Levels of PCDDs and PCDFs in the Bleached Pulp from Chinese Pulp and Paper Industry.

The article discusses the results of the study on the levels of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in some bleached pulps that were taken from five paper mills in China. Raw materials from the mills are pulped with the use of the kraft process, bleached and then converted into paper. It was found out that the content of 2378-tetrachlorodibenco-p-Dioxin in the pulps is higher than that of softwood pulps and bleached hardwood. The quantity of PCDFs is low compared to PCDDs. The study also revealed that dibenzo-p-dioxin,dibenzofuran and chlorinated phenols are not precursors of PCDD's and PCDF's in the bleaching of non-wood fiber pulps with hypochlorite.