Lecture No_3 Waste water treatment

1.1 Introduction To remove contaminants from waste water there are three mechanisms 1 . Physical Mainly physical properties like  Screening  Sedimentation  Floatation  Filtration 2. Chemical Chemical properties like  Precipitation  Coagulation  Disinfection A.B@JiT 2 Cont’d 3. Biological The biological includes  Biological filtration Activated sludge Combination of physical and chemical process Air striping Carbon adsorption Oxidation and reduction Ion exchange Membrane process A.B@JiT 3 Cont’d 1.2 Waste water treatment WWT process generally grouped as 1. Primary  Remove identifiable  Suspended solids  Floating matter 2. Secondary(biological) Organic matter that is soluble or insoluble 3. Tertiary (advanced) May involve  Physical, chemical or biological processes or their combination As it is expensive ,used for high quality if required than primary and secondary.