TABLE 2.
Summary of studies regarding enhancement effect of DIET in anaerobic digestion systems.
| Material type | Dose | Particle size | Substrate | Strengthening effect | Section | References |
| Biochar | 10 g/L | 75 μm | Glucose | Lag phase decreased by 38.0%. | Shortening Lag Period and Start-Up Time | Luo et al., 2015 |
| Carbon nanotube | 1 g/L | 1–2 nm | Glucose | Start-up period shortened by around 40%. | Shortening Lag Period and Start-Up Time | Yan et al., 2017 |
| Biochar | 15 g/L | 0.25–1 mm | Phenol | Lag phase decreased from 15.0 days to 1.1–3.2 days | Shortening Lag Period and Start-Up Time | Wang et al., 2020a |
| Hematite or magnetite | 25 mmol/L Fe | – | Benzoate | Lag phase shortened by 8–12 days | Shortening Lag Period and Start-Up Time | Zhuang et al., 2015 |
| Biochar | 2–15g/L | 0.25–1 mm | Activated and food waste | Lag time decreased by 27.5–64.4%. | Shortening Lag Period and Start-Up Time | Wang P. et al., 2018a |
| Fe3O4 | 10 g/L | – | Synthetic wastewater | Lag time decreased by 13.9%. | Shortening Lag Period and Start-Up Time | Yin et al., 2017b |
| Biochar | 20 g/L | – | VFAs | Lag phase shortened by 9.1–29.2%. | Shortening Lag Period and Start-Up Time | Wang et al., 2020b |
| GAC | 6 g/L | <100 μm | Acetic acid and ethanol | CH4 yield increased by 31%. | Improving Methane Yield | Park et al., 2018b |
| GAC | – | 8–20 mesh | Lipid-rapeseed oil | CH4 yield increased by 3.9 times. | Improving Methane Yield | Zhang et al., 2020 |
| Biochar | 10 g/L | 10–15 mm | Kitchen wastes and waste sludge | CH4 yield increased by about 44%. | Improving Methane Yield | Li et al., 2020a |
| Biochar | 0.5–1.5 g/g⋅VS | 100 mesh | Food waste and sewage sludge | Lag time of CH4 production decreased. | Improving Methane Yield | Jiang et al., 2020 |
| Activated carbon | 2–12 g/L | 180–200 mesh | Sewage sludge | CH4 yields improved by 124.0–146.3%. | Improving Methane Yield | Sun et al., 2020 |
| Graphene | 30 and 120 mg/L | Nano | Glucose | CH4 yields increased by 17.0 and 51.4%, respectively. | Improving Methane Yield | Tian et al., 2017 |
| Carbon-based materials | – | – | Dog food | Higher organic loading rates were permitted. | Enhancing System Stability | Dang et al., 2016 |
| Carbon-based materials | – | – | Municipal solid waste | CH4 production was promoted under high VFAs concentrations. | Enhancing System Stability | Dang et al., 2017 |
| Biochar | 10 g/L | 2–5 mm | Glucose | Lag phase shortened and CH4 yields were improved. | Enhancing System Stability | Lu et al., 2016 |
| Magnetite | 25 mmol/L Fe | 50–100 nm | Pig manure | CH4 yields increased with high ammonia concentrations. | Enhancing System Stability | Zhuang et al., 2018 |
| Magnetite | 20 mmol/L Fe | 1.2 ± 0.2 μm | Artificial wastewater | CH4 production was increased 3–10 folds. | Enhancing System Stability | Jin et al., 2019 |
| Stainless steel | 25.7 g/L | 0.5–2 mm | Artificial wastewater | CH4 production increased by 7.5–24.6%. | Enhancing System Stability | Li et al., 2017 |