiveness of biochars in binding the compounds studied. The sorption capacity of the biochars decreased several times after they had been mixed with the soil compared to pure biochars. The study found dissolved organic carbon (DOC) and clay minerals present in the soils to have a significant effect on reducing the efficiency of PHE and PYR sorption by biochar. A greater impact of fouling was observed in the case of BC500 biochar characterized by lower porosity than BC700 biochar.
اظهر المزيد [+] اقل [-]Radiocaesium in Cortinarius spp. mushrooms in the regions of the Reggio Emilia in Italy and Pomerania in Poland النص الكامل
2016
Zalewska, Tamara | Cocchi, Luigi | Falandysz, Jerzy
Activity concentrations of ¹³⁴Cs and ¹³⁷Cs have been determined in 23 species of mushrooms of the genus Cortinarius (59 individual samples) collected from the Reggio Emilia in Italy 1992–1999 and in 4 species (16 composite samples and 413 individuals) from the Pomerania region in Poland from 1996 to 2015. Across all the Cortinarius species from the Reggio Emilia, the activity concentrations were relatively high in Cortinarius alboviolaceus, Cortinarius duracinus, Cortinarius orellanus, Cortinarius rapaceus, and Cortinarius subannulatus, in which ¹³⁷Cs was at 10,000 ~ 100,000 Bq kg⁻¹ dry biomass (db) in 1994. Smaller activity concentrations were found in Cortinarius bivelus, Cortinarius bulliardii, Cortinarius cotoneus, Cortinarius largus, Cortinarius lividoviolaceus, Cortinarius purpureus, Cortinarius rufo-olivaceus, Cortinarius torvus, and Cortinarius venetus with levels at 1000 ~ 6000 Bq kg⁻¹ db from 1992 to 1994, and further in Cortinarius anserinus, Cortinarius auroturbinatus, C. largus, Cortinarius praestans, Cortinarius purpurascens, Cortinarius scaurus, Cortinarius sebaceous, Cortinarius talus, and Cortinarius variecolor with activity concentrations at 100 ~ 600 Bq kg⁻¹ db in 1994. All the data were calculated for dehydrated fungal material corrected back to the exact date samples of collection. The greatest activity concentrations of ¹³⁷Cs both in Italy (1992–1999) and Poland (1996–2010) were found in the popular Cortinarius caperatus, confirming its very high capacity of radiocaesium accumulation. Besides ¹³⁷Cs, the isotope ¹³⁴Cs was detected in some species from the Reggio Emilia. An average calculated ratio of activities of ¹³⁴Cs to ¹³⁷Cs referenced to 1986 was equal to 0.38 in mushrooms from the Reggio Emilia, and this value slightly differ from that specific for Chernobyl fallout, which was 0.54. It was calculated that ¹³⁷Cs originating from Chernobyl accident constituted about 68 % of the total activity concentration of the isotope in Reggio Emilia in 1986, while as much as 32 % of ¹³⁷Cs in mushrooms were from the global fallout from nuclear bomb testing.
اظهر المزيد [+] اقل [-]Occurrence and diversity of tetracycline resistance genes in the agricultural soils of South Korea النص الكامل
2016
Kim, Song Yeob | Kuppusamy, Saranya | Kim, Jang-hwan | Yoon, Young-Eun | Kim, Kwon-Rae | Lee, Yong Bok
Reports on the occurrence and diversity of antibiotic-resistant bacteria and genes, which are considered to be emerging pollutants worldwide, have, to date, not been published on South Korean agricultural soils. This is the first study to investigate the persistence of tetracycline (oxytetracycline, tetracycline, and chlortetracycline)-resistant bacterial community and genes in natural and long-term fertilized (NPK, pig, and cattle manure composts) agricultural soils in South Korea. The results showed that oxytetracycline and chlortetracycline could be the dominant residues in animal manures; regular fertilization of manures, particularly pig manures, may be the prime cause for the spread and abundance of tetracycline resistance in South Korean agricultural soils. Both the country’s natural and agricultural soils are reservoirs of antibiotic-resistant species. Of the 113 tetracycline-resistant isolates identified (19 typical bacterial genera and 36 distinct species), approximately 40 to 99 % belonged to Gram-positive bacteria and Bacillus constituted the predominant genera. Of the 24 tet genes targeted, tetG, tetH, tetK, tetY, tetO, tetS, tetW, and tetQ were detected in all soil samples, highlighting their predominance and robust adaptability in soils. Meanwhile, it is suggested that tetC, tetE, tetZ, tetM, tetT, and tetP(B) are the common residues in pig manures, and furthermore, the treatment of soils with pig manures may wield a different impact on the tet gene resistome in agricultural soils. This study thus highlights the necessity for regulating the usage of tetracyclines in South Korean animal farming. This must be followed by proper monitoring of the subsequent usage of animal manures especially that derived from pig farms located in agricultural soils.
