Waste Management xxx (2015) xxx–xxx

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Waste Management journal homepage: www.elsevier.com/locate/wasman

Characterization of odor emission on the working face of landfill and establishing of odorous compounds index Lu Wenjing a,⇑, Duan Zhenhan a,b, Li Dong a, Luis Miguel Caicedo Jimenez a, Liu Yanjun a, Guo Hanwen a, Wang Hongtao a a b

School of Environment, Tsinghua University, Beijing 100084, China Administrative Bureau for Environmental Sanitation of Changchun City, Changchun 130021, China

a r t i c l e

i n f o

Article history: Received 4 December 2014 Accepted 27 April 2015 Available online xxxx Keywords: Landfill Working face Odor concentration Odorous compounds index Selection criteria

a b s t r a c t Temporal variation (seasonal and daily) of odor emission on the working face of a large sanitary landfill in China was characterized through a 2 yearlong case study. Odor pollution was most serious in spring and autumn, while lower odor concentrations were detected in summer and winter. The daily fluctuation of odor concentration on the working face showed that 2:00 am, 6:00 am, 2:00 pm and 10:00 pm were the ‘‘most probable times’’ for odor pollution occurrence, which deserves focused attention in odor control projects. Correlations analysis found that 41% of the variance in odor concentrations can be explained by the chemical concentrations of odorous compounds. Moreover, the selection criteria for the index of odorous compounds were also established by evaluating the odor concentration, contribution to odor strength and the frequency of each compound present in all the samples. Ethyl alcohol, a-piene, hydrogen sulfide, dimethyl sulfide, limonene, methyl mercaptan, dimethyl disulfide, and diethyl sulfide comprise the index of odorous compounds on the working face of typical municipal solid waste landfill in China. Ó 2015 Elsevier Ltd. All rights reserved.

1. Introduction China has become the largest waste generator in the world since 2004 (Chen et al., 2010; Zhang, 2010). Odor pollution associated with the waste management process in cities is an issue that has aroused opposition for location and construction of new municipal solid waste (MSW) treatment facilities (Tian et al., 2013; Zou et al., 2003; Fang et al., 2012; Ying et al., 2012). Exposure to environmental odorants may lead to high symptom prevalence, such as affective, gastrointestinal, head-related, cardiac, cognitive, neuromuscular, and musculoskeletal symptoms (Andersson et al., 2009). Odorous gases emitted from landfills can exert a negative influence on the surrounding environment and significantly lower the quality of life. The working face (especially without covering) requires utmost attention because it is a significant odor source in landfills. Previous studies on odor pollution caused by landfills mainly focused on two aspects: (1) the foundation of odor assessment standards and relative regulations based on olfactory experiments and ⇑ Corresponding author at: Room 803, Sino-Italian Environmental and Energy Efficient Building, School of Environment, Tsinghua University, Beijing 100084, China. Tel./fax: +86 10 62796540. E-mail address: [email protected] (L. Wenjing).

health risk assessment; (2) the identification of odorous compounds released from landfills based on the results of chemical analysis, e.g. gas-chromatography coupled with mass-spectrometry (GC–MS) (Capelli et al., 2008) . Olfactometry is a way for measuring odor concentration, and dynamic olfactometry method and triangle odor bag method are the most common ones (SEPA of China, 1993; Taiwan EPA, 1994; ASTM, 1997; CEN, 2003; Japan Ministry of the Environment, 2003a). The Japanese regulation Offensive Odor Control Law (1995) recommended triangle odor bag method as standard method in measuring odor emission from factories and livestock; emission limitation for 22 odorous compounds were given in the law. The Atmosphere and Environment Protection Law of Korea established maximum emission concentrations of 8 odorous compounds. Chinese regulation Emission standards for odor pollutants (GB14554-93) also regulated ammonia, trimethylamine, hydrogen sulfide, methanthiol, dimethyl sulfide, dimethyl disulfide, carbon disulfide and styrene as significant odorous compounds from industry. When comparing the regulations from different countries, it could be found that though various compounds were recognized as odorants, sulfur compounds, nitrogen compounds, oxygenated compounds and several aromatics often aroused more attention due to their low odor thresholds. Hence, those

http://dx.doi.org/10.1016/j.wasman.2015.04.030 0956-053X/Ó 2015 Elsevier Ltd. All rights reserved.

