Formation mechanisms of polychlorinated dibenzo-p-dioxins and dibenzofurans during pulp chlorination

Dimmel, Donald R.; Riggs, Karen; Pitts, Gerry; White, Jon; Lucas, Steven M.

doi:10.1021/es00048a037

Cited by 24 publications

(12 citation statements)

References 8 publications

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“…In the last years, some very detail studies in the field of pulp bleaching are carried out (Dimmel et al 1993;Hrutfiord et al 1992;Luthe et al 1994;Luthe 1996;Santl et al1994), but the investigations were made only in these mills which use wood or recycled wastepaper for fiber. There is still no report on the levels of PCDDs and PCDFs in pulps that use non-wood plant fibers as raw materials.…”

mentioning

confidence: 99%

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

Zheng

Bao

Wang

et al. 1997

Bulletin of Environmental Contamination and Toxicology

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mentioning

confidence: 99%

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

Zheng

Bao

Wang

et al. 1997

Bulletin of Environmental Contamination and Toxicology

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“…The congener profile in the pulp after the enzyme-aided bleaching stage C process was quite different from the profile after the conventional Cl 2 bleaching stage C, indicating that the presence of the enzyme affected the PCDD/F formation mechanisms. It has previously been found that the less chlorinated PCDD/F congeners may be formed through the chlorination of DBD and DBF in pulp and the chlorination of nonextractable precursors (Dimmel et al, 1993). We found that enzyme-aided chlorine bleaching caused more OCDD to be formed during stages C and E (causing OCDD to contribute a much larger proportion of the total PCDD/F concentrations in the pulp and effluents from stages C and E) than when conventional Cl 2 bleaching was adopted.…”

Section: Comparison Of Pcdd/f Congener Profiles Between Enzymeaided Cmentioning

confidence: 65%

“…PCDD/Fs released from pulp and paper mills have been found to have adversely affected the surrounding environment and biota (Macdonald et al, 1998;Peek et al, 2002;Yunker et al, 2002;Oakes et al, 2013). Comprehensive investigations into the formation, emission, and control of PCDD/Fs during pulp bleaching were therefore carried out (Jokela and Salkinojasalonen, 1992;Koistinen et al, 1992;Dimmel et al, 1993;Luthe and Prahacs, 1993;Peck and Daley, 1994;Zheng et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

Unexpected promotion of PCDD/F formation by enzyme-aided Cl2 bleaching in non-wood pulp and paper mill

et al. 2017

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Enzyme-aided Cl bleaching is widely considered as promising replacements for conventional Cl bleaching in wood pulp and paper mills. However, the effects of using enzyme-aided bleaching on the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the non-wood pulp and paper mills are unclear. A field study was performed to investigate PCDD/F formation when enzyme-aided Cl bleaching was used to replace conventional Cl bleaching in non-wood pulp and paper mills. Unexpectedly, the PCDD/F toxic equivalents (TEQs) in solid samples were higher when using enzyme-aided bleaching (0.49-5.4 pg TEQ/g) than that using conventional Cl bleaching (0.15-2.44 pg TEQ/g). Large amounts of octachlorodibenzo-p-dioxin were formed during the enzyme-aided bleaching process. This could have been because enzyme strongly promoted the release of organic molecules bound to lignin and thus accelerated the formation of octachlorodibenzo-p-dioxin through organic molecular precursors. Although enzyme-aided Cl bleaching was previously considered to be efficient for reducing PCDD/F releases and to be the best available technologies and best environmental practices for wood pulp and paper mills, the results obtained in this study suggested the necessity and urgency to evaluate the suitability of enzyme-aided Cl bleaching for non-wood pulp and paper mills that intensively practiced in developing countries.

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“…Email address: paqui.gomez@ua.es (M. Francisca Gomez-Rico) pean dioxin inventories (Quass et al, 1999). Manufacture of chlorophenols (Field and Sierra-Alvarez, 2008), pulp chlorination (Dimmel et al, 1993), incineration of wastes (Tuppurainen et al, 2003), iron ore sintering (Zhang and Bukens, 2016) and non-ferrous metals smelters and sintering plants (Pitea et al, 2008) are sources which have been previously studied.…”

Section: Introductionmentioning

confidence: 99%

PCDD/F determination in sewage sludge composting. Influence of aeration and the presence of PCP

Muñoz

Garrido

Gómez-Rico

et al. 2018

Science of The Total Environment

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Composting of sewage sludge is a common practice for sludge disposal. Some previous studies found high levels of polychorodibenzo-p-dioxins and polychorodibenzofurans (PCDD/Fs) after composting, especially octachlorodibenzo-p-dioxin (OCDD) but also 1234678-heptachlorodibenzo-p-dioxin (1234678-HpCDD) to a lesser extent. In this work, the concentrations of OCDD, 1234678-HpCDD and the rest of the 17 toxic congeners of PCDD/Fs were determined in compost obtained under different conditions. Although the toxicity of the two compounds mentioned above is small, their generation may reach undesirable levels. The PCDD/F content was analyzed in a composting plant and in a laboratory test. In both cases, the composted material was a mixture of sewage sludge, straw and sawdust. The composting plant was a tunnel with air turbine aeration and with a turner to homogenize and move the mixture upwards. The laboratory tests were carried out with Dewar vessels (with air dispersion at the bottom and controlled temperature) and with small vessels inside a controlled oven with non-forced aeration. The laboratory runs were also carried out with the addition of pentachlorophenol in some runs, as a dioxin precursor. The highest OCDD levels were found in three samples of the composting plant (30000-90000pg/g dry matter or dm), with toxicity values surpassing the limit level for soil amendment (17pgI-TEQ/gdm). Their formation was analyzed considering their concentration vs. that of octachorodibenzofuran (OCDF), which is not formed during composting. In the laboratory, in experiments carried out in a vessel with non-forced aeration conditions and with the addition of pentachlorophenol, the formation of OCDD was significant (e.g. from 80 to 1500pg/gdm). That means that these two factors, non-forced aeration and the presence of pentachlorophenol, can cause the OCDD formation.

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Formation mechanisms of polychlorinated dibenzo-p-dioxins and dibenzofurans during pulp chlorination

Cited by 24 publications

References 8 publications

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

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

Unexpected promotion of PCDD/F formation by enzyme-aided Cl2 bleaching in non-wood pulp and paper mill

PCDD/F determination in sewage sludge composting. Influence of aeration and the presence of PCP

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