scholarly journals Concentrations and Loads of Dissolved and Particulate Organic Carbon in Urban Stormwater Runoff

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1031 ◽  
Author(s):  
Stefan Kalev ◽  
Gurpal S. Toor

Urban landscapes are significant contributors of organic carbon (OC) in receiving waters, where elevated levels of OC limit the light availability, increase the transport of pollutants, and result in high costs of potable water treatment. Our objective in this study was to investigate the concentrations, fractions (dissolved and particulate), and loads of OC in a residential catchment (3.89 ha drainage area) located in Florida, United States. The outlet of the stormwater pipe draining the residential catchment was instrumented with an automated sampler, a flowmeter, and a rain gauge. The rainfall and runoff samples collected over 25 storm events during the 2016 wet season (June to September) were analyzed for dissolved organic carbon (DOC) and total organic carbon (TOC), with particulate OC (POC) calculated as the difference between TOC and DOC. Mean concentration of DOC was 2.3 ± 1.7 mg L−1 and POC was 0.3 ± 0.3 mg L−1 in the rainfall, whereas DOC was 10.5 ± 6.20 mg L−1 and POC was 2.00 ± 4.05 mg L−1 in the stormwater runoff. Concentrations of DOC were higher during the rising limb of the hydrograph in 15 out of 25 storm events, suggesting flushing of DOC, with an increase in the amount of runoff, from the landscape sources in the residential catchment. The estimated total export of OC during the 2016 wet season was 66.0 kg ha−1, of which DOC was 56.9 kg ha−1 (86.2% of TOC), and POC was 9.1 kg ha−1 (13.8% of TOC). High concentrations and loads of OC, especially DOC, in the stormwater runoff imply that residential catchments in urban watersheds are hot-spots of DOC influx to water bodies. Reducing DOC transport in the urban landscapes is complex and require identifying the origin of DOC and then using site-specific targeted approaches to mitigate DOC loss.

2014 ◽  
Vol 69 (12) ◽  
pp. 2460-2467 ◽  
Author(s):  
F. K. F. Geronimo ◽  
M. C. Maniquiz-Redillas ◽  
J. A. S. Tobio ◽  
L. H. Kim

Particulates, inorganic and toxic constituents are the most common pollutants associated with urban stormwater runoff. Heavy metals such as chromium, nickel, copper, zinc, cadmium and lead are found to be in high concentration on paved roads or parking lots due to vehicle emissions. In order to control the rapid increase of pollutant loads in stormwater runoff, the Korean Ministry of Environment proposed the utilization of low impact developments. One of these was the application of tree box filters that act as a bioretention treatment system which executes filtration and sorption processes. In this study, a tree box filter located adjacent to an impervious parking lot was developed to treat suspended solids and heavy metal concentrations from urban stormwater runoff. In total, 11 storm events were monitored from July 2010 to August 2012. The results showed that the tree box filter was highly effective in removing particulates (up to 95%) and heavy metals (at least 70%) from the urban stormwater runoff. Furthermore, the tree box filter was capable of reducing the volume runoff by 40% at a hydraulic loading rate of 1 m/day and below.


2006 ◽  
Vol 53 (2) ◽  
pp. 235-243 ◽  
Author(s):  
Y.H. Han ◽  
S.L. Lau ◽  
M. Kayhanian ◽  
M.K. Stenstrom

Stormwater runoff from highway land use is a common non-point source of pollutants. A large quantity of highway stormwater runoff characteristics were collected in California during the past three years. Correlations among various water quality parameters and constituents were performed using data sets collected over the 2000–2001, 2001–2002, and 2002–2003 wet seasons for 18, 21 and 23 storm events at three highway sites in west Los Angeles, California. In addition, statistical and graphical correlation analysis of the mass first flush ratio (MFF) with storm characteristics was made to determine if the first flush is related to site or storm characteristics. The results and analyses performed indicate that (1) TSS correlates well with most particulate-bound metals. However, TSS was poorly correlated with most other pollutants. (2) Strong correlations were also observed among dissolved and total metals; DOC, COD, TKN and oil and grease; conductivity and Cl. (3) Total metals, COD and DOC were generally well correlated with mass first flush, suggesting that BMPs that treat the early portion of runoff have an opportunity to remove high concentrations of these pollutants. Keywords Correlation analysis; highway stormwater runoff; mass first flush; storm characteristics


2018 ◽  
Vol 250 ◽  
pp. 06014
Author(s):  
Noor Atiqah Zuraini ◽  
Noraliani Alias ◽  
Zainab Mohamed Yusof ◽  
Muhammad Nassir Hanapi ◽  
Sobri Harun

An increase of pollutants that are present in the initial stage of stormwater runoff hydrograph compared to a later stage of runoff is defined as a first flush phenomenon. This study aims to investigate the occurrence of first flush from samples of urban stormwater runoff obtained from the grounds of a University in Skudai, Johor, Malaysia. In order to achieve the study’s objective; field investigations, manual sampling of urban stormwater runoff, laboratory testing and data analysis were carried out and the evaluation of the first flush phenomenon was calculated using concentration-based first flush (CBFF) and mass-based first flush (MBFF. A total of 90 stormwater samples were collected from six (6) rainfall events and were tested for total suspended solids (TSS). For each rainfall event, the pollutographs and the dimensionless curves of the cumulative pollutant mass versus the cumulative discharged volume were plotted. The first flush coefficient was also determined in order to evaluate the occurrence of first flush. The results indicated that the storm events demonstrated a weak presence of first flush.


