| Increase oxygen (O2) |
Promote NH3 oxidation; increase the ORP, inhibit the growth of SRB; maybe produce the blow-off effect |
Different aeration rates from 0.1 to 0.3 L per (kg DM min) |
High aeration rate reduces VSCs and NH3 by 30.7% and 51.33%, respectively |
18
|
| Aeration rates from 100 to 1100 L h−1
|
Increase NH3 up to 600% |
56
|
| Adjust pH |
NH3: affect the NH4+ to NH3 ratio, a high pH will promote NH3 volatilization |
Lower the pH from close to 9 to about 7.5 |
Reduce the cumulative NH3 emissions by 47.80%, but increase the H2S emissions by 55% |
108
|
| VSCs: H2S is an acidic gas, alkaline environment reduces it production |
| Composting bulking agent |
Adjust the water content of the substrate and provide organic matter; has a certain adsorption function; improve the sizes and numbers of inter-particle voids, providing air space |
Addition of dry cornstalks at a mixing ratio of 4 : 1 (wet weight) |
Reduce the VSCs emissions by 66.8%, the TN loss of the compost dropped from 45.8 to 24.9% |
66
|
| Addition of dry cornstalks at a mixing ratio of 15% w/w |
Reduced the total NH3 by 30.5% |
74
|
| Chemical agents (iron salt) |
NH3: FeCl3 being an effective flocculant and causing coagulation to occur |
FeCl3 dosage in the raw materials was calculated to be 10% of the TN (by molar mass) |
Reduce NH3 and H2S emissions by 38% and 33%, respectively |
68
|
| VSCs: iron salts can react with dissolved sulfide to form elemental sulfur and sulfates |
| Chemical agents (struvite) |
NH3: a chemical reaction occurred, NH4+-N can be conserved in the form of struvite |
Mg(OH)2 and H3PO4 dosage were calculated to be 10% of the TN (by molar mass) |
Reduce NH3 and H2S emissions by about 50% |
65
|
| VSCs: increasing the pH of the compost |
| Adsorbents |
Adsorbents with porous structure and high surface area can adsorb huge amounts of odors generated in compost |
Addition of biochar at a mixing ratio of 20% w/w |
Reduce NH3 and VSCs emissions by 64% and 71%, respectively |
90
|
| Microbial agents |
Affect the composting microbial community, or may inhibit odor-causing microorganisms |
Inoculate 5% of laboratory-preserved strain Thiobacillus thioparus 1904 |
Reduce NH3 by 21.83%, reduce the cumulative emissions of H2S, Me2S, MeSH and Me2SS by 33.24%, 81.24%, 32.70% and 54.22%, respectively |
108
|
| Mature compost |
Can be used as a bulking agent to improve inter-particle voids; has adsorption function; rich in microorganisms, can affect the composting microbial community |
Addition of mature compost at a mixing ratio of 10% w/w |
Reducing the NH3 emission by 58.0% |
120
|
| Addition of mature compost at a mixing ratio of 10% w/w |
Reduce 65.1% H2S emission |
28
|
