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Copyright of Chinese Journal of Computational Mechanics / Jisuan Lixue Xuebao is the property of Chinese Journal of Computational Mechanics Editorial Office, Dalian University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Meteorological factors and anthropogenic activities significantly affect atmospheric ammonia （NH 3 ） concentration and its dry deposition. Former studies have examined the spatial and temporal variability in atmospheric NH 3 concentrations at monthly scales. However, the characteristics of atmospheric concentrations at finer time scales such as hourly and daily scales and the influencing factors remain unclear. In this study, atmospheric NH 3 concentration and related meteorological factors were continuously monitored online for one year in a double cropping rice region in subtropical China, and atmospheric NH 3 concentration and its meteorological influencing factors as well as dry deposition were analyzed at different time scales （hourly, daily, and monthly）. The main results were as follows： The annual average daily concentration of NH 3 in the rice area varied from 0.01 to 58.0 μg·m -3 （in N, same below）, and the annual average concentration was 5.3 μg·m -3 . On the hourly scale, the 24-hour dynamics of atmospheric NH 3 concentration showed a unimodal pattern, and the time of the NH 3 peak appearance in different seasons was different； the time of the peak that appeared in winter lagged behind that in the other seasons. From the perspective of daily scale, NH 3 concentration was mainly affected by fertilization in the paddy fields, peaking at 1-3 days after fertilization and then gradually decreasing. On the monthly scale, NH 3 concentration peaked at 12.8 μg·m -3 in July and was the lowest in October at 1.6 μg·m -3 . On the hourly scale, NH 3 concentration varied seasonally due to the influences of meteorological factors, mainly as follows： NH 3 concentration showed significant positive correlations with air temperature and solar radiation in all four seasons and with wind speed in spring and summer, whereas it showed significant negative correlations with relative humidity except in winter. On the daily scale, NH 3 concentration showed a significant positive correlation with air temperature, rainfall, and solar radiation, whereas it showed a significant negative correlation with relative humidity. On the monthly scale, no significant correlation existed between each meteorological factor and NH 3 concentration. The annual dry deposition flux （in N） calculated from the hourly average NH 3 concentration was 8.5 kg·（hm 2 ·a） -1 , which was 11.6% higher than the annual flux calculated from the daily average and 12.4% higher than the annual flux calculated from the monthly average. In summary, there were significant daily and seasonal variations in atmospheric NH 3 concentration in the paddy rice region in subtropical China, and conducting hourly-scale observations of NH 3 concentration can help to reveal the multi-time scale variations in NH 3 concentration and to quantify NH 3 dry deposition more accurately.

To identify emerging contaminants （ECs） in rainwater is a topic that has gradually received widespread attention. Rainwater resources, specifically urban roofs, play a crucial role in utilizing rainwater efficiently by understanding the occurrence and migration characteristics of pollutants in precipitation. This study selected a typical roof and studied the differences in rainwater quality and pollution occurrence at different collection stages during six rainfall events from March to May in 2023. Principal component analysis （PCA） and correlation analysis were used to explore the distribution, migration, and transformation of ECs in the collection process of roof rainwater. The findings revealed the presence of 44/54 ECs in wet deposition, dry and wet deposition, and roof runoff processes, with a total concentration range of 63.0 to 432.4 ng·L -1 and an average concentration of 166.8 ng·L -1 . Notably, bisphenol A （BPA） exhibited the highest concentration, ranging from 14.7 to 265.6 ng·L -1 , with an average concentration of 62.5 ng·L -1 , followed by ofloxacin （OFX） and ethylhexyl methoxycinnamate （EHMC）, with detected concentrations up to 45.5 ng·L -1 and 44.8 ng·L -1 . Dissolved organic matter （DOM）, nitrogen pollutants, and particulate matter were important factors affecting the occurrence characteristics of ECs, with a mantel correlation coefficient of up to 0.98 （ P <0.01）. Based on the analysis of different rainfall events and collection stages, variations were observed in the accumulation pathways and contribution ratios of different pollutants. The wet deposition exhibited the highest content of ECs in the initial stage, whereas the dry and wet deposition and roof runoff processes displayed higher ECs content in the later stages. Additionally, the average ECs contribution rates of dry and wet deposition to roof runoff were 21.48% and 78.52%, respectively. Due to the influence of roof material and surface roughness retention performance, over 30% of ECs, including pharmaceuticals and personal care products （PPCPs）, endocrine-disrupting compounds （EDCs）, and pesticides, were deposited on the roof during the runoff collection. The results of this research can provide the theoretical foundation and technical support for the identification and control of ECs in urban roof runoff and for the safe storage of rainwater.

