Effects of runoff from land clearing and urban development on the distribution and abundance of macroinvertebrates in pool areas of a river

1991 ◽  
Vol 42 (5) ◽  
pp. 507 ◽  
Author(s):  
ID Hogg ◽  
RH Norris
Keyword(s):  
Particle Size ◽  
Urban Development ◽  
Suspended Solids ◽  
Inorganic Material ◽  
Storm Event ◽  
Storm Events ◽  
Land Clearing ◽  
River Monitoring ◽  
High Concentrations ◽  
Macroinvertebrate Density

We examined the effects of runoff from urban land clearing and development on the macroinvertebrate pool fauna of the Murrumbidgee River, Australia, over 1 year. Tuggeranong Creek, which flows through the urban development, often recorded higher instantaneous (storm) discharges than did the Murrumbidgee River. Monitoring of suspended solids during one storm event revealed high concentrations of suspended solids (max. 560 mg L-1) entering the Murrumbidgee River for an 8 h period. Such concentrations were not detected by regular two-monthly sampling, although concentrations were generally higher downstream of Tuggeranong Creek. Analysis of substratum particle size revealed a higher proportion of fine inorganic material (<250 pm) at stations downstream of Tuggeranong Creek, suggesting a settling of fine material discharged during storm events. Number of taxa and macroinvertebrate density were lower at downstream stations. We conclude that the deposition of fine inorganic sediment following storm events, and the resulting change in the composition of the substratum, was the major cause of low invertebrate numbers in pools downstream of the cleared catchment.

Hydraulic and treatment performance of pervious pavements under variable drying and wetting regimes

2011 ◽  
Vol 64 (8) ◽  
pp. 1692-1699 ◽  
Author(s):  
C. F. Yong ◽  
A. Deletic ◽  
T. D. Fletcher ◽  
M. R. Grace
Keyword(s):  
Suspended Solids ◽  
High Flow ◽  
Pollutant Removal ◽  
Low Flow ◽  
Storm Event ◽  
Stormwater Treatment ◽  
Storm Events ◽  
Treatment Technology ◽  
Porous Asphalt ◽  
Treatment Performance

Pervious pavements are an effective stormwater treatment technology. However, their performance under variable drying and wetting conditions have yet to be tested, particularly under a continuous time scale. This paper reports on the clogging behaviour and pollutant removal efficiency of three pervious pavement types over 26 accelerated years. These pavements were monolithic porous asphalt (PA), Permapave (PP) and modular Hydrapave (HP). Over a cycle of 13 days, the period of which was equivalent to the average annual Brisbane, Australia rainfall (1,200 mm), the pavements were randomly dosed with four different flows. Drying events of 3 h duration were simulated during each flow. Inflow and outflow samples were collected and analysed for Total Suspended Solids (TSS), Total Phosphorus (TP) and Total Nitrogen (TN). To evaluate the rate of clogging, a 1 in 5 year Brisbane storm event was simulated in the 6th, 8th, 12th, 16th, 20th and 24th week. Under normal dosing conditions, none of the pavements showed signs of clogging even after 15 years. However, under storm conditions, both PA and HP started to clog after 12 years, while PP showed no signs of clogging after 26 years. The drying and various flow events showed no effects in TSS removal, with all systems achieving a removal of approximately 100%. The average TP removal was 20% for all flows except for low flow, which had a significant amount of leaching over time. Leaching from TN was also observed during all flows except high flow. The TSS, TP and TN results observed during storm events were similar to that of high flow.

scholarly journals Algal growth at environmentally relevant concentrations of suspended solids: implications for microplastic hazard assessment

2020 ◽  
Author(s):  
Elena Gorokhova ◽  
Karin Ek ◽  
Sophia Reichelt
Keyword(s):  
Particle Size ◽  
Adverse Effects ◽  
Growth Inhibition ◽  
Hazard Assessment ◽  
Suspended Solids ◽  
Algal Growth ◽  
Toxicity Testing ◽  
Distribution Data ◽  
Test Organisms ◽  
High Concentrations

