Environmental Engineering 343
description
Transcript of Environmental Engineering 343
ENVIRONMENTAL ENGINEERING
343Lecture 7:
Water Treatment
Philadelphia UniversityFaculty of Engineering
Department of Civil EngineeringFirst Semester, 2013/2014
OBJECTIVES OF WATER TREATMENT“ To remove harmful microorganisms
or chemicals, thereby preventing the spread of disease in order to supply clean and safe water for public demand”
WATER SOURCEWater 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
WATER TREATMENT PROCESSES
SELECTION OF TREATMENT PROCESSESSelection of the set of Treatment Processes will be based
on : Sources of water intake Characteristic of waterDetailed 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
WATER TREATMENT PROCESSES 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
SURFACE WATER TREATMENTTypical treatment plant for surface water1. Screening and grit removal2. Primary sedimentation (settling/clarification)3. Coagulation (Rapid mixing)4. Flocculation5. Secondary sedimentation6. Filtration7. Sludge processing8. Disinfection
GROUNDWATER TREATMENT
Typical treatment plant for groundwater1. Aeration2. Flocculation/precipitation3. Sedimentation4. Recarbonation5. Filtration6. Disinfection7. Solids processing