Please cite this article in press as: Wenjing, L., et al. Characterization of odor emission on the working face of landfill and establishing of odorous compounds index. Waste Management (2015), http://dx.doi.org/10.1016/j.wasman.2015.04.030

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L. Wenjing et al. / Waste Management xxx (2015) xxx–xxx

compounds discharged in the operation of landfills deserves concern in the odor control project. Chemical analysis of the odorous gas based on instruments has proven to be helpful to track down the compounds which are the potential odor source in the tested samples. This characterization is fundamental to further study on the mechanism of odorous gas formation and finally improve the operation of waste treatment system by controlling the odor formation and emissions. Efforts have been made during the last decades on qualitative and quantitative analysis of odorous compounds from different landfills, and Table 1 is the summary of these results (Brosseau and Heitz, 1994; Chiriac et al., 2007; Davoli et al., 2003; Deipser and Stegmann, 1994; Demeestere et al., 2008; Dincer et al., 2006; Fang et al., 2012). Both instrumental and olfactometric analyses are recommended in many cases as methods for investigation on odorous compounds emission as well as assessment of odor annoyance in the living environment (Romain et al., 2008). However, how to build connection between olfactory results and chemical concentrations of odorous compounds remains to be a big challenge since human olfactory system is sensitive and complex, especially to get a clue how human olfactory system reacts to emissions from MSW facilities when hundreds of odorous or odorless compounds are mixed together. Based on the above situation, the authors conducted a 2-yearlong study on a typical anaerobic landfill in China to characterize odor emission on the working face. Moreover, an attempt was made to investigate the relationship between odor concentrations and chemical concentrations of odorous compounds, which may bring new insight to this challenging topic. Finally, a method that could screen significant odorous compounds was established, and index compounds of odor pollution for Chinese landfills were proposed.

The landfill mainly deals with MSW that originate from several districts of Beijing. The compacted waste is covered with an HDPE membrane, except for the working face (i.e., the open cell), which often causes serious odor pollution to surrounding communities. Sampling campaigns were conducted at the working face of the landfill on selected days in different seasons from 2012 to 2014 (Table 2). Air samples at a height of 1.5 m above the surface (i.e., breathing zone) of the working face were withdrew to 8 L bio-oriented polyester odor free bags (Environmental Science and Technology Development Co., Ltd., China) through a specially designed sampler. Detailed sampling method was described by the authors elsewhere (Duan et al., 2014). Meteorological data including temperature, wind speed, and humidity were also recorded during sampling. All the samples were taken to the laboratory and analyzed within 24 h. A total of 42 gas samples were taken and analyzed during this 2-yearlong sampling campaign. 2.2. GC–MS analysis The chemical components of each gas sample were analyzed according to EPA TO14 (US-EPA, 1999a, Compendium Method TO14) by using a three-stage cold trap concentrator (Entech 7100, USA) and a gas chromatograph (GC, Agilent 7890A, USA) equipped with a mass selective detector (Agilent 5975C, USA). 400 mL air sample was first injected into the pre-concentration system and get concentrated by cryogenic liquid nitrogen; then the gas passed through a DB-5ms GC column

Table 2 Sampling campaign for odor characterization on the working face. Year

Season

Day

Time for each sampling campaign

2012–2013

Spring Summer Autumn Winter

March, 2012 August, 2012 November, 2012 January, 2013

10:00, 14:00, 18:00, 23:00, 3:00

2013–2014

Spring Summer Autumn Winter

March, 2013 August, 2013 November, 2013 February, 2014

10:00, 14:00, 18:00, 22:00, 2:00, 6:00

2. Materials and methods 2.1. Landfill description and gas sampling Field studies were conducted at a typical flat sanitary landfill in northern China with a designed filling capacity of 1.19  107 m3.

Table 1 A summary of major odorous compounds in landfills from documents. Compounds (lg m3)

Hydrogen sulfide Methanthiol Dimethyl sulfide Dimethyl disulfide Carbon disulfide Ethyl alcohol Acetone Benzene Toluene Ethylbenzene Nonane Decane Limonene a-Pinene Trichlorofluoromethane Dichloromethane 1,2-Dichloroethane Dichlorodifluoromethane a b c d

Zou et al. (2003)

Dincer et al.(2006)

Summer

Winter

May

September

–a – – – – – – 41–167 82–202 12–52 0.8–5.2 1.1–4.5 23–162 9.5–121 – 1.5–31 – –

– – – – – – – 1.2–15 1.7–23 0.1–3.5 0.1–1.8 0.1–2.2 0.1–34 0.1–15 – 0.2–23 – –

– – – – 0.41–5.05 – 7.95–67.60 0.09–0.59 1.56–47.42 0.21–4.94 – – – – – 1.62–7.95 – –

– – – – 0.24–2.36 – 11.20–28.57 0.34–1.06 1.51–11.18 0.15–0.76 – – – – – 0.68–2.58 – –

Ying et al.(2012)b

Allen et al. (1997)

Chiriac et al. (2007)c

Sadowska-Rociek et al. (2009)d

514.52 5.30 18.52 0.04 0.66 – – 3.82 60.04 23.30 – – – – – – 0.44 –

– – – – –

Characterization of odor emission on the working face of landfill and establishing of odorous compounds index.

Temporal variation (seasonal and daily) of odor emission on the working face of a large sanitary landfill in China was characterized through a 2 yearl...
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