Emission measurements of heavy metals with the European standard reference methods EN 14385 and EN 13211—observations from interlaboratory comparison (ILC) measurements performed at waste-to-energy plant in Finland

Figures & data

Table 1. Comparison of IED-ELVs with WI-BREF BAT-AEL values (heavy metals).

	IED- ELV values	WI-BREF BAT-AEL values
sum of Cd and Tl	0.05 mg/m^3	0.005–0.02 mg/m^3, as the average over the sampling period (BAT conclusion 25 of WI BREF)
sum of As+Cr+Co+Cu+Mn+Ni+Pb+Sb+V	0.5 mg/m^3	0.01–0.3 mg/m^3, as the average over the sampling period (BAT conclusion 25 of WI BREF)
Hg	0.05 mg/m^3	0.005–0.020 mg/m^3 for an existing plant, as a daily average or as the average over the sampling period or 1–10 µg/m^3 for a long term sampling period (BAT conclusion 31 of WI BREF)

Table 2. Examples of different rules for summation for the results which are below either LOD or LOQ.

Country	LOD or LOQ used?	Rule for making summation
Finland	LOQ	If some, but not all values are < LOQ, then the values which are < LOQ are set to zero in summation and the final result is presented without “<” sign. If all results are < LOQ, the highest of these values is reported with a “<”-sign.
UK (England)	LOD	Values below LOD are set to LOD (unless the standard method specifies another approach)
France	LOQ	For results lower than LOQ/3: the compound will be considered as not detected; a zero value will be considered for the summation. For results between LOQ/3 and LOQ: the compound will be considered as detected; a value of LOQ/2 will be considered for the summation.
Denmark	LOD	If some, but not all values are < LOD, then values below LOD are set to the LOD value. The result of the average is presented without a “<”-sign. If all results are < LOD, then values below LOD are set to the LOD value. The result of the average is presented with a “<”-sign.

Table 3. Examples of the summation of concentrations which are below LOQ (marked with “<”).

	Concentration in the gaseous phase, µg/m^3	Concentration in the particulate phase, µg/m^3	Sum, method A, µg/m^3	Sum, method B, µg/m^3	Sum, method C, µg/m^3
Tl	<0.20	<0.01	0.21	0.11	0
Cd	<0.10	0.51	0.61	0.56	0.51
Cr	<9	0.97	9.97	5.47	0.97
Cu	<2.2	5.0	7.2	6.10	5
Ni	<5.1	2.3	7.4	4.85	2.3
Pb	<2.1	4.4	6.5	5.45	4.4
Co	<0.14	0.08	0.22	0.15	0.08
Mn	<1.3	1.1	2.4	1.75	1.1
Sb	<0.51	<0.16	0.67	0.34	0
As	<0.9	0.06	0.96	0.51	0.06
V	<0.5	<0.04	0.54	0.27	0
Hg	<1.0	0.65	1.65	1.15	0.65

Note. Sign ” <” means that this concentration was below LOQ

Table 4. Final results calculated with different methods (A, B, and C) based on the measured concentrations given in Table 3 and compared with BAT-AEL ranges.

Pollutant	Method A	Method B	Method C
Hg, µg/m^3	1.65	1.15	0.65
BAT-AEL (WI BREF) for Hg, µg/m^3	1–10
sum of Cd + Tl, µg/m^3	0.8	0.7	0.5
BAT-AEL (WI BREF) for sum of Cd + Tl, µg/m^3	5–20
sum of As+Cr+Co+Cu+Mn+Ni+Pb+Sb+V, µg/m^3	36	25	14
BAT-AEL (WI BREF) for the sum of As+Cr+Co+Cu+Mn+Ni+Pb+Sb+V, µg/m^3	10–300

Table 5. Average emission limit values for heavy metals at a waste-to-energy plant, values given at NTP (NTP specified in Europe as 273.15 K and 101.3 kPa).

Pollutant	Emission limit value, given at 11% O2, mg/m^3, NTP
Hg	0.05^a
sum of Cd and Tl	0.05^a
sum of As, Cd, Cr, Co, Cu, Mn, Ni, Pb, Sb, TI and V	0.5^a

Note. ^agiven for a sampling period of a minimum of 30 minutes and a maximum of 8 hours

Table 6. Limits of quantification (LOQ) given by analytical laboratories (µg/l) for the absorption solution.

