Recently, several studies have been conscious of the promotion effect of hydrogen peroxide (H2O2), a self-decay product of ferrate (Fe(VI)), on Fe(VI) to oxidize contaminations, but the pivotal activation mechanism has not been thoroughly evaluated. This work aims to compare and reveal the promoting mechanism of H2O2 in Fe(VI) and Fe(VI)−H2O2 processes, and to illustrate the practical use potential of Fe(VI)−H2O2 system. Many lines of evidence verified the involvement of •OH and O2•− in pollutant degradation were excluded in Fe(VI) and Fe(VI)−H2O2 systems, meaning that high dosage of H2O2 cannot trigger an activation pathway different from in-situ H2O2. The better oxidation performance of the Fe(VI)−H2O2 system than Fe(VI) alone was ascribed to the catalytic role of in-situ and ex-situ H2O2, which can directly and/ or indirectly facilitate the formation of Fe(IV) and Fe(V). Considering the structural similarity of peroxymonosulfate (PMS) and peroxydisulfate (PDS) with H2O2 as well as their universality in water pollutant remediation, the oxidation properties and reactive oxidants of Fe(VI)−PMS and Fe(VI)−PDS processes were also examined. Besides, the Fe(VI)−H2O2 system suffered from less restriction by inorganic ions and natural organic matter, and exhibited satisfactory pollutant removal effects in real water. Overall, this work provides a further and comprehensive cognition about the role of H2O2 in Fe(VI) and Fe(VI)−H2O2 systems.
The recent discovery of comammox Nitrospira as complete nitrifiers has significantly enriched our under-standing on the nitrogen cycle, yet little is known about their metabolic transcripts in natural aquatic ecosystems. Using the genome-centric metatranscriptomics, we provided the first in-situ expression pat-terns of comammox Nitrospira along the Yangtze River. Our study confirmed widespread expressions of comammox Nitrospira, with the highest transcription accounting for 33.3% and 63.8% of amoA and nxrAB genes expressed in ammonia-oxidizing prokaryotes (AOPs) and Nitrospira sublineages I/II, respectively. Moreover, comammox two clades differed in nitrification, with clade A acting as the dominator to am-monia oxidation in comammox, and clade B contributing more transcripts to nitrite oxidation than to ammonia oxidation. Compared to canonical Nitrospira, comammox community had lower expressions of ammonia/nitrite transporters and nitrogen assimilatory genes, but far higher expressions in urea trans-port and hydrolysis, facilitating to derivation of ammonia and energy mainly through intracellular ure-olytic metabolism. This suggests no need for "reciprocal-feeding" between canonical Nitrospira and AOPs in a natural river. Aerobic mixotrophy of comammox bacteria was suggested by expressions of genes coding for respiratory complexes I-V, oxidative/reductive TCA cycle, oxygen stress defenses, and trans-port/catabolism of simple carbohydrates and low-biosynthetic-cost amino acids. Intriguingly, significant positive correlations among expressions of ammonia monooxygenases, hydroxylamine dehydrogenase and copper-dependent nitrite reductase indicated that comammox Nitrospira had the potential of converting nitrite to nitric oxide accompanied by ammonia oxidation under low-C/N and aerobic conditions, while gene expressions in this pathway were significantly and positively associated with pH. Overall, this study illustrated novel transcriptional characteristics of comammox Nitrospira, and highlighted the necessity of reassessing their contributions to biogeochemical carbon and nitrogen cycling with perspective of in-situ meta-omics as well as culture experiments. (c) 2021 Elsevier Ltd. All rights reserved.
Experimental estimates of residential intake fractions for indoor volatile organic compound (VOC) releases are scarce. We evaluated individual intake fractions (iFi, mass inhaled by an individual per unit mass emitted) using approximately five months of time-resolved VOC measurements acquired at two residences. First, we directly estimated iFi using inert tracer gases that were released at fixed rates. Tracer gas iFi values were generally consistent between occupants and comparable across seasons. Furthermore, iFi for sources released on different floors of a residence were statistically indistinguishable, suggesting that source location within the living space was not strongly influential. Emissions from living space sources (iFi ∼ 0.3% = 3000 ppm) contributed to occupant exposures at rates 2–4 times higher than crawl space sources (iFi ∼ 1000 ppm) and greater than 40 times higher than attic sources (iFi < ∼70 ppm). Second, we indirectly estimated iFi for 251 VOCs using net emission rates estimated by indoor–outdoor material balance. Although emission patterns varied between compounds, all VOC-specific iFi estimates were clustered near the values of the living space tracer gases. These experimental observations substantiate the theoretical expectation that iFi values are largely independent of analyte characteristics, a useful simplification for exposure assessments.
