PARENT SESSION
3G Environmental partitioning processes
9:00 AM to 7:00 PM, Tuesday, 08 May 2001

(T/MF149) Long contact times and desorption kinetics of spiked HCB and PCB-28 from Lake Ketelmeer sediment.

ten Hulscher, Dorien¹, Vrind, Bea¹, van den Heuvel, Henny¹, van Noort, Paul¹, Govers, Harry², ^{1 2}

ABSTRACT- The present study describes the influence of contact times up to four years on the desorption kinetics of HCB and PCB-28 spiked to a field contaminated sediment. A gas-purge technique was employed to measure the desorption kinetics of these (relatively volatile) compounds. With prolonged contact times the desorption of the studied compounds became slower. This was caused by a redistribution of the contaminants over fast, slowly, and very slowly desorbing sites. The desorption rate constants for these sites were not influenced by the contact times. After prolonged contact times the slowly and very slowly desorbing fractions dominate the desorption.

Key words: desorption, kinetics, sediment, contact time