Source apportionment and transport of pollutants within the South African paper recycling chain

Recycled paper is a valuable commodity that forms an intrinsic part of promoting sustainable resource utilisation. In this study, we aimed to investigate the possible sources and transport of semi-volatile organic pollutants in paper grades used in the recycled paperboard value chain. Accelerated solvent extraction followed by gas chromatography-mass spectrometry were employed for the analyses. The results show that diethylhexyl phthalate and dibutyl phthalate were the most prominent pollutants, whilst tris (2,4-di-tert-butylphenyl) phosphite and butylated hydroxytoluene were the least significant pollutants. Tris (2,4-di-tert-butylphenyl) phosphate was predominantly detected at the recycling sites, with a maximum concentration of 3.054 mg/kg, whereas N-butylbenzene sulfonamide was found in retail and post-consumer samples but not at pre-consumer sites. Manufacturing additives and retail activities were identified as possible exposure sources. Post-consumer usage, collection, sorting and mingling of various waste materials were also identified as factors that influence the prevalence of pollutants. The presence of pollutants in pre-consumer samples indicates that certain compounds may potentially accumulate or circulate within the paper recycling chain and that other pollutants may be removed during the reprocessing of recycled fibre.