AbstractHazard assessment of microplastic is challenging because standard toxicity testing is mostly developed for soluble (at least partially) chemicals. Adverse effects can occur when test organisms are exposed to turbid environments with various particulate matter (PM), both natural, such as sediment, and anthropogenic, such as microplastic. It is, therefore, relevant to compare responses to PM exposure between the microplastic and other suspended solids present at ecologically relevant concentrations; this can be done by using reference materials when assessing hazard potential of microplastics. Here, we evaluated growth inhibition in unicellular alga Raphidocelis subcapitata exposed to different suspended solids (microplastic, kaolin, and cellulose; 10, 100 and 1000 mg/L) during 72 h; algae without added solids were used as a control. In addition, aggregate formation in the exposure systems was analyzed using particle size distribution data. At 10 and 100 mg/L, no adverse growth effects were observed in any treatments; moreover, algal growth was significantly stimulated in kaolin and cellulose treatments compared to the control. However, at 1000 mg/L, all tested materials exerted growth inhibition, with no significant differences among the treatments. The comparison among particle size distributions across the treatments showed that both PM concentration and size of the particle aggregates were significant growth predictors for all materials tested. Therefore, at high concentrations, both natural and anthropogenic materials have similar capacity to cause adverse effects in algal growth inhibition tests, which must be taken into account in hazard assessment of plastic litter.

Performance evaluation and a sizing method for hydrodynamic separators treating urban stormwater runoff

2014 ◽  
Vol 69 (10) ◽  
pp. 2122-2131 ◽  
Author(s):  
D. H. Lee ◽  
K. S. Min ◽  
J.-H. Kang
Keyword(s):  
Particle Size ◽  
Removal Efficiency ◽  
Performance Monitoring ◽  
Particle Diameter ◽  
Storm Event ◽  
Weibull Function ◽  
Storm Events ◽  
Mean Values ◽  
Median Particle ◽  
Urban Catchments

This study reports on 6 years of performance monitoring of stormwater hydrodynamic separators in Korean urban catchments. One hundred and thirty-seven storm events were monitored in four hydrodynamic separators of two different types from 2006 to 2012. Mean values of the event average removal efficiencies of total suspended solids (TSS) for the four hydrodynamic separators were 43.69, 8.54, 42.84, and 14.35% with corresponding mean values of the event average surface overflow rates of 28.62, 40.07, 16.02, and 38.81 m/h, respectively. The low TSS removal efficiency was due to the high instantaneous surface overflow rates frequently occurring throughout a storm event and the abundance of fine particle fractions in the inflow (median particle diameter &lt;75 μm). The Weibull function was used to simulate particle size distribution (PSD) in the runoff and the simulated PSD functions were further applied to the discrete settling theory to develop curves of TSS removal efficiency, as a function of surface overflow rate and median particle size of the inflow. The developed curves should be useful in determining the design peak flow rate and the size of a hydrodynamic separator for a stated goal of TSS removal efficiency.

Suspended solids transport: an analysis based on turbidity measurements and event based fully calibrated hydrodynamic models

2005 ◽  
Vol 52 (3) ◽  
pp. 93-101 ◽  
Author(s):  
J.G. Langeveld ◽  
R.G. Veldkamp ◽  
F. Clemens
Keyword(s):  
Suspended Solids ◽  
Point Of View ◽  
Quality Data ◽  
Storm Event ◽  
Theoretical Point ◽  
Storm Events ◽  
Solids Transport ◽  
Measuring Period ◽  
Measuring Network ◽  
Fluvial Environments

Modelling suspended solids transport is a key issue for predicting the pollution load discharged by CSOs. Nonetheless, there is still much debate on the main drivers for suspended solids transport and on the modelling approach to be adopted. Current sewer models provide suspended solids transport models. These models, however, rely upon erosion–deposition criteria developed in fluvial environments, therewith oversimplifying the sewer sediment characteristics. Consequently, the performance of these models is poor from a theoretical point of view. To get an improved understanding of the temporal and spatial variations in suspended solids transport, a measuring network was installed in the sewer system of Loenen in conjunction with a hydraulic measuring network from June through December 2001. During the measuring period, 15 storm events rendered high-quality data on both the hydraulics and the turbidity. For each storm event, a hydrodynamic model was calibrated using the Clemens' method. The conclusion of the paper is that modelling of suspended solids transport has been and will be one of the challenges in the field of urban drainage modelling. A direct relation of either shear stress or flow velocity with turbidity could not be found, likely because of the time varying characteristics of the suspended solids.

