Table 3.
Process-specific and Total Retardation Factors
| Retention Processa | PFOA | PFOS | FTOH |
|---|---|---|---|
| Sorption | 3.0 (15)b | 11.4 (22) | 157 (2) |
| Air-water Partitioning | 1.0 (0) | 1.0 (0) | 2.0 (0) |
| Air-water Interfacial Adsorption | 8.2 (55) | 24.4 (50) | 1.2 (0) |
| NAPL-water Partitioning | 3.1 (16) | 8.2 (15) | 9749 (98) |
| NAPL-water Interfacial Adsorption | 2.8 (14) | 6.9 (12) | 1.0 (0) |
| Total Retardation Factor | 14.1 | 47.9 | 9906 |
| Rtotal/Rsorption | 4.7 | 4.2 | 63 |
a
Retardation factors for individual retention processes are calculated using the relevant process-specific equations. An R value of 1 denotes no retention.
b
Percentage of total retention associated with each retention process (rounded), calculated as (Ri-1)/(Rt-1)*100, where Ri and Rt are the process-specific and total retardation factors, respectively.