1. Water and Wastewater Treatment
DISPOSAL TECHNOLOGY
SCT 3043

2. Introduction
• Wastewater
– Any water that has been adversely affected in quality by
anthropogenic influence.
– Have variety of potential contaminants
• Waste Treatment
– Waste treatment is to restore organic matter and energy
from waste streams
– E.g. : composting and incineration.
• Wastewater Treatment
– The objective of wastewater treatment is depending on
where the wastewater is to be sent after treatment.

3. Wastewater treatment plant

4. Wastewater Treatment Methods
• The waste treatment method can be classified into
three (3) main categories which is physical, chemical
and biological treatment method.
• Physical Treatment Method (Gravity, electrical
attraction, van der Walls or physical barrier)
 Screening
 Sedimentation
 Flotation
 Filtration

5. Flocculation or coagulation

6. Wastewater Treatment Methods
 Chemical treatment method
› Rely on chemical reactions. Chemical characteristics of the
pollutants and chemical characteristics of the products.
› Precipitation
› Wet Oxidation
› Ion Exchange
› Chemisorption

7. Wastewater Treatment Methods
• Biological treatment method
– Use living organisms either to consume and break down
into a non-hazardous form.
• Aerobic degradation
• Anaerobic degradation
• Microorganisms

8. Stage In Wastewater Treatment
Process

9. Preliminary Treatment
• Uses screens to remove the larger solid inorganic
material such as paper and plastic.
• Followed by the removal of particles such as grit and
silt
The objective of preliminary treatment is the
removal of coarse solids and other large materials
often found in raw wastewater.
The purpose of screening also to protect
downstream mechanical plant from damage

10. Secondary Treatment
Biological process which breaks down dissolved and suspended
organic solids by using naturally occurring micro-organisms. It is
called the activated sludge process.
Secondary treatment technologies include the basic activated
sludge process
 Activated Sludge
 Trickling Filters
 Rotating Biological Contactors

11. Tertiary Treatment
• Use disinfection for tertiary treatment to reduce
pathogens, which are micro-organisms which can
pose a risk to human health. – Chlorine
Effluent storage
• Although not considered a step in the treatment
process, a storage facility is, in most cases, a critical
link between the wastewater treatment plant and
the irrigation system.

12. Use of treated wastewater
o Reuse of treated wastewater for irrigation
o Soil injection and land spreading
o Animal feed
o Recycling of bio-solids and sludge

13. Advantage of wastewater
treatment
• To reduce the demand for fresh water drinking
sources
• Reduce the amount of wastewater discharged
without treatment.
• The preparation of the waste water rich in nutrients
can increase agricultural production in areas that lack
water resources.
• It indirectly could also reduce the pollution of rivers
and groundwater flow.

14. Disadvantage of wastewater
treatment
• If the process is carried out on a large scale, the
results of water and wastewater utilities may fall.
• For some countries the seasonal, re-use of waste
water may also be used only in certain seasons.
• The production of gases such as sulfuric acid
produced during the treatment process that can lead
to chronic health problems.
• Application of untreated waste water properly as
irrigation water or injected water flow can cause
groundwater contamination.

15. Summary
• By now, you should be able to understand the
concept of water and wastewater treatment
References
NESC. 2005. Wastewater Reuse Conserves Water and Protect Waterways. USA:
National Environmental Services Centre.
EPA,1995. Waste Water Treatment Manuals Preliminary Treatment. Ireland.
Environmental Protection Agency
DAF. August 2004. Eco-efficiency for Australian dairy processors. Australia: Dairy
Australia.

16. Thank you
Q&A SESSION