- use of water: domestic, recreational, agricultural, industrial.
- Sources of water: groundwater, surface water, reclaimed water.
- Multiple barrier approach: monitoring SW protection -> treatment ->
distribution -> comsumers
- Water treatment objective: safe for human -> colour and odour, appealing to
customer -> operate at reasonable costs.
- Water treatment removal: 1,pathogenic organism 2, suspended material 3,
hazardous contaminants 4, odour, unpleasant tastes and colour.
- Waste water treatment objective: 1, removal of suspended and floatable
material 2, treatment of biodegradable organics, 3,elimination of pathogenic
organism 4, removal of nutrient. 5 removal of toxic compound.
- TDI: tolerable daily intake is the amount of a substance that can be comsumed
from all sources each day by an adult without risk.
- Disinfection: destroy pathogenic organisms
- Threshold: a level below which adverse effects will not occur.
- Carcinogen: some possibility of harm, no threshold level
- 2 approach for deriving guideline: 1, chemical with toxic effects. 2,
- Water quality parameters Class: 1, physical, chemical, microbiological,
- Turbidity: reduction in clarity
- Solid: filterable, nonfilterable, volatile solid burn at 600
- True color: true color, apparent color
- Odour: due to biological activity
- Chemical characteristics: alkalinity, hardness, nitrogen, heavy metal.
- Organics:carbonhydrates, oil, fat
Water treatment methods
- contaminant remove by: physical, chemical, biological
- physical unit operation: (apply physical force)1, screening 2,mixing 3, gas
transfer 4. Sedimentation. 5 filtration
- chemical unit operation: (chemical addition) 1.chemical precipitation 2.
Adsorption 3. Disinfection
- biological unit operation: remove biodegradable substances, convert into
gasees and biological cell tissue.
- Include: biological filtration, activated sludge treatment, anaerobic digestion.
- Drinking water treatment: 1. Screening 2.pre-sedimentaion (alum) 3.chemical treatment (chlorine) 4. Aerarion
- Coagulation: add chemical particle come together. (coagulant: alum, ferric
- Flocculation: particles growth.
- Filtration: sand or mix media filters
- Disinfection: ensure control of pathogenic organisms.
- Sources of sludge: 1, chemical coagulation, precipitation, softening removed in
sedimentation tanks 2. Filter backwash
- Disposal sludge: 1,discharge to municipal sewer 2,air drying 3,centrifugation 4,
pressure filtration 5 chemical recovery (ultimately to landfill)
- Watershed management: 1. Limit access 2.limit discharge 3. Pretreat water
- Water in lake influenced by: 1. Climatic conditions 2. Seasonal changes (spring
- Wastewater types: 1. Sanitary 2. Industrial 3. Stormwater 4. Infiltration
- Purpose of wastewater treatment: reduction of solid concentration and BOD
- Wastewater treatment method: pretreatment, primary sedimentation,
secondary biological stabilization, tertiary
- Pretreatment: 1. Screening ( bar screen, remove rocks) 2.comminution (grind
solid) 3.grit removal (sand, gravel by reducing water velocity ) 4. Flow
measurement 5. Pumping
- Primary sedimentation: removes suspended matter by reducing water velocity,
removes 30-50% of suspended solids, removes a portion of organic matter.
- Secondary sedimentation: removes biodegradable organics and suspended
matter not removed by primary treatment.
- Secondary treatment including: 1. Activated sludge 2. Fixed film reactors 3.
Lagoons. (BRC: rotating biological contact)
- Tertiary treatment: nutrient removal to reduce eutrophication
- Tertiary treatment including: 1. Chemical addition alum 2. Special biological
processes 3. disinfection
- Sedimentation: use gravity to separate suspended material from water. Basin
large enough allow particle hit the bottom. Factor: 1. Particle size. 2.expected