2. WHAT IS WASTEWATER?
• Liquid waste/sewage discharged into
water bodies
• Used water/liquid that contains
impurities or pollutants in different
forms
• Produced from different activities
(Industrial, Commercial, Household etc)
• Waste from kitchen, toilet, laundry,
swimming pools etc.
3. SOURCES OF WASTEWATER?
1 – Domestic Wastewater
Ø Wastewater from normal living area
Ø Sanitary wastewater
Ø Generated by home dwellings, public restrooms, hotels, hospitals
& other health centers
Ø Mostly residential and commercial area
Ø 99.9% of water containing only 0.1% of organic & inorganic
solids & also microorganisms
2 – Industrial Wastewater
Ø Generated by large scales from industry areas
Ø Contains conventional pollutants
Ø Contains toxic pollutants
4. SUSTAINABLE WASTEWATER TREATMENT
• Effective, simple to
operate & low cost
• Environmental-
friendly
• Combination of
physical, chemical &
biological processes
• To remove solids,
organic matter from
wastewater
• Partial reduction or
complete removal
of excessive
impurities in
wastewater
Objectives of
wastewater treatment :
• Protect the health
of humans &
environment
• Preserve & protect
environmental
quality
• Need to be able to
recover nutrients
and energy from
wastewater
5. WASTEWATER TREATMENT METHODS
• Application of physical forces to treat sewage
• No changes chemically or biologically
• Eg. Screening, mixing, sedimentation, filtration
etc
• Involves using chemical reaction to
improve water quality
• Removal or conversion of pollutants are
done by addition of chemicals
• Eg. Precipitation, disinfection,
chlorination etc.
• Removes pollutants by biological activity
• Microorganisms such as bacteria are used
in biochemical decomposition
• Can be divided into aerobic/anaerobic
methods based on availability of oxygen
6. TYPES OF WASTEWATER TREATMENT SYSTEM
INDIVIDUAL
SEPTIC
TANK
CONNECTED
SEWAGE
SYSTEM
7. INDIVIDUAL SEPTIC TANK - Commonly used in Msia
- Multi chamber storage tank that
separates the liquid between the
solid waste
- Liquid is allowed to flow out of the
storage tank & be disposed
separately
- Can partially treat sewage
- Of low quality & bad smell
- Works by allowing raw sewage to
flow into tank whereby the solid
waste/ sludge settles at the bottom
of the tank
8. CONNECTED SEWAGE SYSTEM
- have sewage outlets that are
directly linked to a sewage
treatment plant
- Is a combined plant that converts
raw sewage into effluent and solid
waste
- Treats water by combining oxygen
and organic waste to speed up a
natural biological breakdown
- Comprises a network of
underground sewer pipes, pump
stations, sewage treatment plants
& sludge treatment facilities
- Generally operate by gravity
10. PRELIMINARY TREATMENT
What is the
purpose?
to protect the operation of
the wastewater treatment
plant.
-Preliminary Treatment
operations typically includes
screening, grit removal.
-.Remove or to reduce in size
the large, entrained, suspended
or floating solids.
Example: pieces of wood,
cloth, paper, plastics, garbage
-Remove heavy inorganic
solids , called grit. Example:
sand and gravel, metal or
glass.
-Remove excessive
amounts of oils or
greases.
11. Primary
Secondary
Tertiary
• Mainly involves removing
solids & some organic
materials
• Solids are removed or
separated from
wastewater by
sedimentation
• Purpose : reduce the
velocity of wastewater
sufficiently to permit
solids to settle and
floatable materials to
surface
• Biological treatment is used
to remove organic &
suspended solid waste
• Uses biological activity to
catch dissolved organic
matter
• Purpose : reduce BOD
(biochemical oxygen
demand). Wastewater is
cleaned by microorganisms
• Water is thoroughly cleaned
by using advance treatment
systems
• Chemicals such as disinfection
are poured to reduce nitrogen
& phosphates
• Bacteria is used to denitrify
nitrates in water to produce
N02 which is then released
into atmosphere
• Includes both biological &
chemical treatments
CONVENTIONAL
WASTEWATER
TREATMENT
PROCESS
12. SEDIMENTATION TANKS AND CLARIFIERS
Typical
Sedimentation
Tanks
Rectangular
Horizontal Flow
Tank
Circular,
Radial-flow
tank
Hopper
bottomed,
upward
flow tank
17. WASTEWATER MANAGEMENT
SYSTEM
A PROCESS USED TO CONVERT WASTEWATER
• REUSE AND RECYCLING
• COLLECTION of WASTEWATER
1) CENTRALIZED SYSTEMS
2) DECENTRALIZED SYSTEMS
• AWARENESS of WASTEWATER
• TREATMENT of WASTEWATER
18. 1. REUSE & RECYCLING WASTEWATER
• TREATED WASTEWATER OR IN SOME CASES
URBAN RUNOFF OR STORM WATER ( RAIN
WATER HARVESTING ) COULD NE REUSED
EFFICIENTLY.
