Contribution of Calcite to the Particle-Size Spectrum of Lake Michigan Seston and Its Interactions with the Plankton

We determined the contribution of calcite to the total particle-size spectrum of Lake Michigan seston during different seasons in 1978–83 and 1985, employing a novel Coulter counter method, to examine the intensity and ecological effects of calcite whitings that result from autogenic precipitation of calcite. The whitings were most intense during September, when 12–56% of the total particle volume was calcite. Overall, food web dynamics were more controlling of than controlled by whitings. Year-to-year variation in calcite concentration was probably caused by predation-controlled variation in primary production, which drives calcite precipitation through CO2 uptake. Feeding rate of cladocerans in Lake Michigan is slightly reduced (16%) by calcite, but that of copepods is not. Light extinction is only slightly increased. Coprecipitation and sinking of P with calcite is probably a minor factor in regulating P concentration in the epilimnion of Lake Michigan. Removal of nutrients is enhanced by increased sinking rates caused by inclusion of calcite in fecal pellets and matter. Although all of the effects of calcite on plankton dynamics appear to be subtle in Lake Michigan, large effects can be expected for lakes of greater calcium hardness and eutrophy.

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Improvement of monitoring of tertiary filtration with particle counting

Water Science & Technology Water Supply ◽

10.2166/ws.2006.001 ◽

2006 ◽

Vol 6 (1) ◽

pp. 1-9

Author(s):

V. Miska ◽

J.H.J.M. van der Graaf ◽

J. de Koning

Keyword(s):

Particle Surface ◽

Minor Effect ◽

Particle Size Distributions ◽

Particle Volume ◽

Mass Distributions ◽

Particle Counting ◽

Total Particle ◽

Particle Counts ◽

A Minor ◽

Sample Dilution

Nowadays filtration processes are still monitored with conventional analyses like turbidity measurements and, in case of flocculation–filtration, with phosphorus analyses. Turbidity measurements have the disadvantage that breakthrough of small flocs cannot be displayed, because of the blindness regarding changes in the mass distributions. Additional particle volume distributions calculated from particle size distributions (PSDs) would provide a better assessment of filtration performance. Lab-scale experiments have been executed on a flocculation–filtration column fed with effluent from WWTP Beverwijk in The Netherlands. Besides particle counting at various sampling points, the effect of sample dilution on the accuracy of PSD measurements has been reflected. It was found that the dilution has a minor effect on PSD of low turbidity samples such as process filtrate. The correlation between total particle counts, total particle volume (TPV) and total particle surface is not high but is at least better for diluted measurements of particles in the range 2–10 μm. Furthermore, possible relations between floc-bound phosphorus and TPV removal had been investigated. A good correlation coefficient is found for TPV removal versus floc-bound phosphorus removal for the experiments with polyaluminiumchloride and the experiments with single denitrifying and blank filtration.

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A Continuous Size Spectrum for Particulate Matter in the Sea

Journal of the Fisheries Research Board of Canada ◽

10.1139/f67-081 ◽

1967 ◽

Vol 24 (5) ◽

pp. 909-915 ◽

Cited By ~ 145

Author(s):

R. W. Sheldon ◽

T. R. Parsons

Keyword(s):

Particle Diameter ◽

Particulate Material ◽

Size Spectrum ◽

Particulate Carbon ◽

Particle Volume ◽

Carbon And Nitrogen ◽

Total Particle ◽

Volume Measurements ◽

Good Agreement

The size spectrum of particulate material in seawater can easily be expressed as total particle volume versus the logarithm of particle diameter. This appears to be the most informative way to present the data and it is also aptly suited to the classical divisions of nanno-, micro-, and macroplankton.A realistic measure of the volume of irregularly shaped particles such as phytoplankton chains could be made with a Coulter Counter. Particle volume measurements were in good agreement with estimates based on microscopic determination of particle diameter. There were also highly significant correlations between total particle volume, as indicated by the counter, and particulate carbon and nitrogen.

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A comparison of light backscattering and particle size distribution measurements in tropical cirrus clouds

Atmospheric Measurement Techniques ◽

10.5194/amt-4-557-2011 ◽

2011 ◽

Vol 4 (3) ◽

pp. 557-570 ◽

Cited By ~ 8

Author(s):

F. Cairo ◽

G. Di Donfrancesco ◽

M. Snels ◽

F. Fierli ◽

M. Viterbini ◽

...

