The impact of atmospheric wet deposition on roof runoff quality in an urbanized area

2015 ◽  
Vol 46 (6) ◽  
pp. 880-892 ◽  
Author(s):  
Hua-Peng Qin ◽  
Qiao-Ling Tang ◽  
Li-Yu Wang ◽  
Guangtao Fu
Keyword(s):  
Organic Acids ◽  
Wet Deposition ◽  
Rainwater Harvesting ◽  
Urban Site ◽  
Chemical Components ◽  
Roof Runoff ◽  
Alkaline Dust ◽  
Rooftop Rainwater Harvesting ◽  
The Impact ◽  
Fast Increase

Understanding the sources of chemical components in roof runoff can help to prevent water quality problems in rooftop rainwater harvesting. To identify the contribution of wet deposition to the mass of components in roof runoff, the samples from air, rainwater, dust buildup and roof runoff were collected from an urban site in Shenzhen of China in 2011–2012. The results indicate that: (1) wet deposition has a dominant contribution to the mass of total organic carbon (TOC), NH4+, NO3–, Cl– and organic acids in the roof runoff, while the mass of NH4+, acetic acid and formic acid in the roof runoff may be greatly reduced by the neutralization between the components with alkaline dust buildup on the rooftop; and (2) wet deposition partially contributes to the mass of Na+, K+, Mg2+, Ca2+, F– and SO42– in the roof runoff, while other factors like dust buildup on the rooftop and chemical reactions also have a non-negligible impact. Furthermore, TOC, NH4+, NO3– and organic acids in the wet deposition are mainly influenced by the atmospheric pollution due to fast increase in fossil fuel consumption (e.g. vehicle emissions). Therefore, the effects of wet deposition should be carefully considered for rooftop rainwater harvesting in urbanized areas.

Source identification of aerosol chemical composition in the Atlas region of North Africa.

2021 ◽  
Author(s):  
Nabil Deabji ◽  
Khanneh Wadinga Fomba ◽  
Eduardo José dos Santos Souza ◽  
Hartmut Herrmann
Keyword(s):  
High Altitude ◽  
Complex Mixture ◽  
Saharan Dust ◽  
Atmospheric Composition ◽  
Urban Site ◽  
Chemical Components ◽  
Research Station ◽  
African Region ◽  
Aerosol Composition ◽  
The Impact

<p>Aerosol particles are important constituents of the atmosphere due to their role in controlling climate-related processes. In addition, their impacts on air quality and human health make it essential to study. However, the characterization and the identification of natural and anthropogenic atmospheric particles can be challenging due to the complex mixture occurring during atmospheric transport. Background locations such as high-altitude sites provide valuable infrastructure for obtaining representative data for understanding various pathways for aerosol interactions useful in assessing atmospheric composition. However, information about aerosol characteristics at high-altitude in the African regions and their relation to urban aerosol composition is still not well understood. In the present study, PM<sub>10</sub> and PM<sub>2.5</sub> particulate matter was characterized at two different sites in the North African region of Morocco. A background site located at the newly established AM5 research station in the Middle Atlas region at an altitude of 2100 m and an urban site situated in a polluted city, Fez. The goal was to determine chemical components, evaluate Saharan dust’s role on the PM10 concentrations between the sites, and assess the impact of urban pollution on background aerosol composition. The results indicate that the background aerosol composition is influenced by both regional and trans-regional transport. Despite the site's proximity to the Sahara Desert, the deserts influence on the atmospheric composition was observed for only 22% of the time and this was mainly seasonal. Marine air masses were more dominant with a mixture of sea salt and polluted aerosol from the coastal regions especially during wintertime. Furthermore, high concentrations of mineral dust were observed during the daytime due to the resuspension of road dust. At the same time, an increase of PAHs and anthropogenic metals such as Pb, Ni, and Cu were found during the nighttime because of the boundary layer variation. The Fez's urban site is characterized by a high contribution of elemental carbon (6%) and organic biomass tracers (3%) such as Levoglucosane and 4-nitrophenol.</p>

scholarly journals The impact of a deep convection on sulfate transport and redistribution

