Treated Municipal Wastewater (109 m3 / year)
Definition :

Treated wastewater (primary, secondary and tertiary) annually produced by municipal wastewater treatment facilities in the country. Primary treatment: municipal wastewater effectively treated by a physical and/or chemical process involving settlement of suspended solids, or other process in which the BOD5 of the incoming wastewater is reduced by at least 20% and the total suspended solids of the incoming wastewater are reduced by at least 50% before discharge. Treatment processes can include: sedimentation tank, septic tank, skimming, chemical enhanced primary treatment. Secondary treatment: municipal wastewater effectively treated by a process generally involving biological treatment with a secondary settlement or other process, resulting in a BOD removal of at least 70% and a COD removal of at least 75% before discharge. Treatment processes can include: aerated lagoon, activated sludge, up-flow anaerobic sludge blanket, trickling filters, rotating biological contactors, oxidation ditch, settling basin digester. For the purpose of this database natural biological treatment processes are also considered under secondary treatment as the constituents of the effluents from this type of treatment is similar to the conventional secondary treatment. Natural biological treatment refers to the process other than conventional wastewater treatment (primary, secondary, tertiary). This treatment makes use of natural bio-chemical processes to treat wastewater and can include: waste stabilization pond, constructed wetlands, overland treatment, nutrient film techniques, soil aquifer treatment, high-rate algal pond, floating aquatic macrophyte systems. Tertiary treatment: municipal wastewater effectively treated by a process in addition to secondary treatment of nitrogen and/or phosphorous and/or any other specific pollutant affecting the quality or a specific use of water: microbiological pollution, colour, etc. This treatment is meant to remove at least 95% for BOD and 85% for COD and/or a nitrogen removal of at least 70% and/or a phosphorus removal of at least 80% and/or a microbiological removal. Treatment process can include: membrane filtration (micro-; nano-; ultra- and reverse osmosis), infiltration / percolation, activated carbon, disinfection (chlorination, ozone, UV)