1. 1 IV. Wastewater Treatment Technologies Topic. IV. 1. Wastewater Quality; General Classification Wastewater Quality Definition: Wastewater is heterogenic mixture, containing impurities with various chemical composition, origin and dispersion, defining its quality. Wastewater Quality Parameters Classification: I. According to the Impurities Nature §Physical Parameters l Dispersion l Dry residuals l Suspended solids l Color l Smell § Chemical Parameters l Organic substances l Non-organic substances l Salts l Fats l Proteins l Carbohydrates l Dissolved gases l Ions §Biological Parameters l Bacteria l Viruses l Protozoa

2. 2 Wastewater Quality; General Classification II. According to the Impurities Dispersion §Dissolved - d < 10 -6 mm §Colloidal - d = 10 -6 - 10 -4 mm §Suspended - d > 10 -4 mm §Fine - d = 10 -4 - 10 -2 mm §Coarse - d > 10 -2 mm III. According to the Impurities Chemical Content §Organic Substances - 60 % §Mineral substances - 40 % IV. According to Biological Impurities Nature §Bacteria l Saprophytes l Pathogens §Viruses V. According to the Suspended Solids Settling Ability by 2 h §Norm - totally 65 g/d.ca §Settling - 60 - 70 % §Non-settling - 30 - 40 %

3. 3 Wastewater Quality; General Classification Dissolved and Colloidal Substances I. Mineral substances §Chlorides - 9 g/d.ca §Alkali substances §Sulphates (toxic if > 200 mg/l) §Phosphates l Organic l Mineral (orthophosphates) l Norm - 4,4 /d.ca §Nitrogen - 8 - 12 g/d.ca l Organic (proteins, aminoacids) l Mineral ( ) §Heavy metals ions §Radioactive elements l Measure - Kurie (Ku) 1 Ku = M RAD, which realises 3,7  / s

4. 4 Wastewater Quality; General Classification Dissolved and Colloidal Substances II. Organic substances §Fats - 10 % §Carbohydrates - 25 - 50 % §Proteins - 40 - 60 % §Carbamide §Detergents, Herbicides, Pesticides