Response of nephelometric turbidity to hydrodynamic particle size of fine suspended sediment

2020 ◽  
Vol 35 (5) ◽  
pp. 444-454 ◽  
Author(s):  
Christina Bright ◽  
Sarah Mager ◽  
Sophie Horton
Keyword(s):  
Particle Size ◽  
Suspended Sediment ◽  
Fine Suspended Sediment

Application of artificial bee colony algorithm for particle size distribution measurement of suspended sediment based on focused ultrasonic sensor

2021 ◽  
pp. 014233122198911
Author(s):  
Yeming Li ◽  
Yidan Xia ◽  
Dailiang Xie ◽  
Ya Xu ◽  
Zhipeng Xu ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Suspended Sediment ◽  
Artificial Bee Colony ◽  
Ultrasonic Sensor ◽  
Inversion Algorithm ◽  
Distribution Measurement ◽  
Bee Colony ◽  
Particle Size Distribution Measurement

A new focused ultrasonic sensor is proposed, based on which the measurement system for particle size distribution measurement of suspended sediment is established. Compared with the traditional ultrasonic sensors, the one used in this paper is equipped with piezoelectric transducer (PZT) on an arc-shaped shell, to concentrate ultrasonic beams on one measurement point. The sensor is used to measure the particle size distribution of suspended sediment. The experiments were carried out on water-sediment mixtures with different particle size distribution. Due to multiple parameters and non-linearity of the ultrasonic attenuation model, the artificial bee colony (ABC) inversion algorithm is used to estimate particle size distribution, thus improving measurement accuracy. The particle sizes obtained by sieving method are seen as reference values. The results indicate that whether the suspended particles are subject to a unimodal distribution, uniform distribution or random distribution, the particle size distribution obtained by ABC inversion algorithm is consistent with the result obtained by the sieve method. The results demonstrate that the method has good utility and accuracy within the low concentration range.

Inferring suspended sediment carbon content and particle size at high frequency from the optical response of a submerged spectrometer 

2021 ◽  
Author(s):  
Dhruv Sehgal ◽  
Núria Martínez-Carreras ◽  
Christophe Hissler ◽  
Victor Bense ◽  
AJF (Ton) Hoitink
Keyword(s):  
Particle Size ◽  
Absorption Spectrum ◽  
Carbon Content ◽  
Suspended Sediment ◽  
High Frequency ◽  
Suspended Sediments ◽  
Ex Situ ◽  
Frequency Measurements ◽  
Component Form

<p>Manual and unattended sampling in the field and laboratory analysis are common practices to measure suspended sediment (SS) carbon content and particle size. However, one of the major drawbacks of these ex-situ methods is that they make high frequency measurements challenging. This includes restricted data collection due to limited access to the sampling locations during turbulent conditions or high flows, when the largest amount of sediments is transported downstream, introducing uncertainty in quantification of SS properties (particle size and carbon content) and sediment loads. Knowledge on SS carbon content and particle size is also important to better understand the multi-component form of suspended sediments (i.e. flocs) that directly affect sediment transport and other sediment properties (e.g. settling velocity and density). Moreover, SS carbon content and particle size exert an impact on the optical sensor readings that are traditionally used to measure turbidity. In that respect, high frequency measurements of SS carbon content and particle size could eventually help us to move from ‘local’ calibrations towards ‘global’ dependencies based on in-situ SS characterization.</p><p>In this study, we propose to use a submerged UV-VIS spectrometer to infer SS carbon content and particle size. The sensor measures the entire light absorption spectrum of water between 200 nm and 750 nm at sampling intervals as short as 2-minutes. To this end, we first test our approach under controlled conditions with an experimental laboratory setup consisting of a cylindrical tank (40-L) with an open top. An UV-VIS spectrometer and a LISST-200X sensor (to measure particle size distribution) are installed horizontally. A stirrer facilitates the homogeneous mixing of SS and prevents the settling of heavy particles at the bottom. We use the sediments sampled from 6 sites in Luxembourg with contrasting composition and representing different land use types and geological settings. The sampled sediments were wet sieved into 3 size classes to clearly recognize the effect of particle size on absorption. In our investigation, we use specific wavelengths, chemometric techniques and carbon content specific absorbance indices to infer SS composition and particle size from the absorption spectrum. Results are then validated using in-situ field data from two instrumented field sites in Luxembourg. Amid the challenge of associating laboratory and field results, the preliminary results indicate that the absorption spectrum measured with a submerged UV-VIS spectrometer can be used to estimate SS particle size and carbon content.</p>

Changes in particle size distribution of suspended sediment affected by gravity erosion: a field study on steep loess slopes

2019 ◽  
Vol 20 (3) ◽  
pp. 1730-1741 ◽  
Author(s):  
Wenzhao Guo ◽  
Xiangzhou Xu ◽  
Tongxin Zhu ◽  
Hongwu Zhang ◽  
Wenlong Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Field Study ◽  
Size Distribution ◽  
Suspended Sediment

scholarly journals Numerical modelling of hydro-morphological processes dominated by fine suspended sediment in a stormwater pond

2018 ◽  
Vol 556 ◽  
pp. 87-99 ◽  
Author(s):  
Mingfu Guan ◽  
Sangaralingam Ahilan ◽  
Dapeng Yu ◽  
Yong Peng ◽  
Nigel Wright
Keyword(s):  
Numerical Modelling ◽  
Suspended Sediment ◽  
Stormwater Pond ◽  
Morphological Processes ◽  
Fine Suspended Sediment
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