ENVIRONMENTAL CONTROL & MANAGEMENT

Muhd Hasyir Mirza b. Dazirman

SEWAGE TREATMENT

INTRODUCTION OF SEWAGE TREATMENT- Process of removing contaminants from wastewater, primarily from household sewage. Physical process Chemical process Biological process - Sewage treatment may also be referred to as wastewater treatment.

SEWAGE SLUDGEA by-product of a sewage

treatment; semi solid waste or

slurry

SEWAGESewage is generated by:

It includes household waste liquid from toilets, baths, showers, kitchens, and sinks draining into sewers. In many areas, sewage also includes liquid waste from industry and commerce.

PROCESS STEPSSewage treatment involved three stages:• Primary• Secondary• Tertiary

PRELIMINARY TREATMENT• Physically process• Use screens, grit removal and settling

tanks.• To remove large solids, dead animals,

rocks, sticks, tree limbs, leaves, branches, and other large objects. from enter the treatment line.

PRIMARY TREATMENT• Consists of temporarily holding the sewage in a

quiescent basin • Heavy solids can settle to the bottom while oil,

grease and lighter solids float to the surface. • The settled and floating materials are removed

and the remaining liquid may be discharged or subjected to secondary treatment.

SECONDARY TREATMENT

To remove the residual organics and suspended solids. Degrading most of the organic matter – Aerobic biological treatment Removed during secondary sedimentation is normally combined with

primary sludge for sludge processing. Process include: - Activated sludge - Tricking filters - Rotating biological contactor

TERTIARY TREATMENT

To provide a final treatment stage to further improve the effluent quality before it is discharged to the receiving environment

Process includes: - Filtration - Nitrogen removal - Biological nutrient removal