Ottomoran3001

Our previous studies showed hydrophobic organic compounds (HOCs) in the sediments of drinking water reservoirs caused DNA damage in human cells (Caco-2) after chlorination. However, the main mechanisms remained unclear. This study compared oxidative damage and EROD activity in Caco-2 cells upon exposure to chlorinated HOCs, and the role of antioxidants (catalase, vitamin C and epigallocatechin gallate (EGCG)) in reducing the toxicities was examined. The result showed that chlorinated HOCs induced a 4-fold increase in production of reactive oxygen species (ROS) compared with HOCs. Antioxidants supplement significantly reduced ROS yields and DNA peroxidation. HOCs with relatively higher TEQbio were greatly reduced (about 98%) after chlorination, indicating dioxin-like toxicity is not the main factor inducing oxidative damage by chlorinated HOCs. selleck inhibitor Yet, ROS and the associated oxidative damage seem to be more responsible for causing DNA damage in the cells. Antioxidants including catalase, Vitamin C and EGCG showed protective effect against chlorination.Surface urban heat islands (SUHIs) are present in all cities, derived from their thermal properties. While looking at the spatiotemporal variability of land surface temperature (LST), there is still a gap in understanding patterns of change. In this paper, we analysed diurnal and nocturnal annual mean LST trends in continental (Beijing), temperate (Mexico City and Santiago), and arid (Cairo, Hyderabad, and Riyadh) cities employing 1 km MODIS data (2003-2019). Each time-series was assessed with the structure of a space-time cube. Hot and cold spots were detected for each year and the LST trends were analysed. Each pixel was classified into different space-time LST trends and their SUHIs were estimated. Cities exhibit trends of increasing temperatures in cold and hot spots for diurnal and nocturnal data. Temperatures are increasing faster in hot spots for diurnal and in cold spots for nocturnal scenes. Steady hot spots and warming hot spots exhibit the highest SUHIs for day and night. Our approach provides a framework to empirically delineate the spatial intraurban heterogeneity of LST patterns over time. This spatially explicit information provides insights into urban areas requiring heat mitigation strategies and can be used to monitor the performance of measures already implemented for climate adaptation.With the rapid development of society, the soil and water environments in many countries are suffering from severe pollution. Pollutants in different phases will eventually gather into the soil and water environments, and a series of migrations and transformations will take place at ecohydrological interfaces with water flow. However, it is still not clear how ecohydrological interfaces affect the migration and the transformation of pollutants. Therefore, this paper summarizes the physical, ecological, and biogeochemical characteristics of ecohydrological interfaces on the basis of introducing the development history of ecohydrology and the concept of ecohydrological interfaces. The effects of ecohydrological interfaces on the migration and transformation of heavy metals, organic pollutants, and carbon‑nitrogen‑phosphorus (C-N-P) pollutants are emphasized. Lastly, the prospects of applying ecohydrological interfaces for the removal of pollutants from the soil and water environment are put forward, including strengthening the ability to monitor and simulate ecohydrological systems at micro and macro scales, enhancing interdisciplinary research, and identifying main influencing factors that can provide theoretical basis and technical support.Microbial conversion of methane to electricity, fuels, and liquid chemicals has attracted much attention. However, due to the low solubility of methane, it is not considered a suitable substrate for microbial fuel cells (MFCs). In this study, a conductive fiber membrane (CFM) module was constructed as the bioanode of methane-driven MFCs, directly delivering methane. After biofilm formation on the CFM surface, a steady voltage output of 0.6 to 0.7 V was recorded, and the CFM-MFCs obtained a maximum power density of 64 ± 2 mW/m2. Moreover, methane oxidation produced a high concentration of intermediate acetate (up to 7.1 mM). High-throughput 16S rRNA gene sequencing suggests that the microbial community was significantly changed after electricity generation. Methane-related archaea formed a symbiotic consortium with characterized electroactive bacteria and fermentative bacteria, suggesting a combination of three types of microorganisms for methane conversion into acetate and electricity.The deep-sea mussel Gigantidas platifrons is a representative species that relies on nutrition provided by chemoautotrophic endosymbiotic bacteria to survive in both hydrothermal vent and methane seep environments. However, vent and seep habitats have distinct geochemical features, with vents being more harsh than seeps because of abundant toxic chemical substances, particularly hydrogen sulfide (H2S). Until now, the adaptive strategies of G. platifrons in a heterogeneous environment and their sulfide detoxification mechanisms are still unclear. Herein, we conducted 16S rDNA sequencing and metatranscriptome sequencing of G. platifrons collected from a methane seep at Formosa Ridge in the South China Sea and a hydrothermal vent at Iheya North Knoll in the Mid-Okinawa Trough to provide a model for understanding environmental adaption and sulfide detoxification mechanisms, and a three-day laboratory controlled Na2S stress experiment to test the transcriptomic responses under sulfide stress. The results revealed ibionts, endosymbionts, and mussel host collaborated on sulfide detoxification from extracellular to intracellular space