Geology ◽  
2020 ◽  
Author(s):  
C.R. Woltz ◽  
S.M. Porter ◽  
H. Agić ◽  
C.M. Dehler ◽  
C.K. Junium ◽  
...  

Much of our understanding of early eukaryote diversity and paleoecology comes from the record of organic-walled microfossils in shale, yet the conditions controlling their preservation are not well understood. It has been suggested that high concentrations of total organic carbon (TOC) inhibit the preservation of organic fossils in shale, and although this idea is supported anecdotally, it has never been tested. Here we compared the presence, preservational quality, and assemblage diversity of organic-walled microfossils to TOC concentrations of 346 shale samples that span the late Paleoproterozoic to middle Neoproterozoic in age. We found that fossil-bearing samples have significantly lower median TOC values (0.32 wt%, n = 189) than those containing no fossils (0.72 wt%, n = 157). Preservational quality, measured by the loss of surface pattern, density of pitting, and deterioration of wall margin, decreases as TOC increases. Species richness negatively correlates with TOC within the ca. 750 Ma Chuar Group (Arizona, USA), but no relationship is observed in other units. These results support the hypothesis that high TOC content either decreases the preservational quality or inhibits the preservation of organic-walled microfossils altogether. However, it is also possible that other causal factors, including sedimentation rate and microbial degradation, account for the correlation between fossil preservation and TOC. We expect that as TOC varies in space and time, so too does the probability of finding well-preserved fossils. A compilation of 13,940 TOC values spanning Earth history suggests significantly higher median TOC levels in Mesoproterozoic versus Neoproterozoic shale, potentially biasing the interpreted pattern of increased eukaryotic diversity in the Tonian.


1984 ◽  
Vol 49 (5) ◽  
pp. 1061-1078 ◽  
Author(s):  
Jiří Čeleda ◽  
Stanislav Škramovský

Based on the earlier paper introducing a concept of the apparent parachor of a solute in the solution, we have eliminated in the present work algebraically the effect which is introduced into this quantity by the additivity of the apparent molal volumes. The difference remaining from the apparent parachor after substracting the contribution corresponding to the apparent volume ( for which the present authors suggest the name metachor) was evaluated from the experimental values of the surface tension of aqueous solutions for a set of 1,1-, 1,2- and 2,1-valent electrolytes. This difference showed to be independent of concentration up to the very high values of the order of units mol dm-3 but it was directly proportional to the number of the free charges (with a proportionality factor 5 ± 1 cm3 mol-1 identical for all studied electrolytes). The metachor can be, for this reason, a suitable characteristic for detection of the association of ions and formation of complexes in the solutions of electrolytes, up to high concentrations where other methods are failing.


2015 ◽  
Vol 40 (3) ◽  
pp. 480-492 ◽  
Author(s):  
Geoff J. Vietz ◽  
Christopher J. Walsh ◽  
Tim D. Fletcher

The urban stream syndrome is an almost universal physical and ecological response of streams to catchment urbanization. Altered channel geomorphology is a primary symptom that includes channel deepening, widening and instability. While the common approach is to treat the symptoms (e.g. modifying and stabilizing the channel), many stream restoration objectives will not be achieved unless the more vexing problem, treating the cause, is addressed in some way. Research demonstrates that the dominant cause of geomorphic change in streams in urban catchments is an altered flow regime and increase in the volume of stormwater runoff. Thus, managers can choose to treat the symptoms by modifying and controlling the channel to accommodate the altered flow regime, or treat the cause by modifying the flow regime to reduce the impact on channel morphology. In both cases treatments must, at the least, explicitly consider hydrogeomorphology—the science of the linkages between various hydrologic and geomorphic processes—to have a chance of success. This paper provides a review of recent literature (2010 to early 2015) to discuss fluvial hydrogeomorphology in the management of streams subject to urbanization. We suggest that while the dominant approach is focused on combating the symptoms of catchment urbanization (that we refer to as channel reconfiguration), there is increasing interest in approaches that attempt to address the causes by using stormwater control measures at a range of scales in the catchment (e.g. flow-regime management). In many settings in the oft-constrained urban catchment, effective management of stream morphology may require multiple approaches. To conclude, we identify five research areas that could inform urban hydrogeomorphology, one of the most challenging of which is the extent to which the volume of excess urban stormwater runoff can be reduced to mitigate the impact on stream geomorphology.


