Sources of nitrate‑nitrogen in urban runoff over and during rainfall events with different grades

2021 ◽  
pp. 152069
Author(s):  
Pu Zhang ◽  
Lei Chen ◽  
Tiezhu Yan ◽  
Jin Liu ◽  
Zhenyao Shen
Keyword(s):  
Nitrate Nitrogen ◽  
Urban Runoff ◽  
Rainfall Events

Collection and Analysis of Urban Runoff Data in Finland

1985 ◽  
Vol 17 (6-7) ◽  
pp. 1175-1185 ◽  
Author(s):  
M. J. Melanen
Keyword(s):  
Waste Water Treatment ◽  
Urban Runoff ◽  
Waste Waters ◽  
Runoff Water ◽  
Rainfall Events ◽  
Water Treatment Plants ◽  
The City ◽  
City Centres ◽  
Sewer Networks

An extensive three-year urban hydrology programme was carried out in Finland. Data were collected and analysed on the quantity and quality of precipitation and runoff water at seven urban test catchments. During rainfall events, on the average, the proportion of surfaces generating direct runoff was found to account for 50-80 per cent of the proportion of paved surfaces in the residential catchments, and for 80-90 per cent in the city centres. Under Finnish conditions, the pollutant loads discharged to recipients with untreated runoff waters are relatively minor in comparison to those of purified waste waters, regarding organic matter and nutrients. Further measures in the Finnish sewage works should thus be focused on other factors, such as increasing the effectiveness of the existing waste water treatment plants, and decreasing the amount of leakage inflows to sewer networks.

Effect of age and rainfall pH on contaminant yields from metal roofs

2014 ◽  
Vol 69 (10) ◽  
pp. 2166-2173 ◽  
Author(s):  
Daniel Wicke ◽  
Thomas A. Cochrane ◽  
Aisling D. O'Sullivan ◽  
Simon Cave ◽  
Mark Derksen
Keyword(s):  
Urban Runoff ◽  
Weather Conditions ◽  
Urban Streams ◽  
Galvanized Steel ◽  
Combined Effects ◽  
Metal Mobilization ◽  
Runoff Water ◽  
Roof Runoff ◽  
Rainfall Events ◽  
Effect Of Age

Metal roofs are recognized for conveying significant metal loads to urban streams through stormwater runoff. Metal concentrations in urban runoff depend on roof types and prevailing weather conditions but the combined effects of roof age and rainfall pH on metal mobilization are not well understood. To investigate these effects on roof runoff, water quality was analysed from galvanized iron and copper roofs following rainfall events and also from simulating runoff using a rainfall simulator on specially constructed roof modules. Zinc and copper yields under different pH regimes were investigated for two roof materials and two different ages. Metal mobilization from older roofs was greater than new roofs with 55-year-old galvanized roof surfaces yielding more Zn, on average increasing by 45% and 30% under a rainfall pH of 4 and 8, respectively. Predominantly dissolved (85–95%) Zn and Cu concentrations in runoff exponentially increased as the rainfall pH decreased. Results also confirmed that copper guttering and downpipes associated with galvanized steel roof systems can substantially increase copper levels in roof runoff. Understanding the dynamics of roof surfaces as a function of weathering and rainfall pH regimes can help developers with making better choices about roof types and materials for stormwater improvement.

scholarly journals Nitrate Nitrogen (NO3-N) Export Regimes Based on High-frequency Measurements in the Kuzlovec Stream Catchment

2021 ◽  
pp. 25-38
Author(s):  
Klaudija Sapač ◽  
Nejc Bezak ◽  
Andrej Vidmar ◽  
Simon Rusjan
Keyword(s):  
High Frequency ◽  
Nitrate Nitrogen ◽  
Regression Line ◽  
Point Of View ◽  
Wilcoxon Test ◽  
Rainfall Events ◽  
N Concentration ◽  
Significant Difference ◽  
Concentration Changes ◽  
Relative Change

In the paper, the determination of nitrate nitrogen (NO3-N) export regimes from the Kuzlovec catchment during rainfall events is presented employing various determination methods: the ratio of coefficient of variation of NO3-N concentration and discharge (CVC/CVQ), the slope of the regression line to the points of concentration and discharge logarithms (b), both mentioned indices together, and the relative change of the NO3-N concentration during the event (Crs). According to previous analyses, the amount of exported NO3-N during rainfall events comprises approx. 30% of the total export amount, while from a temporal point of view, rainfall events represent only 10% of the time. Export regimes were identified as chemostatic (concentration does not change with discharge) and chemodynamic (concentration changes with discharge). The latter were further divided into dilution and flushing regimes. 43 rainfall events from the period April 2018–April 2020 were included in the analysis. For these events, high-frequency data of 20-minute intervals were available for concentration and discharge. All applied indices showed that the catchment responds differently from a concentration-discharge perspective and that chemodynamic behaviour is predominant, with flushing most frequently prevalent. A possible seasonal connection with regime diversity was tested using the non-parametric, statistical Wilcoxon test. A statistically significant difference was not found for any of the indices. Nevertheless, a detailed analysis of CVC/CVQ revealed that the ratio is likely related to seasonal variability in rainfall characteristics and consequently to the hydrological conditions in the catchment. Hence, it would be of great importance to include data about rainfall and hydrological properties in future studies.