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to study the nitrogen characteristics of atmospheric dry and wet deposition in Handan City, Hebei Province, the dry and wet deposition samples were collected monthly by the automatic separation dry and wet deposition sampler. The dry and wet deposition amount and nitrogen concentrations were measured, and the nitrogen deposition flux was calculated. During the monitoring period, the dry deposition and wet deposition fluxes of nitrogen were 14.60 kg/(hm² ⋅ a) and 33.44 kg/(hm² ⋅a) respectively, and the wet deposition was dominated. The nitrogen wet deposition fluxes in spring, summer and autumn were 7.37 kg/hm², 12.34 kg/hm² and 13.15 kg/hm², respectively. The nitrogen dry deposition fluxes in spring, summer, autumn and winter were 5.36 kg/hm², 4.64 kg/hm², 2.78 kg/hm² and 3.28 kg/hm², respectively. The wet deposition fluxes of TN, NH4+, NO3- and DON were closely related to rainfall, they had a significant negative exponential power correlation with rainfall amount. The nitrogen dry deposition flux was not only related to the amount of dust, but also affected by temperature, humidity, wind speed and other factors. The use of chemical fertilizer, automobile emission, fossil fuel combustion and NH3 from sewage treatment plant were the important sources of nitrogen deposition. The deposition of total nitrogen in Handan could meet the demand of wheat in no fertilizer area, and it is suggested to reduce the use of nitrogen fertilizer. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The dry deposition of heavy metals in atmospheric particulates is one of the important sources of heavy metals in agricultural areas, but there are few observational studies on the atmospheric deposition of heavy metals in agricultural areas. In this study, the concentrations of atmospheric particulates with different particle sizes and ten kinds of metal elements in them were analyzed by sampling a typical rice-wheat rotation area in the suburb of Nanjing for one year, and the dry deposition fluxes were estimated using the big leaf model, so as to understand the input characteristics of particulates and heavy metals. The results showed that the particulate concentrations and dry deposition fluxes were high in winter and spring but low in summer and autumn. In winter and spring, coarse particulates (2.1-9.0 μm) and fine particulates (<2.1 μm) had dual effects on particulate pollution, whereas in summer and autumn, particulate pollution was mainly attributed to the fine particulates. The concentrations of metal elements were the lowest in giant particulates (>9.0 μm) and were similar in coarse particulates and fine particulates, whereas Pb, Mn, As, and Cd elements were relatively high in fine particulates. The average annual dry deposition fluxes[g·(m 2 ·a) -1 ] of particulates was giant particulates (8.31)>coarse particulates (5.99)>fine particulates (0.629). The order of average annual dry deposition fluxes[mg·(m 2 ·a) -1 ] of the 10 metals was Ca(2096.4)>Al(1710.4)>Zn(855.0)>Fe(256.1)>Pb(40.35)>Cu(31.93)>V(26.21)>Mn(9.10)>As(2.48)>Cd(0.28). The average annual dry deposition fluxes of the 10 metal elements in fine particulates, coarse particulates, and giant particulates were 179.03, 2124.97, and 2724.18 mg·(m 2 ·a) -1 , respectively. These results will provide a reference for a more comprehensive understanding of the impact of human activities on the quality and safety of agricultural products and soil ecological environment.