Heavy metal	Unit	Analytical laboratory 1	Analytical laboratory 2	Analytical laboratory 3, LOR value	Analytical laboratory 3, LOQ^a
Hg	µg/l	1	1	0.001	0.02
As	µg/l	1	0.02	0.05	1
Cd	µg/l	0.1	0.02	0.025	0.5
Co	µg/l	0.5	0.01	0.025	0.5
Cr	µg/l	1	0.1	0.15	3
Cu	µg/l	1	0.5	0.05	1
Mn	µg/l	2	0.05	0.025	0.5
Ni	µg/l	1	0.5	0.25	5
Pb	µg/l	0.5	0.1	0.025	0.5
Sb	µg/l	0.5	2	0.025	0.5
Tl	µg/l	1	0.02	0.025	0.5
V	µg/l	1	0.02	0.05	1

Notes. ^avalue calculated from the LOR (limit of reporting) value given by this analytical laboratory (LOR is given as µg/sample. In the analysis certificate it is stated that typical sample amount is 50 ml and LOQ, as µg/l, is thus calculated based on this information).

Figure 1. Hg-concentration results measured by stack testing teams A, B, C and D, 8.5.2019, waste-to-energy plant, Finland.

Figure 2. Hg-concentration results measured by stack testing teams E (result below LOQ), F and H (* team H only had results from gaseous phase), 15.5.2019, waste-to-energy plant, Finland.

Figure 3. Sum of Cd and Tl concentrations measured by stack testing teams A, B, C and D, 8.5.2019, waste-to-energy plant, Finland.

Figure 4. Sum of Cd and Tl concentrations measured by stack testing team E (below LOQ), F, G (below LOQ) and H (* stack testing team H only had results from gaseous phase), 15.5.2019, waste-to-energy plant, Finland.

Figure 5. Sum of heavy metal concentrations (As, Cr, Co, Cu, Mn, Ni, Pb, Sb and V) measured by stack testing teams A, B, C and D, 8.5.2019, waste-to-energy plant, Finland.

Figure 6. Sum of heavy metal concentrations (As, Cr, Co, Cu, Mn, Ni, Pb, Sb and V) measured by stack testing teams E, F, G (below LOQ) and H (* stack testing team H had only results from gaseous phase, result below LOQ), 15.5.2019, waste-to-energy plant, Finland.

Table 7. Measurement uncertainties reported by stack testing teams (A-H) for heavy metals, Cd + Tl and Hg, ILC, 2019, Finland.

	A	B	C	D	E	F	G	H
	±%	±%	±%	±%	±%	±%	±%	±%
Sum of heavy metals	40	20^a	40	70	60	19	^b	30
Sum of Cd and Tl	31	20^a	35	50	^b	38	^b	30
Hg	26	^b	42	^b	^b	311	-	30

Notes. ^ameasurement uncertainty does not include the measurement uncertainty of the analysis

^bmeasurement uncertainty was not reported since the result was < LOQ

Figure 7. Hg distribution (stack testing teams A, B, C, D, E and F) to particulate and gaseous phases at ILC in 2019.

Figure 8. Sb distribution (stack testing teams A, B, C, D, E and F) to particulate and gaseous phases at ILC in 2019.

Figure 9. Cd distribution (stack testing teams A, B, C, D, E and F) to particulate and gaseous phases at ILC in 2019.

Figure 10. Tl distribution (stack testing teams A, B, C, D, E and F) to particulate and gaseous phases at ILC in 2019.

Figure 11. As distribution (stack testing teams A, B, C, D, E and F) to particulate and gaseous phases at ILC in 2019.

Figure 12. Co distribution (stack testing teams A, B, C, D, E and F) to particulate and gaseous phases at ILC in 2019.

Figure 13. Cr distribution (stack testing teams A, B, C, D, E and F) to particulate and gaseous phases at ILC in 2019.

Figure 14. Ni distribution (stack testing teams A, B, C, D, E and F) to particulate and gaseous phases at ILC in 2019.

Figure 15. Cu distribution (stack testing teams A, B, C, D, E and F) to particulate and gaseous phases at ILC in 2019.

Figure 16. Pb distribution (stack testing teams A, B, C, D, E and F) to particulate and gaseous phases at ILC in 2019.

Figure 17. Mn distribution (stack testing teams A, B, C, D, E and F) to particulate and gaseous phases at ILC in 2019.

