1. E NVIRONMENTAL E NGINEERING 441 Lecture 3: Water Treatment Philadelphia University Faculty of Engineering Department of Civil Engineering First Semester, 2013/2014

2. O BJECTIVES OF W ATER T REATMENT “ To remove harmful microorganisms or chemicals, thereby preventing the spread of disease in order to supply clean and safe water for public demand”

3. W ATER S OURCE Water source could be River Lakes Groundwater; most likely better quality than surface water Rainwater ++/ Dam Raw water quality varies with the source, and if the source is surface water, the quality vary seasonally, particularly with flooding, upland and lowland, etc

8. W ATER T REATMENT P ROCESSES

10. S ELECTION OF T REATMENT P ROCESSES Selection of the set of Treatment Processes will be based on : Sources of water intake Characteristic of water Detailed raw water quality analysis for a minimum of one year, or longer, at periods of high, low and medium flows. The parameters to be looked at all those listed in the legislative standards Cost Suitability of the processes for removing particulate impurities. Example: Turbidity; suitable process might be coagulation, sedimentation or filtration For pathogen, pre or post chlorination, UV, ozone, or chloramines

12. W ATER T REATMENT P ROCESSES Pretreatment of water Screening Storage, Equalization & Neutralization Aeration Chemical pretreatment Sedimentation, coagulation and flocculation Filtration Slow Sand filtration Rapid Gravity filters Disinfestations Chloramines Ozone UV radiation Chlorination Fluoridation Advance Water Treatment Iron & Manganese Removal Water Softening by Chemical Precipitation Ion Exchange Adsorption Chemical oxidation Membrane Processes

13. S URFACE W ATER T REATMENT Typical treatment plant for surface water 1. Screening and grit removal 2. Primary sedimentation (settling/clarification) 3. Coagulation (Rapid mixing) 4. Flocculation 5. Secondary sedimentation 6. Filtration 7. Sludge processing 8. Disinfection

14. G ROUNDWATER T REATMENT Typical treatment plant for groundwater 1. Aeration 2. Flocculation/precipitation 3. Sedimentation 4. Recarbonation 5. Filtration 6. Disinfection 7. Solids processing