An Instrument System for High-Speed Mapping of Chlorophyll a and Physico-Chemical Variables in Surface Waters

Estuaries ◽  
1992 ◽  
Vol 15 (3) ◽  
pp. 421 ◽  
Author(s):  
Christopher J. Madden ◽  
John W. Day
Keyword(s):  
Chlorophyll A ◽  
Surface Waters ◽  
High Speed ◽  
Physico Chemical

scholarly journals Performance of a Handheld Chlorophyll-a Fluorometer: Potential Use for Rapid Algae Monitoring

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1409
Author(s):  
Hamdhani Hamdhani ◽  
Drew E. Eppehimer ◽  
David Walker ◽  
Michael T. Bogan
Keyword(s):  
Chlorophyll A ◽  
Surface Waters ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Water Quality Monitoring ◽  
Ambient Light ◽  
Calibration Equation ◽  
Field Samples ◽  
Potential Use

Chlorophyll-a measurements are an important factor in the water quality monitoring of surface waters, especially for determining the trophic status and ecosystem management. However, a collection of field samples for extractive analysis in a laboratory may not fully represent the field conditions. Handheld fluorometers that can measure chlorophyll-a in situ are available, but their performance in waters with a variety of potential light-interfering substances has not yet been tested. We tested a handheld fluorometer for sensitivity to ambient light and turbidity and compared these findings with EPA Method 445.0 using water samples obtained from two urban lakes in Tucson, Arizona, USA. Our results suggested that the probe was not sensitive to ambient light and performed well at low chlorophyll-a concentrations (<25 µg/L) across a range of turbidity levels (50–70 NTU). However, the performance was lower when the chlorophyll-a concentrations were >25 µg/L and turbidity levels were <50 NTU. To account for this discrepancy, we developed a calibration equation to use for this handheld fluorometer when field monitoring for potential harmful algal blooms in water bodies.

scholarly journals Study of Physico-Chemical Quality of the Surface Waters of the Estuary of the Western Basin of the Oued Oum Errabia-Morocco

2017 ◽  
Vol 10 (05) ◽  
pp. 41-49 ◽  
Author(s):  
Y. Asfers ◽  
H. Taouil ◽  
A. Amine, ◽  
S. Elanz ◽  
S. Ibn Ahmed
Keyword(s):  
Surface Waters ◽  
Chemical Quality ◽  
Western Basin ◽  
Physico Chemical

scholarly journals Controllable synthesis of pomelo peel-based aerogel and its application in adsorption of oil/organic pollutants

2019 ◽  
Vol 6 (2) ◽  
pp. 181823 ◽  
Author(s):  
Guangyu Shi ◽  
Yizhu Qian ◽  
Fengzhi Tan ◽  
Weijie Cai ◽  
Yuan Li ◽  
...  
Keyword(s):  
High Speed ◽  
Chemical Properties ◽  
Absorption Capacity ◽  
High Porosity ◽  
X Ray Diffraction ◽  
Water Separation ◽  
Physico Chemical ◽  
Wide Range ◽  
Oil Water Separation ◽  
Oil Water

Oil/water separation is a field of high significance as it might efficiently resolve the contamination of industrial oily wastewater and other oil/water pollution. In this paper, an environmentally-friendly hydrophobic aerogel with high porosity and low density was successfully synthesized with renewable pomelo peels (PPs) as precursors. Typically, a series of sponge aerogels (HPSA-0, HPSA-1 and HPSA-2) were facilely prepared via high-speed dispersion, freeze-drying and silanization with methyltrimethoxysilane. Indeed, the physical properties of aerogel such as density and pore diameter could be tailored by different additives (filter paper fibre and polyvinyl alcohol). Hence, their physico-chemical properties including internal morphology and chemical structure were characterized in detail by Fourier transform infrared, Brunauer–Emmett–Teller, X-ray diffraction, scanning electron microscope, Thermal gravimetric analyzer (TG) etc. Moreover, the adsorption capacity was further determined and the results revealed that the PP-based aerogels presented excellent adsorption performance for a wide range of oil products and/or organic solvents (crude oil 49.8 g g −1 , soya bean oil 62.3 g g −1 , chloroform 71.3 g g −1 etc.). The corresponding cyclic tests showed the absorption capacity decreased slightly from 94.66% to 93.82% after 10 consecutive cycles, indicating a high recyclability.

scholarly journals Water quality in Lake Xochimilco, Mexico: zooplankton indicators and Vibrio cholerae

2015 ◽  
Author(s):  
Sarma Nandini ◽  
Pedro Ramirez García ◽  
S.S.S. Sarma
Keyword(s):  
Water Quality ◽  
Vibrio Cholerae ◽  
Chlorophyll A ◽  
Local Population ◽  
Secchi Depth ◽  
Treatment Plant ◽  
Nitrogen And Phosphorus ◽  
Physico Chemical ◽  
Eutrophic Water ◽  
Depth Water

