scholarly journals Natural fluorescence emission – an indirect measurement of applied ozone dosages to remove pharmaceuticals in biologically treated wastewater

2019 ◽  
pp. 1-13 ◽  
Author(s):  
Aikaterini Spiliotopoulou ◽  
Maria G. Antoniou ◽  
Henrik R. Andersen
Keyword(s):  
Fluorescence Emission ◽  
Indirect Measurement ◽  
Treated Wastewater ◽  
Natural Fluorescence

Measurement of Temperatures on In-Flight Water Droplets by Laser Induced Fluorescence Thermometry

2003 ◽  
Author(s):  
V. Salazar ◽  
J. E. Gonza´lez ◽  
L. A. Rivera
Keyword(s):  
Temperature Distribution ◽  
Fluorescence Emission ◽  
Laser Induced Fluorescence ◽  
Numerical Results ◽  
Temperature Measurements ◽  
Water Droplets ◽  
Fluorescence Dye ◽  
Instantaneous Temperature ◽  
Natural Fluorescence ◽  
Fluorescence Thermometry

This work presents the use of laser induced fluorescence for instantaneous temperature measurements of a 200μm diameter water droplets monodispersed stream traveling downward in a standard stagnant atmosphere. The droplets are doped with small concentrations of a natural fluorescence dye (Pyrene), and with a surfactant substance, cetyldimetylbenzylammoniumchloride (CDBAC) to improve the fluorescence emission. The rate of the two-band pyreme emission (excimer to monomer) is used to determine the temperature. The temperature distribution along the stream of droplets determined for different initial temperatures: (30°C, 40°C and 50°C) at the exit of the nozzle compared very favorably with numerical results.

Measurement of Temperatures on In-Flight Water Droplets by Laser Induced Fluorescence Thermometry

2004 ◽  
Vol 126 (2) ◽  
pp. 279-285 ◽  
Author(s):  
V. M. Salazar ◽  
J. E. Gonza´lez ◽  
L. A. Rivera
Keyword(s):  
Temperature Distribution ◽  
Fluorescence Emission ◽  
Laser Induced Fluorescence ◽  
Temperature Measurements ◽  
Water Droplets ◽  
Band Emission ◽  
Fluorescence Dye ◽  
Instantaneous Temperature ◽  
Natural Fluorescence ◽  
Fluorescence Thermometry

This work presents the use of laser induced fluorescence for instantaneous temperature measurements of 200 μm water droplets in a monodisperse stream while traveling downward in a standard stagnant atmosphere. The droplets are doped with small concentrations of a natural fluorescence dye (Pyrene), and with a surfactant substance, cetyldimetylbenzylammoniumchloride (CDBAC) to improve the fluorescence emission and the rate of its two band emission (excimer to monomer) is used to determine the temperature. The temperature distribution along the stream of droplets was determined for three different initial temperatures: 30°C, 40°C, and 50°C at the exit of the nozzle and it is compared very favorably with numerical results.

Compliance Testing for Ocean Outfall Performance Utilising Natural Fluorescence of Effluent in Seawater Mixtures

1992 ◽  
Vol 25 (9) ◽  
pp. 41-48 ◽  
Author(s):  
R. B. Kaye ◽  
P. R. Haddad
Keyword(s):  
Fluorescence Emission ◽  
Emission Spectra ◽  
Indicator Bacteria ◽  
Excitation Wavelength ◽  
Recreational Waters ◽  
Fluorescence Excitation ◽  
Compliance Testing ◽  
Sydney Harbour ◽  
Natural Fluorescence ◽  
The One

Water samples were collected from public beaches at Sydney, Australia. The beaches were situated at various distances from the three major shoreline ocean outfalls discharging primary effluent. The samples were tested for faecal conform and faecal streptococci indicator bacteria. The same samples were also analysed for natural fluorescence. Excitation wavelength used was 280 nm and fluorescence emission from seawater effluent mixtures was observed at 445 nm. Indicator bacteria densities correlated well with fluorescence intensities for beach monitoring stations north of Sydney Harbour. Best correlations were observed for the stations situated within 5 kilometres from the outfall. Indicator bacteria densities were not as well correlated with fluorescence intensities for the stations south of Sydney Harbour. However, similar emission spectra were observed for all samples collected from stations both north and south of Sydney Harbour. Nevertheless, indicator bacteria densities for southern stations were observed to be better correlated with fluorescence intensities on particular days. The stations north of Sydney Harbour are believed to be impacted only by the one outfall at North Head. However the system south of Sydney Harbour is more complex. The southern stations are known to be impacted by any, or all of the three major outfalls at Bondi, Malabar, and North Head. Fluorescence can be used to determine effluent concentration in ocean waters where the origin of the effluent is known. There should also be opportunities for the development of fluorescence as an alternative indicator for “real time” public health monitoring of recreational waters.