to adapt to harsh H2S-rich environments.NO3 radicals can clean the atmospheric primary contaminants during the night. However, it can also effect the formation of secondary organic aerosol (SOA) and nitrate, which may worsen air quality. We report field observations of NO3 radicals with a home-made long path differential optical absorption spectroscopy (LP-DOAS) at a rural site in the polluted North China Plain in the summer of 2014. The detection limit (1σ) of NO3 with 3.4 km optical path was 3.4 ppt. The observed mean NO3 mixing ratios were 21 ppt with the maximum value of 104 ppt. The average calculated production rates and steady state lifetime of NO3 were 952 ppt/h and 103 s, respectively. The increase of both PM2.5 (>60 μg/m3) and RH (>60%) would result in an increase of the loss of NO3. The proportion of indirect losses rise with the increase of RH (>50%). The fitting kNO3 ranged from 0.0018 to 0.012 s-1 while γN2O5 was 0.0012 to 0.072. The ratios of direct loss ranged from 20.95% to 90.36% with an average of 56.81% during the campaign.Enormous production of cosmetic products and its indiscriminate use tends to discharge into the aquatic environment and might threaten non-target organisms inhabiting aquatic ecosystems. In the present study, developmental toxicity of 4-methylbenzylidene camphor (4-MBC), a widely used organic UV filter in personal care products has been evaluated using zebrafish embryo-larval stages. Waterborne exposure induced developmental toxicity and deduced 2.71 mg/L as 96 h LC50 whereas embryos exposed to sub-lethal concentrations (50 and 500 μg/L) caused a significant delay in hatching rate, heart rate, reduced larval length, and restricted hatchlings motility besides the axial curvature. Chronic exposure to 10 dpf resulted in significant decrease in SOD activity at 500 μg/L with no changes in CAT level besides a significant increase in GST enzyme at 5 μg/L concentration in 5 dpf sampled larvae. However, all the three enzymes were significantly elevated in 10 dpf larvae indicating differential oxidative stress during txicity of 4-MBC and the information shall be used for aquatic toxicity risk assessment.A two-stage tidal flow constructed wetland (referred to as TFCW-A and TFCW-B) was used to treat low chemical oxygen demand/total nitrogen (COD/TN or simply C/N) ratio influent at low temperatures ( less then 15 °C). The influence of the flooding-resting time (A 8 h-4 h, B 4 h-8 h) and effluent recirculation on nitrogen removal and microbial community characteristics were explored. TFCW-B achieved optimal average nitrogen removal efficiency with effluent recirculation (96.05% ammonium nitrogen (NH4+-N); 78.43% TN) and led to nitrate nitrogen (NO3--N) accumulation due to the lack of a carbon source and longer resting time. Ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) were inhibited at low temperatures. Except for nrfA, AOA, AOB, narG and nirS were separated by the flooding-resting time rather than by spatial position. Furthermore, the dominant genera in TFCW-A were Arthrobacter, Rhodobacter, Pseudomonas, and Solitalea, whereas prolonging resting time promoted the growth of Thauera and Zoogloea in TFCW-B. Spearman correlation analysis showed that Zoogloea and Rhodobacter had the strongest correlations with other genera. Moreover, the NH4+-N concentration was significantly positively influenced by Arthrobacter, Rhodobacter, Pseudomonas, and Solitalea but negatively influenced by Thauera and Zoogloea. There was no significant correlation between TN and the dominant genera. This study not only provides a practicable system for wastewater treatment with a low C/N ratio but also presents a theoretical basis for the regulation of microbial communities in nitrogen removal systems at low temperatures.Pyrene, a typical four-ring polycyclic aromatic hydrocarbon, is abundantly present in the environment and is potentially harmful to the human body. In this study, single-chamber air-cathode microbial fuel cells (MFCs) were used to treat pyrene, and the ensuing degradation, electrical parameters, and microbial changes were analyzed. The results showed that MFCs could degrade pyrene, and the maximum degradation rate for 30 mg/L reached 88.1 ± 5.4%. The addition of pyrene reduced the electrical performance of the MFCs and suppressed the power output. Analysis of the anodic microbial community showed that the proportion of Alcaligenes and Stenotrophomonas increased with an increase in pyrene concentration, which may explain the high degradation rate of pyrene.Severe haze episodes occur frequently in the Seoul Metropolitan Area (SMA) and throughout East Asian countries, especially during the winter and early spring. We investigated the sources and chemistry of particulate matter (PM) during three winter haze episodes in Seoul that occurred between January 1st and February 10th in 2017 using a high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) and positive matrix factorization (PMF) analysis. The average concentration of sub-micrometer aerosol (PM1 = NR-PM1 + black carbon (BC)) was 32.6 μg/m3, which was composed of 42% organics, 27% nitrate, 11% sulfate, 13% ammonium and 4% BC by mass. Six distinct sources of organic aerosol (OA) were identified vehicle emitted hydrocarbon-like OA (HOA), cooking OA (COA), biomass burning OA (BBOA), and 3 different types of secondary OA (SOA) with varying degrees of oxidation and temporal trends. The nitrate mass fraction increased during the three haze episodes, with nitrate accounting for 27-33% of PM1 mass. Enhanced nitrate concentrations and higher nitrate oxidation ratios (NOR), despite lower enhancement in relative humidity (RH) than the low PM loading period, suggest that regional transport of nitrate contributed to the nitrate mass during the haze periods.