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To investigate the farmland soil nitrogen input from atmospheric dry and wet deposition, a 1-year observation was conducted in the Yulin and Luochuan areas of North Shaanxi Province from June 2007 to May 2008. The total inorganic nitrogen (TIN) deposition in Yulin and Luochuan was 22.17 and 16.95 kg·hm-2·a-1, among which, wet deposition accounted for 95.1% and 90.4%, while dry deposition accounted for 4.9% and 9.6%, respectively, illustrating that the nitrogen deposition in both Yulin and Luochuan was mainly come from wet deposition. In the TIN deposition, the amount of nitrate in Yulin and Luochuan was 12.22 and 9.24 kg·hm-2·a-1, accounting for 55.1% and 54.5%, respectively. The amount of wet deposition and the percentage of nitrate in TIN deposition were higher in Yulin than in Luochuan, because of the differences in pollution level, weather condition, and underlying surface characteristics. [ABSTRACT FROM AUTHOR]

As an important component of global nitrogen (N) biogeochemical cycle, atmospheric N deposition refers to the removal process of reactive N, including oxidized N (NO y ) and reduced N (NH x ), from the atmosphere to earth surface through dry and wet deposition. Nitrogen deposition can exert important impacts on the structure and functioning of both terrestrial and aquatic ecosystems. Increasing N deposition poses a potential threat to natural ecosystems and human health. It is a challenge to accurately monitor the composition and flux of dry and wet N deposition in different ecosystems, using a unified technology. Here, we reviewed the research progress on monitoring methods of dry and wet N deposition in China and aboard, including micrometeorology, inferential method, model estimation, surrogate surface, precipitation collection, and ion exchange resin methods. We further discussed the advantages and disadvantages of each method in terms of its applications at regional, national, and global scales. This review would provide a methodological support to establish national monitoring network for atmospheric N deposition.

To characterize the dry and wet deposition of atmospheric trace elements in urban Beijing, both active and passive samplers were used to collect bulk and wet sedimentation samples between May 2014 and April 2015.The concentrations of 19 trace elements (Na, Mg, Al, K, Ca, V, Cr, Mn, Fe, Cu, Zn, As, Se, Mo, Cd, Sb, Tl, Th, and U) in the samples were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The results show that the concentrations of metals in bulk deposition samples[7160.68 μg·L -1 (Ca)-0.02 μg·L -1 (Th)] were generally higher than those in wet deposition samples[4237.74 μg·L -1 (Ca)-0.01 μg·L -1 (Th)], but the enrichment factors of each metal in the two kinds of samples were less different. Of note, the enrichment factors of Cu, As, Tl, Zn, Cd, Se, and Sb were all larger than 100, thus indicating that these heavy metals were mainly from anthropogenic sources. The statistical analysis of the air mass trajectory shows that the precipitation chemistry in urban Beijing is mainly affected by southward air flows. The air mass originating from the southwest region always had higher concentrations of Ca, Mg, Fe, Al, Cu, Mo, U, and Th, whereas the air mass from the south had higher concentrations of K, Zn, Mn, Sb, Cd, and Tl. During the observation period, the bulk deposition fluxes of metals varied from 3591.35 mg·(m 2 ·a) -1 (Ca)-0.01 mg·(m 2 ·a) -1 (Th), and wet deposition fluxes varied from 1847.78 mg·(m 2 ·a) -1 (Ca)-0.01 mg·(m 2 ·a) -1 (Th). The dry deposition fluxes of the 19 metals varied from 1743.57 mg·(m 2 ·a) -1 (Ca)-0.01 mg·(m 2 ·a) -1 (Th). The particle size has important implications in the evaluation of the relative importance of dry deposition versus wet deposition during the scavenging of trace elements in air.