A correlation to predict the performance characteristics of centrifugal pumps handling slurries

1997 ◽  
Vol 211 (2) ◽  
pp. 147-157 ◽  
Author(s):  
K A Kazim ◽  
B Maiti ◽  
P Chand
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Suspended Solids ◽  
Reduction Factor ◽  
Performance Characteristics ◽  
Centrifugal Pumps ◽  
Pump Performance ◽  
New Correlation ◽  
Effect Of Particle Size ◽  
The Individual

Centrifugal pumps are being used increasingly for transportation of slurries through pipelines. To design a slurry handling system it is essential to have a knowledge of the effects of suspended solids on the pump performance. A new correlation to predict the head reduction factor for centrifugal pumps handling solids has been developed. This correlation takes into account the individual effect of particle size, particle size distribution, specific gravity and concentration of solids on the centrifugal pump performance characteristics. The range of validity of the correlation has been verified by experiment and by using experimental data available from the literature. The present correlation shows better agreement with the experimental data than existing correlations.

Characteristics of an air-fluidized-bed biofilm reactor system with a multi-media filter

1994 ◽  
Vol 30 (11) ◽  
pp. 101-110
Author(s):  
Toshiaki Tsubone ◽  
Seiichi Kanamori ◽  
Tatsuo Takechi ◽  
Masahiro Takahashi
Keyword(s):  
Particle Size ◽  
Fluidized Bed ◽  
Suspended Solids ◽  
Pilot Scale ◽  
Biofilm Reactor ◽  
Reactor System ◽  
Multi Media ◽  
Bod Removal

A pilot scale study was conducted using an Air-Fluidized-Bed Biofilm Reactor (AFBBR) system with a Multi Media Filter (MMF). Soluble BOD (S-BOD) concentration in the effluent of the AFBBR had a correlation with total BOD (T-BOD) and Suspended Solids (SS) concentration in the effluent of the MMF. The lower the S-BOD in the effluent of the AFBBR was, the lower was not only T-BOD but also SS in the effluent of the MMF. It was found that as treatment proceeded, S-BOD was removed and the particle size of SS increased in the AFBBR. These results suggested that the mechanism of BOD removal in this system was: S-BOD was removed and a part of the S-BOD was changed to SS and the particle size of the SS increased in the AFBBR, and then the SS was removed by the MMF. Thus not only the T-BOD but also the SS in the effluent of MMF was lower when the S-BOD in the effluent of the AFBBR was lower. When the S-BOD in the effluent of the AFBBR was 8mg/L, T-BOD and the SS in the effluent of the MMF were 10mg/L and 4mg/L, respectively. In order to have an average S-BOD value in the effluent of the AFBBR of about 8mg/L, the T-BOD loading and the S-BOD loading needed to be less than 1.3kg/m3/day and 0.45 kg/m3/day, respectively. Even when the BOD loading was high, nitrification still occurred in this system.

Dynamic behavior of suspended pollutants and particle size distribution in highway runoff

2002 ◽  
Vol 46 (11-12) ◽  
pp. 413-418 ◽  
Author(s):  
H. Furumai ◽  
H. Balmer ◽  
M. Boller
Keyword(s):  
Heavy Metals ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Suspended Solids ◽  
Dynamic Change ◽  
First Flush ◽  
Highway Runoff ◽  
Runoff Rate ◽  
Highway Drainage

Continuous runoff quality monitoring was conducted for one month at urban highway drainage with an area of 8.4 ha. Dynamic change of suspended solids and heavy metal concentrations were investigated during first flush periods, taking the particle size distribution into consideration. Except for Pb, the concentrations of TSS and heavy metals in runoff were within the range of the EMC reported in recent highway runoff research. Particle-bound heavy metals (Zn, Pb, and Cu) accounted for more significant pollutant loads than soluble fractions. Their content decreased with increasing total SS concentration in runoff samples. The results of particle size distribution (PSD) analysis of runoff samples indicate that high TSS concentration samples contained coarser particles. Based on the PSD results, a stepwise wash-off phenomenon of TSS under varying runoff rate conditions was explained by the different washoff behavior of fine (&lt; 20 mm) and coarser particles.

