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Environmental Science and Pollution Research - Aedes aegypti and Culex quinquefasciatus are vectors of diseases that constitute public health problems. The discovery of products capable of...  相似文献   
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Effective water quality management depends on enactment of appropriately designed monitoring programs to reveal current and forecasted conditions. Because water quality conditions are influenced by numerous factors, commonly measured attributes such as total phosphorus (TP) can be highly temporally varying. For highly varying processes, monitoring programs should be long-term and periodic quantitative analyses are needed so that temporal trends can be distinguished from stochastic variation, which can yield insights into potential modifications to the program. Using generalized additive mixed modeling, we assessed temporal (yearly and monthly) trends and quantified other sources of variation (daily and subsampling) in TP concentrations from a multidecadal depth-specific monitoring program on Big Platte Lake, Michigan. Yearly TP concentrations decreased from the late 1980s to late 1990s before rebounding through the early 2000s. At depths of 2.29 to 13.72 m, TP concentrations have cycled around stationary points since the early 2000s, while at the surface and depths ≥?18.29 concentrations have continued declining. Summer and fall peaks in TP concentrations were observed at most depths, with the fall peak at deeper depths occurring 1 month earlier than shallower depths. Daily sampling variation (i.e., variation within a given month and year) was greatest at shallowest and deepest depths. Variation in subsamples collected from depth-specific water samples constituted a small fraction of total variation. Based on model results, cost-saving measures to consider for the monitoring program include reducing subsampling of depth-specific concentrations and reducing the number of sampling depths given observed consistencies across the program period.  相似文献   
3.
Arabic gum (AG) is the most common emulsifier used for beverage emulsions. Cashew tree gum (CG) is a biological macromolecule that has been proposed as a substitute for the AG, although their technological properties comparison is still necessary. The aim of this study was to evaluate an isolation method for CG, and then evaluate CG technological properties in comparison to AG. The CG isolation methodology was improved using a small solvent amount. CG zeta-potential ranged from +8.0 mV (pH 2) to ?9.7 mV (pH 5), while the electric charge in solution of AG ranged from ?2.7 mV (pH 2) to ?28.6 mV (pH 6). As compared to AG, the CG showed a 50 % higher swelling, a 36 % lower oil absorption capacity, a slightly lower (4–8 %) solubility and lower consistency. CG is a feasible polyelectrolyte, promotes lower consistency solutions, and exhibits good swelling property.  相似文献   
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Environmental Science and Pollution Research - The total cultivated area in Brazil reached to 62 million ha in 2018, with the predominance of genetically modified soybean and corn (36 and 17...  相似文献   
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The effect of dissolved organic matter (DOM) and oil on the removal of the water-soluble compounds benzene, toluene, ethylbenzene, and xylene isomers (BTEX) by two low-cost biosorbents Macrocystis pyrifera and Ulva expansa) was evaluated. DOM decreased the adsorption capacity of toluene, ethylbenzene, and xylenes of the two biosorbents. In contrast, the removal of benzene increased under the same conditions in single and multi-solute systems: this effect was dominant in U. expansa biomass treatments. In the presence of DOM and oil in solutions, the removal of BTEX notoriously increased, being oil that contributed the most. Solubility and hydrophobicity of pollutants played a key role in the adsorption process. The attractions between BTEX molecules and biosorbents were governed by π–π and hydrophobic interactions. Affinities of biosorbents for BTEX were mainly in the order of X > E > T > B. The Langmuir and Sips equations adjusted the adsorption isotherms for BTEX biosorption in deionized and natural water samples, but in the case of oily systems, the Freundlich equation seemed to have a better fit. The biosorption processes followed a pseudo-second-order rate in all the cases.  相似文献   
7.
Waste from wastewater treatment plants (WWTP) for Helianthus annuus L. production may be a viable solution to obtain biodiesel. This study achieved two objectives: assess the agronomical viability of waste (wastewater and sludge) from the Alcázar de San Juan WWTP in central Spain for H. annuus L. production; use H. annuus L. seeds grown in this way to obtain biodiesel. Five study plots, each measuring 6 m × 6 m (36 m2), were set up on the agricultural land near the Alcázar de San Juan WWTP. Five fertilizer treatment types were considered: drinking water, as the control; treated wastewater; 10 t ha?1 of air-dried sewage sludge; 20 t ha?1 of air-dried sewage sludge; 0.6 t ha?1 of commercial inorganic fertilizer. Soil, irrigation water, sewage sludge, crop development and fatty acid composition in achenes oil were monitored. The 20 t ha–1 dose of sewage sludge proved effective to grow H. annuus L. with similar results to those grown with a commercial fertilizer. However, precautions should be taken when irrigating with wastewater because of high salinity and nutrient deficiency. Sunflower oil was composed mostly of linoleic and oleic acid. The remaining fatty acids were linolenic, estearic, nervonic, palmitoleic, and palmitic.  相似文献   
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Aquatic environments are often exposed to toxic heavy metals, which gain access to the food chain via microalgae and may cause severe problems at higher trophic levels. However, such a metabolic specificity can be taken advantage of in bioremediation strategies. The potential of a novel wild strain of Scenedesmus obliquus, previously isolated from a heavy metal-contaminated site in northern Portugal, to remove Zn from aqueous solutions was thus studied, using several initial concentrations. The removal extent reached its maximum by 1 day: 836.5 mg Zn/g biomass, at the initial concentration of 75 mg/L, mainly by adsorption onto the cell surface. Comparative studies encompassing a commercially available strain of the same microalgal species led to a maximum removal extent of only 429.6 mg Zn/g biomass, under identical conditions. Heat-inactivated cells permitted a maximum removal of 209.6 mg Zn/g biomass, at an initial concentration of 50 mg Zn/L. The maximum adsorption capacity of Zn, estimated via Langmuir’s isotherm, was 330 mg Zn/g biomass. Finally, Zn removal was highest at pH 6.0–7.0. It was proven, for the first time, that such a wild microalga can uptake and adsorb Zn very efficiently, which unfolds a particularly good potential for bioremediation. Its performance is far better than similar (reference) species, especially near neutrality, and even following heat-treatment.  相似文献   
10.
Chiral pharmaceuticals in the environment   总被引:1,自引:1,他引:0  
Many pharmaceutical pollutants are chiral, existing in the environment as a single enantiomer or as mixtures of the two enantiomers. In spite of their similar physical and chemical properties, the different spatial configurations lead the enantiomers to have different interactions with enzymes, receptors or other chiral molecules, which can give diverse biological response. Consequently, biodegradation process and ecotoxicity tend to be enantioselective. Despite numerous ongoing research regarding analysis and monitorization of pharmaceutical ingredients in the environment, the fate and effects of single enantiomers of chiral pharmaceuticals (CP) in the environment are still largely unknown. There are only few chiral analytical methods to accurately measure the enantiomeric fraction (EF) in environmental matrices and during biodegradation processes. Furthermore, the ecotoxicity studies usually consider the enantiomeric pair as unique compound. We reviewed the current knowledge about CP in the environment, as well as the chiral analytical methods to determine the EF in environmental matrices. The degradation and removal processes of CP of important therapeutic classes, usually detected in the environment, and their toxicity to aquatic organisms were also reviewed. On the other hand, this review demonstrate that despite the great importance of the stereochemistry in pharmaceutical science, pharmacology and organic chemistry, this is normally neglected in environmental studies. Therefore, CP in the environment need much more attention from the scientific community, and more research within this subject is required.  相似文献   
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