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McLaughlin Kofod posted an update 16 days ago
These new techniques are promising for bacterial biolipids extraction. Challenges and future research needs for cost-effective lipid extraction are identified in this review.The rapid sulfate formation is a crucial factor determining the explosive growth of fine particles and the frequent occurrence of severe haze events in China. Recent field observations also show that brown carbon is one of the most critical components in aerosol particles sampled during haze episodes. To this day, there is limited knowledge that accesses the role of brown carbon in atmospheric chemistry. Batimastat manufacturer In fact, these carbonaceous particulate matters, mainly derived from forest fires, biomass burning, and biogenic release, can act as photosensitizers and produce varieties of active intermediates to alter oxidation capacity. Experimental results in this work provide evidence that hydroxyl radical (∙OH) stems from brown carbon proxies fulvic acid /humic acid (FA/HA) upon irradiation, leading to rapid SO2 oxidation on brown carbon particles in the atmosphere. Further correlation analyses for sulfate formation and chromophore properties of 12 model compounds demonstrate that brown carbon particles with higher aromaticity and E2/E3 (the ratio of absorbance at 254 nm to that at 365 nm) would facilitate ∙OH production and SO2 photo-oxidation. Uptake coefficient measurements and sulfate production rate estimation indicate that brown carbon could gain importance in atmospheric SO2 oxidation. A better understanding of SO2 uptake kinetics on brown carbon surfaces favors in defining new regulations to improve air quality and reduce the harmful effects of haze events on resident health and the environment.One of the largest releases of radioactive contamination in history occurred at Japan’s Fukushima Daiichi Nuclear Power Plant (FDNPP). Although the accident happened in 2011, questions still persist regarding its ecological impacts. For example, relatively little is known about radiocesium accumulation in snakes, despite their high trophic status, limited home range sizes, and close association with soil where many radionuclides accumulate. This study presents one of the most comprehensive radioecological studies of snakes published to date using a combination of whole-body radiocesium analyses, GPS transmitters, and optically stimulated luminescence (OSL) dosimeters. The objectives were to 1) quantify whole-body radiocesium activity concentrations and internal dose rates among several common species of snakes within and around the Fukushima Exclusion Zone (FEZ), 2) determine effects of species, sex, and body size on radiocesium activity concentrations, 3) measure external dose rates using GPS-coupled dosimetas.Pesticides are increasingly used worldwide to protect crops. However, only a small fraction of pesticides really hit their target organisms, with the remaining fraction reaching the environment by several phenomena such as leaching, and ending up in aquatic ecosystems the final receptor of micropollutants. Chemical stressors induce changes in taxonomic composition of fauna and flora which are now the focus of many biomonitoring studies. Interspecific competition and predation are structuring factors of community composition. But the combined effects of biotic relationships (competition, predation) and pesticides are rarely accounted for. We tested four factors (Predation, Competition, Diuron (Herbicide) and Imidacloprid (insecticide)) separately on three distinct morphotypes of two diatoms species Planothidium lanceolatum and Gomphonema gracile (normal and teratogen forms), to quantify the daily growth kinetics of each under varied pressures. The predator used was a nematode, cosmopolitan in soils and aquatic ecosystems (Aphelenchoides bicaudatus). We reproduced experiments combining the factors in binary and ternary combinations. Diuron had lower toxicity than expected, while imidacloprid affected the growth of non-target diatoms. Interalgal competition had marked negative effects on diatom growth kinetics, which increased as supplementary pressures (nematodes and/or pesticides) were added. These results demonstrate that ecological relationships in freshwater biofilms (competition, predation) have a non negligible effect on community composition, population behavior and impacts usually observed. Multistress conditions including the presence of pesticides in freshwaters are expected to affect biodiversity in ways that are hard to predict from simple toxicity assays.This paper presents the heavy metal content in river water, sediment and bedrock in the karst area of the Pearl River Basin in China to evaluate the long-term impact of natural weathering and mining on the ecological environment. The results show that Cd and As is 2-3 times more enriched within the carbonate bedrock of the Pearl River Basin compared to the upper continental crust (UCC), which is indicative of high geological background values. Within the river water of the upper reaches of the Diaojiang River (a tributary of the Pearl River), which flows through the Dachang super-large orefield, Zn, As, Cd and Sb exceeds the environmental quality standards for surface water (WQS) by more than an order of magnitude. Among these, Zn and Cd sharply decreases to within the WQS in the lower reaches of the river, but the content of As and Sb in the estuary is still several times higher than the WQS. Cd in the sediments of the small carbonate watersheds and in the mainstream of the Pearl River only present a low-moderate ecological risk. In contrast, severe heavy metal pollution of the sediments of the Diaojiang River Basin is observed. Even in the lower reaches, remote from the mining area, the content of Pb, Zn, As and Cd in the sediments is still two orders of magnitude higher than the soil background values. The content of both Cd and As presents a very high ecological risk, indicating that under the cumulative effect of high geological background values and mining, full restoration of the ecological environment in the Diaojiang River Basin is a complex and long-term process.After anaerobic-oxic (A/O) treatment, there are often high chromaticity levels in piggery bio-treatment effluents, which still contain a high concentration of refractory organics. This paper describes the use of piggery biogas residue biochar (BioC) to support MnO2 to prepare a catalyst (MnO2/BioC) and examines the effects of catalyst addition, pH and ozone dosage on chromaticity and organic matter degradation in the ozonation process. Three-dimensional fluorescence spectroscopy (3D-EEM) and GC-MS were used to analyse changes in the organic component of the effluent before and after ozonation. The results indicate that the decolorization percentages reached 91.29% and that the UV254 and CODcr removal percentages reached 81.64% and 61.07%, respectively, when the MnO2/BioC catalyst addition amount was 1.0 g·L-1, the pH was 9.0, and the ozone dosage was 0.45 g·L-1. The 3D-EEM analysis results showed that the macromolecular organics mainly consisted of humic acids before treatment, and the removal of humic acid organic matter after treatment had an obvious effect.