<p>Lake Xochimilco is a eutrophic water body in Mexico City used by the local population for aquaculture and agriculture. Water level is maintained with inputs of partially treated waste water from the Cerro de la Estrella treatment plant. In this study we analysed the water quality at two sites of Lake Xochimilco, Lake Xaltocan and the Santa Cruz Canal using various indicators such as zooplankton diversity, saprobic indices, bacterial concentrations and physico-chemical variables. Eighty litres of water was filtered from Lake Xochimilco from each site, once a month from March to October of 2012, and the rotifers, cladocerans and copepods were enumerated and identified. Physico-chemical parameters such as temperature, pH, Secchi depth, water depth, nitrogen and phosphorus and chlorophyll a concentrations, and bacterial densities were measured. During the study we recorded 33 species of rotifers, the most abundant being <em>Brachionus angularis</em>, <em>B. calyciflorus</em> and <em>B. havanaensis</em>.  Among the microcrustaceans the most abundant were the cladoceran <em>Moina micrura</em> and the copepods <em>Acanthocyclops americanus</em> and <em>Arctodiaptomus dorsalis</em>. The species diversity was around 2 bits/ind. and the saprobic index between 1.5-2.0, indicating that both sites were β meso-saprobic.  At both sites nitrogen was &lt;1 mg/L and phosphorus ranged between 2.5-7.8 mg/L. Chlorophyll a concentrations were between 66-136 µg/L. The toxigenic (<em>Vibrio cholerae </em>No-O1/No-O139) and the non-toxigenic (<em>Vibrio cholerae </em>No-O135) strains of the bacterium were recorded, closely associated with littoral rotifers and cladocerans particularly <em>Brachionus quadridentatus</em> and  <em>Alona</em> sp. All variables indicate that these sites in Lake Xochimilco are eutrophic and highly contaminated and that the water quality needs to be improved.<strong></strong></p>

scholarly journals Influence of Dispersing Method on the Quality of Nano-Admixtures Homogenization in Cement Matrix

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4865
Author(s):  
Elżbieta Horszczaruk ◽  
Paweł Łukowski ◽  
Cyprian Seul
Keyword(s):  
High Speed ◽  
Mechanical Performance ◽  
Chemical Properties ◽  
Cement Composite ◽  
Cement Matrix ◽  
Cement Composites ◽  
Nano Sio2 ◽  
Mechanical Stirring ◽  
Physico Chemical ◽  
Nano Fe3o4

In recent years, a nano-modification of the cement composites allowed to develop a number of new materials. The use of even small amount of nano-admixture makes possible not only to improve the physico-mechanical properties of the cement materials, but also to obtain the composite with high usability, optimised for the given application. The basic problem of nano-modification of the cement composites remains the effectiveness of dispersing the nanomaterials inside the cement matrix. This paper deals with the effect of the type and size of the nanoparticles on the tendency to their agglomeration in the cement matrix. The main techniques and methods of dispersing the nanomaterials are presented. It has been demonstrated, on the basis of the results of testing of three nanomodifiers of 0D type (nano-SiO2, nano-Fe3O4 and nano-Pb3O4), how the structure and properties of the nanomaterial affect the behaviour of the particles when dissolving in the mixing water and applying a superplasticiser. The nanoparticles had similar size of about 100 nm but different physico-chemical properties. The methods of dispersing covered the use of high-speed mechanical stirring and ultrasonication. The influence of the method of nano-modifier dispersing on the mechanical performance of the cement composite has been presented on the basis of the results of testing the cement mortars modified with 3% admixture of nano-SiO2.

scholarly journals Temporal changes in total and size-fractioned chlorophyll-a in surface waters of three provinces in the Atlantic Ocean (September to November) between 2003 and 2010

2015 ◽  
Vol 150 ◽  
pp. 56-65 ◽  
Author(s):  
Ertugrul Agirbas ◽  
Victor Martinez-Vicente ◽  
Robert J.W. Brewin ◽  
Marie-Fanny Racault ◽  
Ruth L. Airs ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Chlorophyll A ◽  
Surface Waters ◽  
Temporal Changes

scholarly journals The beidellite clays from the Bełchatów lignite deposit as a raw material for constructing waterproofing barriers

2017 ◽  
Vol 33 (2) ◽  
pp. 53-67 ◽  
Author(s):  
Tadeusz Ratajczak ◽  
Elżbieta Hycnar ◽  
Piotr Bożęcki
Keyword(s):  
Mechanical Properties ◽  
Surface Waters ◽  
Natural Environment ◽  
Environmental Engineering ◽  
Raw Material ◽  
Underground Waters ◽  
Physico Chemical ◽  
Clay Rocks ◽  
Significant Distance ◽  
Artificial Water

Abstract Disposal sites for both industrial and communal waste are hazardous for the natural environment due to the accumulated materials and their chemical, physical and biological transformations. The products of these processes migrating at a significant distance contaminate mainly underground waters, surface waters and soils. The spreading of the pollutants may be prevented by horizons of clay rocks that form natural geological barriers. The clay rocks of properly selected parameters may be used in the environmental engineering for constructing artificial water-sealing layers. The mineral, chemical, physico-chemical and physico-mechanical properties of the beidellite clays occurring within the lignite deposit in Bełchatów were studied to find out whether they meet the criteria of waterproofing engineering contained in the Polish recommendations and instructions. The results indicate that the beidellite clays of Bełchatów are rocks suitable for this kind of environmental engineering and may be used in constructing the barriers preventing the migration of effluents from landfills.

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