Desorbing fraction
WebAug 15, 2016 · The slow and very slow desorbing fractions tend to increase with soil ageing, which results in lower PAH bioaccessibility. More or less good relationships could be demonstrated between PAH bioaccessibility, obtained by various non-exhaustive extractions and biodegradation by microorganisms [19]. WebJul 1, 1997 · The rate constants of slow desorption correlate well with the molecular volumes of the compounds used and decrease between 2 and 34 d of equilibration. …
Desorbing fraction
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WebJun 15, 2024 · Three fractions of organic pollutants in sediments have been widely recognized: ( i) the fast−desorbing fraction is weakly and reversibly bound to sediments … WebMay 27, 2024 · The linear regression was well fitted, and 0.86 times that of the rapid-desorbing fraction. These results were consistent with other studies, e.g., Cornelissen et al. [ 49 ], who found that the 6 h extracted fraction was about 0.5 times that of the rapid-desorbing fraction, which implied that 6 h Tenax could be regarded as an efficient ...
WebCitation 5] The rapidly desorbing (bioavailable) fraction has been used successfully to predict the extent of PAH degradation in field-contaminated sediments.[Citation 48] In this study, the addition of increasing concentrations of lipopetide helped to increase the PAH desorption and expand the rapidly desorbing fraction. Accordingly, from the ... WebMar 4, 1999 · This indicated that high-energy adsorption was not responsible for the slow-desorbing fraction, and suggested that mineral precipitation leads to blockage of intragranular micropores. The activation energy for TCE desorption from water-saturated silica gel was measured using temperature-programmed desorption. The TCE desorption …
WebMay 18, 2024 · In Eq. (), S t and S 0 correspond to the accumulated mass of PAHs adsorbed by XAD-2 and the initial mass of PAHs in bulk soil or HU sample, respectively, … WebComparison of the calculated pyrethroid concentration in the rapidly desorbing fraction (CrapT0) based on the use of the nominal concentration and exhaustive concentration to represent the...
WebMar 1, 2010 · The rapid-desorbing fraction plays an important role in the bioavailability of organic pollutants in soil. In the present study, DDT's desorption from the cotton field soils was investigated by...
WebMar 15, 2024 · Furthermore, biodegradation rate of sorbed phenanthrene in slowly desorbing sites can be expressed as: (5) dS s d t = − a s ( S s − f s K d C) − k s S s where C (mg·L −1) is phenanthrene concentration in pore water, and Kd (L·kg −1) is the sorption distribution coefficient. clipper ayurvedicWebThe bioavailable BEQs (passive equilibrium sampling) typically were 10–100 times and up to 420 times lower than the total BEQ (solvent extraction) for the AhR and AREc32 assays, indicating that the readily desorbing fraction of the bioactive chemicals was substantially lower than the fraction bound strongly to the sediment sorptive phases. clipper awardsWebDec 12, 2024 · The rate constants (k s) for the slowly desorbing fraction of heavy metals were found to be 5 to 6 orders of magnitude lower than the corresponding rate constants … bob seger hits playlistWebApr 13, 2024 · The EPA analyzed the responses from the December 2024 questionnaire and September 2024 ICR to update the fraction of EtO that is apportioned to SCV, ARV, CEV, and room air emissions. The data for the ARV analyses included flow rate (or room volume combined with air changeover rate), EtO concentration, and average aeration … bob seger home michiganWebDec 12, 2024 · The fractionation of strongly adsorbing metals like Pb was not as dependent on release time and pH as it was for the weakly bonded metals like Mn and Cd. The results indicate that in situ heavy metals may … bob seger hollywood nights live videoWebSep 1, 2024 · The fraction present in the soil after desorption can be considered as the very slowly desorbing fraction or a residual fraction that will not degrade. In the mathematical model (Eq. (1)) rapid, slow and very slow desorption/degradation occurs simultaneously and all start at t = 0. bob seger hits youtubeWebFeb 15, 2024 · The results of desorption kinetics were suitably fitted with first order three-compartment model to estimate the rapidly desorbing fraction, Moreover, the Tenax: sediment ratio of 1 and desorption time of 24 h were found to be suitable for the desorption of phenanthrene and fluoranthene from sediments. bob seger home photos