iv- Select the correct sequence of the treatments or methods which are generally given to treat raw water supplies. 1. Screening, sedimentation coagulation, filtration, disinfection 2. Screening, sedimemation disinfection aeration coagulation 3. Filtration sedimentation cosgulation disinfection 4. Sedimentation, screening disinfection, filtration, coagulation 5. Screening, fatration coagulation sedimentation disinfection Choose the correct sequence of filtration processes used for sequential removal of particles from coarser (1,m ) to finer grain sizes A. Microfiltration 2. Uerafiltation Nanofiltration Reverse Osmosio Choose the correct answer from the options given below D. C, B, A A. .n. C. 0 3. D.C.A.B A. E, D, C vi- Which coagulant is widely used for sewage treatment? 1. time 2. Alum 3. Fertic chloride 4. Ferric sulphate