Bentondaniel7265

Dissolved organic matter (DOM) is the precursor of disinfection by-products (DBPs) which is widely found in the aquatic environment. The analysis of DOM in raw water is helpful to evaluate the formation potentials of DBPs. However, there is relatively little research on the DOM identification of raw water in northern China. In this study, the variation in DOM in M reservoir water in one year by fluorescence excitation-emission matrix-parallel factor analysis (EEM-PARAFAC) was investigated to evaluate the DBP formation potential (DBPFP). The results suggested that five components, namely, two humic-like substances (C2, C3), two fulvic-like substances (C1, C4) and one protein-like substance (C5), were identified in the DOM of M reservoir water. The content of DOM in autumn and winter was higher than that in spring and summer. The source of DOM in the water body of M reservoir was mainly from terrestrial source, but less from aquatic source. The source, types and humification degree of DOM affect the formation of DBPs. The formation potential of DBPs had the following order trihalomethanes (THMs) > dichloroacetic acid (TCAA) > trichloroacetic acid (DCAA) > chloral hydrate (CH). The formation potentials of THM and TCAA were strongly correlated with C2 (rTHM = 0.805, rTCAA = 0.857). Bcl-2 lymphoma The formation potential of CH has a good correlation with C1 (r = 0.722). The formation of DCAA has a good correlation with C4 (r = 0.787). DOM and DBPFP were negatively correlated with the biological index (BIX) and fluorescence index (FI) of the raw water, and positively correlated with the humification index (HIX).Antibiotic resistance and biodiversity were investigated in microbial communities attached to inner surfaces of water supply fittings in a chlorinated drinking water distribution system (DWDS) supplied by two independent water treatment plants (WTPs) drawing the same source water. The investigation of the effect of the season, the applied water treatment technology, and type, material, and age of water supply fittings on both antibiotic resistance and biodiversity in biofilms involved collection of tubercles during summer and winter seasons throughout the DWDS. A total of 16 samples were collected (8 per season) from areas supplied by two independent WTPs. Culturable aerobic antibiotic resistant bacteria (ARB) proved more prevalent in summer. Various antibiotic resistance genes (ARGs) were detected, confirming the role of biofilms as ARGs reservoirs, but the abundances of quantified genes (sulI, ermB, qacEΔ1, intI1) were low (a range of less then LOQ to 2313 gene copies/mg dry mass of tubercles) throughout the DWDS. In terms of microbial community composition, Proteobacteria were dominant in each sample (51.51-97.13%), and the most abundant genus was Desulfovibrio (0.01-66.69%) belonging to sulphate-reducing bacteria. Biodiversity of microbial communities was shaped by many coexisting factors, including season, water supply fitting material, and sampling site location. Spatial distribution analysis revealed that although only samples collected at the same sampling sites were similar to each other in terms of antibiotic resistance, some samples collected in the close proximity were similar in terms of biodiversity. This suggests that antibiotic resistance spreads only locally over small distances in drinking water biofilms. Although actual drinking water biofilms have been previously investigated in terms of microbial biodiversity, this is the first study that characterised both antibiotic resistance and biodiversity of microbial communities attached to inner surfaces of a real DWDS functioning for decades.Significant attention, especially in the last decade, has been focussed on elevated concentrations of ultrafine particulate matter (UFP) in urban areas and the adverse health effects associated with exposure to UFP. Despite this, there is a relative scarcity of long-term ambient UFP measurements. This study examined trends in UFP measurements made continuously near a busy roadway in downtown Toronto, Canada, between the years 2006 and 2019 using a fast mobility particle sizer (FMPS). These long-term trends were associated with other air pollutant concentrations-namely nitric oxide (NO), nitrogen dioxide (NO2), sulphur dioxide (SO2), and fine particulate matter mass concentrations (PM2.5)-and persistent declining trends were observed for each during the study period. From 2006 to 2019, reductions of 45%, 68%, 39%, 83%, and 41%, for UFP, NO, NO2, SO2, and PM2.5, respectively, were observed. These reductions are in part associated with a total phase-out of coal-fired electricity generation in Ontario, Canada, between 2004 and 2015, and continuous improvements in vehicle emissions control technologies. Additionally, deconvolution of the time-series yielded seasonal fluctuations which were analysed as a function of particle diameter and ambient temperature, the results from which may aid in the comparison of UFP measurements made in climates with different ambient temperature ranges in a meaningful way. Finally, the UFP data were background-subtracted and it was found that local sources (such as vehicle traffic) contributed ~45% to total concentrations and this fraction remained relatively constant throughout the study. A multilinear function regressed on these local and background concentrations better elucidated the sources contributing to UFP variability-background concentrations were largely covariate with SO2 emissions whereas local concentrations were more affected by NO emissions. The data in this study shows clear co-benefits to reducing UFP concentrations by targeting NOx and SOx emissions.Excessive inorganic nitrogen (IN) compound content in groundwater is generally attributed to anthropogenic activities. Here, natural nitrogen sources in Quaternary sediments from aquifers and aquitards of Jianghan Plain (JHP), China were identified. Ammonium and nitrate content in groundwater samples collected from 129 well sites were determined through chemical analysis. Subsequent 4 boreholes were drilled at areas with high nitrogen concentration in the Quaternary aquifer. Indicators from hydrochemistry and soil geochemistry analysis, as well as optically stimulated luminescence dating and various of radioactive isotope δ14C-CO2 and stable isotopes including δ15N-NH4+, δ15N-total organic nitrogen (TON), δ15N-NO3-, δ18O-NO3-, δ18O-H2O, δD-H2O, and δ13C-total organic carbon (TOC) were used to identify high-concentration N compound sources and transformation mechanisms (NO3- 0.02-770 mg L-1; NH4-N 0-30.5 mg L-1) in the porous media. The thick clay layer protected the underlying media. Paleo-precipitation characteristics were preserved in the porewater; that is, it had not been affected by anthropogenic activities.