Identifying EDCs in Paper Mill Wastewaters

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Researchers investigating paper mill effluents and their impact on surface waters in Slovenia have identified endocrine disrupting compounds (EDCs) and their mutagenic and genotoxic properties using gas chromatography–mass spectrometry (GC–MS) (1).

The pulp and paper industry is the sixth largest industrial polluter in the world releasing a wide range of solid, liquid, and gaseous waste into the environment (2). Most waste is discharged as wastewater, with one ton of paper production creating more than 12 m3 of wastewater. This wastewater represents a significant risk to surface waters often relied upon for drinking water, agricultural activities, industrial use, and in sports and leisure. However, little is known about the types and concentrations of individual toxic compounds released via the paper mill effluents, therefore researchers aimed to quantify the levels of EDCs in effluent from the two major types of paper mill - those which use virgin fibres and those which use recycled fibres. EDCs are significant and known pollutants of paper mill wastewaters, negatively affecting wildlife, and in humans EDCs are suspected to cause cryptorchidism, hypospadias, abnormalities in sperm, and increased hormone-related cancers (3,4). Furthermore, researchers also investigated the mutagenic and cytotoxic activities of the same water samples. 

Using GC–MS and bacterial assays researchers confirmed the presence of seven EDCs in both the raw and biologically treated effluents from both paper mills. Significantly higher concentrations in waste from the paper mill that used recycled fibres were found. However, concentrations of EDCs were reduced by 30% following aerobic biological treatment in both mills, and a further 20% reduction was found after anaerobic biological treatment in the recycled fibre paper mill.

Significantly, the study also demonstrated that more than half of raw wastewater samples from the recycled fibre mill were mutagenic and two-thirds were genotoxic. This was not the case in samples taken from virgin fibre mills, and the study therefore concluded that paper mills using virgin fibres do not release mutagenic compounds into the environment during the paper production process, whereas recycled fibre mills do. The researchers were keen to stress that more research was needed to confirm this definitively, but given the results, and the associated risks of mutagenic and genotoxic activity to humans and wildlife, appropriate treatment methods need to be implemented into existing industrial water and wastewater treatment facilities with membrane filtration or advance oxidation processes (AOPs) suggested as potential solutions. - L.B.

References

1. D. Balabaniča et al., Sci. Total Environ.574, 78–89 (2017).
2. M. Ali and T.R. Sreekrishnan, Adv. Environ. Res.5, 175–196 (2001).
3. D. Balabaniča et al., Reprod. Fertil. Dev.23, 403–416 (2011).
4. A.C. Gore et al., Endocr. Rev. 36, 593–602 (2015).