The removal of short-chain and long-chain perfluoroalkyl acids and sulfonates via granular activated carbons: A comparative column study

2018 ◽  
Vol 29 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Philippe Westreich ◽  
Richard Mimna ◽  
Jenalle Brewer ◽  
Frederic Forrester
Keyword(s):  
Activated Carbons ◽  
Short Chain ◽  
Perfluoroalkyl Acids ◽  
Column Study ◽  
Long Chain

Long-Chain Perfluoroalkyl acids (PFAAs) Affect the Bioconcentration and Tissue Distribution of Short-Chain PFAAs in Zebrafish (Danio rerio)

2017 ◽  
Vol 51 (21) ◽  
pp. 12358-12368 ◽  
Author(s):  
Wu Wen ◽  
Xinghui Xia ◽  
Diexuan Hu ◽  
Dong Zhou ◽  
Haotian Wang ◽  
...  
Keyword(s):  
Tissue Distribution ◽  
Danio Rerio ◽  
Short Chain ◽  
Perfluoroalkyl Acids ◽  
Long Chain

Adsorption of short-chain perfluoroalkyl acids (PFAAs) from water/wastewater

2020 ◽  
Vol 6 (11) ◽  
pp. 2958-2972
Author(s):  
Chi Thanh Vu ◽  
Tingting Wu
Keyword(s):  
Short Chain ◽  
Perfluoroalkyl Acids ◽  
Long Chain

The adsorption of short-chain PFAAs has recently received increasing attention due to their potential for replacing the long-chain homologs.

scholarly journals The absorption of stearic acid from triacylglycerols: an inquiry and analysis

2000 ◽  
Vol 13 (2) ◽  
pp. 185-214 ◽  
Author(s):  
Geoffrey Livesey
Keyword(s):  
Fatty Acids ◽  
Body Weight ◽  
Melting Point ◽  
Cocoa Butter ◽  
Stearic Acid ◽  
Short Chain ◽  
Apparent Digestibility ◽  
Long Chain Fatty Acids ◽  
Long Chain ◽  
Chain Fatty Acids

AbstractAlthough stearic acid is a saturated fatty acid, its influence on plasma cholesterol acid other health variables is neutral; possibly owing in part to poor absorption. Reduced absorption of stearic acid from particular triacylglycerols, cocoa butter and novel fats formulated with short- and long-chain acid triacylglycerol molecules (Salatrims) has been attributed to high intakes. However, the circumstances and causes of poor stearic acid digestion from triacylglycerols are unclear; published data were therefore collected and analysed, with emphasis on human studies. Of twenty-eight studies conducted in adults, most are in men (>90%). The assertion that reduced absorption is due to a high intake of stearoyl groups is not supported: dietary intakes of stearoyl of 0·05–0·65 g stearic acid equivalent/kg body weight (cf typical intake of 0·2 g stearic acid equivalent/kg body weight in the Western diet) indicate that the ‘true’ digestibility of stearoyl is 0·98 (SE 0·01) g/g, with apparent digestibility less than this value at low intakes owing to endogenous stearic acid excretion and to inter-publication variation of unidentified cause. The neutral health impact of stearic acid must be due to factors other than availability. Exceptions include cocoa butter, Salatrims and tristearin, for which digestibility is an additional factor. The efficiency with which human subjects digest stearoyl from cocoa butter still remains uncertain, while the digestion of total long-chain fat from this source is 0·89–0·95 g/g, high in comparison with 0·33 g/g for Salatrim 23CA and 0·15 g/g for tristearin in their prepared states. Salatrims contain the highest proportion of long-chain fatty acids that are stearic acid-rich other than tristearin, which is the main component of fully-hydrogenated soyabean and rapeseed oil. Analysis shows that apparent digestibility of stearic acid is associated with stearoyl density within the triacylglycerol molecule and that, in Salatrims, the occurrence of short-chain fatty acids in place of long-chain fatty acids increases this density. Soap formation appears not to be a major factor in the reduced digestion of stearic acid from tristearin under regular dietary circumstances, but both microcrystallinity and reduced digestibility of tri-, di- and monostearoylglycerols appears to be important. Solubilisation of high-melting-point tristearin in low-melting-point oils improves the digestibility of its stearic acid, particularly when emulsified or liquidized at above melting point. However, without such artificial aids, the digestive tracts of the rat, dog and man have a low capacity for emulsifying and digesting stearic acid from tristearin. Reduced digestibility of stearic acid from Salatrim 23CA also appears to be attributable to reduced digestibility of di- and monostearoylglycerols and is particularly due to remnants with the 1- or 3-stearoylglycerol intact after initial hydrolytic cleavage. Short-chain organic acid in Salatrim 23CA, which is readily hydrolysed, leaves such remnants. Unlike tristearin, Salatrim 23CA melts at body temperature and mixing it with low-melting-point oils is not expected to cause further disruption of microcrystalline structures to aid digestibility of its stearoyl groups. The low digestibility of stearoyl in Salatrim 23CA, together with the occurrence of short-chain organic acids in this product, account for its relatively low nutritional energy value (about 20 kJ (5 kcal)/g) compared with traditional fats (37 kJ (9 kcal)/g) and low fat value (<20:37 kJ/kJ; <5:9 kcal/kcal) relative to traditional fats. In part these differences are because of minor effects of Salatrim 23CA on the excretion of other fat and protein, due to the bulking properties of this poorly-digestible fat.