2010 ◽  
Vol 11 (3) ◽  
pp. 781-796 ◽  
Author(s):  
Jonathan J. Gourley ◽  
Scott E. Giangrande ◽  
Yang Hong ◽  
Zachary L. Flamig ◽  
Terry Schuur ◽  
...  

Abstract Rainfall estimated from the polarimetric prototype of the Weather Surveillance Radar-1988 Doppler [WSR-88D (KOUN)] was evaluated using a dense Micronet rain gauge network for nine events on the Ft. Cobb research watershed in Oklahoma. The operation of KOUN and its upgrade to dual polarization was completed by the National Severe Storms Laboratory. Storm events included an extreme rainfall case from Tropical Storm Erin that had a 100-yr return interval. Comparisons with collocated Micronet rain gauge measurements indicated all six rainfall algorithms that used polarimetric observations had lower root-mean-squared errors and higher Pearson correlation coefficients than the conventional algorithm that used reflectivity factor alone when considering all events combined. The reflectivity based relation R(Z) was the least biased with an event-combined normalized bias of −9%. The bias for R(Z), however, was found to vary significantly from case to case and as a function of rainfall intensity. This variability was attributed to different drop size distributions (DSDs) and the presence of hail. The synthetic polarimetric algorithm R(syn) had a large normalized bias of −31%, but this bias was found to be stationary. To evaluate whether polarimetric radar observations improve discharge simulation, recent advances in Markov Chain Monte Carlo simulation using the Hydrology Laboratory Research Distributed Hydrologic Model (HL-RDHM) were used. This Bayesian approach infers the posterior probability density function of model parameters and output predictions, which allows us to quantify HL-RDHM uncertainty. Hydrologic simulations were compared to observed streamflow and also to simulations forced by rain gauge inputs. The hydrologic evaluation indicated that all polarimetric rainfall estimators outperformed the conventional R(Z) algorithm, but only after their long-term biases were identified and corrected.


2013 ◽  
Vol 726-731 ◽  
pp. 1801-1804 ◽  
Author(s):  
Shu Min Wang ◽  
Hui Yu

In order to know the characteristic of spatial and temporal distribution of heavy metal concentrations in urban stormwater runoff, rainfall runoff from impervious underlying surfaces in urban region was observed during rain events. Results showed that during the precipitation process, heavy metal concentrations decreased gradually temporally (except Cd); concentrations of Fe, Cu and Zn meet Class III standard of Environmental Quality Standards for Surface Water in terminal runoff, but concentrations of Cd and Pb go beyond this standard far. Heavy metal concentrations in runoff from different types of landuses were significantly different. The arithmetic average concentrations of Fe, Cd, Cu and Zn in stormwater runoff from roof (e.g.,34.4mg/L, 0.15mg/L, 1.25mg/L and 1.23mg/L, respectively) were obviously higher than that in stormwater runoff from road (e.g., 11.8mg/L, 0.05mg/L, 0.13mg/L and 0.69mg/L, respectively).


Thorax ◽  
2001 ◽  
Vol 56 (6) ◽  
pp. 468-471
Author(s):  
G B Marks ◽  
J R Colquhoun ◽  
S T Girgis ◽  
M Hjelmroos Koski ◽  
A B A Treloar ◽  
...  

BACKGROUNDA study was undertaken to assess the importance of thunderstorms as a cause of epidemics of asthma exacerbations and to investigate the underlying mechanism.METHODSA case control study was performed in six towns in south eastern Australia. Epidemic case days (n = 48) and a random sample of control days (n = 191) were identified by reference to the difference between the observed and expected number of emergency department attendances for asthma. The occurrence of thunderstorms, their associated outflows and cold fronts were ascertained, blind to case status, for each of these days. In addition, the relation of hourly pollen counts to automatic weather station data was examined in detail for the period around one severe epidemic of asthma exacerbations. The main outcome measure was the number of epidemics of asthma exacerbations.RESULTSThunderstorm outflows were detected on 33% of epidemic days and only 3% of control days (odds ratio 15.0, 95% confidence interval 6.0 to 37.6). The association was strongest in late spring and summer. Detailed examination of one severe epidemic showed that its onset coincided with the arrival of the thunderstorm outflow and a 4–12 fold increase in the ambient concentration of grass pollen grains.CONCLUSIONSThese findings are consistent with the hypothesis that some epidemics of exacerbations of asthma are caused by high concentrations of allergenic particles produced by an outflow of colder air, associated with the downdraught from a thunderstorm, sweeping up pollen grains and particles and then concentrating them in a shallow band of air at ground level. This is a common cause of exacerbations of asthma during the pollen season.


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