LCI for solid treatment processes (per m3 wastewater treated)
| Treatment process . | Inventory item . | Units/m3 . | Baseline . | . | Partial capacity . | . | Full capacity . | . | ||
|---|---|---|---|---|---|---|---|---|---|---|
| . | Low AD . | Base AD . | . | Low AD . | Base AD . | . | ||||
| SSO processing | Transport | tkm | – | * | 0.122 | 0.122 | * | 0.244 | 0.244 | * |
| Electricity | kWh | – | * | 0.012 | 0.012 | * | 0.024 | 0.024 | * | |
| Water | m3 | – | * | 1.19 × 10−3 | 1.19 × 10−3 | * | 2.40 × 10−3 | 2.40 × 10−3 | * | |
| Dewatering | Electricity | kWh | 4.20 × 10−3 | ★ | 0.065 | 0.065 | ★ | 6.08 × 10−3 | 6.08 × 10−3 | ★ |
| Polymer | kg | 4.20 × 10−3 | ★ | 6.08 × 10−3 | 6.08 × 10−3 | ○ | 7.92 × 10−3 | 7.92 × 10−3 | ○ | |
| Anaerobic digestion | Electricity | kWh | 0.051 | ★ | 0.065 | 0.065 | ♦ | 0.065 | 0.065 | ♦ |
| Natural gas | MJ | 0.123 | ★ | 0.134 | – | ✚ | – | – | ✚ | |
| Ferric chloride | kg | 5.93 × 10−4 | ★ | 6.67 × 10−4 | 6.67 × 10−4 | ○ | 7.42 × 10−4 | 7.42 × 10−4 | ○ | |
| Process emission, CH4 | kg CH4 | 2.56 × 10−3 | ♦ | 5.22 × 10−3 | 7.26 × 10−3 | ♦ | 8.43 × 10−3 | 0.012 | ♦ | |
| Biogas, to flare | m3 | 0.022 | ✚ | 0.051 | 0.035 | ✚ | 0.081 | 0.057 | ✚ | |
| Biogas, to pellet drier | m3 | 0.067 | ✚ | 0.105 | 0.105 | ✚ | 0.142 | 0.142 | ✚ | |
| Biogas, to glycol boiler | m3 | 0.036 | ✚ | – | – | ✚ | – | – | ✚ | |
| Biogas, to CHP | m3 | – | ✚ | 0.098 | 0.213 | ✚ | 0.184 | 0.369 | ✚ | |
| Avoided electricity | kWh | – | ✚ | 0.226 | 0.490 | ✚ | 0.424 | 0.848 | ✚ | |
| Avoided natural gas | MJ | 2.10 | ✚ | 3.14 | 4.29 | ✚ | 4.74 | 6.58 | ✚ | |
| Avoided landfill | kg SSO | – | ● | 0.661 | 0.661 | ● | 1.32 | 1.32 | ● | |
| Avoided WTE | kg SSO | – | ● | 1.40 | 1.40 | ● | 2.81 | 2.81 | ● | |
| Concrete | m3 | – | □ | 7.37 × 10−7 | 7.37 × 10−7 | □ | 7.37 × 10−7 | 7.37 × 10−7 | □ | |
| Excavation | m3 | – | □ | 4.44 × 10−6 | 4.44 × 10−6 | □ | 4.44 × 10−6 | 4.44 × 10−6 | □ | |
| Steel | kg | – | □ | 4.91 × 10−5 | 4.91 × 10−5 | □ | 4.91 × 10−5 | 4.91 × 10−5 | □ | |
| Gravel | kg | – | □ | 3.60 × 10−4 | 3.60 × 10−4 | □ | 3.60 × 10−4 | 3.60 × 10−4 | □ | |
| Building | m3 | – | □ | 3.67 × 10−6 | 3.67 × 10−6 | □ | 3.67 × 10−6 | 3.67 × 10−6 | □ | |
| Pellet drying | Electricity | kWh | 0.063 | ★ | 0.089 | 0.089 | ○ | 0.120 | 0.120 | ○ |
| Natural gas | MJ | 0.033 | ★ | 0.022 | – | ✚ | – | – | ✚ | |