اظهر المزيد [+] اقل [-]Evaluation of an integrated constructed wetland to manage pig manure under Mediterranean climate النص الكامل
2016
Nehmtow, Julie | Rabier, Jacques | Giguel, Raphaël | Coulomb, Bruno | Farnet, Anne Marie | Perissol, Claude | Alary, Arnaud | Laffont-Schwob, Isabelle
Pig manure is a complex mixture with excessive nutrients such as ammonium, microbial pathogens and may contain contaminants such as antibiotics. Conventional pig manure management practices caused water contamination. Sludge treatment wetland has been evaluated to determine its potential use under Mediterranean climate aiming at a parsimonious use of water and preventing water contamination, two major steps to preserve water resources in the Mediterranean Basin. Preliminary NH₄-N degradation was tested using aeration process and/or addition of commercial bacterial products. Aeration alone appeared to be sufficient to ensure nitrogen transformation of the pig manure at lab small-scale (10 L) and medium-scale (300 L). Selected plant species e.g., Carex hispida for use in the integrated constructed wetland tolerated the nitrogen content after aeration enabling their use in a treatment vertical bed.
اظهر المزيد [+] اقل [-]Vermicomposting of sludge from animal wastewater treatment plant mixed with cow dung or swine manure using Eisenia fetida النص الكامل
2016
Xie, Dan | Wu, Weibing | Hao, Xiaoxia | Jiang, Dongmei | Li, Xuewei | Bai, Lin
Vermicomposting of animal wastewater treatment plant sludge (S) mixed with cow dung (CD) or swine manure (SM) employing Eisenia fetida was tested. The numbers, weights, clitellum development, and cocoon production were monitored for 60 days at a detecting interval of 15 days. The results indicated that 100 % of the sludge can be the suitable food for growth and fecundity of E. fetida, while addition of CD or SM in sludge significantly (P < 0.05) increased the worm biomass and reproduction. The sludge amended with 40 % SM can be a great medium for the growth of E. fetida, and the sludge amended with 40 % CD can be a suitable medium for the fecundity of E. fetida. The addition of CD in sludge provided a better environment for the fecundity of earthworm than SM did. Moreover, vermicomposts obtained in the study had lower pH value, lower total organic carbon (TOC), lower NH₄ ⁺-N, lower C/N ratio, higher total available phosphorous (TAP) contents, optimal stability, and maturity. NH₄ ⁺-N, pH and TAP of the initial mixtures explained high earthworm growth. The results provided the theory basic both for management of animal wastes and the production of earthworm proteins using E. fetida.
اظهر المزيد [+] اقل [-]A comprehensive approach to actual polychlorinated biphenyls environmental contamination النص الكامل
2016
Risso, F. | Magherini, A. | Ottonelli, M. | Magi, E. | Lottici, S. | Maggiolo, S. | Garbarino, M. | Narizzano, R.
Worldwide polychlorinated biphenyls (PCBs) pollution is due to complex mixtures with high number of congeners, making the determination of total PCBs in the environment an open challenge. Because the bulk of PCBs production was made of Aroclor mixtures, this analysis is usually faced by the empirical mixture identification via visual inspection of the chromatogram. However, the identification reliability is questionable, as patterns in real samples are strongly affected by the frequent occurrence of more than one mixture. Our approach is based on the determination of a limited number of congeners chosen to enable objective criteria for Aroclor identification, summing up the advantages of congener-specific analysis with the ones of total PCBs determination. A quantitative relationship is established between congeners and any single mixture, or mixtures combination, leading to the identification of the actual contamination composition. The approach, due to its generality, allows the use of different sets of congeners and any technical mixture, including the non-Aroclor ones. The results confirm that PCB environmental pollution in northern Italy is based on Aroclor. Our methodology represents an important tool to understand the source and fate of the PCBs contamination.
اظهر المزيد [+] اقل [-]Volatile emissions during storing of green food waste under different aeration conditions النص الكامل
2016
Agapiou, A. | Vamvakari, J. P. | Andrianopoulos, A. | Pāppā, Ā.
Controlled field experiments were carried out for monitoring the emissions of three plastic commercial household waste bins, which were adapted for studying the effect of aeration process in the evolved volatiles, during house storing of green food waste for 2 weeks, prior to collection. Three experimental scenarios were examined based on no aeration (“NA,” closed commercial waste bin), diffusion-based aeration (“DA,” closed commercial waste bin with tiny holes), and enforced aeration (“EA,” closed commercial waste bin with tiny holes and enforced aeration). The monitoring of volatile organic compounds (VOCs) emitted from organic household kitchen waste was performed using solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) analysis. Portable sensors were also used for monitoring selected gases and parameters of environmental, bioprocess, and health interest (e.g., CO₂, O₂, H₂S, CH₄, NH₃, % RH, waste temperatures). VOC emissions are strongly dependent on the waste material. The most frequent VOCs identified over the storing waste, showing over 50 % appearance in all examined samples, were terpenes (e.g., di-limonene, beta-myrcene, delta-3-carene, alpha-pinene, alpha-terpinolene, linalool, etc.), sulfides (dimethyl disulfide), aromatics (benzene, 1-methyl-2-(2-propenyl)), alkanes (e.g., decane, dodecane), ketones (2-propanone), esters (e.g., acetic acid ethyl ester, acetic acid methyl ester), and alcohols (e.g., 3-cyclohexen-1-ol, 4-methyl-1-(1-methylethyl)). The prominent role of terpenes in the “pre-compost” odor and especially that of di-limonene was highlighted. In all examined scenarios, the emitted volatiles were increased at raised temperatures and later decreased in time. Aeration of waste bins slightly affected the volatilization process resulting in higher profiles of VOCs; uniformity in the composition of VOCs was also noted. Slight modifications of commercial waste bins may favor the initiation of home composting.
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