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811.
Rocío Reina Christiane Liers Juan Antonio Ocampo Inmaculada García-Romera Elisabet Aranda 《Chemosphere》2013
The in vivo conversion of dry olive mill residue (DOR) by wood- and dung-dwelling fungi − Auricularia auricula-judae, Bjerkandera adusta and Coprinellus radians − increases peroxidase secretion up to 3.2–3.5-fold (∼1.3, 3.5 and 7.0 U g−1 DOR for dye-decolorizing peroxidase, manganese peroxidase and aromatic peroxygenases, respectively). The incubation of DOR with these fungi produced a sharp decrease in total phenolic content (100% within 4 wk), a reduction in phytotoxicity as well as a certain degree of plant growth caused by the stimulating effect of fungal-treated DOR. These findings correlate with a characteristic shift in the fragmentation pattern of water-soluble aromatics (detected at 280 nm) from low (0.2, 1.5 and 2.2 kDa, respectively) to high molecular mass (35 to >200 kDa), which demonstrates the presence of a polymerization process. Phenol-rich agricultural residues are a useful tool for enzyme expression and production studies of peroxidase-producing Agaricomycetes which could make DOR a valuable organic fertilizer. 相似文献
812.
813.
814.
Branco V Vale C Canário J Santos MN 《Environmental pollution (Barking, Essex : 1987)》2007,150(3):373-380
Muscle, liver and stomach contents of 64 blue sharks and 52 swordfishes, caught between September 2004 and February 2005 near the Azores (area A) and the Equator (area E), were analysed for mercury and selenium. Levels of mercury were relatively high (blue shark: 0.032-2.5microgg(-1); swordfish: 0.031-9.8microgg(-1)) and comparable to values reported in the literature. However, mercury and organic mercury concentrations in muscle and liver of specimens from E were significantly higher than those from A. A similar trend was registered in stomach contents, suggesting higher uptake of Hg in specimens from E. This difference was also observed in the relationship between concentration in muscle and size, indicating a higher accumulation rate in specimens from E. The accumulation of Se in the liver of both species showed a positive correlation with inorganic mercury concentrations, pointing to a detoxifying mechanism of organic mercury in these species through Se-Hg liasons. 相似文献
815.
壳聚糖混凝剂除氟的研究 总被引:1,自引:0,他引:1
合成了壳聚糖和丙烯酰胺改性壳聚糖两种高分子混凝剂,并以NaF溶液为研究对象,考察了两种壳聚糖混凝剂投加量、pH值、接触时间及温度对除氟性能的影响.实验结果表明:丙烯酰胺改性壳聚糖的除氟效果优于未改性的壳聚糖;随着两种混凝剂投量的增加,除氟效率增大,当剂量分别大于50 mg/L和60 mg/L时,除氟效率趋于稳定;壳聚糖与改性壳聚糖混凝剂分别在pH值为6.2和5.4时,获得了最佳的除氟效果;接触时间小于12 min时,随着接触时间延长,除氟效率快速增加,大于20 min时,除氟率趋于稳定;混凝温度升高有利于提高除氟率,两种混凝剂在25℃即达到最大除氟率. 相似文献
816.
817.
人工神经网络在深圳市水库富营养化评价中的应用 总被引:1,自引:0,他引:1
对富营养化评价标准进行插值获取大量的样本,建立了基于BP人工神经网络的富营养化评价模型。将模型应用于评价深圳市13座主要水库的富营养化状况,对其成因进行分析,并提出了对策与建议。研究结果表明,石岩水库与深圳水库为轻度富营养化,占评价水库总数的15.4%;西丽水库等11座水库为中营养,占评价水库总数的84.6%。人工神经网络用于建立湖库富营养评价模型是适合的。 相似文献
818.
Martins LD da Silva Júnior CR Solci MC Pinto JP Souza DZ Vasconcellos P Guarieiro AL Guarieiro LL Sousa ET de Andrade JB 《Environmental monitoring and assessment》2012,184(5):2663-2676
In this study, particulate matter (PM) were characterized from a place impacted by heavy-duty vehicles (Bus Station) fuelled
with diesel/biodiesel fuel blend (B3) in the city of Londrina, Brazil. Sixteen priority polycyclic aromatic hydrocarbons (PAH)
concentrations were analyzed in the samples by their association with atmospheric PM, mass size distributions and major ions
(fluorite, chloride, bromide, nitrate, phosphate, sulfate, nitrite, oxalate; fumarate, formate, succinate and acetate; lithium,
sodium, potassium, magnesium, calcium and ammonium). Results indicate that major ions represented 21.2% particulate matter
mass. Nitrate, sulfate, and ammonium, respectively, presented the highest concentration levels, indicating that biodiesel
may also be a significant source for these ions, especially nitrate. Dibenzo[a,h]anthracene and indeno[1,2,3,-cd]pyrene were the main PAH found, and a higher fraction of PAH particles was found in diameters lower than 0.25 μm in Londrina bus station. The fine and ultrafine particles were dominant among the PM evaluated, suggesting that biodiesel
decreases the total PAH emission. However, it does also increase the fraction of fine and ultrafine particles when compared
to diesel. 相似文献
819.
820.
Franco Teixeira-de Mello Esben A. Kristensen Mariana Meerhoff Iván González-Bergonzoni Annette Baattrup-Pedersen Carlos Iglesias Peter B. Kristensen Néstor Mazzeo Erik Jeppesen 《Environmental monitoring and assessment》2014,186(3):1665-1677
Electrofishing is considered a reliable tool to assess the assemblages and biodiversity of fish in wadeable streams. The most widely used electrofishing techniques (point [P], single-pass [S-P], and multiple-pass [M-P]) vary as to the effort needed for sample collection, and this may potentially influence the degree of accuracy. Moreover, little is known about the comparability of the methods and their specific performance in streams with different fish assemblages. The aim of this investigation was to validate (using M-P sampling as reference) the use of P and S-P electrofishing techniques to accurately assess the richness, density and size distribution of fishes in small streams at both regional and global scale independently of fish assemblages and geographical region. We sampled 50-m-long reaches in a total of 33 lowland stream reaches that were located in different climatic and biogeographical regions (Uruguay and Denmark) and hosted different fish assemblages. Subtropical fish communities exhibited higher richness (Uy: 12–32, Dk: 1–9) and densities (Uy: 1.3–5.2, DK: 0.1–4.9 in. m?2) than temperate streams. We applied both "global models" using the entire database (33 sites) and "local models" including the same number of sites but using the climatic region as a model variable. Regression analyses revealed that the P, S-P and M-P methods all provided an adequate picture of the species composition and size distribution, and transfer equations for comparison between methods are thus not required. Conversely, richness was better predicted by S-P and by P techniques for regional and global models, respectively. Transfer equations obtained for abundance revealed that the P and S-P models can accurately transform catch data into M-P estimations. The transfer equations provided here may have great relevance as they allow relatively reliable comparisons to be made between data obtained by different techniques. We also show that less intensive sampling techniques may be equally useful for monitoring purposes as those requiring more intensive efforts (and costs). We encourage validation of our developed transfer equations on data from other regions of the world. 相似文献