Evaluation of Emission Factor of Harmful Elements from Open Burning J. S. Choi D. K. Lee K. H. Kim Y. M. Jo

Dept. of Environmental Eng., Kyung Hee University, South Korea Dept. of Environmental Eng., Kyung Hee University, South Korea Dept. of Environmental Eng., Kyung Hee University, South Korea Dept. of Environmental Eng., Kyung Hee University, South Korea

EXECUTIVE SUMMARY Open burning of the wastes tends to be an incomplete combustion generating particulate matters containing noxious compounds such as PAHs, heavy metals and dioxins. In this work, several materials which are frequently fired by open burning in the vicinity of large cities were incinerated using a lab scale furnace. Combustion was carried out with natural air feeding through lower inlet holes of the incinerator, which may allow the lap test to close to the field. The test combustible materials were waste plastics, waste paper, wood/street leaves and municipal solid wastes which were taken from a local incineration plant. Particulate matters released from the test incineration were collected by an isokinetic sampler, and then PAHs and heavy metals in them were analyzed by GC/MS and ICP, respectively. The emission factor (EF) of heavy metal was evaluated in terms of Pb, Ni, Cu, Cd, Cr and Zn. EF of zinc was 14.16mg/kg of MSW, which was the highest value amongst of all elements from each waste. Waste wood generates high level of heavy metal elements. Benzopyrene[a] which is known as a carcinogenic element was found in a high EF, 56.6mg/kg-plastics. Total emission factor was the highest in street leaves. Introduction Definition of open burning is to get rid of the unwanted materials such as MSW (Municipal solid waste), crop residues and construction wastes through the incineration in open yard without any appropriate pollutant control system. Since open burning is carried out in a short period irregularly, it is difficult to control. The open burning site is usually observed in the vicinity of residential area, in which exposes to people and urban atmosphere. Thus, many countries are studying the problems of open burning with regard to the local air quality and human risks. (Paul et.al, 2004) EPA (1997) has performed the researches since the middle of 1990s, estimating the emission factor and emission volume from the waste open burning. Most researches have focused on the analysis of air pollutants such as dioxins, carcinogenic elements, carbon monoxide and particulate matters. A recent research on the burning of agricultural residues indicated a variety of harmful releases. (Moon, 2007) On the other hand, particulate matters contain many heavy metal elements. This work attempts

to find emission factors of heavy metals and PAHs from the incineration of sample wastes. Materials and Method Test equipment and sampling Based on previous researches, major combustible wastes including paper, plastic, wood and MSW (Municipal Solid Waste) were collected from a local incineration plant. (Segey et. al., 2003) Basically one kilogram of each sample waste was fed to the test incinerator as schematically shown in Figure 1. (Kim, 2009) Combustion has continued until the oxygen concentration of flue gas reaches at over 20%. During the combustion, sampling of dust and gas was made by a dust collector and a flue gas analyzer( KM-9106, Kane-May). (Kim, 2008)

Fig. 1. Test incinerator

Fig. 2. Schematic for particle sampling facility

Analysis The particulate matters were collected on quartz filters inhaling at 15 lpm. Six metal species (Pb, Ni, Cu, Cd, Cr, Zn) present in PM were analyzed by ICP after a few steps’ pretreatment. Then, the emission factor (EF) of each element was calculated by equation (1):

(1) EF means g-emissions of target element/kg of burned wastes. Q is the flow rate of flue gas [L/min], and C is the concentration of the target element in the flue gas [g/L]. t, test burning time[min]; M, the amount of test waste [kg]. In order to analyze the PAHs, the sampled dust has been preserved in a refrigerator until analyzing by GC/MS. Major sixteen elements were examined as in Table 2 and the emission factor of total PAH was evaluated in each test waste.

Results and Discussion Analysis of Heavy metals This work focuses on six heavy metal elements despite of a large number of metallic traces such as As, Hg, Mn etc. Lead (Pb) is the only metal specified in the natural air pollution regulation of Korea. Lead, which is present in air as a particulate material, was not observed significantly from every waste. A remarkable element is zinc especially in waste wood and MSW. MSW samples were prepared from the annual average basis of a local incineration plant in Y-city. The combustible sample was composed of paper (23 w/w%), plastics (30w/w%), wood (12 w/w%) food waste (20.5 w/w%), fabrics (9.5 w/w%) and non-combustible wastes (3 w/w%). The content of heavy metal elements in each waste sample depend variously on secondary treatment of process such as printing, coating, formulating and other surface contamination.