2002 ◽  
Vol 2 (2) ◽  
pp. 385-430
Author(s):  
V. Spiridonov ◽  
M. Curic
Keyword(s):  
Chemical Reactions ◽  
Wet Deposition ◽  
Deep Convection ◽  
Aerosol Particles ◽  
Parameterization Scheme ◽  
Chemical Components ◽  
Total Sulfur ◽  
Henry's Law ◽  
Henry’S Law ◽  
The Impact

Abstract. A three-dimensional compressible cloud model was used to simulate the processes related to dynamics, microphysics and chemistry of continental non-polluted and continental polluted clouds. The chemical components are formulated in terms of continuity equations for different chemical species in the aqueous phase within the cloud. Their evolution in this model came from not only by the processes of advection and turbulence transport, but also the chemical reactions and microphysical transfers. The model includes a method of kinetic uptake limitations. Gases with low solubility H* < 103 mol dm-3 atm-1 are in Henry's law equilibrium with temperature dependence of Henry's law coefficients. Seven pollutant groups are currently included in the chemistry parameterization scheme: S(IV), S(VI), (H2O2), (O3), N(V), (NH3), (CO2). The present model contains explicit treatment of SO2 and O3, a kinetic method of gas uptake as well as an improved microphysical parameterization scheme. The primary objective of this model is to study the impact of the deep convection on the pollutant transport, redistribution and deposition. It is done through chemical reactions, oxidation, scavenging of aerosol particles and transfer via microphysical transitions among water categories. Two base run simulation parameters are used to initialize the model. The first model run is for the 6 July 1995 event, characterized by intensive convective cloud activity and a large amount of precipitation, manifested as a flashflood. The second one is related to transboundary dust transport and sulfate wet deposition. The chemical field initialization is based on the vertical distribution profiles of gases and aerosols for continental non-polluted and continental polluted background. The study has revealed the importance of considering interactions between dynamics, microphysics and cloud chemistry. Deep convection in the first analyzed case generates rapid upward and downward transport of pollutants. It stimulates the impact of scavenging processes and microphysical conversions, pollutant redistribution and wet deposition. We find good agreement between calculated and observed rainfall, pH, sulfate concentration and wet deposition, in the second simulated case. Aerosol particles partially dissolved in precipitation changed their qualitative and quantitative features, acidity and increment of all chemical components. A lot of sensitivity tests of the terms included in the chemistry parameterization scheme indicate that assumption of Henry's law equilibrium leads to a factor 2 to 3 underestimate of a soluble gas in cloud water and 3 to 5 in rainwater, respectively. Our calculations demonstrate that assumption of Henry's law leads to a factor of about 1.0 to 1.3 overestimation of the integrated sulfur mass removed by wet deposition. Analysis of the relative contribution of some parameters implies that 20% - 24% of total sulfur mass deposited belongs to both nucleation and impact scavenging. Liquid phase oxidation contributed 22% and 28% of the total sulfur mass deposited for continental non-polluted and continental polluted background, respectively. Neglecting liquid-ice phase chemical reactions leads to underestimation of the total sulfur mass deposited by about a factor of 1.0 to 1.2 for continental non-polluted and continental polluted distributions, relative to the base run.

scholarly journals Salt Intake in Nigeria: a nationwide population survey

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A.N Odili ◽  
B.S Chori ◽  
B Danladi ◽  
P.C Nwakile ◽  
J.O Ogedengbe ◽  
...  
Keyword(s):  
Salt Intake ◽  
Sodium Intake ◽  
Population Analysis ◽  
Cost Effective ◽  
Rural Site ◽  
Urban Site ◽  
Funding Source ◽  
Salt Reduction ◽  
High Salt Intake ◽  
The Impact

Abstract Background Population wide salt reduction programmes are cost effective strategies for control of cardiovascular diseases (CVDs). Obtaining a nationwide salt consumption data in a multi-cultural setting as Nigeria's is key for proper implementation and monitoring of such strategy. Methods We measured sodium in 24-hour urine of free-living adult Nigerians selected from an urban and a rural site each from the 6 geopolitical zones of Nigeria to evaluate patterns of salt intake and its associations with blood pressures (BP). Results Across the 12 sites, sodium intake ranged from 97.9 in the rural South-South to 210 mmol/day in the urban site of the same zone. Overall, the median (IQR) daily sodium intake was 143.5 (97.8) mmol; with higher (p=0.0028) levels among the urban 149.7 (113.8) compared to the rural 133.1 (105.2) dwellers. Overall, 20% of the subjects consumed less than the recommended 2g (86mmol) of sodium daily. After adjustment for age, sex and BMI; sodium intake and BP (systolic and diastolic) were positively associated in 8 out of the 12 sites; significantly so in 2 (p&lt;0.05) for systolic. Within population analysis; which included 973 individuals, increasing sodium intake tended (not significantly) to increase SBP but decrease DBP. However, among subjects whose sodium intake was in excess of 257mmol/day, a 100 mmol/day increase in sodium intake was significantly (p=0.04) associated with a 3.3 mmHg increase in SBP. Conclusion Salt intake among Nigerians is higher than the recommended. The impact of sodium intake on BP appears to be evident only among individuals with high salt intake. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Wellcome Trust

