CHAPTER 11 : WASTEWATER MANAGEMENT

DEFINITION OF WASTEWATER AND SEWAGE


Wastewater

• Waste Water is any water that has been adversely affected in quality by anthropogenic influence.
• It comprises liquid waste discharged by domestic
residences, commercial properties, industry, and or agriculture and can encompass a wide range of potential contaminants and concentrations.


Sewage

• “sewage” means any liquid waste or wastewater discharge containing human, animal, domestic, or
putrescible matter in suspension or solution, and includes liquids containing chemicals in solution either in the raw, treated or partially treated form;

Sewage Content
• Organic matter
• Nutrients (Nitrogen, Phosphorus, Potassium)
• Inorganic matter (dissolved minerals)
• Toxic chemicals (heavy metal and pesticides)
• Pathogens

Individual Septic Tank
• Premises with a proper individual septic tank (Malaysian Standards - MS 1228 ) has 3 to 4 rectangular metal covers and is usually located outside the premises.
• It only provides partial sewage treatment that flows into it & needs to be desludged approximately once in two years.

Individual Septic Tank

- It only provides partial sewage treatment that flows into it and needs to be desludged approximately once in two years.

- Premises with a proper individual septic tank (Malaysian Standards -MS 1228 ) has 3 to 4 rectangular metal covers and is usually located outside the premises.

(http://kerschners.com/wp-content/uploads/2014/07/locate-septic.jpg)

Sludge

• Residual, semi-solid material left from sewage treatment processes or settled suspension from
conventional drinking water treatment.
• Untreated sludge is a significant environmental & public health hazard.
• However, treated stabilized sludge is inert, stable and safe to use.


Effluent discharge

• Must be accomplished without transmitting diseases, endangering aquatic organisms, impairing the soil, or causing unsightly or foul-smelling conditions.
• Effluent standards define what is allowed within the wastewaters discharged into the aquatic environment.
• 2 most important parameters are Biochemical Oxygen Demand (BOD) and Suspended Solids (SS).
• BOD - amount of oxygen that sewage consumes over a given time. High BOD means, sewage rapidly consume all the naturally-dissolved oxygen instreams, rivers and lakes, thus killing off all aquatic life.
• SS - undissolved material in sewage. High SS lead sto sludge deposits in the waterways, thus causing significant environmental deterioration.

Health Effects
• Contaminate via inhalation, ingestion, or direct contact to human by chemical, microbiological and biological properties of the sewage or sludge.
• The Centers for Disease Control and Prevention (CDC) says sewage workers are not at more risk of Hepatitis A infection than other workers.

References
-https://www.youtube.com/watch?v=YW6GBciRHLg
-http://kerschners.com/wp-content/uploads/2014/07/locate-septic.jpg
-noted that had been given from my lecterur Sir Mohd Jamalil Azam Bin Mustafa