Table 8 Grading standard of wastewater treatment evaluation for enterprises
Index | Grading standard | |||
|---|---|---|---|---|
Excellent | Good | Middle | Bad | |
COD effluent concentration | 100 | 200 | 300 | 400 |
NH3-N effluent concentration | 5 | 15 | 25 | 35 |
TP effluent concentration | 1 | 2 | 3 | 4 |
TN effluent concentration | 25 | 35 | 45 | 55 |
Effluent colority | 10 | 30 | 50 | 70 |
Unit product water consumption | 100 | 150 | 200 | 250 |
Unit product wastewater discharge | 80 | 120 | 160 | 200 |
Wastewater treatment cost per ton | 1 | 1.2 | 1.4 | 1.6 |
Operating load of sewage treatment | 80 | 70 | 60 | 50 |
Recycling rate of industrial water | 40 | 30 | 20 | 10 |
Reuse rate of tail water | 40 | 30 | 20 | 10 |
Stability compliance rate of wastewater treatment | 100 | 99.5 | 99 | 98.5 |