• WATER RECYCLING IS REUSING TREATED
WASTEWATER FOR BENEFICIAL PURPOSES
- AGRICULTURAL AND LANDSCAPE
IRRIGATION
- DRINKING WATER
- INDUSTRIAL PROCESSES
- TOILET FLUSHING
- REPLENISHING A GROUND WATER BASIN.
• ENSURE WATER QUALITY APPROPRIATE FOR
THE USE
19. 2. COLLECTION OF WASTE WATER
• GATHER THE USED WATER FROM OUR HOMES, BUSINESSES AND INDUSTRIES
AND CONVEY IT TO A WASTEWATER TREATMENT PLANT
• TWO WAYS CAN BE USED TO COLLECT WASTEWATER :
I) CENTRALIZED SYSTEMS
II) DECENTRALIZED SYSTEMS
20. I) CENTRALIZED SYSTEMS
• PUBLIC SEWER SYSTEMS
• SERVE ESTABLISHED TOWNS AND
CITIES
• PROVIDE TREATMENT AND DISPOSAL
SERVICES FOR NEIGHBORING SEWER
DISTRICTS
• LARGE-SCALE SYSTEM
• GATHER WASTEWATER FROM MANY
USERS FOR TREATMENT AT ONE OR
FEW SITES
• ECONOMICAL, ALLOW FOR GREATER
CONTROL, REQUIRE FEWER PEOPLE
• PRODUCE ONLY ONE DISCHARGE TO
MONITOR INSTEAD OF SEVERAL.
21. II) DECENTRALIZED SYSTEMS
• DO NOT CONNECT TO A PUBLIC SEWER SYSTEM
• MAY BE TREATED ON SITE (MOST COMMON) OR
DISCHARGED TO A PRIVATE TREATMENT PLANT
• REQUIRE WELL TRAINED STAFFS AND HIGH
COST OF MAINTENANCE
q failure cases happened
q lack of improper
maintenance
q overcome by providing
the person in charge of
maintaining the system
with enough skills and
practices
22. 3. TREAMENT OF WASTEWATER
• TO REDUCE THE LEVEL OF
POLLUTANTS IN THE
WASTEWATER
• ALLOW HUMAN AND INDUSTRIAL
EFFLUENTS TO BE DISPOSED OF
WITHOUT DANGER TO HUMAN
HEALTH
• UNACCEPTABLE DAMAGE TO THE
NATURAL ENVIRONMENT
• CAN BE NATURALLY TREATED BY
THE SUN, VEGETATION,SOILS
AND MICROORGANISMS
23. ADVANTAGES & DISADVANTAGES OF
WASTEWATER TREATMENT
Can provide clean water that is potable
Maintain clean water for reuse
Filter out potential disease-causing microorganisms
& destroys harmful organisms
Purifies water
Provides job opportunities for water treatment
researches & maintenance
Saves time, energy & resources
Increased cost & financing
Maintenance troubles
Triggered health concerns among public
24. CASE STUDY 1 : MALAYSIA
- A SOUTHEAST ASIAN COUNTRY WITH A
POPULATION OF 30 MILLION PEOPLE.
- HAS 100% ACCESS TO IMPROVED
WATER SOURCE AND 96% ACCESS TO
IMPROVED SANITATION.
25. WATER CATCHMENT AREAS
• ONE OF THE MAINS SOURCE OF
WATER FOR MOST OF MALAYSIA.
• TOTAL OF 189 RIVER BASINS IN THE
ENTIRE MALAYSIA.
• BIGGEST WATER CATCHMENT AREA
IN WEST MALAYSIA: BANJARAN
TITIWANGSA.
27. DAMS
• ANOTHER MAIN SOURCE OF WATER
FOR MALAYSIANS.
