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- 1. SUSTAINABLE WASTEWATER TREATMENT ADAM WONG| CHLOE SIM | KOK KA SHING | PUI CHUN SHIAN | YEONG POH LING | ZACHARY OOI
- 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 WASTEWATERTREATMENT 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
- 9. WASTEWATER TREATMENT PROCESSES Wastewaterundergoes several stages in its treatment process which can be classified into 3 different stages.
- 10. PRELIMINARY TREATMENT What isthe 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 involvesremoving 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 ANDCLARIFIERS Typical Sedimentation Tanks Rectangular Horizontal Flow Tank Circular, Radial-flow tank Hopper bottomed, upward flow tank
- 13. APPROACHES TO SECONDARYTREATMENT Fixed Film Systems Suspended Film Systems Lagoon Systems
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- 17. WASTEWATER MANAGEMENT SYSTEM A PROCESSUSED 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 OFWASTE 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 OFWASTEWATER • 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 & DISADVANTAGESOF 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.
- 26. HOW DO THEYWORK?
- 27. DAMS • ANOTHER MAINSOURCE 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 GREENINITIATIVE 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
- 32. PROCESS OF MAKINGBIOEFFLUENT
- 33. POSSIBLE PROBLEMS TOTHE 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 FORNEW 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 • HAPPENSMORE 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 HASALWAYS 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”.
- 39. 1. WATER FROMLOCAL 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 • THEMAIN 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
- 44. NEWATER TECHNOLOGY TREATMENTPROCESS (4 STEPS)
- 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: UVDISINFECTION • 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 NEWATERTHE MAIN PILLAR OF SINGAPORE’S WATER SUSTAINABILITY? • BECAUSE NEWATER HAS MORE QUALITY THAN PUB WATER
- 48. 1) COLOUR • 20,000EXAMINATIONS 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 OFORGANIC 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
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- 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 TREATMENTSYSTEM (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 • INCLUDEIMPROVED MEMBRANES AND CONFIGURATIONS • MORE EFFICIENT PUMPING AND ENERGY-RECOVERY SYSTEMS • THE DEVELOPMENT OF PROCESS TECHNOLOGY, SUCH AS MEMBRANE DISTILLATION.
- 56. 4) MICROBIAL FUELCELLS • 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.
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