The addition of modified attapulgite reduces the emission of nitrous oxide and ammonia from aerobically composted chicken manure

Figures & data

Table 1. Physicochemical properties of artifactitious attapulgite and raw attapulgite (dry weight basis determined on triplicate samples)

Material	Particle size (mm)	Density (g/cm^3)	Average pore size (nm)	Specific surface area (m^2/g)
Artifactitious attapulgite	2.0–2.5	1.30	68.12	150.86
Raw attapulgite	2.0–2.5	3.45	0.54	501.34

Table 2. Physicochemical characteristics of the composting raw materials (dry weight basis determined on triplicate samples)

Composting material	Moisture content (%)	Organic matter (%)	C/N ratio	EC (ms/cm)	Total N (%)	Total P (%)	Total K (%)
Fresh chicken feces	75.35	48.58	11.50	6.15	2.45	2.88	3.96
Rice husks	10.57	36.25	37.57	2.85	0.56	0.23	1.07
Rice bran	18.8	63.19	35.96	2.40	1.02	1.69	1.52
Mushroom residue	8.93	80.54	38.00	1.55	1.23	1.60	1.44

Figure 1. Schema of the experimental bioreactor. 1, Fermenting vessel; 2, motor; 3, reducer; 4, stirring paddle; 5, probes; 6, air vent; 7, flow meter; 8, blower; 9, computer system.

Figure 2. Influence of attapulgite on the evolution of the temperature during aerobic composting.

Figure 3. Influence of attapulgite on the evolution of the pH during aerobic composting. The error bars represent the standard deviation.

Figure 4. Influence of attapulgite on the evolution of the total organic carbon (TOC) during aerobic composting. The error bars represent the standard deviation.

Figure 5. Influence of attapulgite on the evolution of the carbon-to-nitrogen ratios (C/N) during aerobic composting. The error bars represent the standard deviation.

Figure 6. Influence of attapulgite on the electrical conductivity (EC) during aerobic composting. The error bars represent the standard deviation.

Figure 7. Influence of attapulgite on the evolution of the seed germination indices (GI) during aerobic composting. The error bars represent the standard deviation.

Figure 8. Influence of attapulgite on the evolution of the ammonium nitrogen during aerobic composting. The error bars represent the standard deviation.

Figure 9. Influence of attapulgite on the evolution of the nitrate nitrogen during aerobic composting. The error bars represent the standard deviation.

Figure 10. Influence of attapulgite on the evolution of the ammonium emissions during aerobic composting.

Figure 11. Influence of attapulgite on the evolution of the nitrogen dioxide emissions during aerobic composting.

Figure 12. Influence of attapulgite on the evolution of the ammonia-oxidizing bacteria populations during aerobic composting. The error bars represent the standard deviation.