LCI by treatment process for liquid treatment processes (per m3 wastewater treated)a
| Treatment process . | Inventory item . | Units/m3 . | Baseline . | . | Partial capacity . | . | Full capacity . | . | ||
|---|---|---|---|---|---|---|---|---|---|---|
| . | Low AD . | Base AD . | . | Low AD . | Base AD . | . | ||||
| Preliminary and primary treatment | Electricity | kWh | 0.202 | ★ | 0.202 | 0.202 | ★ | 0.202 | 0.202 | ★ |
| Activated carbon | kg | 1.71 × 10−4 | ★ | 1.71 × 10−4 | 1.71 × 10−4 | ★ | 1.71 × 10−4 | 1.71 × 10−4 | ★ | |
| Septage transport | tkm | 0.095 | ★ | 0.095 | 0.095 | ★ | 0.095 | 0.095 | ★ | |
| Grit disposal | kg | 0.012 | ★ | 0.012 | 0.012 | ★ | 0.012 | 0.012 | ★ | |
| Potassium permanganate | kg | 4.62 × 10−5 | ★ | 4.62 × 10−5 | 4.62 × 10−5 | ★ | 4.62 × 10−5 | 4.62 × 10−5 | ★ | |
| Secondary treatment | Electricity | kWh | 0.167 | ★ | 0.169 | 0.169 | ♦ | 0.172 | 0.172 | ♦ |
| Process emission, CH4 | kg CH4 | 3.67 × 10−3 | ♦ | 3.68 × 10−3 | 3.68 × 10−3 | ♦ | 3.69 × 10−3 | 3.69 × 10−3 | ♦ | |
| Process emission, N2O | kg N2O | 9.52 × 10−5 | ♦ | 1.05 × 10−4 | 1.05 × 10−4 | ♦ | 1.12 × 10−4 | 1.12 × 10−4 | ♦ | |
| Plant water and disinfection | Electricity | kWh | 0.029 | ★ | 0.029 | 0.029 | ★ | 0.029 | 0.029 | ★ |
| Sodium hypochlorite | kg | 3.40 × 10−3 | ★ | 3.40 × 10−3 | 3.40 × 10−3 | ★ | 3.40 × 10−3 | 3.40 × 10−3 | ★ | |
| Sodium bisulfite | kg | 3.97 × 10−3 | ★ | 3.97 × 10−3 | 3.97 × 10−3 | ★ | 3.97 × 10−3 | 3.97 × 10−3 | ★ | |
| Avoided potable water | m3 | 0.126 | ★ | 0.126 | 0.126 | ★ | 0.126 | 0.126 | ★ | |
| Effluent | Ammonia, to water | kg NH3 | 0.022 | ★ | 0.025 | 0.024 | ○ | 0.027 | 0.026 | ○ |
| Biological oxygen demand | kg O2 | 0.017 | ★ | 0.018 | 0.018 | ○ | 0.018 | 0.018 | ○ | |
| Nitrate | kg NO3 | 2.80 × 10−3 | ★ | 3.14 × 10−3 | 3.06E-3 | ○ | 3.42 × 10−3 | 3.26 × 10−3 | ○ | |
| Nitrogen, organic | kg N | 1.41 × 10−3 | ★ | 1.58 × 10−3 | 1.54 × 10−3 | ○ | 1.73 × 10−3 | 1.65 × 10−3 | ○ | |
| Phosphorus, total | kg P | 3.61 × 10−4 | ★ | 3.81 × 10−4 | 3.73 × 10−4 | ○ | 4.02 × 10−4 | 3.84 × 10−4 | ○ | |
| Suspended solids | kg TSS | 5.95 × 10−3 | ★ | 6.20 × 10−3 | 6.20 × 10−3 | ○ | 6.48 × 10−3 | 6.48 × 10−3 | ○ | |
| Nitrous oxide, to air | kg N2O | 1.62 × 10−4 | ★ | 1.80 × 10−4 | 1.76 × 10−4 | ○ | 1.96 × 10−4 | 1.87 × 10−4 | ○ | |
| Operation, facilities | Electricity | kWh | 7.24 × 10−3 | ★ | 7.60 × 10−3 | 7.60 × 10−3 | ★ | 7.60 × 10−3 | 7.60 × 10−3 | ★ |
| Natural gas | MJ | 0.401 | ★ | 0.401 | – | ✚ | – | – | ✚ | |
| Potable water | m3 | 4.52 × 10−4 | ★ | 4.52 × 10−4 | 4.52 × 10−4 | ★ | 4.52 × 10−4 | 4.52 × 10−4 | ★ | |