Keyword(s):

Particle Size ◽

Optical Properties ◽

Volume Density ◽

Size Distributions ◽

Backscatter Coefficient ◽

Particle Size Distributions ◽

Particle Volume ◽

Total Particle ◽

Research Aircraft

Abstract. An FSSP-100 Optical Particle Counter designed to count and size particles in the micron range and a backscattersonde that measures in-situ particle optical properties such as backscatter and depolarization ratio, are part of the payload of the high altitude research aircraft M55 Geophysica. This aircraft was deployed in tropical field campaigns in Bauru, Brasil (TROCCINOX, 2004) Darwin, Australia (SCOUT-Darwin, 2005) and Ouagadougou, Burkina Faso (SCOUT-AMMA, 2006). In those occasions, measurements of particle size distributions and optical properties within cirrus cloud were performed. Scope of the present work is to assess and discuss the consistency between the particle volume backscatter coefficient observed by the backscattersonde and the same parameter retrieved by optical scattering theory applied to particle size distributions as measured by the FSSP-100. In addition, empirical relationships linking the optical properties measured in-situ by the backscattersonde, which generally can be obtained by remote sensing techniques (LIDAR), and microphysical bulk properties like total particle number, surface and volume density will be presented and discussed.

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A comparison of light backscattering and particle size distribution measurements in tropical cirrus clouds

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-3-4059-2010 ◽

2010 ◽

Vol 3 (5) ◽

pp. 4059-4089 ◽

Cited By ~ 2

Author(s):

F. Cairo ◽

G. Di Donfrancesco ◽

M. Snels ◽

F. Fierli ◽

M. Viterbini ◽

...

Keyword(s):

Particle Size ◽

Optical Properties ◽

Volume Density ◽

Size Distributions ◽

Backscatter Coefficient ◽

Particle Size Distributions ◽

Particle Volume ◽

Total Particle ◽

Research Aircraft

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Rapid formation of large aggregates during the spring bloom of Kerguelen Island: observations and model comparisons

Biogeosciences Discussions ◽

10.5194/bgd-11-4949-2014 ◽

2014 ◽

Vol 11 (3) ◽

pp. 4949-4993 ◽

Cited By ~ 2

Author(s):

M.-P. Jouandet ◽

G. A. Jackson ◽

F. Carlotti ◽

M. Picheral ◽

L. Stemmann ◽

...

Keyword(s):

Particle Size ◽

Mixed Layer ◽

Late Summer ◽

Surface Mixed Layer ◽

Particle Volume ◽

Kerguelen Island ◽

Underwater Vision ◽

Rapid Formation ◽

Total Particle ◽

Spherical Diameter

Abstract. We recorded vertical profiles of particle size distributions (PSD, sizes ranging from 0.052 to several mm in equivalent spherical diameter) in the natural iron-fertilized bloom southeast of Kerguelen Island (Southern Ocean) from pre-bloom to early bloom stage. PSD were measured by the Underwater Vision Profiler during the Kerguelen Ocean and Plateau Compared Study cruise 2 (KEOPS 2, October–November 2011). The total particle numerical abundance was more than 4 fold higher during the early bloom phase compared to pre-bloom conditions as a result of the 2-weeks bloom development. We witnessed the rapid formation of large particles and their accumulation at the base of the mixed layer within a two days period, as indicated by changes in total particle volume (VT) and particle size distribution. The VT profiles suggest sinking of particles from the mixed layer to 200 m, but little export deeper than 200 m during the observation period. The results of a one dimensional particles dynamic model support coagulation as the mechanism responsible for the rapid aggregate formation and the development of the VT subsurface maxima. Comparison with KEOPS1, which investigated the same area during late summer, and previous iron fertilization experiments highlights physical aggregation as the primary mechanism for large particulate production during the earlier phase of iron fertilized bloom and its export from the surface mixed layer.

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Particle size grouping method as a control system of efficiency flotation process on the example of coal

Journal of Mining and Metallurgy Section B Metallurgy ◽

10.2298/jmmb200317033k ◽

2020 ◽

pp. 33-33

Author(s):

Dorota Kalisz ◽

Kamil Kuglin ◽

Anna Młynarczykowska

Keyword(s):

Particle Size ◽

Fine Particles ◽

Flotation Kinetics ◽

Particle Volume ◽

Initial Size ◽

Flotation Process ◽

Carbon Particles ◽

Coal Particles ◽

Total Particle ◽

Size Of Particles

Agglomeration of coal particles during flotation can be analysed with the Particle Size Grouping (PSG) method. Numerous experiments were carried out to theoretically explain the effect of carbon particles agglomeration, but the result still remains incomplete. In this paper the PSG method was used to analyse agglomeration groups of carbon particles of initial size 100-400 ?m, maintaining the total particle volume. The size of particles population with definite radius and density was determined for 1 Mg coal. The influence of density and size of particles with given mixing energies and parameter ? on agglomeration was analysed. It was stated that the size of the particles had an effect on their agglomeration. In the analysed cases the dimensionless parameter of collision turbulence t* needed for particles agglomeration in particular size groups was importantly shorter for particles of initial size 300 and 400 ?m. The change of the mixing energy did not have influence on the agglomeration of coal particles. The theoretical analyses based on computer calculations were supplemented by the analyses of the coal flotation process on an aqueous model. Experiments lied in introducing a foaming agent in the form of aqueous solution of hexanol which, without changing pH of the pulp, lowered surface tension value, and consequently increased the dispersion of air in the suspension. The experimental results were presented in the form of flotation kinetics curves. Fine particles 100-200?m. turned out to be best for flotation, unlike coarse 400-500 ?m.

