Can chlorophenols, decontaminated through binding to humic acid, be released?

The binding of xenobiotics to humus is considered a novel approach for decontamination of the environment, but little is known yet on the possible release of humus-bound chemicals and on related delayed pollution effects. To evaluation this problem, they enzymatically incorporated 14C-labelled chlorophenols into model and natural humic acid polymers and exposed these complexes to mixed microbial cultures isolated from different soils. The experiments were performed using air-flow systems equipped with a series of traps absorbing radioactive volatiles and 14CO2. After a 3-month incubation period the media were analyzed by HPLC and gel chromatography (Sephadex G-150) for detecting the distribution of radioactivity. For comparison, some polymers were treated chemically with NaOH, KMnO4 and Na-amalgam and the reaction solution analyzed for the released radioactivity