| Treatment process . | Inventory item . | Units/m3 . | Baseline . | . | Partial capacity . | . | Full capacity . | . | ||
|---|---|---|---|---|---|---|---|---|---|---|
| . | Low AD . | Base AD . | . | Low AD . | Base AD . | . | ||||
| Preliminary and primary treatment | Electricity | kWh | 0.202 | ★ | 0.202 | 0.202 | ★ | 0.202 | 0.202 | ★ |
| Activated carbon | kg | 1.71 × 10−4 | ★ | 1.71 × 10−4 | 1.71 × 10−4 | ★ | 1.71 × 10−4 | 1.71 × 10−4 | ★ | |
| Septage transport | tkm | 0.095 | ★ | 0.095 | 0.095 | ★ | 0.095 | 0.095 | ★ | |
| Grit disposal | kg | 0.012 | ★ | 0.012 | 0.012 | ★ | 0.012 | 0.012 | ★ | |
| Potassium permanganate | kg | 4.62 × 10−5 | ★ | 4.62 × 10−5 | 4.62 × 10−5 | ★ | 4.62 × 10−5 | 4.62 × 10−5 | ★ | |
| Secondary treatment | Electricity | kWh | 0.167 | ★ | 0.169 | 0.169 | ♦ | 0.172 | 0.172 | ♦ |
| Process emission, CH4 | kg CH4 | 3.67 × 10−3 | ♦ | 3.68 × 10−3 | 3.68 × 10−3 | ♦ | 3.69 × 10−3 | 3.69 × 10−3 | ♦ | |
| Process emission, N2O | kg N2O | 9.52 × 10−5 | ♦ | 1.05 × 10−4 | 1.05 × 10−4 | ♦ | 1.12 × 10−4 | 1.12 × 10−4 | ♦ | |
| Plant water and disinfection | Electricity | kWh | 0.029 | ★ | 0.029 | 0.029 | ★ | 0.029 | 0.029 | ★ |
| Sodium hypochlorite | kg | 3.40 × 10−3 | ★ | 3.40 × 10−3 | 3.40 × 10−3 | ★ | 3.40 × 10−3 | 3.40 × 10−3 | ★ | |
| Sodium bisulfite | kg | 3.97 × 10−3 | ★ | 3.97 × 10−3 | 3.97 × 10−3 | ★ | 3.97 × 10−3 | 3.97 × 10−3 | ★ | |
| Avoided potable water | m3 | 0.126 | ★ | 0.126 | 0.126 | ★ | 0.126 | 0.126 | ★ | |
| Effluent | Ammonia, to water | kg NH3 | 0.022 | ★ | 0.025 | 0.024 | ○ | 0.027 | 0.026 | ○ |
| Biological oxygen demand | kg O2 | 0.017 | ★ | 0.018 | 0.018 | ○ | 0.018 | 0.018 | ○ | |
| Nitrate | kg NO3 | 2.80 × 10−3 | ★ | 3.14 × 10−3 | 3.06E-3 | ○ | 3.42 × 10−3 | 3.26 × 10−3 | ○ | |
| Nitrogen, organic | kg N | 1.41 × 10−3 | ★ | 1.58 × 10−3 | 1.54 × 10−3 | ○ | 1.73 × 10−3 | 1.65 × 10−3 | ○ | |
| Phosphorus, total | kg P | 3.61 × 10−4 | ★ | 3.81 × 10−4 | 3.73 × 10−4 | ○ | 4.02 × 10−4 | 3.84 × 10−4 | ○ | |
| Suspended solids | kg TSS | 5.95 × 10−3 | ★ | 6.20 × 10−3 | 6.20 × 10−3 | ○ | 6.48 × 10−3 | 6.48 × 10−3 | ○ | |
| Nitrous oxide, to air | kg N2O | 1.62 × 10−4 | ★ | 1.80 × 10−4 | 1.76 × 10−4 | ○ | 1.96 × 10−4 | 1.87 × 10−4 | ○ | |
| Operation, facilities | Electricity | kWh | 7.24 × 10−3 | ★ | 7.60 × 10−3 | 7.60 × 10−3 | ★ | 7.60 × 10−3 | 7.60 × 10−3 | ★ |
| Natural gas | MJ | 0.401 | ★ | 0.401 | – | ✚ | – | – | ✚ | |
| Potable water | m3 | 4.52 × 10−4 | ★ | 4.52 × 10−4 | 4.52 × 10−4 | ★ | 4.52 × 10−4 | 4.52 × 10−4 | ★ | |
a★ – based on plant data, ○ – scaled baseline value, ✚ – allocated based on biogas use hierarchy, ♦ – based on GPS-X output.
AD – anaerobic digestion, tkm – ton kilometers, TSS – total suspended solids.