| Land application | Transport | tkm | 0.019 | ▪ | 0.027 | 0.027 | ▪ | 0.037 | 0.037 | ▪ |
| Diesel, spreading | liters | 1.69 × 10−4 | ▪ | 2.39 × 10−4 | 2.39 × 10−4 | ▪ | 3.21 × 10−4 | 3.21 × 10−4 | ▪ | |
| Avoided fertilizer, urea | kg N | 3.50 × 10−3 | ▪ | 4.95 × 10−3 | 4.95 × 10−3 | ▪ | 6.66 × 10−3 | 6.66 × 10−3 | ▪ | |
| Avoided fertilizer, single superphosphate | kg P2O5 | 3.03 × 10−3 | ▪ | 4.28 × 10−3 | 4.28 × 10−3 | ▪ | 5.75 × 10−3 | 5.75 × 10−3 | ▪ | |
| Phosphorus, to water | kg P | 6.23 × 10−6 | ▪ | 8.80 × 10−6 | 8.80 × 10−6 | ▪ | 1.18 × 10−5 | 1.18 × 10−5 | ▪ | |
| Nitrate, to water | kg NO3 | 3.81 × 10−3 | ▪ | 5.38 × 10−3 | 5.38 × 10−3 | ▪ | 7.23 × 10−3 | 7.23 × 10−3 | ▪ | |
| Ammonia, to air | kg NH3 | 2.96 × 10−4 | ▪ | 4.18 × 10−4 | 4.18 × 10−4 | ▪ | 5.62 × 10−4 | 5.62 × 10−4 | ▪ | |
| Nitrous oxide, to air | kg N2O | 7.19 × 10−5 | ▪ | 1.02 × 10−4 | 1.02 × 10−4 | ▪ | 1.37 × 10−4 | 1.37 × 10−4 | ▪ | |
| Carbon, sequestered | kg CO2 | 0.014 | ▪ | 0.020 | 0.020 | ▪ | 0.027 | 0.027 | ▪ | |
| Treatment process . | Inventory item . | Units/m3 . | Baseline . | . | Partial capacity . | . | Full capacity . | . | ||
|---|---|---|---|---|---|---|---|---|---|---|
| . | Low AD . | Base AD . | . | Low AD . | Base AD . | . | ||||
| SSO processing | Transport | tkm | – | * | 0.122 | 0.122 | * | 0.244 | 0.244 | * |
| Electricity | kWh | – | * | 0.012 | 0.012 | * | 0.024 | 0.024 | * | |
| Water | m3 | – | * | 1.19 × 10−3 | 1.19 × 10−3 | * | 2.40 × 10−3 | 2.40 × 10−3 | * | |
| Dewatering | Electricity | kWh | 4.20 × 10−3 | ★ | 0.065 | 0.065 | ★ | 6.08 × 10−3 | 6.08 × 10−3 | ★ |
| Polymer | kg | 4.20 × 10−3 | ★ | 6.08 × 10−3 | 6.08 × 10−3 | ○ | 7.92 × 10−3 | 7.92 × 10−3 | ○ | |
| Anaerobic digestion | Electricity | kWh | 0.051 | ★ | 0.065 | 0.065 | ♦ | 0.065 | 0.065 | ♦ |
| Natural gas | MJ | 0.123 | ★ | 0.134 | – | ✚ | – | – | ✚ | |
| Ferric chloride | kg | 5.93 × 10−4 | ★ | 6.67 × 10−4 | 6.67 × 10−4 | ○ | 7.42 × 10−4 | 7.42 × 10−4 | ○ | |
| Process emission, CH4 | kg CH4 | 2.56 × 10−3 | ♦ | 5.22 × 10−3 | 7.26 × 10−3 | ♦ | 8.43 × 10−3 | 0.012 | ♦ | |
| Biogas, to flare | m3 | 0.022 | ✚ | 0.051 | 0.035 | ✚ | 0.081 | 0.057 | ✚ | |
| Biogas, to pellet drier | m3 | 0.067 | ✚ | 0.105 | 0.105 | ✚ | 0.142 | 0.142 | ✚ | |
| Biogas, to glycol boiler | m3 | 0.036 | ✚ | – | – | ✚ | – | – | ✚ | |
| Biogas, to CHP | m3 | – | ✚ | 0.098 | 0.213 | ✚ | 0.184 | 0.369 | ✚ | |