scholarly journals Optimal Sizing of Rooftop Rainwater Harvesting Tanks for Sustainable Domestic Water Use in the West Bank, Palestine

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 573
Author(s):  
Sameer Shadeed ◽  
Sandy Alawna
Keyword(s):  
Storage Tank ◽  
Rainwater Harvesting ◽  
West Bank ◽  
Family Members ◽  
Optimal Size ◽  
Storage Tanks ◽  
Domestic Water ◽  
The West ◽  
Average Family ◽  
Rooftop Rainwater Harvesting

In highly water-poor areas, rooftop rainwater harvesting (RRWH) can be used for a self-sustaining and self-reliant domestic water supply. The designing of an optimal RRWH storage tank is a key parameter to implement a reliable RRWH system. In this study, the optimal size of RRWH storage tanks in the different West Bank governorates was estimated based on monthly (all governorates) and daily (i.e., Nablus) inflow (RRWH) and outflow (domestic water demand, DWD) data. In the estimation of RRWH, five rooftop areas varying between 100 m2 and 300 m2 were selected. Moreover, the reliability of the adopting RRWH system in the different West Bank governorates was tested. Two-time series scenarios were assumed: Scenario 1, S1 (12 months, annual) and scenario 2, S2 (8 months, rainy). As a result, reliable curves for preliminary estimation of optimal RRWH storage tanks for the different West Bank governorates were obtained. Results show that the required storage tank for S1 (annual) is more than that of the S2 (rainy) one. The required storage tank to fulfill DWD is based on the average rooftop area of 150 m2, the average family members of 4.8, and the average DWD of 90 L per capita per day (L/c/d) varies between (75 m3 to 136 m3) and (24 m3 to 84 m3) for S2 for the different West Bank governorates. Further, it is found that the optimal RRWH tank size for the 150 m2 rooftop ranges between 20 m3 (in Jericho) to 75 m3 (in Salfit and Nablus) and between 20 m3 (in Jericho) to 51 m3 (in Jerusalem) for S1 and S2 scenarios, respectively. Finally, results show that the implementation of an RRWH system for a rooftop area of 150 m2 and family members of 4.8 is reliable for all of the West Bank governorates except Jericho. Whereas, the reliability doesn’t exceed 19% for the two scenarios. However, the reduction of DWDv is highly affecting the reliability of adopting RRWH systems in Jericho (the least rainfall governorate). For instance, a family DWDv of 3.2 m3/month (25% of the average family DWDv in the West Bank) will increase the reliability at a rooftop area of 150 m2 to 51% and 76% for S1 and S2, respectively.

scholarly journals Assessment of Pellets from Three Forest Species: From Raw Material to End Use

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 447
Author(s):  
Miguel Alfonso Quiñones-Reveles ◽  
Víctor Manuel Ruiz-García ◽  
Sarai Ramos-Vargas ◽  
Benedicto Vargas-Larreta ◽  
Omar Masera-Cerutti ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Ash Content ◽  
Hot Water ◽  
Raw Material ◽  
Chemical Components ◽  
Energy Yield ◽  
Cellulose Content ◽  
Fixed Carbon ◽  
End Use ◽  
The Impact