• TOTAL OF 34 DAMS IN MALAYSIA THAT
SUPPLIES WATER.
• SG. SELANGOR DAM, BATU AND
KLANG GATES DAM AND ETC SUPPLIES
98% OF WATER TO CITIES LIKE KUALA
LUMPUR & SELANGOR.
28. PROBLEMS WITH DAMS
• CANNOT REPLENISH FAST
ENOUGH DURING THE DRY
SEASON.
• CAN ONLY STORE SO MUCH
WATER THAT IS ENOUGH FOR
A PERIOD OF TIME.
• DESTROYS SURROUNDING
ECOSYSTEM.
29. INDAH WATER KONSORTIUM
• A WHOLLY OWNED GOVERNMENT
COMPANY TASKED WITH
DEVELOPING AND MAINTAINING
AN EFFICIENT SEWERAGE SYSTEM IN
WEST MALAYSIA.
• FOUNDED IN 1994
• OPERATES IN EVERY STATE IN WEST
MALAYSIA EXCEPT KELANTAN AND
JOHOR.
30. BIOEFFLUENT
• A GREEN INITIATIVE PROGRAM.
• REUSES FILTERED WASTEWATER
TO BE USED IN OTHER SECTORS.
• USES PREVIOUS TECHNOLOGY
LIKE REVERSE OSMOSIS, SAND
FILTERING AND ETC.
31. BENEFIT OF BIOEFFLUENT
• EFFICIENT POLLUTION CONTROL
• ALLOWS FOR A MORE SUSTAINABLE WATER RESOURCE
• REDUCE PRESSURE ON NATURAL WATER RESOURCES
33. POSSIBLE PROBLEMS TO THE SYSTEM
BAD ODOUR COMING FROM SEWAGE
PLANTS
• ONE OF THE MOST NOTABLE PROBLEM.
• CAUSES AN UNHAPPY WORKING
PLACE AND EFFECTS RESIDENCES
NEARBY.
• HYDROGEN SULPHIDE IS THE CAUSE
OF THE BAD SMELL.
34. INSUFFICIENT SPACE FOR NEW WATER
TREATMENT PLANTS
• MORE NOTICEABLE IN PLACES LIKE
SINGAPORE OR WHERE LAND IS
SCARCE.
• HARD TIME FOR OLD PLANTS TO
DEAL WITH NEW LARGER VOLUME
OF WASTE.
• RETROFIT OLD PLANTS WITH NEWER
TECHNOLOGY TO INCREASE
TREATMENT CAPACITY.
35. AGING INFRASTRUCTURE
• HAPPENS MORE FREQUENTLY IN
STILL DEVELOPING COUNTRIES.
• HIGHER AND HIGHER
MAINTENANCE COST THUS
CAUSING A WASTAGE OF
TAXPAYERS MONEY.
• RISK OF A TREATMENT PLANT
SHUTTING DOWN.
36. CASE STUDY 2 : SINGAPORE
• Southeast Asian island
country, with an estimated
population of 5.5 million
living on less than 750
square kilometers of land
• Singapore is known for its
robust economy but is
insufficient in one of the
world’s most important daily
resources, water
• Location of centre: 20 Koh
Sek Lim Road, Singapore
37. • WATER HAS ALWAYS BEEN SINGAPORE’S FIRST
NATIONAL PRIORITY
• LEE KUAN YEW, SINGAPORE’S FIRST PRIME
MINISTER, PUSHED TO DEVELOP A SELF-
SUFFICIENT WATER SUPPLY OF SINGAPORE IN
RESPONSE TO THE SHORTAGE OF WATER IN THE
1960S AND ‘70S
• OVER THE LAST 50 YEARS, SINGAPORE HAS BUILT
A ROBUST AND DIVERSIFIED SUPPLY OF WATER
KNOWN AS THE “FOUR NATIONAL TAPS”.
38.
39. 1. WATER FROM LOCAL CATCHMENT
• REPRESENTS ONE OF THE PILLARS OF SINGAPORE’S
SUSTAINABLE WATER SUPPLY
• SINCE 2011, THE WATER CATCHMENT AREA HAS BEEN
INCREASED FROM HALF TO TWO-THIRDS OF
SINGAPORE’S LAND SURFACE
- THE MARINA, PUNGGOL AND SERANGOON RESERVOIR.
