Table 4 Cha rac teristics of water treatment utility in the lower catchment part of the Guapi-Macacu watershed in 2011
Treatment unit: Laranjal - CEDAE | Municipality: São Gonçalo |
|---|---|
Captivation area from the GMW | 1,263 km2 |
Forest cover in the watershed | 48.8% |
Treatment type | Conventional |
General treatment phases | Captivation, sedimentation, coagulation, flocculation, decantation, filtration, disinfection, water fluoridation and pH correction |
Treated water flow | Average flow in 2011, 5.35 m3 s-1 |
Population supplied with treated water | 2,000,000 inhabitants |
General chemical products used | Aluminium sulphate Al2(SO4)3, polyelectrolyte, hexafluorosilicic acid H2SIF6, chlorine, calcium oxide CaO |
Costs with chemical products for the treatment of raw water | 2.31 × 106 BRL (year 2011) |
Turbidity of raw water, average values | 17.10 NTU |
Treated water characteristics | Colour, 2.50 uH |
Turbidity, 0.34 NTU | |
Total costs with chemical products and electricity in a year for the water treatment unit | For the treatment of 6 m3 s-1, |
• 300,000 [BRL] (monthly expenditure for chemical products) | |
• 100,000 [BRL] (monthly expenditure for electricity in the captivation and production area within the unit) |