This study aimed to evaluate and compare the relationship between chemical properties, energy efficiency, and emissions of wood and pellets from madroño Arbutus xalapensis Kunth, tázcate Juniperus deppeana Steud, and encino colorado Quercus sideroxyla Humb. & Bonpl. in two gasifiers (top-lit-up-draft (T-LUD) and electricity generation wood camp stove (EGWCS)) in order to determine the reduction of footprint carbon. In accordance with conventional methodologies, we determined the extracts and chemical components (lignin, cellulose, holocellulose), and the immediate analyses were carried out (volatile materials, fixed carbon, ash content and microanalysis of said ash), as well as the evaluation of emission factors (total suspended particulate matter (PM2.5), CO, CO2, CH4, black carbon (BC), elemental carbon (EC), and organic carbon (OC)). The results were statistically analyzed to compare each variable among species and gasifiers. The raw material analyzed showed how the pH ranged from 5.01 to 5.57, and the ash content ranged between 0.39 and 0.53%. The content values of Cu, Zn, Fe, Mg, and Ca ranged from 0.08 to 0.22, 0.18 to 0.19, 0.38 to 0.84, 1.75 to 1.90, and 3.62 to 3.74 mg kg−1, respectively. The extractive ranges from cyclohexane were 2.48–4.79%, acetone 2.42–4.08%, methanol 3.17–7.99%, and hot water 2.12–4.83%. The range of lignin was 18.08–28.60%. The cellulose content ranged from 43.30 to 53.90%, and holocellulose from 53.50 to 64.02%. The volatile material range was 81.2–87.42%, while fixed carbon was 11.30–17.48%; the higher heating value (HHV) of raw material and pellets presented the ranges 17.68–20.21 and 19.72–21.81 MJ kg−1, respectively. Thermal efficiency showed statistically significant differences (p < 0.05) between pellets and gasifiers, with an average of 31% Tier 3 in ISO (International Organization for Standardization) for the T-LUD and 14% (ISO Tier 1) for EGWCS, with Arbutus xalapensis being the species with the highest energy yield. The use of improved combustion devices, as well as that of selected raw material species, can reduce the impact of global warming by up to 33% on a cooking task compared to the three-stone burner.

In-situ treatment of fluoride in a hard rock setting by rooftop rainwater harvesting recharge scehme

2019 ◽  
Author(s):  
P.R Pujari ◽  
C. Padmakar ◽  
R. Quamar ◽  
L. Deshpande ◽  
R. Janipella ◽  
...  
Keyword(s):  
Hard Rock ◽  
Rainwater Harvesting ◽  
Rooftop Rainwater Harvesting

Budget of nitrous acid (HONO) and its impacts on atmospheric oxidation capacity at an urban site in Guangzhou of China

2021 ◽  
Author(s):  
Yihang Yu ◽  
Peng Cheng ◽  
Huirong Li ◽  
Wenda Yang ◽  
Baobin Han ◽  
...  
Keyword(s):  
Nitrous Acid ◽  
Emission Rate ◽  
Chemical Mechanism ◽  
Atmospheric Oxidation ◽  
Urban Site ◽  
Homogeneous Reaction ◽  
Pearl River Delta Region ◽  
Oxidation Capacity ◽  
High Concentrations ◽  
The Impact

