Water Pollution Abatement II Effluent Treatment Chapter 26 PPT 110

Primary Treatment Means to remove suspended solids Sedimentation Also reduces BOD & toxicity Sedimentation Quiescent flow and time Flotation Clarifiers Dissolved air and float

Sedimentation Different zones Clarification and Thickening Lab settling trials Particle density/shape/size Use of chemicals

Flotation Clarifiers Tiny Bubbles Flocculant Particle density Scoop or skim High Efficiency – high operating cost Whitewater Saveall applications

Secondary/Biological Treatment Duplicate Nature’s purification process Sufficient Aeration and mixing Micro’s eat O2 and make CO2 & water Adding nutrients to stimulate metabolic action

Water Treatment- Primary and Secondary

Aeration Lagoon

Secondary Treatment? Oxidation/Aeration lagoon Activated Sludge System Area and methodology Capital and operating cost 50% less than Activated Sludge System Even less space High nutrient requirement even when down Sensitive to changes in character and pH Biological Filter

Color Removal Brown Color Bleach Process Modifications Tannin and Lignin derivatives Bleach Process Modifications Lime/alum coagulation Precipitate color bodies out at high pH Incinerate in the lime kiln Rapid infiltration Through soil Adsorption and precipitation

Solid Handling Concentrate the Sludge Landfill Incinerate Pressure filters Belt Presses Reduce volume and transport cost Easier to handle Reduce environmental impact Improve heat value Landfill Incinerate Governmental Control – ground/surface water