• IN THE LONG RUN, THE WATER CATCHMENT AREA WILL
INCREASE TO 90% OF SINGAPORE’S LAND AREA
- MADE UP OF UNPROTECTED CATCHMENTS WHICH
CONSISTS OF LAND SUCH AS RESIDENTIAL, COMMERCIAL
AND NON-POLLUTIVE INDUSTRIAL
40. 2. IMPORTED WATER
• ONLY ABLE TO SUPPLY HALF THE
NATION’S WATER SUPPLY.
• 50% MORE IS IMPORTED FROM,
JOHOR, MALAYSIA
• THE CONTRACT DUE TO EXPIRE IN
2061
41. 3. NEWATER
• THE MAIN PILLAR OF SINGAPORE’S WATER
SUSTAINABILITY
• IS A HIGH-GRADE RECLAIMED WATER TREATMENT
PLANT USING DOMESTIC WASTEWATER WHICH IS
THEN FURTHER PURIFIED USING ADVANCED
MEMBRANE TECHNOLOGY AND ULTRA-VIOLET
DISINFECTION
• CURRENTLY, SINGAPORE’S FOUR NEWATER
PLANTS ARE ABLE TO CONTRIBUTE 30% OF THE
NATION’S CURRENT WATER NEEDS
• IS FORESEEN THAT BY 2060, NEWATER WILL BE
ABLE TO MEET UP TO 50% OF SINGAPORE’S
FUTURE WATER NEEDS.
42. 4. DESALINATED WATER
• TREATING SEAWATER
• IS THE MOST ENERGY-INTENSIVE AND
MOST EXPENSIVE SOURCE OF WATER
TO PRODUCE
• TWO DESALINATION PLANTS WITH A
COMBINED CAPACITY OF 100MGD CAN
NOW MEET 25% OF WATER NEEDS IN
SINGAPORE
• IS ANTICIPATED THAT DESALINATED
WATER CAN MEET UP APPROXIMATELY
30% OF SINGAPORE’S FUTURE WATER
NEEDS
45. STEP 1: MICROFILTRATION (MF)
• WHERE THE TREATED UTILIZED WATER IS PASSED THROUGH A MEMBRANE. SUSPENDED SOLIDS,
COLLOIDAL PARTICLES, DISEASE-CAUSING MICROBES, AND PROTOZOAN CYSTS ARE FILTERED
OUT AND RETAINED ON THE MEMBRANE SURFACE
• THE FILTRATE CONTAINS ONLY WATER, DISSOLVED SALTS AND ORGANIC MOLECULES.
Step 2: Reverse Osmosis (RO)
• In which a semi-permeable membrane is used
• has very small pores, allowing only very small molecules like water molecules
to pass through
• undesirable contaminants such as bacteria, viruses, heavy metals, nitrate,
chloride, sulphate, disinfection by-products, aromatic hydrocarbons, pesticides
and others cannot pass through
• the processed water is free from viruses, bacteria and contains negligible
amount of salts and organic matters.
46. STEP 3: UV DISINFECTION
• THE WATER IS ALREADY OF A HIGH GRADE WATER QUALITY
• ACTS AS A FURTHER SAFETY BACK-UP TO THE RO
• ULTRAVIOLET OR UV DISINFECTION IS USED TO ENSURE THAT ALL MICROORGANISMS ARE
INACTIVATED AND THE PURITY OF THE PRODUCT WATER GUARANTEED.
Step 4: Before Storing
• the pH value of the NEWater is to be are balanced with the addition
of some alkaline chemicals to restore the acid-alkali or pH balance
• After the pH balance has been achieved, the NEWater is now ready to
be piped off to its wide range of applications.
47. WHY IS NEWATER THE MAIN PILLAR OF SINGAPORE’S
WATER SUSTAINABILITY?
• BECAUSE NEWATER HAS MORE QUALITY THAN PUB WATER
48. 1) COLOUR
• 20,000 EXAMINATIONS IN THE COURSE OF
THE RECENT TWO YEARS HAVE BEEN
DIRECTED
• HAVE DETERMINED THAT NEWATER IS
CLEANER THAN (PUBLIC UTILITIES BOARD)
PUB WATER
• PHYSICALLY, NEWATER IS CLEAR AND
SHINING
• THE RIVER SOURCES AND RESERVOIR
WATER HAS MORE COLOR AS THEY
CONTAIN MORE MINERALS AND NATURAL
SUBSTANCE
49. 2) SUSPENDED PARTICLES
• THE RIVER SOURCES AND RESERVOIR
WATER ALSO CONTAIN MORE
SUSPENDED PARTICLES
• THESE PARTICLES ARE WASHED INTO
RIVERS AND RESERVOIRS BY RAINFALL
RUNNING OFF THE GROUND
• NEWATER THEN AGAIN IS CLEARER,
MUCH CLEARER THAN PUB WATER.
