Table 2.
Product yield from poultry and slaughterhouse wastes under different treatment technologies
| Substrate | Operating conditions | Product yield | References |
|---|---|---|---|
| Mixed cow dung, waste fleshings, and leaf litter | Co-composting; hydrolysis of fleshing using Selenomonas ruminantium; square-shaped compost bioreactor (Size: 0.5 m × 0.5 m × 0.5 m); composting time: 49 days | Germination index of 84% (cucumber), 86% (bottle guard) and 94% (tomato) | [66] |
| Poultry wastes | Batch AD tests; 1 L glass reactor bottles; substrate to inoculum ratio—0.25; temperature: 35 °C | 262 mL CH4/g VS added | [30] |
| Bovine slaughterhouse wastes | Batch AD tests; 1 L glass reactor bottles; substrate to inoculum ratio—0.25; temperature: 35 °C | 572 mL CH4/g VS added | [30] |
| Mixed cattle manure and food wastes | Batch AD tests; 1 L glass reactor bottles; temperature: 35 °C; mixed food wastes (1 proportion) with cattle manure (2 proportion) | 388 mL CH4/g VS added | [67] |
| Mixed slaughterhouse and food wastes | Semi-continuous AD tests; 5 L lab scale reactor; temperature: 35 °C; helix type mechanical stirrer: 70 rpm; Retention time: 30 days | 630 mL CH4/g VS added | [68] |
| Commercial feather meal | Biodiesel production; transesterification process; temperature: 70 °C; process time: 1 h | 7–11% biodiesel (on dry matter basis) | [69] |
| Poultry waste feathers | Keratin extraction; feather with reducing agent (1:20); reaction time: 6 h; temperature: 40 °C | Keratin yield of 88% (with sodium sulphide) and 66% (with L-cysteine) | [70] |
| Chestnut Burrs (CB), Cow Manure (CM), Bovine Bone (BM) | Co-composting; waste shredding using mechanical shredder; 50 L compost bins; composting period: 38 days | Best compost yield with 15% BM; 55% CM to CB, Rich in macro and micronutrients; Relative seed germination (98.36%); Germination Index (104.21%); pH-6.02; C/N-18.32 | [71] |
| Cattle manure with sewage sludge | Incineration; pilot-scale rotary kiln incinerator; Temperature: 750–850 °C and air ratio (0.9–1.4) | N2O Emission factor = 1.9–6.0% g-N2O-N/g-N; CH4 Emission factor = 0.0046–0.26 g-CH4/g of burning object | [72] |
| Poultry litter | Fast pyrolysis; temperature: 530 °C; lab scale bubbling fluidized bed reactor; bedding material: Aluminium oxide | Bio-oil yield: 27%; Heating value: 32 MJ/kg | [73] |
| Meat and bone meal | Protein meal; plasticizer added: glycerol; bioplastic sheets synthesis; composition of meal: 4–7% moisture, 50% protein, 8–12% fat, and 35% ash | Bioplastic sheets; Tensile strength of sheet: 0.8 ± 0.1 MPa | [74] |
| Poultry waste feathers | Protein extraction; plasticizer added: glycerol; bioplastic sheets synthesis; 60 ml of keratin solution with varying glycerol concentration of (2, 5, 10 wt %) | Bioplastic sheets; SEM revealed good morphologies without cavity, holes and edge; Keratin with 2% of glycerol showed best thermal and mechanical properties | [75] |
| Slaughterhouse wastes | Protein extraction; operation conditions: pH: 9; reaction time: 1 h; temperature: 20–40 °C | Protein yield of 75% (pork lungs); 64% (beef lungs); 83% (chicken meat) | [76] |
| Poultry waste feathers | Keratin extraction; dissolving of feathers (50 g feather + 2 L of sodium sulphide solution (0.5 M)); protein precipitation (feather filtrate solution and ammonium sulfate solution (1:1)) and protein extraction | Keratin yield of 53% (sodium sulphide as reducing agent) | [77] |