Determination of perfluorinated compounds (PFCs) in solid and liquid phase river water samples in Chao Phraya River, Thailand

2011 ◽  
Vol 64 (3) ◽  
pp. 684-692 ◽  
Author(s):  
Chinagarn Kunacheva ◽  
Shuhei Tanaka ◽  
Shigeo Fujii ◽  
Suwanna Kitpati Boontanon ◽  
Chanatip Musirat ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Suspended Solids ◽  
Solid Phase ◽  
Industrial Applications ◽  
Perfluorinated Compounds ◽  
River Water Samples ◽  
Liquid Phases ◽  
Chao Phraya River ◽  
Solid Liquid

Perfluorinated compounds (PFCs), especially perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), are fully fluorinated organic compounds, which have been used in many industrial applications. These chemicals have contaminated surface water all over the world even in developing countries like Thailand. The previous study showed the contamination in Chao Phraya River in 2006 and 2007. The purposes of this field study were to determine the solid and liquid phase of PFCs contamination in Chao Phraya River and to compare the changes of PFC concentration in 2008. Surveys were conducted in the lower reach of Chao Phraya River in the industrialized area. A solid phase extraction (SPE) coupled with HPLC-ESI-MS/MS were used for the analysis for ten PFCs. Ten PFCs were analyzed to identify the contamination in both solid and liquid phases. PFCs were detected in both the solid and liquid phase in every sample. PFOA was the most dominant PFC while PFPA and PFOS were also highly detected in most samples. The average loadings of PFPA, PFOA and PFOS in Chao Phraya River were 94.3, 284.6 and 93.4 g/d, respectively. PFOS concentrations did not show differences between 2006 and 2008. However, PFOA concentrations were higher in 2008/5/26, while comparing other samplings. The ratio of solid : liquid PFPA (2.1 : 1.0) [(ng/g)/(ng/L)] was lower than PFOA (13.9 : 1.0) [(ng/g)/(ng/L)] and PFOS (17.6 : 1.0) [(ng/g)/(ng/L)]. The shorter chain (more hydrophilic) PFC was better to dissolve in water rather than adsorb onto suspended solids. PFOS also showed more potential to attach in the suspended solids than PFOA.

Multi-walled Carbon Nanotubes Reinforced into Hollow Fiber by Chitosan Sol-gel for Solid/Liquid Phase Microextraction of NSAIDs from Urine Prior to HPLC-DAD Analysis

2019 ◽  
Vol 20 (5) ◽  
pp. 390-400 ◽  
Author(s):  
Nabil N. AL-Hashimi ◽  
Amjad H. El-Sheikh ◽  
Rania F. Qawariq ◽  
Majed H. Shtaiwi ◽  
Rowan AlEjielat
Keyword(s):  
Carbon Nanotubes ◽  
Liquid Phase ◽  
Hollow Fiber ◽  
Sol Gel ◽  
Liquid Phase Microextraction ◽  
Extraction Device ◽  
Multi Walled Carbon Nanotubes ◽  
Solid Liquid ◽  
Walled Carbon Nanotubes

Background: The efficient analytical method for the analysis of nonsteroidal antiinflammatory drugs (NSAIDs) in a biological fluid is important for determining the toxicological aspects of such long-term used therapies. Methods: In the present work, multi-walled carbon nanotubes reinforced into a hollow fiber by chitosan sol-gel assisted-solid/ liquid phase microextraction (MWCNTs-HF-CA-SPME) method followed by the high-performance liquid chromatography-diode array detection (HPLC–DAD) was developed for the determination of three NSAIDs, ketoprofen, diclofenac, and ibuprofen in human urine samples. MWCNTs with various dimensions were characterized by various analytical techniques. The extraction device was prepared by immobilizing the MWCNTs in the pores of 2.5 cm microtube via chitosan sol-gel assisted technology while the lumen of the microtube was filled with few microliters of 1-octanol with two ends sealed. The extraction device was operated by direct immersion in the sample solution. Results: The main factors influencing the extraction efficiency of the selected NSAIDs have been examined. The method showed good linearity R2 ≥ 0.997 with RSDs from 1.1 to 12.3%. The limits of detection (LODs) were 2.633, 2.035 and 2.386 µg L-1, for ketoprofen, diclofenac, and ibuprofen, respectively. The developed method demonstrated a satisfactory result for the determination of selected drugs in patient urine samples and comparable results against reference methods. Conclusion: The method is simple, sensitive and can be considered as an alternative for clinical laboratory analysis of selected drugs.

