Chemosphere, Vol. 14, No. 8, pp 1081-1086, 1985

The production of polychlorinated dioxins and dibenzofurans shows a strong correlation with the production of hexachlorobenzene. Hexachlorobenzene can be used as an indicator for the production of chlorinated aromatics.

The sampling and chemical analysis of polychlorinated dioxins (PCDD) and dibenzofurans (PCDF) in flue gases is a complicated, time-consuming and expensive process. A simple indirect indicator for the production of PCDD and PCDF is obviously a necessity. It has been reported that chlorinated benzenes correlate well with PCDD and PCDF (1). Such a correlation can form the basis for the use of chlorinated benzenes as an indicator for the production of PCDD and PCDF. 

Here we report results from studies on several Scandinavian combustion plants.

Flue gas samples were collected using an all glass sampling train (2). Chlorinated benzenes, PCDD and PCDF were quantified relative to standard mixtures. The chemical analyses of PCDD and PCDF were performed either by us or at the University of Umeå, Sweden.

Previously we have reported results indicating a close relationship between the chlorine input to the kiln and the production of chlorinated aromatics from the combustion of hazardous waste (3). Such a relationship can also be seen from the combustion of other fuels as reported in tables 1 and 2.

Table 1
Emissions of hexachlorobenzene

Fuel	Plant	Chlorine in fuel	Hexachlorobenzene µg/Nm3
		%	mean	n
Hazardous waste	A	3.9	2.8	29
	B	~4	5.1	4
Municipal waste	C	0.6	3.5	2
	D	0.6	0.041	1
	E	0.6	0.94	3
Coal	F	0.13	0.07	1
Hazardous waste	G	0.01	0.03	2

Table 2
Emissions of chlorinated dioxins and dibenzofurans

Fuel	Plant	Chlorine in fuel, %	n	Sum TCDD ng/Nm3	Sum TCDF ng/Nm3
Hazardous waste	A	3.9	14	1.2	22
	B	~4	3	3.4	62
Municipal waste	C	0.6	1	0.6	4.5
	D	0.6	1	0.3	4
	E	0.6	2	0.5	21
Hazardous waste	G	0.01	2	<0.25	<0.4
Peat	H	0.03	1		<0.0006
	I1	0.03	1	<0.023	0.015

1) Sample collected by the Institute for Water- and Air Research, Sweden

Combustion conditions have been satisfactory and fully comparable in the plants reported. The numerical data are illustrated in figures 1 and 2.

Figure 1

Figure 2

In figure 3 we report data from 31 flue gas samples collected from eight different waste incineration plants, both hazardous and municipal waste. The combustion conditions have in most cases been satisfactory.

Figure 3

The relationship seen in figure 3, between hexachlorobenzene and tetra-CDD, is statistically significant: r = 0.57, n = 31 and p <0.001.

Penta-CDD and penta-CDF also show statistically significant correlations to hexachlorobenzene: r = 0.58, n = 23 and p <0.01 respectively r = 0.55, n = 25 and p <0.01.

The data reported are collected from different combustion plants, burning different fuels and with different combustion conditions. Despite this heterogeneous background of the database, we have been able to demonstrate a strong connection between hexachlorobenzene and other chlorinated aromatics. This fact implies not only a common background of formation but also gives support to the idea of using chlorinated benzenes (hexachlorobenzene) as a general indicator for the production of chlorinated aromatics. The use of chlorinated benzenes as an indicator parameter enables both rapid sampling and a relatively simple analytical procedure.

The production of chlorinated aromatics from a combustion plant is influenced by the chlorine input and the operating conditions. Therefore it may prove to be more productive to use a set of parameters, e g chlorine input, combustion efficiency and emissions of chlorinated benzenes, as indicators. Further studies are needed to clarify these questions. We hope to be able to continue this work and also study the use of other simple chlorinated aromatics as indicator parameters.

We like to thank our own staff and the other laboratories participating for skilled technical assistance. We gratefully acknowledge the use of measurement data obtained from Project Peat-Health-Environment, National Energy Administration, Sweden.

1. OLIE K, LUSTENHOUWER J W A, HUTZINGER O
   "Polychlorinated dibenzo-p-dioxins and related compounds in incinerator effluents", p 227-244 in "Chlorinated dioxins and related compounds. Impact on the environment". Editors HUTZINGER O, Frei RW, Merian E, Pocchiari P, Pergamon press, Oxford, 1982.
2. BERGSTRÖM J G T, EKLUND G, WARMAN K
   Presented at the Sixth International Symposium on Polynuclear Aromatic Hydrocarbons, 27-29 October 1981 in Columbus, Ohio, USA.
3. ÖBERG T, AITTOLA J-P, BERGSTRÖM J G T
   Chemosphere 14, 215-221 (1985).

(Received in Germany 3 May 1985; accepted 15 May 1985)

Reprinted from Chemosphere, Volume 14, Öberg, T, Bergström, J G T, Hexachlorobenzene as an indicator of dioxin production from combustion, Pages No. 1081-1086, Copyright (1985), with permission from Elsevier Science. Single copies of the article can be downloaded and printed for the reader's personal research and study.

DOI: 10.1016/0045-6535(85)90028-1