| Avoided electricity | kWh | – | ✚ | 0.226 | 0.490 | ✚ | 0.424 | 0.848 | ✚ | |
| Avoided natural gas | MJ | 2.10 | ✚ | 3.14 | 4.29 | ✚ | 4.74 | 6.58 | ✚ | |
| Avoided landfill | kg SSO | – | ● | 0.661 | 0.661 | ● | 1.32 | 1.32 | ● | |
| Avoided WTE | kg SSO | – | ● | 1.40 | 1.40 | ● | 2.81 | 2.81 | ● | |
| Concrete | m3 | – | □ | 7.37 × 10−7 | 7.37 × 10−7 | □ | 7.37 × 10−7 | 7.37 × 10−7 | □ | |
| Excavation | m3 | – | □ | 4.44 × 10−6 | 4.44 × 10−6 | □ | 4.44 × 10−6 | 4.44 × 10−6 | □ | |
| Steel | kg | – | □ | 4.91 × 10−5 | 4.91 × 10−5 | □ | 4.91 × 10−5 | 4.91 × 10−5 | □ | |
| Gravel | kg | – | □ | 3.60 × 10−4 | 3.60 × 10−4 | □ | 3.60 × 10−4 | 3.60 × 10−4 | □ | |
| Building | m3 | – | □ | 3.67 × 10−6 | 3.67 × 10−6 | □ | 3.67 × 10−6 | 3.67 × 10−6 | □ | |
| Pellet drying | Electricity | kWh | 0.063 | ★ | 0.089 | 0.089 | ○ | 0.120 | 0.120 | ○ |
| Natural gas | MJ | 0.033 | ★ | 0.022 | – | ✚ | – | – | ✚ | |
| Land application | Transport | tkm | 0.019 | ▪ | 0.027 | 0.027 | ▪ | 0.037 | 0.037 | ▪ |
| Diesel, spreading | liters | 1.69 × 10−4 | ▪ | 2.39 × 10−4 | 2.39 × 10−4 | ▪ | 3.21 × 10−4 | 3.21 × 10−4 | ▪ | |
| Avoided fertilizer, urea | kg N | 3.50 × 10−3 | ▪ | 4.95 × 10−3 | 4.95 × 10−3 | ▪ | 6.66 × 10−3 | 6.66 × 10−3 | ▪ | |
| Avoided fertilizer, single superphosphate | kg P2O5 | 3.03 × 10−3 | ▪ | 4.28 × 10−3 | 4.28 × 10−3 | ▪ | 5.75 × 10−3 | 5.75 × 10−3 | ▪ | |
| Phosphorus, to water | kg P | 6.23 × 10−6 | ▪ | 8.80 × 10−6 | 8.80 × 10−6 | ▪ | 1.18 × 10−5 | 1.18 × 10−5 | ▪ | |
| Nitrate, to water | kg NO3 | 3.81 × 10−3 | ▪ | 5.38 × 10−3 | 5.38 × 10−3 | ▪ | 7.23 × 10−3 | 7.23 × 10−3 | ▪ | |
| Ammonia, to air | kg NH3 | 2.96 × 10−4 | ▪ | 4.18 × 10−4 | 4.18 × 10−4 | ▪ | 5.62 × 10−4 | 5.62 × 10−4 | ▪ | |
| Nitrous oxide, to air | kg N2O | 7.19 × 10−5 | ▪ | 1.02 × 10−4 | 1.02 × 10−4 | ▪ | 1.37 × 10−4 | 1.37 × 10−4 | ▪ | |
| Carbon, sequestered | kg CO2 | 0.014 | ▪ | 0.020 | 0.020 | ▪ | 0.027 | 0.027 | ▪ | |
a★ – based on plant data, ○ – scaled baseline value, ● – based on Massachusetts disposal routes, ✚ – allocated based on biogas use hierarchy, □ – estimated based on unit dimensions, ♦ – based on GPS-X output, ▪ – calculated based on pellet characteristics, *– estimated using proxy assumptions.
AD – anaerobic digestion, CHP – combined heat and power, SSO – source separated organics, tkm – ton kilometers, WTE – waste to energy.