scholarly journals The effects of the big storm events in the first half of 2015 on the radiation belts observed by EPT/PROBA-V

2016 ◽  
Vol 34 (1) ◽  
pp. 75-84 ◽  
Author(s):  
V. Pierrard ◽  
G. Lopez Rosson
Keyword(s):  
Charged Particle ◽  
High Resolution ◽  
Geomagnetic Storm ◽  
Energetic Particle ◽  
High Energy ◽  
Radiation Belts ◽  
Radiation Environment ◽  
Storm Event ◽  
Storm Events ◽  
Particle Radiation

Abstract. With the energetic particle telescope (EPT) performing with direct electron and proton discrimination on board the ESA satellite PROBA-V, we analyze the high-resolution measurements of the charged particle radiation environment at an altitude of 820 km for the year 2015. On 17 March 2015, a big geomagnetic storm event injected unusual fluxes up to low radial distances in the radiation belts. EPT electron measurements show a deep dropout at L > 4 starting during the main phase of the storm, associated to the penetration of high energy fluxes at L < 2 completely filling the slot region. After 10 days, the formation of a new slot around L = 2.8 for electrons of 500–600 keV separates the outer belt from the belt extending at other longitudes than the South Atlantic Anomaly. Two other major events appeared in January and June 2015, again with injections of electrons in the inner belt, contrary to what was observed in 2013 and 2014. These observations open many perspectives to better understand the source and loss mechanisms, and particularly concerning the formation of three belts.

Measurement of the Particle Size of a High-Lightfastness Direct Dye in Cellulose by p-Nitrophenol Adsorption

1977 ◽  
Vol 47 (5) ◽  
pp. 347-350 ◽  
Author(s):  
Charles H. Giles ◽  
Ronald Haslam
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Aggregation Number ◽  
Regenerated Cellulose ◽  
Cellulose Film ◽  
Adsorption Method ◽  
Regenerated Cellulose Film ◽  
Direct Dye ◽  
High Concentrations ◽  
Film Weight

The p-nitrophenol adsorption method has been used to determine the specific surface, and hence the particle size and aggregation number, of a high-lightfastness direct dye (C.I. Direct Green 26) in regenerated cellulose film. The particle size found at high concentrations is of the same order as that found for other dyes of this type, in cellulose film, by Weissbein and Coven, using electron microscopy. The aggregation number rises rapidly with rise in dye concentration in the film to a maximum of the order of 106 at shade depths above about two percent pure dye on film weight.

scholarly journals Fine Sediment Modeling During Storm-Based Events in the River Bandon, Ireland

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1523 ◽  
Author(s):  
Juan T. García ◽  
Joseph R. Harrington
Keyword(s):  
Suspended Sediment ◽  
Suspended Sediment Concentration ◽  
Sediment Concentration ◽  
Fine Sediment ◽  
Storm Event ◽  
Storm Events ◽  
Event Scale ◽  
Model Based ◽  
Sediment Volume ◽  
Bed Erosion

The River Bandon located in County Cork (Ireland) has been time-continuously monitored by turbidity probes, as well as automatic and manual suspended sediment sampling. The current work evaluates three different models used to estimate the fine sediment concentration during storm-based events over a period of one year. The modeled suspended sediment concentration is compared with that measured at an event scale. Uncertainty indices are calculated and compared with those presented in the bibliography. An empirically-based model was used as a reference, as this model has been previously applied to evaluate sediment behavior over the same time period in the River Bandon. Three other models have been applied to the gathered data. First is an empirically-based storm events model, based on an exponential function for calculation of the sediment output from the bed. A statistically-based approach first developed for sewers was also evaluated. The third model evaluated was a shear stress erosion-based model based on one parameter. The importance of considering the fine sediment volume stored in the bed and its consolidation to predict the suspended sediment concentration during storm events is clearly evident. Taking into account dry weather periods and the bed erosion in previous events, knowledge on the eroded volume for each storm event is necessary to adjust the parameters for each model.

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