scholarly journals Characterization of Urban Runoff Pollution between Dissolved and Particulate Phases

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Zhang Wei ◽  
Li Simin ◽  
Tang Fengbing
Keyword(s):  
Oxygen Demand ◽  
Urban Runoff ◽  
Total Suspended Solid ◽  
Suspended Solid ◽  
Roof Runoff ◽  
Event Mean Concentration ◽  
Rainfall Events ◽  
Urban Catchments ◽  
Runoff Pollution

To develop urban stormwater management effectively, characterization of urban runoff pollution between dissolved and particulate phases was studied by 12 rainfall events monitored for five typical urban catchments. The average event mean concentration (AEMC) of runoff pollutants in different phases was evaluated. The AEMC values of runoff pollutants in different phases from urban roads were higher than the ones from urban roofs. The proportions of total dissolved solids, total dissolved nitrogen, and total dissolved phosphorus in total ones for all the catchments were 26.19%–30.91%, 83.29%–90.51%, and 61.54–68.09%, respectively. During rainfall events, the pollutant concentration at the initial stage of rainfall was high and then sharply decreased to a low value. Affected by catchments characterization and rainfall distribution, the highest concentration of road pollutants might appear in the later period of rainfall. Strong correlations were also found among runoffs pollutants in different phases. Total suspended solid could be considered as a surrogate for particulate matters in both road and roof runoff, while dissolved chemical oxygen demand could be regarded as a surrogate for dissolved matters in roof runoff.

Spatial variability of characteristics and origins of urban wet weather pollution in combined sewers

2005 ◽  
Vol 52 (3) ◽  
pp. 53-62 ◽  
Author(s):  
M. Kafi-Benyahia ◽  
M.G. Gromaire ◽  
G. Chebbo
Keyword(s):  
Heavy Metals ◽  
Organic Matter ◽  
Suspended Solids ◽  
Spatial Scales ◽  
Urban Runoff ◽  
Urban Catchment ◽  
Rainfall Events ◽  
Wet Weather ◽  
Wet Weather Flow ◽  
Dry Weather Flow

An experimental on-site observatory of urban pollutant loads in combined sewers was created in the centre of Paris to quantify and characterise the dry and wet weather flow in relation to spatial scale. Eight rainfall events were studied from April 2003 to May 2004. Samples were analysed for suspended solids, organic matter, nitrogen and heavy metals. Results confirm the extent of wet weather pollution. They have shown the relative homogeneity of SS and organic matter characteristics from one urban catchment area to another. Two groups of heavy metals were identified. The first one concerns Cu, which has a higher concentration in wet weather flow (WWF) than in dry weather flow (DWF), and runoff. The second includes Cd, Pb and Zn, where higher concentrations were measured in urban runoff than in WWF and DWF. A first evaluation of contribution of wastewater, urban runoff and sewer deposit erosion sources to wet weather pollution was established and has highlighted the contribution of wastewater and sewer deposits to this pollution. However, it has shown that sewer deposit erosion remains an important source of wet weather pollution at different spatial scales.

The Influence of Geographical Factors on Extreme Rainfalls in Lampung Province

2019 ◽  
Vol 1 (1) ◽  
pp. 33
Author(s):  
M Welly
Keyword(s):  
Geographical Location ◽  
Daily Rainfall ◽  
Extreme Rainfall ◽  
Design Flood ◽  
Extreme Rainfall Events ◽  
Rainfall Events ◽  
Ungauged Basin ◽  
Flood Discharge ◽  
Design Rainfall ◽  
Geographical Factors

Many people in Indonesia calculate design rainfall before calculating the design flooddischarge. The design rainfall with a certain return period will eventually be convertedinto a design flood discharge by combining it with the characteristics of the watershed.However, the lack of a network of rainfall recording stations makes many areas that arenot hydrologically measured (ungauged basin), so it is quite difficult to know thecharacteristics of rain in the area concerned. This study aims to analyze thecharacteristics of design rainfall in Lampung Province. The focus of the analysis is toinvestigate whether geographical factors influence the design rainfall that occurs in theparticular area. The data used in this study is daily rainfall data from 15 rainfallrecording stations spread in Lampung Province. The method of frequency analysis usedin this study is the Gumbel method. The research shows that the geographical location ofan area does not have significant effect on extreme rainfall events. The effect of risingearth temperatures due to natural exploitation by humans tends to be stronger as a causeof extreme events such as extreme rainfall.Keywords: Influence, geographical, factors, extreme, rainfall.

Preliminary study on removal of nitrate nitrogen in aqueous samples by microbial nano-silica ball

2014 ◽  
Author(s):  
Jia Lu ◽  
Xiaohou Shao ◽  
Chao Yin ◽  
Xinyu Mao ◽  
Long Wang ◽  
...  
Keyword(s):  
Nitrate Nitrogen ◽  
Aqueous Samples ◽  
Nano Silica ◽  
Preliminary Study
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