84
3 Bio-augmented Composting of Organic Wastes in Villages and Towns
3.3.4 Control Technology for Odorous Pollutants During
Composting
3.3.4.1 Emission Law of Odorous Pollutants During Mechanical
Separation and Biological Pre-treatment
Conducting mechanical separation based on the difference of physical properties of
different components of municipal solid wastes is a key technological link of qualitybased resourceful utilization of complex wastes. The dispersion of odor pollutants
caused by various mechanical actions (including turning, winnowing and shaking)
during the separation is an important secondary pollution source. Based on limited
emission concentrations of eight odor pollutants specified in standard GB14554-93
(as shown in Table 3.6), the emission law of odor pollutants during technological
links (the mechanical separation and biological pre-treatment) of municipal solid
wastes was analyzed.
The results showed that the concentration of methyl mercaptan in fresh wastes was
far larger than the national standard in which the methyl sulfide showed the lowest
concentration (0.0236 mg/m
3 ) while the concentration (0.395 mg/m
3 ) of styrene
was the largest. During mechanical separation, the concentration of odorous gases
generated by municipal wastes gradually declined. However, during the screening
link using a rotary screen, the odor concentrations of ammonia, hydrogen sulfide,
carbon disulfide and methyl sulfide slightly rose. Moreover, the odor concentrations
of ammonia, hydrogen sulfide, carbon disulfide, styrene and methyl sulfide at rotary
screen were 11.67%, 3.8%, 25.42%, −17.67% and 128.93% higher compared with
those at the manual sorting table, respectively.
Table 3.6 Standard values of odor pollutants from factory sector
Serial
number
Control item
Unit
First
grade
Second grade
Third grade
1
Ammonia
mg/m 3
1
1.5
2
4
5
2
Trimethylamine mg/m 3
0.05
0.08
0.15
0.45
0.8
3
Hydrogen
sulfide
mg/m 3
0.03
0.06
0.1
0.32
0.6
4
Methyl
mercaptan
mg/m 3
0.004
0.007
0.01
0.02
0.035
5
Methyl sulfide
mg/m 3
0.03
0.07
0.15
0.55
1.1
6
Dimethyl
disulfide
mg/m 3
0.03
0.06
0.13
0.42
0.71
7
Carbon
disulfide
mg/m 3
2
3
5
8
10
8
Styrene
mg/m 3
3
5
7
14
19
9
Odor
concentration
Dimensionless 10
20
30
60
70
3 Bio-augmented Composting of Organic Wastes in Villages and Towns
3.3.4 Control Technology for Odorous Pollutants During
Composting
3.3.4.1 Emission Law of Odorous Pollutants During Mechanical
Separation and Biological Pre-treatment
Conducting mechanical separation based on the difference of physical properties of
different components of municipal solid wastes is a key technological link of qualitybased resourceful utilization of complex wastes. The dispersion of odor pollutants
caused by various mechanical actions (including turning, winnowing and shaking)
during the separation is an important secondary pollution source. Based on limited
emission concentrations of eight odor pollutants specified in standard GB14554-93
(as shown in Table 3.6), the emission law of odor pollutants during technological
links (the mechanical separation and biological pre-treatment) of municipal solid
wastes was analyzed.
The results showed that the concentration of methyl mercaptan in fresh wastes was
far larger than the national standard in which the methyl sulfide showed the lowest
concentration (0.0236 mg/m
3 ) while the concentration (0.395 mg/m
3 ) of styrene
was the largest. During mechanical separation, the concentration of odorous gases
generated by municipal wastes gradually declined. However, during the screening
link using a rotary screen, the odor concentrations of ammonia, hydrogen sulfide,
carbon disulfide and methyl sulfide slightly rose. Moreover, the odor concentrations
of ammonia, hydrogen sulfide, carbon disulfide, styrene and methyl sulfide at rotary
screen were 11.67%, 3.8%, 25.42%, −17.67% and 128.93% higher compared with
those at the manual sorting table, respectively.
Table 3.6 Standard values of odor pollutants from factory sector
Serial
number
Control item
Unit
First
grade
Second grade
Third grade
1
Ammonia
mg/m 3
1
1.5
2
4
5
2
Trimethylamine mg/m 3
0.05
0.08
0.15
0.45
0.8
3
Hydrogen
sulfide
mg/m 3
0.03
0.06
0.1
0.32
0.6
4
Methyl
mercaptan
mg/m 3
0.004
0.007
0.01
0.02
0.035
5
Methyl sulfide
mg/m 3
0.03
0.07
0.15
0.55
1.1
6
Dimethyl
disulfide
mg/m 3
0.03
0.06
0.13
0.42
0.71
7
Carbon
disulfide
mg/m 3
2
3
5
8
10
8
Styrene
mg/m 3
3
5
7
14
19
9
Odor
concentration
Dimensionless 10
20
30
60
70