PSAPSAPhilippine Sanitation AlliancePhilippine Sanitation Alliance

Low-Cost Wastewater Treatment OptionsLow-Cost Wastewater Treatment OptionsEngineer Carlito Santos, Jr.Engineer Carlito Santos, Jr.

Philippine Sanitation Philippine Sanitation AllianceAlliance

Helping cities and the private sector implement Clean Water Act

• 3 year project funded by USAID, led by AECOM International Development

• Promoting low-cost, low-maintenance wastewater treatment technologies (housing, markets, hospitals, hotels/restaurants)

• Promoting improved sanitation and hand washing through information and media campaigns

• Working with four new cities (Cagayan de Oro, Meycauayan, Sta. Rosa, Zamboanga) and six LINAW cities (Calbayog, Dumaguete, Iloilo, Malaybalay, Muntinlupa, Naga)

Technology MatrixTechnology Matrix

• Presents common Presents common wastewater technologies for:wastewater technologies for:– Pretreatment: grease, grit Pretreatment: grease, grit

and trash controland trash control– Primary treatment: Septic Primary treatment: Septic

tanks and other devicestanks and other devices– Secondary treatment: Secondary treatment:

natural and mechanical natural and mechanical systems systems

• Compares cost of Compares cost of equipment, operation and equipment, operation and maintenance, and space maintenance, and space neededneeded

Pretreatment Device Pretreatment Device Grease InterceptorGrease Interceptor

• Removes grease from wastewater before treatment in a septic tank

• Useful for restaurants, commercial kitchens

• Install outside of the facility and size according to Plumbing Code

Pretreatment Device Trash Trap

• Removes solids and trash from wastewater

• Useful at markets for meat, fish and vegetable preparation areas

• Install where it will be easy to clean and maintain

Pretreatment Device Pretreatment Device Bar ScreenBar Screen

• Removes rags, twigs and other solids from the wastewater before entering the treatment plant.

• Some are manual and some mechanical.

• Always observe safety procedures. Turn off power prior to servicing.

Primary Treatment System Primary Treatment System

BiodigesterBiodigester

• Decomposes high strength organic waste to generate methane

• Useful for hog and animal raising, septage treatment, food processing

• Methane can be captured and used as an energy source

Primary Treatment Device Primary Treatment Device Septic TankSeptic Tank

• Sealed, multi-chambered tank used to partially treat sewage

• Allows heavy solids to settle to form sludge

• Fats, oil and grease float to form scum

• Must be cleaned every 3 to 5 years to function properly

Primary Treatment Device Primary Treatment Device Anaerobic Baffled Reactor Anaerobic Baffled Reactor (ABR)(ABR)

UASB ModuleBaffled Module

Pre-treatedinfluent

granularsludge

bedsludge blanket

downflowchamber

upflowchamber Vertical baffles

effluentgutter

solid media(plasitc

(beverage crates)

gas/liquid/solidsphase separator

settling zone• Multi-chambered tank used to partially treat sewage

• Sewage flows up through sludge blanket where solids are trapped

• Low-maintenance, low O&M costs

•Can be built under parking lot or bb court

Secondary Treatment Device Secondary Treatment Device Sequencing Batch Reactor Sequencing Batch Reactor (SBR)(SBR)

• Mechanical system for larger volumes of sewage

• Performs treatment processes in one tank

• Lower cost to install and operate than conventional mechanical systems

Secondary Treatment Secondary Treatment System System Planted Gravel FilterPlanted Gravel Filter

• Treats septic tank or ABR effluent so that it may be discharged

• All water stays under the surface of the gravel so no odor or mosquitoes

• Plants add beauty and flowers may attract birds and butterflies

Secondary Treatment Secondary Treatment System System Surface Flow WetlandsSurface Flow Wetlands

• Used for larger housing developments, golf courses or other large sources of wastewater

• Require large land area

• Can create habitat for birds, wildlife

Secondary Treatment Secondary Treatment Device Device Media FilterMedia Filter

• Wastewater flows from septic tanks to media filter for further treatment

• Media can be sand, gravel, cocopeat, or plastic

• Can be above or below ground depending on land availability

Secondary Treatment Secondary Treatment System System Sewage LagoonSewage Lagoon

• Sewage is treated in open ponds through natural processes

• Can be designed without the need for electricity or chemicals

• Locate far from houses as odor and mosquitoes can be a nuisance

Secondary Treatment Secondary Treatment System System Leach Fields Leach Fields

• Long trenches filled with gravel to dispose of septic tank effluent

• Soils must not contain too much sand or clay

• Groundwater must be deep enough to prevent contamination

Thank you!Thank you!

Engineer Carito Santos, Jr.Philippine Sanitation Alliance

AECOM International DevelopmentSuite 4022, Golden Rock Bldg.

168 Salcedo StreetLegaspi Village, Makati City 1229

Tel/Fax (632) 819-0687Cell: 0922-829-7696

E-mail: clsantos41@yahoo.com