Table 14.7 - Reduction efficiencies of different wastewater treatment processes (%)
Sources: Modified from Winther et al, 1978; MiljØstyrelsen, 1990
  | Heavy metals | |||||||
---|---|---|---|---|---|---|---|---|
Treatment process | Suspended solids | BOD | P | N | E. coli | Viruses | Cd, Zn | Cu, Pb, Cr |
Primary | 6070 | 2040 | 1030 | 1020 | 6090 | 3070 | 520 | 4060 |
Constructed reedbeds1 | | 6080 | 2040 | 2550 | | | | |
Secondary | 8095 | 7090 | 2040 | 2040 | 9099 | 9099 | 2040 | 7090 |
Tertiary | 9095 | >95 | 8597 | 20402 | >99 | >99 | 4060 | 8095 |
Notes: