کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4411421 1618879 2010 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Fluxes of PAHs from coal tar-impacted river sediment under variable seepage rates
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست شیمی زیست محیطی
پیش نمایش صفحه اول مقاله
Fluxes of PAHs from coal tar-impacted river sediment under variable seepage rates
چکیده انگلیسی

The flux of several polycyclic aromatic hydrocarbons (PAHs) from coal tar-impacted river sediment was measured under various seepage rates in a laboratory scale. The batch PAH equilibrium data between aqueous phase (Ceq) and sediment phase was well-explained using a Raoult’s law approach. In the flux measurement from column study, the steady-state PAH concentrations (C∞) in the effluent solution were affected by a time-dependent nonequilibrium process; the seepage velocity was inversely proportional to the C∞ of PAH in the effluents. With a high seepage velocity of 4.06 cm d−1, a large initial concentration was observed, possibly due to the greater disparity between C∞ and Ceq. This initial-flush export leveled off after a few pore volumes had been displaced. The chemical flux pattern of PAH was conceptually depicted by superimposing two analytical solutions, such as a slug lease followed by rate-limited solute lease. Under quiescent conditions, the sediment pore-water reached dissolution equilibrium with the solid phase. However, under dynamic groundwater seepage conditions, the seepage water flowing through sediment pores did not reach dissolution equilibrium, which was evidence of nonequilibrium dissolution. In conclusion, the mass flux of PAHs from coal tar-impacted sediment is determined by concurrent effect of the groundwater seepage rate and rate-limited PAH concentration in seepage water.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemosphere - Volume 80, Issue 11, September 2010, Pages 1261–1267
نویسندگان
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