6533b86cfe1ef96bd12c7f66

RESEARCH PRODUCT

Chlorophenanthrenes, alkylchlorophenanthrenes and alkylchloronaphthalenes in kraft pulp mill products and discharges

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Abstract Chlorinated phenanthrenes (PCPHs; P=1–5), alkylphenanthrenes (C4-PCPHs; P=1–3), dimethylnaphthalenes (C2-PCNs; P=1–4) and trimethylnaphthalenes (C3-PCNs; P=1–2) were analyzed by high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) in pulp, effluent and biosludge of two kraft pulp mills (mills 1 and 2). These compounds were indicated to be formed in the manufacture of both bleached hardwood and softwood kraft pulp. Different compound groups dominated in mill 1 samples compared to mill 2 samples. Differences between birch and pine pulp from mill 1 were observed for all substance groups but in mill 2 pulp only for PCPHs. The highest concentrations of PCPHs in pulp (3 ng/g dry weight) were measured in pine pulp from mill 2. PCPHs occurred at a higher level in pine pulp compared to birch pulp. The sum levels of C4-PCPHs in pulp ranged from 0.9 to 8.7 ng/g dw, those of C2-PCNs from 0.7 to 8.2 ng/g dw and those of C3-PCNs from 0.3 to 4.5 ng/g dw. Drying and pressing of pulp to sheets seemed to effect on the amounts of extractable C4-PCPHs in pulp, because concentrations measured in dried sheet pulp were lower than in wet pulp slurry. Mill 2 biosludge had C4-PCPHs (61 ng/g dw) at a higher level than C2-PCNs (35 ng/g dw). In mill 1 biosludge these groups were at a similar level (72 ng/g dw). The sum concentration of C3-PCNs in mill 1 sludge was 47 ng/g dw and in mill 2 sludge 16 ng/g dw. All studied groups were found both as particle-bound and dissolved in filtrates. Total levels in effluents ranged from 2 ng/L for C3-PCNs in mill 2 effluent to 56 ng/L for C4-PCPHs in mill 1 effluent.