Figure 18. V distributions (stack testing teams A, B, C, D, E and F) to particulate and gaseous phases at ILC in 2019.

Table 8. Particulate phase (heavy metals) reported by stack testing teams A, B, C, D, E, and F, ILC, May 2019, Finland.

	Particulate phase, µg/m^3, NTP, dry
Laboratory	A, 8.5.	B, 8.5.	C, 8.5.	D, 8.5.	E, 15.5.	F, 15.5.
Hg	< 0.08	< 0.02	< 0.01	< 0.108	< 0.2	0.0418
Cd	< 0.1	< 0.039	0.003	0.004	0.05	0.0199
Tl	< 0.09	< 0.19	0.04	< 0.162	< 0.3	< 0.0358
Sb	< 0.1	< 0.19	< 0.03	0.189	0.04	0.0844
As	< 0.1	< 0.19	0.13	0.009	< 0.3	0.0248
Co	< 0.1	< 0.19	0.01	0.013	< 0.3	< 0.0303
Cr	0.2	1	1.2	0.617	0.5	0.145
Cu	< 0.2	0.52	31	2.338	0.3	1.14
Pb	< 0.1	0.15	8.4	3.143	0.6	0.36
Mn	0.05	< 3.9	0.2	0.256	0.5	< 0.767
Ni	0.1	< 0.97	1.2	1.369	0.6	0.251
V	< 0.1	< 0.19	0.01	4.302	< 0.3	< 0.0358

Table 9. Gaseous phase (heavy metals) reported by stack testing teams A, B, C, D, E, and F, ILC, May 2019, Finland.

	Gaseous phase, µg/m^3, NTP, dry
Laboratory	A, 8.5.	B, 8.5.	C, 8.5.	D, 8.5.	E, 15.5.	F, 15.5.
Hg	< 0.5	< 0.44	0.87	< 0.327	< 0.7	< 0.413
Cd	0.02	< 0.06	0.07	0.088	< 0.06	0.811
Tl	< 0.009	< 0.8	< 0.02	0.033	< 0.5	< 0.647
Sb	< 0.9	< 0.4	< 0.28	< 2.421	< 0.5	0.325
As	< 0.01	< 0.8	0.11	< 0.024	< 0.5	< 0.647
Co	0.6	< 0.4	0.09	0.387	< 0.5	< 0.325
Cr	1.3	1.1	3.4	0.638	< 0.5	< 0.647
Cu	5	1.5	31	3.314	< 0.5	1.37
Pb	0.9	0.5	11	4.429	0.3	3.05
Mn	0.2	< 1.6	6.2	1.067	< 1	< 1.29
Ni	1	1.5	0.41	1.611	< 0.5	< 0.647
V	< 0.01	< 0.8	0.12	0.227	< 0.5	< 0.647

Table 10. Comparison of chemical analysis, sample taken on 8.5.2019, waste-to-energy plant.

	Hg	As	Cd	Co	Cr	Cu	Mn	Ni	Pb	Sb	Tl	V
Laboratory	µg/l	µg/l	µg/l	µg/l	µg/l	µg/l	µg/l	µg/l	µg/l	µg/l	µg/l	µg/l
A	<1	<0.02	0.08	0.37	0.59	2.03	0.99	1.49	4.29	<2	0.03	0.21
B	-	0.1	0.1	0.5	0.6	1.9	0.8	0.9	4.4	0.1	-	0.2
C	-	<0.05	0.03	0.4	0.62	1.5	0.72	0.89	3.7	<0.05	<0.1	<0.5
D	0.38	<0.5	0.048	0.37	0.46	1.6	0.6	0.79	4	0.45	<0.05	0.074

Table 11. Comparison of chemical analysis, sample taken on 9.5.2019, waste-to-energy plant.

	Hg	As	Cd	Co	Cr	Cu	Mn	Ni	Pb	Sb	Tl	V
Laboratory	µg/l	µg/l	µg/l	µg/l	µg/l	µg/l	µg/l	µg/l	µg/l	µg/l	µg/l	µg/l
A	<1	<0.02	0.16	0.48	1.38	2.49	0.98	1.86	6.41	<2	0.34	0.14
E	-	<1	<0.1	0.58	1.5	2.7	<2	<1	6	<0.5	<1	<1
F	<0.1	<0.1	0.099	0.56	1.5	2.7	0.59	0.81	6.4	<0.4	<0.02	<0.1