Characteristic analysis for odor gas emitted from food waste anaerobic fermentation in the pretreatment workshop

Figures & data

Table 1. Main composition of food waste and weather condition survey during sampling

Month	Main composition of food waste	Temperature	Relative humidity (RH, %)	Atmospheric pressure (kPa)	Weather condition
March	Cooked wheaten food, leftovers (fish, meat), oil and grease	11.5–12.3	66.9–88.0	101.3	Sunny
April	Cooked wheaten food leftovers (meat, vegetables), oil and grease	18.6–19.4	83.8–93.0	101.3	Sunny
May	Peel, leftovers (meat, vegetables), plastic bags	22.3–22.6	64.5–76.2	101.3	Sunny
June	Rice, eggshell, peel, leftovers (fish, meat, vegetables), plastic bags	23.8–24.1	85.2–94.0	101.3	Cloudy
July	Rice, fruit, leftovers (fish, vegetables), plastic bags	26.6–27.6	69.6–75.5	101.3	Sunny

Figure 1. Production process layout of food waste anaerobic fermentation to produce biogas.

Table 2. Odor gases composition and content for food waste in the pretreatment workshop (μg m^{− 3})

Category	Composition	Average concentration	Landfill concentration	Reference
S-compounds	Hydrogen sulfide	44.1 (38.8–54.6)	56.58–514.52	Ying, 2012
	Ethyl sulfide	281.3 (259.9–328.9)
	(Methylthio)ethane	17.9 (12.6–23.7)
	Methyl mercaptan	1.4 (1.0–1.8)	1.56–5.30	Ying, 2012
	Propyl mercaptan	5.2 (1.0–10.9)
	Carbon disulfide	5.4 (2.4–8.3)	0.04–5.05	Dincer et al., 2006; Ying, 2012
	Dimethyl disulfide	8.3 (5.3–9.6)	0.002–0.04	Ying, 2012
N-compounds	Ammonia	500.9 (341.1–628.6)	520–4020	Ying, 2012
	Trimethylamine	340.2 (142.6–475.4)	3.69–108.52	Fang et al., 2012
	Dimethylacetamide	2403.7 (2362.8–2463.3)
Aromatics	Styrene	1646 (1604–1698)	0.1–48	Dincer et al., 2006; Zou et al., 2003
	Toluene	1604 (1594–1614)	1.56–202	Dincer et al., 2006; Zou et al. 2003; Ying, 2012
	Ethylbenzene	1612 (1601–1624)	0.1–52	Dincer et al., 2006; Zou et al. 2003; Ying, 2012
	O-xylene	1587 (1582–1591)	0.02–72	Dincer et al., 2006; Zou et al. 2003; Ying, 2012
	Tetramethylbenzene	1564 (1555–1573)	0.60–10.77	Davoli et al., 2003
	Pentamethylbenzene	1577 (1573–1581)
	Naphthalene	1651 (1639–1666)	0.02–27	Zou et al., 2003; Ying, 2012
	Methylnaphthalene	1612 (1581–1661)	0.1–2.1	Zou et al., 2003
Alkane	Tetradecane	496.0 (481.2–510.7)
	Docosane	504.9 (489.8–520.0)
	Nonacosane	498.9 (493.3–504.4)
Esters	1,2-Benzenedicarboxylic acid, butyl octyl ester	145.5 (143.6–147.5)
	Dibutyl phthalate	157.6 (135.1–180.2)
	3-Cyclohexen-1-ol, acetate	56.9 (50.8–62.9)
Acids	4-(para-Tolyl)-butyric acid	1581 (1547–1615)
	Hexanoic acid, 2-ethyl	522.8 (507.5–548.1)
Others	Decanal	2003 (1993–2014)	0.02–9.42	Dincer et al., 2006; Zou et al., 2003; Ying, 2012
	Phenol	1553 (1406–1737)
	Limonene	3735 (3220–5023)	0.1–162	Zou et al., 2003; Davoli et al., 2003
Note: The compositions of the compounds in the table are the average data for five sampling sites.