50. 3) LEVEL OF ORGANIC SUBSTANCES
• THE ORGANIC SUBSTANCE OF NEWATER IS
LESS THAN ONE-TENTH OF PUB WATER
CAUSING INDUSTRY USERS TO FIND
NEWATER TO BE APPEALING
• THE WAFER FABRICATION PLANTS TAKE THE
PUB WATER AND PROCESS IT TO REDUCE
THE ORGANIC SUBSTANCE TO A LEVEL THAT
IS ACCEPTABLE FOR THEIR OPERATIONS.
• STARTING FROM NEXT YEAR, THE WAFER
FABRICATION PLANTS IN SINGAPORE WILL
UTILIZE NEWATER INSTEAD OF PUB WATER
BECAUSE NEWATER IS CLEANER THAN PUB
WATER, AND IS MORE APPROPRIATE FOR
THEIR OPERATIONS.
51. 4) BACTERIA COUNT
• HARMFUL TO HEALTH AND ARE FOUND
IN ANIMAL WASTE AND SOIL
• RAIN THAT FALLS ONTO THE GROUND
WILL CARRY THE BACTERIA INTO THE
RIVERS AND THE RESERVOIRS
• BACTERIOLOGICAL QUALITY OF
NEWATER IS AS GOOD AS PUB WATER
DUE TO THE FACT THAT PRESENCE OF
BACTERIA AND VIRUS IS NOT
DETECTABLE, THEREBY MEETING THE
WORLD HEALTH ORGANIZATION'S
STANDARDS
53. 1) MEMBRANE BIOREACTOR (MBR)
• MEMBRANE SYSTEMS HAVE BEEN CRITICAL
TO THE DEVELOPMENT OF ADVANCED
WATER-RECLAMATION SYSTEMS
• PROVIDE EXCELLENT PRE-TREATMENT FOR
REVERSE OSMOSIS (RO), WHICH CAN
REMOVE A VARIETY OF DISSOLVED
CONSTITUENTS
54. 2) NATURAL TREATMENT SYSTEM (NTSS)
• HAVE THE ADVANTAGE OF
BEING ABLE TO REMOVE A
WIDE ASSORTMENT OF
CONTAMINANTS, INCLUDING
NUTRIENTS, PATHOGENS,
AND MICRO-CONSTITUENTS
SUCH AS PHARMACEUTICALS
AND ENDOCRINE-
DISRUPTING CHEMICALS
• IS PROVEN EFFECTIVE FOR
THE TREATMENT OF POTABLE
WATER
55. 3) NANOTECHNOLOGY
• INCLUDE IMPROVED MEMBRANES AND CONFIGURATIONS
• MORE EFFICIENT PUMPING AND ENERGY-RECOVERY SYSTEMS
• THE DEVELOPMENT OF PROCESS TECHNOLOGY, SUCH AS MEMBRANE DISTILLATION.
56. 4) MICROBIAL FUEL CELLS
• ELECTRICAL ENERGY CAN BE EXTRACTED
DIRECTLY FROM ORGANIC MATTER PRESENT
IN THE WASTE STREAM BY UTILIZING
ELECTRON EXCHANGE TO CAPTURE THE
ENERGY PRODUCED BY MICROORGANISMS
FOR METABOLIC PROCESSES
• HAS THE POTENTIAL TO PRODUCE
ELECTRICAL ENERGY DIRECTLY FROM
ORGANIC MATTER IN THE WASTE STREAM
57. 5) URINE-SEPARATING TOILET
• 3 DIFFERENT TANKS ARE
CONSTRUCTED, WHICH MAKES THE
PROCESS OF WASTE TREATMENT
MUCH EASIER AND EFFICIENT
• KEY TO MANAGE NUTRIENTS WITH
MINIMAL REQUIREMENTS FOR
OUTSIDE RESOURCES, SUCH AS
ADDITIONAL ENERGY.