Multiphase Reactions and Reactors

2001 ◽  
Author(s):  
L. K. Doraiswamy
Keyword(s):  
Liquid Phase ◽  
Solid Phase ◽  
Complete Classification ◽  
Catalytic Reactions ◽  
Two Phase ◽  
Multiphase Reactions ◽  
Liquid Phases ◽  
Three Phase ◽  
Solid Form

The first three chapters of this part dealt with two-phase reactions. Although catalysts are not generally present in these systems, they can be used in dissolved form in the liquid phase. This, however, does not increase the number of phases. On the other hand, there are innumerable instances of gas-liquid reactions in which the catalyst is present in solid form. A popular example of this is the slurry reactor so extensively employed in reactions such as hydrogenation and oxidation. There are also situations where the solid is a reactant or where a phasetransfer catalyst is immobilized on a solid support that gives rise to a third phase. A broad classification of three-phase reactions and reactors is presented in Table 17.1 (not all of which are considered here). This is not a complete classification, but it includes most of the important (and potentially important) types of reactions and reactors. The thrust of this chapter is on reactions and reactors involving a gas phase, a liquid phase, and a solid phase which can be either a catalyst (but not a phasetransfer catalyst) or a reactant, with greater emphasis on the former. The book by Ramachandran and Chaudhari (1983) on three-phase catalytic reactions is particularly valuable. Other books and reviews include those of Shah (1979), Chaudhari and Ramachandran (1980), Villermaux (1981), Shah et al. (1982), Hofmann (1983), Crine and L’Homme (1983), Doraiswamy and Sharma (1984), Tarmy et al. (1984), Shah and Deckwer (1985), Chaudhari and Shah (1986), Kohler (1986), Chaudhari et al. (1986), Hanika and Stanek (1986), Joshi et al. (1988), Concordia (1990), Mills et al. (1992), Beenackers and Van Swaaij (1993), and Mills and Chaudhari (1997). Doraiswamy and Sharma (1984) also present a discussion of gas-liquid-solid noncatalytic reactions in which the solid is a reactant. In Chapter 7 we saw how Langmuir-Hinshelwood-Hougen-Watson (LHHW) models are normally used to describe the kinetics of gas-solid (catalytic) or liquid-solid (catalytic) reactions, and in Chapters 14 to 16 we saw how mass transfer between gas and liquid phases can significantly alter the rates and regimes of these two-phase reactions.

scholarly journals Stress analysis in solid-liquid parts of solidifying castings

2019 ◽  
Vol 254 ◽  
pp. 02019
Author(s):  
Elżbieta Gawrońska ◽  
Robert Dyja ◽  
Norbert Sczygiol
Keyword(s):  
Finite Element ◽  
Liquid Phase ◽  
Stress Analysis ◽  
Plastic State ◽  
The Finite Element Method ◽  
Element Mesh ◽  
Friction Forces ◽  
Liquid Phases ◽  
Solid Liquid ◽  
Macroscopic Parameters

In the paper, we present results of stress analysis in domains which are a mixture of solid and liquid phases. Such mixtures occur in solidifying castings and are a result of forming a structure with solid skeleton and filling of a liquid phase. In this structure, stress occurs due to the appearance of temperature gradients, different values of material properties for the solid and liquid phase, and the appearance of friction forces between the solidified part of the casting and the mold on a macroscopic scale. This can lead to casting defects, such as hot cracking. The results are obtained with the use of a authors computer program based on the Finite Element Method. The stress analysis takes into account the elastic-plastic state of considered computational area. The presented results are focused on the microscopic scale, for which a finite element mesh is created which imitates the growing grains of the metal alloy in the casting, on the basis of macroscopic parameters.

Comparative Study of the Optimized Hydrocyclones H13 and HCOT3 for Maximum Liquid Recovery

2017 ◽  
Vol 899 ◽  
pp. 154-159 ◽  
Author(s):  
Fernanda Falqueto Salvador ◽  
Yanne Novais Kyriakidis ◽  
Marcos Antonio de Souza Barrozo ◽  
Luiz Gustavo Martins Vieira
Keyword(s):  
Liquid Phase ◽  
Euler Number ◽  
Industrial Applications ◽  
Maximum Amount ◽  
Dispersed Phase ◽  
Total Efficiency ◽  
Oil Well ◽  
Centrifugal Field ◽  
Well Drilling ◽  
Solid Liquid

In industrial applications, it is very common to use multiple hydrocyclones in parallel to improve the separation. This equipment employs the centrifugal field to promote solid-liquid or liquid-liquid separation. In cases where there is interest in recovering the liquid phase by removing the maximum amount of dispersed phase (waste), such as in oil well drilling units and in water treatment systems, the employment of a hydrocyclone able to promote both the recovering liquid and the concentration of suspension is viable. This paper presents a comparison between two hydrocyclones considered concentrators, called H13 and HCOT3. The results obtained showed that both separators have a satisfactory capacity to concentrate aqueous suspensions, with the underflow-to-throughput ratio equivalent. The Euler number of HCOT3 hydrocyclone was 19% lower than that obtained for the H13 hydrocyclone. Moreover, the results showed that the HCOT3 has a total efficiency of separation 34% greater compared to H13.

Determination of solid–liquid phase equilibria by using measured DSC curves

2002 ◽  
Vol 194-197 ◽  
pp. 1107-1117 ◽  
Author(s):  
Hiroshi Takiyama ◽  
Hirobumi Suzuki ◽  
Hirohisa Uchida ◽  
Masakuni Matsuoka
Keyword(s):  
Liquid Phase ◽  
Phase Equilibria ◽  
Solid Liquid ◽  
Dsc Curves
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