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Seasonal Particle-Size Selection by Diaptomus sicilis in Offshore Lake Michigan

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f81-072 ◽

1981 ◽

Vol 38 (5) ◽

pp. 504-517 ◽

Cited By ~ 48

Author(s):

H. A. Vanderploeg

Keyword(s):

Particle Size ◽

Lake Michigan ◽

Food Selectivity ◽

The Other ◽

Size Spectrum ◽

Feeding Rates ◽

Size Selection ◽

Feeding Experiments ◽

Spherical Diameter ◽

Filtering Efficiency

Diaptomus sicilis feeding on offshore Lake Michigan seston exhibited a relatively invariant pattern of particle-size selection in 23 separate feeding experiments conducted from spring through fall over a 2-yr period. This pattern persisted for different feeding rates under varying conditions of particle-size spectrum shape, abundance and food quality of particles, and temperature. Selection was quantified by calculating W′ (filtering efficiency) as a function of particle size (equivalent spherical diameter). In all but one of the few experiments yielding a W′ curve that varied appreciably from the other W′ curves, serious bias from grazer-produced particles was evident and/or elongated particles dominated the seston. The elongated particles could have led to deviations because of differences in filtering efficiency between round and elongated particles of small volume and because elongated particles of large volume have to be captured raptorially. It is argued that the more variable patterns of particle-size selection observed in many of the other studies of zooplankton feeding on natural seston result from: (1) improper methods of quantifying selection, (2) serious bias from grazer-produced particles, and (3) varying particle shape, which is not usually specified. The mechanisms of particle selection by Diaptomus and other species that filter like Diaptomus are reviewed, and it is noted that invariant selection is not inconsistent with both filtering and raptorial modes of feeding operating simultaneously. All the evidence points to a strong passive-mechanical filtering mode of feeding that may be supplemented by a raptorial mode of feeding that selects large particles of high food quality.Key words: Diaptomus sicilis, particle-size selection, filter feeding, peak tracking, passive selection, Lake Michigan, food selectivity

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Faculty Opinions recommendation of The role of the particle size spectrum in estimating POC fluxes from disequilibrium.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1087095.540074 ◽

2007 ◽

Author(s):

Edward Laws

Keyword(s):

Particle Size ◽

Size Spectrum

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Simultaneous Monitoring of Particle-Bound PAHs Inside a Low-Energy School Building and Outdoors over Two Weeks in France

Atmosphere ◽

10.3390/atmos12010108 ◽

2021 ◽

Vol 12 (1) ◽

pp. 108

Author(s):

Céline Liaud ◽

Sarah Chouvenc ◽

Stéphane Le Calvé

Keyword(s):

Particle Size ◽

Air Quality ◽

High Performance ◽

Sampling Period ◽

Temporal Variations ◽

Ventilation Rate ◽

Low Energy ◽

Total Particle ◽

Polycyclic Aromatic ◽

Individual Pahs

The emergence of new super-insulated buildings to reduce energy consumption can lead to a degradation of the indoor air quality. While some studies were carried out to assess the air quality in these super-insulated buildings, they were usually focused on the measurement of gas phase pollutants such as carbon dioxide and volatile organic compounds. This work reports the first measurements of Polycyclic Aromatic Hydrocarbons (PAHs) associated with particles as a function of time and particle size in a low-energy building. The airborne particles were collected indoors and outdoors over three to four days of sampling using two three-stage cascade impactors allowing to sample simultaneously particles with aerodynamic diameter Dae > 10 µm, 2.5 µm < Dae < 10 µm, 1 µm < Dae < 2.5 µm, and Dae < 1 µm. The 16 US-EPA priority PAHs were then extracted and quantified by high-performance liquid chromatography (HPLC) coupled to fluorescence detection. The resulting total particle concentrations were low, in the ranges 3.73 to 9.66 and 0.60 to 8.83 µg m-3 for indoors and outdoors, respectively. Thirteen PAHs were always detected in all the samples. The total PAH concentrations varied between 290 and 415 pg m−3 depending on the particle size, the environment (indoors or outdoors) and the sampling period considered. More interestingly, the temporal variations of individual PAHs highlighted that high molecular weight PAHs were mainly associated to the finest particles and some of them exhibited similar temporal behaviors, suggesting a common emission source. The indoor-to-outdoor concentration ratios of individual PAH were usually found close to or less than 1, except during the event combining rainy conditions and limited indoor ventilation rate.

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