Table 5 Equations’ parameters, specifications, assumptions, and data sources used for the optimization models where we analyze the transport of surplus excreta towards municipalities with a nutrient deficit to meet crop needs.
From: Enhancing nutrient recycling from excreta to meet crop nutrient needs in Sweden – a spatial analysis
Eq. | Param. | Definition/Variables represent (Specifications, assumptions and data sources) |
|---|---|---|
5 | \({W}_{i}\) | Total weight of excreta in municipality \(i\in S\) |
gl | Weight of excreta per individual and year from source l, human sludge or manure. We obtained the coefficient (m3) of slurry and solid manure production of livestock from[58] and human excreta production (as dry mass) per year from57. A m3 of solid manure weighs 0.5 tons, and a m3 of slurry weighs 1 ton[58] | |
Eli | Number of individuals of source l in municipality i | |
6 | \({k}_{i}^{n}\) | Concentration, the amount of nutrient n in each ton of excreta at each surplus municipality i which is used in constraint 8.2 |
\({Q}_{i}^{n}\) | Total quantity of nutrientn in excreta in municipality i, where n represents nutrient (N, P or K), (Eq. 1) | |
7 | \({T}^{n}\) | Total amount of nutrient n transported along with a surplus of P |
\({B}_{i}^{n}\) | Balance of nutrient n in municipalities i, where n represent nutrient N, P, or K (Eq. 3) | |
\({Q}_{i}^{n}\) | Total quantity of nutrient n in excreta in municipality i (Eq. 1) |
