Domestic wastewater
LAIGNÉ EN BELIN | 72 | FranceCapacity in IE : 3 000
Year of construction : 2006
Project owner : SIVOM Laigné Saint Gervais
Consultant : D.D.E.
TYPE OF TREATMENT
Water treatment- Storm water tank 250 m³
- Aeration basin 670 m³
- 3 surface aerator 11 kw
- deaerator
- floating matters storage tank
- Scraper settling tank Ø 15,5 m
- Phosphate removal
Sludge treatment
- Sludge recirculation
- Sludge dewatering by centrifuge decanter
- Lime addition
- Sludge storage area 126 m²
Smells treatment- Deodorizing of the sludge treatment room
TECHNICAL DATA OF PLANT
| Capacity of treatment | Treated water discharge standards | |
| Capacity of treatment | 3 000 IE | |
| Daily volume | 1050 m³/d | |
| Peak flow | 70 m³/h |
| Biological oxygen demand (BOD5) | 180 kg/d | 20 mg/l |
| Chemical oxygen demand (COD) | 460 kg/d | 90 mg/l |
| Suspended solids | 280 kg/d | 30 mg/l |
| Total Kjeldahl nitrogen | 49 kg/d | 5 mg/l |
| Total nitrogen | 49 kg/d | 10 mg/l |
| Total phosphorus | 9,5 kg/d | 2 mg/l |
The Inhabitant Equivalent (IE) is a notion used in sanitation to evaluate the size of waste water treatment plants, it corresponds to an estimate of pollution caused by the "inhabitant equivalent" defined thus :
- 60 g/inhabitant/day for DBO5
- 90 g/inhabitant/day for suspended matter
- 15 g/inhabitant/day for total nitrogen
- 4 g/inhabitant/day for total phosphor