Table 3. Concentration of different type of compounds at sampling sites (odor concentration unit: OU m^{− 3}; chemical concentration unit: μg m^{− 3})

Sampling sites	Odor concentration	Total chemical concentration	S-Compounds	N-Compounds	Aromatics	Alkane	Esters	Acids	Others
Discharge inlet	2924	19725	88.6	3412	7979	504.9	135.1	548.1	7057
Belt opening	2523	22028	343.7	3282	11285	502.4	180.2	507.6	6429
Discharge outlet	3577	24184	409.4	3050	129070	496.0	145.5	521.5	6655
Waste accumulation compartments	3295	22532	320.1	3234	11309	498.9	56.9	2095	5018
Note: OU m^−3 is the content of odor in per cubic meter.

Figure 2. Chemical concentration horizontal distribution of aromatics (a), S-compounds (b), and N-compounds (c).

Table 4. Correlation coefficient analysis between compounds and odors

	Odor concentration	Total chemical concentration	S-Compounds	N-Compounds	Aromatics	Alkanes	Esters	Acids	Others
Odor concentration	1	0.93*	0.65*	0.72*	−0.10	0.44	0.17	0.08	0.82*
Total chemical concentration		1	−0.01	0.02	−0.09	0.64*	0.05	−0.27	0.67*
S-compounds			1	0.85*	0.01	−0.34	0.19	0.65*	0.72*
N-compounds				1	0.63*	0.02	0.68*	0.13	0.64*
Aromatics					1	0.71	0.90*	0.06	0.07
Alkanes						1	0.69*	−0.19	0.22
Esters							1	0.42	0.33
Acids								1	0.26
Others									1
Note: Asterisk indicates statistically significant (P < 0.05).

Table 5. Odor threshold levels and odor activity values of typical odor gases

Compounds	Odor threshold (μg/m^3)	Odor threshold for other researchers (μg/m^3)	Tested chemical concentration (μg/m^3)	Odor activity values
Hydrogen sulfide	0.48	0.7–0.76 (mean: 0.73), from: Devos et al., 1990; Ruth, 1986	44.05	91.77
Propyl mercaptan	5.24	—	5.18	0.99
Ethyl sulfide	7.85	—	281.30	35.83
Ammonia	250	76–4074 (mean: 2075), from: Devos et al., 1990; Nagata, 2003; O'Neil, 1992	500.90	2.00
Trimethylamine	4.82	0.26–6.32 (mean: 3.29), from: Devos et al., 1990; O'Neil, 1992	340.20	70.58
Styrene	390	139–631 (mean: 385), from: Devos et al., 1990; Nagata, 2003	1645.68	4.22
Ethylbenzene	170	13, from: Devos et al., 1990	1612.07	9.48
Limonene	455	10–2455 (mean: 1233), from: Devos et al., 1990; Nagata, 2003	3734.65	8.21
Note: Odor activity value = tested chemical concentration/ odor threshold.

Figure 3. Odor intensity isopleth map in the pretreatment workshop of food waste anaerobic fermentation.

Devos , M. , Patte , F. , Rouault , J. , Laffort , P. and Van Gemert , L. 1990 . Standardized Human Olfactory Thresholds , New York, NY : Oxford University Press .

 Google Scholar

Nagata , Y. 2003 . “ Odor intensity and odor threshold value ” . In Bull. Jpn. Environ. Sanitation Center 17 – 25 .

 Google Scholar

O'Neill , D.H. and Phillips , V.R. 1992 . A review of the control of odour nuisance from livestock buildings: Part 3, Properties of the odorous substances which have been identified in livestock wastes or in the air around them . J. Agric. Eng. Res , 53 : 23 – 50 . doi: 10.1016/0021-8634(92)80072-Z

 Web of Science ®Google Scholar