Table 1 Emission factor of heavy metals

Emission factor (mg/kg) Heavy metal

Waste paper

Waste wood

Waste plastics

MSW

Pb

N.D

0.10

0.0023

0.01

Ni

0.26

0.07

0.24

0.15

Cu

0.22

0.18

0.04

0.04

Cd

0.02

0.19

0.02

0.01

Cr

0.38

0.14

0.36

1.02

Zn

N.D

2.69

N.D

14.16

Analysis of PAHs Table 2 compiled the primary 16 components of the PAHs from open burning. It was found that every sample had high concentration of Phenanthrene, Fluoranthene and Pyrene. Benzo(a)pyrene which is known for a carcinogenic element was also detected in mild concentrations. Emission factors calculated from Equation 1 are summarized in Table 3. As can be noticed, the street leaves show the highest level of PAHs. MSW also emits PAHs as much as the street leaves. The street leaves might be contaminated from the urban air and road surface for at least a few seasons. Thereby, some pollutants could be accumulated in the leaves before and after falling down. The tendency of PAHs’ concentration from open burning would be similar to other experimental results. (Lemieux, 2004)

Table 2 Major PAHs in flue gas dust from test incineration

Unit: [μg/g] PAHs

Waste paper

Waste plastics

MSW

Street leaves

Naphthalene

4.0

18.6

10.0

30.8

Acenaphthylene

24.3

37.8

66.9

114.9

Acenaphthene

N.D

N.D

N.D

10.8

Fluorene

17.6

34.3

37.5

73.5

Phenanthrene

216.9

426.4

245.3

343.2

Anthracene

44.5

59.3

44.9

78.1

Fluoranthene

145.0

358.2

126.3

134.0

Pyrene

129.8

278.4

97.9

118.8

Benz[a]anthracene

29.5

69.9

29.0

33.9

Chrysene

29.9

59.1

26.8

32.0

Benzo[b+j]fluoranthene

31.1

130.5

35.4

39.9

Benzo[k]fluoranthene

7.5

21

7.1

8.9

Benzo[a]pyrene

19.0

56.6

17.6

23.6

Indeno[1,2,3-cd]pyrene

9.4

35.7

11.4

10.3

Dibenz[a,h+a,c]anthracene

N.D

N.D

N.D

N.D

Benzo[g,h,i]perylene

12.5

44.2

13.0

11.8

Table 3 Emission factor of total PAH

Total PAHs EF (mg/kg)

Waste paper

Plastics

MSW

Street leaves

0.26

2.70

2.84

2.98

Conclusions By using a lab scale incinerator (60 Liter), heavy metal and PAHs in particulate matters from burning of some potential waste samples were analyzed with modern technology: ICP and GC/MS. Heavy metals and PAHs were detected from all test sample incineration. In particular, zinc was seen high in MSW and a few elements of PAHs such as Phenanthrene, Fluoranthene and Pyrene were quite high in every sample. Benzo[a]pyrene was also detected with 17.6 μg/g to 56.6 μg/g of dust. The contribution of the above elements to the air quality will be assessed with more accurate evaluation on waste discharge from various sources.

Acknowledgement This work was supported by the Korean Ministry of Environment for NIER Research cooperation under grant 2009. References Dong-ho Moon (2007): A Study for Estimation of Emissions and Profile Characteristics of Dioxins, dioxin-like PCBs and PAHs by Open burning EPA (1997): Evaluation of emissions from the open burning of Household waste in barrels, Vol.1. Technical Report EPA-600/R-97-134a. US. Environmental Protection Agency, Control Technology Center, Research Triangle Park, North Carolina Ki Hong Kim, Dae Kon Kim, Ji Hyung Hong Young Min Jo (2009): Evaluation of Emission factor or Air pollution Emitted from Open Burning of Municipal Solid Waste, Journal of Korea society of waste management. 26(2), 161-167 Paul M. Lemieux, Christopher C. Lutes, Dawn A.Santoianni (2004): Emission of organic air toxics from open burning: a comprehensive review, Progress in Energy and Combustion Science, 30, 1-32 Segey V. Kakareka, Tamara I. Kukharchyk (2003): PAH emissions from the open burning of agricultural debris, The Science of the Total Environment, 308, 257-261 Yong-Jin Kim (2008): Discharge of dioxins by Open-air Burning of domestic and Agricultural Wastes, Journal of Korea society of waste management. 25(1), 66-72