BEHAVIOR OF CHLORINATED PHENOLIC-COMPOUNDS IN BLEACH-PLANT, TREATMENT-SYSTEM AND ARCHIPELAGO AREA

The environmental fate of chlorophenolic compounds and the influence o f process changes for discharges were studied at a Finnish pulp mill d uring two years. Free and bound chlorophenols (FPCPs and BPCPs) and ch lorinated methoxybenzenes (PCAs) were analyzed in samples of bleach-pl ant effluent, and in the influent, effluent, and biosludge of an activ ated treatment plant, as well as in the discharge effluent. In additio n, environmental samples, fish and sea water, were collected ar variou s distances from the mill on the coast of the Gulf of Bothnia. The per centual chlorophenolic composition of effluents did not considerably c hange after the process stages. However, activated treatment considera bly reduced the total concentration of chlorophenolics. In process eff luents, about half of chlorophenolic compounds were already bound and part of free chlorophenolics were subsequently bound to the biosludge in the activated treatment plant. Nevetheless, in the discharge water, the rations of chlorophenolics were nearly the same ar before treatme nt. In sea water, the most widespread compounds were chloroguaiacols a nd 2,4,6 trichlorophenol. Seasonal variation was observed to affect th e levels of chlorophenoles and methoxy benzenes in fish.