&lt;p&gt;Nitrous acid (HONO) can produce hydroxyl radicals (OH) by photolysis and plays an important role in atmospheric photochemistry. Over the years, high concentrations of HONO have been found in the Pearl River Delta region (PRD), which may be one of the reasons for the high atmospheric oxidation capacity. A comprehensive atmospheric observation was conducted at an urban site in Guangzhou from 27 September to 9 November 2018. During the period, HONO ranged from 0.02 to 4.43 ppbv with an average of 0.74&amp;#177;0.70 ppbv. The combustion emission ratio (HONO/NOx) of 0.9&amp;#177;0.4% was derived from 11 fresh plumes. The primary emission rate of HONO during night was calculated with the emission source inventory data to be between 0.04&amp;#177;0.02 and 0.30&amp;#177;0.15 ppbv/h. And the HONO produced by the homogeneous reaction of OH+NO at night was 0.26&amp;#177;0.08 ppbv/h, which can be seemed as secondary results from primary emission. They were both much higher than the increase rate of HONO (0.02 ppbv/h) during night. Soil emission rate of HONO at night was calculated to be 0.019&amp;#177;0.0003 ppbv/h. Deposition was the dominant removal process of HONO during night, and a deposition rate of at least 2.5 cm/s is required to balance the direct emissions and OH+NO reaction. Correlation analysis shows that NH&lt;sub&gt;3&lt;/sub&gt; and relative humidity (RH) may participate in the heterogeneous transformation from NO&lt;sub&gt;2&lt;/sub&gt; to HONO during night. In the daytime, the average primary emission P&lt;sub&gt;emis&lt;/sub&gt; was 0.12&amp;#177;0.01 ppbv/h, and the homogeneous reaction P&lt;sub&gt;OH+NO&lt;/sub&gt; was 0.79&amp;#177;0.61 ppbv/h, which was even larger than the unknown sources P&lt;sub&gt;Unknown&lt;/sub&gt; (0.65&amp;#177;0.46 ppbv/h). The results showed that the direct and indirect contributions of primary emission to HONO are great at the site, both during daytime and nighttime. Similar to previous studies, P&lt;sub&gt;Unknown&lt;/sub&gt; was suggested to be related to the photo-enhanced reaction of NO&lt;sub&gt;2&lt;/sub&gt;. The mean OH production rates by photolysis of HONO and O&lt;sub&gt;3&lt;/sub&gt; were 3.7&amp;#215;10&lt;sup&gt;6&lt;/sup&gt; cm&lt;sup&gt;-3&lt;/sup&gt;&amp;#183;s&lt;sup&gt;-1&lt;/sup&gt; and 4.9&amp;#215;10&lt;sup&gt;6&lt;/sup&gt; cm&lt;sup&gt;-3&lt;/sup&gt;&amp;#183;s&lt;sup&gt;-1&lt;/sup&gt;, respectively. We further studied the impact of HONO on the atmospheric oxidation by a Master Chemical Mechanism (MCM) box model. When constraining observed HONO in the model, OH and O&lt;sub&gt;3 &lt;/sub&gt;increased 59% and 68.8% respectively, showing a remarkable contribution of HONO to the atmospheric oxidation of Guangzhou.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

scholarly journals Triple oxygen isotopes indicate urbanization affects sources of nitrate in wet and dry atmospheric deposition

2018 ◽  
Author(s):  
David M. Nelson ◽  
Urumu Tsunogai ◽  
Ding Dong ◽  
Takuya Ohyama ◽  
Daisuke D. Komatsu ◽  
...  
Keyword(s):  
Dry Deposition ◽  
Wet Deposition ◽  
Urban Environments ◽  
Rural Site ◽  
Urban Site ◽  
Peroxy Radicals ◽  
Long Distance ◽  
Wet And Dry Deposition ◽  
Atmospheric Nitrate ◽  
Nitrate Deposition

Abstract. Atmospheric nitrate deposition resulting from anthropogenic activities negatively affects human and environmental health. Identifying deposited nitrate that is produced locally vs. that originating from long-distance transport would help inform efforts to mitigate such impacts. However, distinguishing the relative transport distances of atmospheric nitrate in urban areas remains a major challenge since it may be produced locally and/or come from upwind regions. To address this uncertainty we assessed spatiotemporal variation in monthly weighted-average Δ17O and δ15N values of wet and dry nitrate deposition during one year at urban and rural sites along the western coast of the northern Japanese island of Hokkaido, downwind of the East Asian continent. Δ17O values of nitrate in wet deposition at the urban site mirrored those of wet and dry deposition at the rural site, ranging between ~ +22 and +30 ‰ with higher values during winter and lower values in summer, which suggests greater relative importance of oxidation of NO2 by O3 during winter and OH during summer. In contrast, Δ17O values of nitrate in dry deposition at the urban site were lower (+19–+25 ‰) and displayed less distinct seasonal variation. Furthermore, the difference between δ15N values of nitrate in wet and dry nitrate deposition was, on average, 3 ‰ greater at the urban than rural site, and Δ17O and δ15N values were correlated for both forms of deposition at both sites with the exception of dry deposition at the urban site. These results suggest that, relative to nitrate in wet deposition in urban environments and wet and dry deposition in rural environments, nitrate in dry deposition in urban environments forms from relatively greater oxidation of NO by peroxy radicals and/or oxidation of NO2 by OH. Given greater concentrations of peroxy radicals and OH in cities, these results imply that dry nitrate deposition results from local NOx emissions more so than wet deposition, which is transported longer distances. These results illustrate the value of stable isotope data for distinguishing the transport distances and reaction pathways of atmospheric nitrate pollution.

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