Jumping on the Omega-3 Bandwagon: Distinguishing the Role of Long-Chain and Short-Chain Omega-3 Fatty Acids

2012 ◽  
Vol 52 (9) ◽  
pp. 795-803 ◽  
Author(s):  
Giovanni M. Turchini ◽  
Peter D. Nichols ◽  
Colin Barrow ◽  
Andrew J. Sinclair
Keyword(s):  
Fatty Acids ◽  
Short Chain ◽  
Omega 3 Fatty Acids ◽  
Omega 3 ◽  
Long Chain

scholarly journals A methylotrophic origin of methanogenesis and early divergence of anaerobic multicarbon alkane metabolism

2021 ◽  
Vol 7 (27) ◽  
pp. eabj1453
Author(s):  
Yinzhao Wang ◽  
Gunter Wegener ◽  
Tom A. Williams ◽  
Ruize Xie ◽  
Jialin Hou ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Energy Conservation ◽  
Life Forms ◽  
Short Chain ◽  
Present Evidence ◽  
Origin And Evolution ◽  
Ancestral Form ◽  
Climate Stability ◽  
Long Chain

Methanogens are considered as one of the earliest life forms on Earth, and together with anaerobic methane-oxidizing archaea, they have crucial effects on climate stability. However, the origin and evolution of anaerobic alkane metabolism in the domain Archaea remain controversial. Here, we present evidence that methylotrophic methanogenesis was the ancestral form of this metabolism. Carbon dioxide–reducing methanogenesis developed later through the evolution of tetrahydromethanopterin S-methyltransferase, which linked methanogenesis to the Wood-Ljungdahl pathway for energy conservation. Anaerobic multicarbon alkane metabolisms in Archaea also originated early, with genes coding for the activation of short-chain or even long-chain alkanes likely evolving from an ethane-metabolizing ancestor. These genes were likely horizontally transferred to multiple archaeal clades including Candidatus (Ca.) Bathyarchaeia, Ca. Lokiarchaeia, Ca. Hadarchaeia, and the methanogenic Ca. Methanoliparia.

Oil Cracking Characteristics by Streamer Discharge in Oil

2003 ◽  
Vol 6 (1) ◽  
Author(s):  
J. Y. Park ◽  
J. G. Jung ◽  
J. S. Kim ◽  
H. J. Ha ◽  
H. S. Goh
Keyword(s):  
Diesel Engine ◽  
Operating Time ◽  
Combustion Efficiency ◽  
Short Chain ◽  
Streamer Discharge ◽  
Cracking Characteristics ◽  
Experimental Works ◽  
Oil Cracking ◽  
Long Chain ◽  
Better Than

AbstractParticulates exhausted from diesel engine are imperfectly burned carbons of oil and are difficult to re­move. Oil is organic compounds composed of hydrogen and carbon and has relatively long chain that the numbers of carbons are from 10 to 18. When a short chain oil is used in diesel engine, the combustion efficiency could be better than that used a long chain oil, and then particulates could be reduced. In this paper, in order to increase combustion efficiency and reduce particle materials exhausted from diesel engine, an experimental works to crack the long chain oil to short chain oil by streamer plasma induced in oil is conducted. The discharge electrode geometries of a needle and a plate are tested. AC high voltage with 60 Hz of frequency is supplied for electrical discharge in oil. Fresh oil and cracked oil are analyzed with GC-MS (Gas Chromatograph-Mass). From the results, Oil cracking is observed at 14 kV, however, it can not observed below 14 kV in two reactor tested. Operating time is not significantly influence to oil cracking. With derived by the results by GC/MS, it is confirmed that a long chain oil with a heavy molecule weight was changed to a short chain oil with a light molecule weight.

Absorption of short-chain to long-chain perfluoroalkyl substances using swellable organically modified silica

2019 ◽  
Vol 5 (11) ◽  
pp. 1854-1866 ◽  
Author(s):  
Eva K. Stebel ◽  
Kyndal A. Pike ◽  
Huan Nguyen ◽  
Heather A. Hartmann ◽  
Mattaeus J. Klonowski ◽  
...  
Keyword(s):  
Short Chain ◽  
Perfluoroalkyl Substances ◽  
Modified Silica ◽  
Wide Range ◽  
Organically Modified ◽  
Organically Modified Silica ◽  
Long Chain

Adsorbents comprising swellable organically modified silica were characterized to optimize the adsorption of a wide range of perfluoroalkyl substances from water.

Sign in / Sign up

Export Citation Format

Share Document