With the increasing demands on energy and environmental domains, not only high oil production but also its accurate quantification has become one of the most important topics in academia and industry. This paper initially proposes a comprehensive workflow in which an integrated hierarchy–correlation model is used to thoroughly evaluate the influences of all relevant reservoir parameters on the ultimate oil recovery for water-flooding oil reservoirs. More specifically, the analytic hierarchy process, grey relation, and entropy weight are combined through the multiplicative weighting method to quantitatively describe the production parameters. Accordingly, novel multivariable linear and nonlinear correlations are developed to predict the production performance and validated through comparisons with numerical reservoir simulations. Seven factors, including five reservoir parameters, namely, permeability and its contrast, porosity, thickness, and saturation, and two production parameters, namely, the injection–production ratio and the operating pressure, have been identified as the most influential factors on recovery performances and thus are employed in the proposed correlations to predict the ultimate oil recovery factor. The results obtained by the proposed method are quite close to the real-time simulation data, while the accuracy is retained. The numerical results show that the recovery factors of water-flooding oil reservoirs are about 33.5–59.5%, and the corresponding linear and nonlinear correlation coefficients are 0.903 and 0.789, respectively. In comparison with the numerical simulation, the approximation error by the linear correlation is about 0.5%, which is lower than that of nonlinear correlation, for example, 12.3%. This study will be beneficial to analyze the reservoir-related parameters and provide a useful tool for rapid production performance evaluation of the water-flooding production scenario.
Emissions of reactive nitrogen as ammonia (NH3) and nitrogen oxides (NO x ), together with sulfur dioxide (SO2), contribute to formation of secondary PM2.5 in the atmosphere. Satellite observations of atmospheric NH3, NO2, and SO2 levels since the 2000s provide valuable information to constrain the spatial and temporal variability of their emissions. Here we present a bottom-up Chinese NH3 emission inventory combined with top-down estimates of Chinese NO x and SO2 emissions using ozone monitoring instrument satellite observations, aiming to quantify the interannual variations of reactive nitrogen emissions in China and their contributions to PM2.5 air pollution over 2005–2015. We find small interannual changes in the total Chinese anthropogenic NH3 emissions during 2005–2016 (12.0–13.3 Tg with over 85% from agricultural sources), but large interannual change in top-down Chinese NO x and SO2 emissions. Chinese NO x emissions peaked around 2011 and declined by 22% during 2011–2015, and Chinese SO2 emissions declined by 55% in 2015 relative to that in 2007. Using the GEOS-Chem chemical transport model simulations, we find that rising atmospheric NH3 levels in eastern China since 2011 as observed by infrared atmospheric sounding interferometer and atmospheric infrared sounder satellites are mainly driven by rapid reductions in SO2 emissions. The 2011–2015 Chinese NO x emission reductions have decreased regional annual mean PM2.5 by 2.3–3.8 μg m−3. Interannual PM2.5 changes due to NH3 emission changes are relatively small, but further control of agricultural NH3 emissions can be effective for PM2.5 pollution mitigation in eastern China.
This research sheds light on the link between social norms and economic development. It explores the determinants of inheriting the mother’s surname in China and its implications for children’s health status and education outcomes. It establishes that children whose mothers are younger, more educated, and from regions with a lower sex ratio are more likely to be named after their mother. Moreover, these children have superior health and education outcomes, reflecting predominantly the impact of women’s higher bargaining power on children’s human capital accumulation.
Abstract Aim Invertebrate-mediated dispersal has previously been proposed to promote angiosperm diversification and distribution. However, little is known about the specific impact of invertebrate-mediated dispersal on the biogeography and current distribution of plants. We aim to infer the influence of vespicochorous (hornet) and myrmecochorous (ant) dispersal on the historical biogeography of herbaceous monocot species. Location Southeast Asia, East Asia, Australia, North America. Taxon Family Stemonaceae. Method We sampled ca. 75% of the species diversity in Stemonaceae (28 out of 37 species), covering the entire distribution range of the family, to reconstruct the biogeographic history of this family. Using phylogenetic logistic regression analyses, we then tested the relationship between dispersal modes and geographic distributions. Results Stemonaceae originated on the Asian mainland during the late Cretaceous and then dispersed to North America, the western Malay Archipelago and eastern Malay Archipelago and Australia between the late Cretaceous and Pliocene. Geographical ranges of ant- versus hornet-dispersed Stemonaceae species are significantly different, with vespicochorous species having broader distribution ranges than myrmecochorous species. Main conclusions Invertebrate-mediated dispersal in Stemonaceae may promote narrow endemism and play an important role in shaping the current distribution of species. Most lineages dispersed by ants failed to cross biogeographic barriers and exhibit limited range expansion overland. Vespicochorous lineages were able to cross oceanic barriers and occupy larger continental areas and/or occur on oceanic islands.