Passive air samplers (PAS-PUF) and passive dry deposition (PAS-DD) samplers were applied in the Bosten Lake watershed located in Xinjiang to estimate the atmospheric concentrations and dry deposition fluxes for 15 US EPA priority polycyclic aromatic hydrocarbons (PAHs) during a heating period in 2016 and no-heating period in 2017, respectively. The results showed that the atmospheric PAHs concentrations in the Bosten oasis area ranged from 6.38 ng·m -3 to 245.43 ng·m -3 during the heating period and 2.33 ng·m -3 to 74.76 ng·m -3 during the non-heating period. The highest atmospheric PAHs concentrations were found in the residential area, followed by regions near Bosten Lake and Tazhong. The atmospheric dry deposition fluxes of PAHs in the Bosten Lake watershed ranged from 0.45 μg·(m 2 ·d) -1 to 18.10 μg·(m 2 ·d) -1 during the heating period and 0.25 μg·(m 2 ·d) -1 to 8.15 μg·(m 2 ·d) -1 during the non-heating period. During the heating period, the atmospheric dry deposition fluxes in the residential area were significantly higher than those in the regions near Bosten Lake and Tazhong. However, the atmospheric PAHs dry deposition flux in Tazhong was much higher than that in other sites during the heating and no-heating periods. In general, the atmospheric PAHs dry deposition fluxes during the heating period were significantly higher than those during the non-heating period. PAH composition for the atmosphere and dry deposition were dominated by 3 and 4 ring congeners, especially by phenanthrene, fluorine, fluoranthene, and pyrene during two sampling periods. In addition, the congener diagnostic ratio shows that coal and biomass combustion were possible sources of atmospheric PAHs in the Bosten Lake watershed. The forward and backward trajectory analysis based on the HYSPLIT model demonstrated that the higher atmospheric PAH emissions from the residential area would be transported to Bosten Lake, which can affect the aquatic environment of this lake by dry deposition.

Bulk precipitation collectors and canopy throughfall collectors were applied to measure the deposition of sulfur, nitrogen, and mercury at two forest ecology stations, Qianyanzhou (QYZ) in Jiangxi Province and Huitong (HT) in Hunan Province, from December 2013 to November 2014. During the observation period, the volume weighted average concentrations of SO 4 2- -S, NO 3 - -N, NH 4 + -N, and Hg at QYZ station were 1.89 mg·L -1 , 0.957 mg·L -1 , 0.401 mg·L -1 , and 12.5 ng·L -1 in the bulk precipitation, respectively, and 2.39 mg·L -1 , 1.18 mg·L -1 , 0.897 mg·L -1 , and 22.2 ng·L -1 in the throughfall, respectively. The concentrations of these components increased by different proportions for the bulk precipitation compared to the throughfall. At HT station, the average concentrations of SO 4 2- -S, NO 3 - -N, NH 4 + -N, and Hg in the throughfall were 2.93 mg·L -1 , 1.60 mg·L -1 , 0.502 mg·L -1 , and 22.0 ng·L -1 , respectively. In addition, atmospheric deposition fluxes based on the throughfall were 3.56 g·(m 2 ·a) -1 for sulfur, 3.02 g·(m 2 ·a) -1 for nitrogen, and 30.6 μg·(m 2 ·a) -1 at HT station. The deposition rates of all three elements were the highest in summer. The contribution of dry deposition to the total deposition of mercury was similar to that of wet deposition, while wet deposition contributed more to the total deposition of sulfur and nitrogen than did dry deposition. Unlike sulfur and nitrogen depositions, which were mainly derived from anthropogenic sources, mercury deposition might have a greater contribution from natural sources, especially at HT station.2 ·a) -1 , 4.48 g·(m 2 ·a) -1 , and 37.3 μg·(m 2 ·a) -1 at HT station. The deposition rates of all three elements were the highest in summer. The contribution of dry deposition to the total deposition of mercury was similar to that of wet deposition, while wet deposition contributed more to the total deposition of sulfur and nitrogen than did dry deposition. Unlike sulfur and nitrogen depositions, which were mainly derived from anthropogenic sources, mercury deposition might have a greater contribution from natural sources, especially at HT station.

