High temporal resolution in situ measurement of the effective particle size characteristics of fluvial suspended sediment

Williams, Neil D.; Walling, D. E.; Leeks, G. J. L.

doi:10.1016/j.watres.2006.11.010

Cited by 53 publications

(46 citation statements)

References 29 publications

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“…Walling and Woodward (1993) employed a field-based "water elutriation apparatus" to investigate in situ particle size characteristics of suspended sediments in the Exe River, UK. The median floc size ranged from 50 to 300 μm (Williams et al 2007). There is little literature on flocculation in large rivers with large sediment and water discharges.…”

Section: Introductionmentioning

confidence: 99%

Freshwater flocculation of suspended sediments in the Yangtze River, China

Guo

2011

Ocean Dynamics

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This study focuses on suspended sediments and in situ flocculation in the Yangtze River, with the goal of improving our understanding of the relationship between freshwater and estuarine flocculation. A field survey with state-of-the-art instruments was carried out in January 2008 in the reach from downstream of the Three Gorges Dam to the estuary. The data show that in situ floc mean diameters range from 22 to 182 μm in the river, whereas the median dispersed grain sizes are 4.4-11.4 μm. This demonstrates that flocculation is an important process during the transport of suspended sediments along the river. The flocculation characteristics, suspended sediment concentration and dispersed grain sizes all vary longitudinally in the main stream of the Yangtze River. Biochemical factors are likely be more significant in the freshwater flocculation than in the estuary, where hydrodynamics and biochemical factors are both important. Flocculation is found in the freshwater river, in the estuary and in coastal waters, which indicates that dynamic break-up/reflocculation processes take place during the suspended sediment transport. The freshwater flocs may behave as parent flocs to the estuarine flocculation. This study enhances our understanding of flocculation from estuarine and coastal areas to fresh river systems and provides insights into the effects of input of riverine flocs to the estuarine flocculation and into the sources and fate of flocs.

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Section: Introductionmentioning

confidence: 99%

Freshwater flocculation of suspended sediments in the Yangtze River, China

Guo

2011

Ocean Dynamics

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“…hillslope runoff) as it is transported through a catchment into a 64 stream, due to a variation in the relative proportion of aggregates (flocs) present in the measured 65 flux (Slattery & Burt 1997). Therefore knowledge of how the PSD varies dynamically in this fluvial 66 context due to a variability in the degree of flocculation (DOF) is important for the study of the 67 transport processes of both sediment and organic species in flocs (Williams et al 2007). There is 68 clearly some variation in the importance given to the parameters of turbidity by the different sub-69 disciplinary groups, and so the aim of this paper is to evaluate how relevant turbidity measurement 70 is to the study of sediment-transport processes specifically, and to propose methods for the 71 improvement of the measurement and reporting of turbidity in a general context.…”

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confidence: 99%

A review of the principles of turbidity measurement

Kitchener

Wainwright

Parsons

2017

Progress in Physical Geography: Earth and Environment

110

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Publisher's copyright statement:Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Turbidity of water due to the presence suspended sediment is measured and interpreted in a variety of ways, which can lead to the misinterpretation of data. This paper re-examines the physics of lightscattering in water, and exposes the extent to which the reporting of turbidity data is inconsistent. It is proposed that the cause of this inconsistency is the fact that the accepted turbidity standards USEPA Method 180.1, ISO 7027 and GLI Method 2 are mutually inconsistent, as these standards give rise to a large number of measurement units that are not based on the optical properties of light absorption and scattering by suspensions in water, but by the arbitrary definition of the degree of turbidity being due to a concentration of formazin or other similar polymerbased calibration standard. It is then proposed that all turbidity-measuring devices should be calibrated with precise optical attenuators such as ND filters. Such calibration would allow for the definition of a beam attenuation coefficient (BAC) for every turbidity measuring instrument which would be cross-comparable with any other instrument calibrated in the same way.The units for turbidity measurements should be based on attenuation and reported as dB m-1. It is also proposed that a new standard should be drafted according to this attenuation-based method, and this new standard should also define the nomenclature for reporting data collected at any specific scattering angle in terms of an attenuation in dB m-1. The importance of multi-parameter turbidity measurements for the improvement of the quality of turbidity data, and the application of parameter-rich data sets to new methods of sediment characterization are discussed. It is suggested that more research into multi-parameter turbidity measurements is needed, as these new methods will facilitate an increase in parity between turbidity and suspended sediment concentration (SSC), a relationship that is subjective.http://mc.manuscriptcentral.com/PiPG Progress in Physical Geography 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 Turbidity of water due to the presence suspended sediment is measured and interpreted in a variety of 2 ways, which can lead to the misinterpretation of data. This paper re-examines the physics of light-3 sc...

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“…When chemical coagulation is used for particle separation in wastewater treatment plants, particle size distribution and the morphology of the suspended particles are the critical parameters that affect the efficiency of the solid-liquid separation process (Grijspeerdt and Verstraete 1997;Wilen and Balmer 1999;Schmid et al 2003;Liao et al 2006). Conventionally, laser particle-size analyzers have been used to measure the particle size distribution during chemical coagulation (Williams et al 2007). However, this measurement was typically conducted in a laboratory using a batch-type method, so on-line or in situ application of laser particle-size analyzers had serious limitations and operational problems.…”

Section: Introductionmentioning

confidence: 99%

On-line evaluating the SS removals for chemical coagulation using digital image analysis and artificial neural networks

Yu¹

2014

Int. J. Environ. Sci. Technol.

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Chemical coagulation is one of the most important processes for industrial wastewater treatment plants to remove the suspended solids (SS), which depend significantly on particle characteristics. A digital image analysis system was set up in this study for the on-line measurements of particle characteristics, including particle size distribution, equivalent diameter, total area, total volume, and the fractal dimension in the both coagulation and flocculation periods in chemical coagulation. Two real industrial wastewaters, textile wastewater and landfill leachate, were used for conducting the coagulation and flocculation processes with different polyaluminum chloride dosages in a batch reactor. The artificial neural network (ANN) models were used to construct the correlations between the monitoring data acquired and the SS removal efficiencies. The experimental results indicated that the ANN models were able to precisely predict the SS removal efficiencies and effluent SS concentration after the chemical coagulation, with the correlation coefficient (R 2 ) of 0.96-0.97 for real landfill leachate and R 2 of 0.93-0.97 for real textile wastewater, which provided significant benefits for the control of chemical coagulation.

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High temporal resolution in situ measurement of the effective particle size characteristics of fluvial suspended sediment

Cited by 53 publications

References 29 publications

Freshwater flocculation of suspended sediments in the Yangtze River, China

Freshwater flocculation of suspended sediments in the Yangtze River, China

A review of the principles of turbidity measurement

On-line evaluating the SS removals for chemical coagulation using digital image analysis and artificial neural networks

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