DECOLOURIZATION AND COD REMOVAL OF WASEWATER FROM ETHANOL PRODUCTION PROCESS FROM MOLASSES BY COAGULANTION USING INORGANIC ALUM

2010 ◽  
Vol 13 (3) ◽  
pp. 92-102
Author(s):  
Trung Duc Le
Keyword(s):  
Ethanol Production ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Treated Wastewater ◽  
Treatment Processes ◽  
Physico Chemical ◽  
Biological Methods ◽  
Treatment Step ◽  
Main Material

The industrial production of ethanol by fermentation using molasses as main material that generates large quantity of wastewater. This wastewater contains high levels of colour and chemical oxygen demand (COD), that may causes serious environmental pollution. Most available treatment processes in Vietnam rely on biological methods, which often fail to treat waste water up to discharge standard. As always, it was reported that quality of treated wastewater could not meet Vietnameses discharge standard. So, it is necessary to improve the treatment efficiency of whole technological process and therefore, supplemental physico-chemical treatment step before biodegradation stage should be the appropriate choice. This study was carried out to assess the effect of coagulation process on decolourization and COD removal in molasses-based ethanol production wastewater using inorganic coaglutant under laboratory conditions. The experimental results showed that the reductions of COD and colour with the utilization of Al2(SO4)3 at pH 9.5 were 83% and 70%, respectively. Mixture FeSO4 – Al2(SO4)3 at pH 8.5 reduced 82% of colour and 70% of COD. With the addition of Polyacrylamide (PAM), the reduction efficiencies of colour, COD and turbidity by FeSO4 – Al2(SO4)3 were 87%, 73.1% and 94.1% correspondingly. It was indicated that PAM significantly reduced the turbidity of wastewater, however it virtually did not increase the efficiencies of colour and COD reduction. Furthermore, the coagulation processes using PAM usually produces a mount of sludge which is hard to be deposited.

Use of vent stack temperature as a feedforward variable for dissolver total titratable alkali (TTA) control

TAPPI Journal ◽  
2018 ◽  
Vol 17 (05) ◽  
pp. 261-269
Author(s):  
Wei Ren ◽  
Brennan Dubord ◽  
Jason Johnson ◽  
Bruce Allison
Keyword(s):  
Feedback Control ◽  
Current Practice ◽  
Feedforward Control ◽  
Control Variable ◽  
Indirect Measurement ◽  
Tight Control ◽  
Transfer Lines ◽  
Green Liquor ◽  
Process Dynamics ◽  
Downstream Processes

Tight control of raw green liquor total titratable alkali (TTA) may be considered an important first step towards improving the overall economic performance of the causticizing process. Dissolving tank control is made difficult by the fact that the unknown smelt flow is highly variable and subject to runoff. High TTA variability negatively impacts operational costs through increased scaling in the dissolver and transfer lines, increased deadload in the liquor cycle, under- and over-liming, increased energy consumption, and increased maintenance. Current practice is to use feedback control to regulate the TTA to a target value through manipulation of weak wash flow while simultaneously keeping dissolver density within acceptable limits. Unfortunately, the amount of variability reduction that can be achieved by feedback control alone is fundamentally limited by the process dynamics. One way to improve upon the situation would be to measure the smelt flow and use it as a feedforward control variable. Direct measurement of smelt flow is not yet possible. The use of an indirect measurement, the dissolver vent stack temperature, is investigated in this paper as a surrogate feedforward variable for dissolving tank TTA control. Mill trials indicate that significant variability reduction in the raw green liquor TTA is possible and that the control improvements carry through to the downstream processes.

Enhanced-Fluorescence of a Dye on DNA- assembled Gold Nano-Dimers Discriminated by Lifetime Correlation Spectroscopy

2017 ◽  
Author(s):  
Pedro M. R. Paulo ◽  
David Botequim ◽  
Agnieszka Jóskowiak ◽  
Sofia Martins ◽  
Duarte M. F. Prazeres ◽  
...  
Keyword(s):  
Single Molecule ◽  
Fluorescence Emission ◽  
Directed Assembly ◽  
Plasmon Mode ◽  
Correlation Spectroscopy ◽  
Enhanced Fluorescence ◽  
Detection Volume ◽  
Relaxation Component ◽  
Good Agreement ◽  
Confocal Detection

<div> <div> <div> <p>We have employed DNA-directed assembly to prepare dimers of gold nanoparticles and used their longitudinally coupled plasmon mode to enhance the fluorescence emission of an organic red-emitting dye, Atto-655. The plasmon- enhanced fluorescence of this dye using dimers of 80 nm particles was measured at single molecule detection level. The top enhancement factors were above 1000-fold in 71% of the dimers within a total of 32 dimers measured, and, in some cases, they reached almost 4000-fold, in good agreement with model simulations. Additionally, fluorescence lifetime correlation analysis enabled the separation of enhanced from non-enhanced emission simultaneously collected in our confocal detection volume. This approach allowed us to recover a short relaxation component exclusive to enhanced emission that is attributed to the interaction of the dye with DNA in the interparticle gaps. </p> </div> </div> </div>

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