This study conducted a full two-year (2014 and 2015) measurements of dry and bulk deposition of atmospheric inorganic nitrogen (N) at the suburb of Xining city, Qinghai province. Dry N deposition fluxes were calculated by multiplying the atmospheric concentrations of NH 3 and NO 2 measured using passive samplers with the modeled dry deposition velocities provided by the GEOS-Chem global chemical transport model, while bulk N deposition fluxes were measured using precipitation gauge. Annual mean concentrations of gaseous NH 3 and NO 2 averaged 8.8 and 19.6 μg·m -3 , respectively, with significantly higher values in 2015 than in 2014. Seasonal mean NH 3 concentrations were higher in spring and summer than in autumn and winter, but the concentrations of NO 2 changed little from season to season, with a small peak in autumn. Annual mean concentrations of NH 4 + -N and NO 3 - -N in precipitation averaged 2.2 and 1.8 mg·L -1 -N in autumn or winter were~26% higher than those in spring and summer. Dry deposition of NH 4 + -N in autumn were~55% lower than those in other seasons, whereas those of NO 3 - -N in autumn or winter were~26% higher than those in spring and summer. Dry deposition of NH 3 and NO 2 was 9.0 and 2.8 kg·(hm 2 ·a) -1 , respectively. Bulk deposition of NH 4 + -N and NO 3 - -N in precipitation was 7.6 and 6.2 kg·(hm 2 ·a) -1 , respectively. Reduced N (gaseous NH 3 and NH 4 + -N in precipitation) was the dominant form of N deposition. The total dry and wet N deposition was 25.6 kg·(hm 2 ·a) -1 , which represented significant nutrient input from the environment to the suburban farmland, but this amount of deposited N exceeded the critical loads[10-20 kg·(hm 2 ·a) -1 ] of terrestrial ecosystems, suggesting a risk of "N saturation" in the local natural environment.

To investigate the dry deposition pattern of particulate matter and lead in urban Beijing, dry deposited particles were collected based on a surrogate surface between December 2013 and November 2014 and subjected to elemental analysis by using microwave digestion and inductively coupled plasma mass spectrometry. The results showed that dry deposition fluxes of particle mass and total lead were 0.84 t·(hm 2 ·a) -1 and 7.56 mg·(m 2 ·a) -1 , respectively, with a seasonal trend of spring > winter > autumn~summer, exhibiting a similar temporal pattern to that of coarse particles. In addition, dry deposition flux of water-soluble lead was 3.14 mg·(m 2 ·a) -1 . It was found that the ratio of soluble fraction to total lead in dry deposited particles reached up to 43%, coinciding with a seasonal variation of ambient sulfur dioxide. The findings highlighted the anthropogenic imprints on the dry deposition flux of particles and heavy metals as well as the solubility of lead. This study also provides a first-hand dataset that can be used to assess ecological and environmental impacts of dry deposited lead, and an up-to-date scientific basis for the crafting abatement strategies to further reduce emission of heavy metals in China.

A total of 84 effective dry deposition samples were collected from July to October, 2014 in Nanjing, and the chemical composition and source apportionment of water-soluble ions dry deposition in the summer and autumn season were discussed. The results indicated that the average pH was 6.2, and the dry deposition samples usually appeared neutral. Ca 2+ and NH 4 + were the major cations and their average daily concentrations were 115.7 μeq·L -1 and 31.2 μeq·L -1 ,accounting for 68.3% and 18.6% of total cations, respectively. SO 4 2- , Cl - , a total of 89.2% of the total anions, respectively. High temperature and humidity of meteorological factors and contaminated air mass affected dry deposition. Local air mass had greater impact on dry deposition pollution, which indicated that dry deposition pollution had local property. In summer and autumn seasons in Nanjing, the stationary sources had more contributions to atmospheric dry deposition of water-soluble ions than mobile sources, while the environmental control measures for the Nanjing Youth Olympic Games had greater effect on stationary sources than mobile sources. Studies of the origins of major ions indicated that SO 3 2- were the main anions, and their average daily concentrations were 30.4, 20.7 and 18.7 μeq·L -1 , a total of 89.2% of the total anions, respectively. High temperature and humidity of meteorological factors and contaminated air mass affected dry deposition. Local air mass had greater impact on dry deposition pollution, which indicated that dry deposition pollution had local property. In summer and autumn seasons in Nanjing, the stationary sources had more contributions to atmospheric dry deposition of water-soluble ions than mobile sources, while the environmental control measures for the Nanjing Youth Olympic Games had greater effect on stationary sources than mobile sources. Studies of the origins of major ions indicated that SO 4 2- and NO 3 2- were mostly attributed by the anthropogenic activities, and Cl - was mainly from ocean sources, while K + and Mg 2+ were mostly from the terrestrial input.