Chlorinated organics in Tropical Hardwood Kraft pulp and paper mill effluents and their elimination in an activated sludge treatment system

The identity and concentration of major chlorinated organics in the combined effluents of the SFI Pulp and Paper Mill in Sabah, Malaysia, were determined. In the biologically treated effluent, chlorinated organics found to occur in a relatively higher concentration were trichloroacetic acid (838-994 ig/L), 1,1-dichlorodimethyl sulfone (DDS) (86-232 [ig/L), dichbroacetic acid (14-18 ig/L), and trichlorosyringol (5-18lg/L). Compared to those of a number of softwood kraft mills, the load of chlorinated phenols and acids in the wastewater of SFI hardwood kraft mill was 3-8 times lower. The effectiveness of oxygen activated sludge treatment system in eliminating these chlorinated organics was found to be as follows: chlorinated phenols 20-70%, DDS 60%, and chlorinated acetic acids 30-99%