This document discusses primary liquid waste management. It begins by defining wastewater as any water affected by human use. The main steps of wastewater treatment are described as collection, preliminary treatment to remove large particles, primary treatment to remove smaller particles physically, secondary biological treatment, tertiary chemical treatment, sludge processing, and effluent discharge. Primary treatment specifically involves screening to remove large debris, sedimentation to allow solids to settle, and removal of floating materials. It removes around 25-50% of biochemical oxygen demand and suspended solids from the water through gravitational separation before secondary biological treatment.

1. Primary Liquid Waste Management
Presented By
Avijit Banerjee
Roll No: 111171220260004
4th Semester B.Sc (Hons.) 2019
DEPARTMENT OF MICROBIOLOGY
MICHAEL MADHUSUDAN MEMORIAL COLLEGE

2. Waste water Treatment
• Any water on earth that has been affected by human use are called Waste water.
•Wastewater treatment is a process used to remove contaminants from waste water
and convert it into effluent that can be returned to water cycle with minimum
impact to the environment.
Source of Waste water
 Industrial source
 Agricultural source
 Domestic Source
Objective-
water reclamation
Water Purification

3. Steps of Waste Water Treatment
 Collection of Waste water
 Preliminary Treatment
Physical treatment and Clarification of large particles.
 Primary Treatment
Physical treatment of smaller particles
 Secondary treatment
Biological treatment
 Tertiary Treatment
Chemical treatment (Ozone, Chlorine treatment)
 Sludge Processing
* Sludge comes from primary and secondary settling tank
*used for increasing fertility of the soil.
*It involves Physical, Biological and Chemical treatment.
 Effluent Discharge
Toxic
Pure

4. Process of Liquid Waste Management

5. Preliminary Treatment
 The first step of Waste water treatment is Preliminary treatment.
 It is a method of Physical Separation of Solids present in waste water.
It involves following methods –
1. Screening – In this method a large screener is present through which water passes
and the large size debris get retained in the screener.
2. Grit Chamber – in the Grit chamber the smaller particles present in water gets
settle down to the bottom and are removed out of the chamber.
Fig- Screener Fig-Grit Chamber

6. Primary Water Treatment
 It is a physical method of separation of Solid particles that remains after the
preliminary treatment.
Materials removed during this process
• Fat, Oil and Greases
• Sand Gravels and Rocks
• Larger Settleable solids including Human Wastes and Floating materials.
Process of Primary Treatment
1) The pre- treated waste came to large primary settling tank.
2) The velocity of water is reduced down.
3) Then the water containing solids wastes are allowed to settle down under the
action of Gravity.
4) The skimmed materials like oil, grease are collected at the surface of the water.
5) The effluent produce then enters the secondary waste water treatment.
6) The settle down solid wastes are considered as sludge and enters the sludge
processing .

7. Fig- Floatation Tank Fig- Skimmer Tank
Machines involve in Primary waste wate Treatment

9. Importances of Primary Waste water management
 Approximately 25 to 50 % of the incoming Biochemical Oxygen
Demand (BOD), 50 to 70 % of total suspended solids(SS) and 65%
of oil and grease are removed during Primary treatment.
 It removes solid particles, oil and greases and also produce
significant amount of sludge.
 It uses gravitational force and physical separation rather than use
of chemicals for producing effluent.
 It protects pumps and other equipments present downstream of
water treatment plant by removing solid debris.

10. Basics about Secondary and Tertiary Water Treatment
Secondary Treatment- It is a kind of Biological treatment of effluent that is
produced as a result of Primary Waste water treatment.
1. Aeration Chamber 2. Secondary Sedimentation Tank
Tertiary Treatment- It Involves Chemical Treatment for killing of
Microorganisms present in water.
1. Gravity Filter 2. Chlorination Tank

11. Name of some Waste water Treatment Plants
1. Detroit Wastewater Treatment Plant (Detroit, USA)
2. Shanghai Zhuyan I Wastewater Treatment Plant (Shanghai, China)
3. Stonecutter Wastewater Treatment Plant ( Hong Kong, China)
4. Beckton Sewage Treatment Works (London, UK)
5. Morigasaki Water reclamation Center (Tokyo, Japan)
6. Western Treatment Plant (Melbourne, Australia)
7. DSP Seweage Treatment Plant
Primary Wastewater Treatment Secondary Wastewater treatment
It uses physical methods for removing waste
from water.
It uses Biological method for removing
waste from water.
It removes large particles and oil from
water.
IT decompose organic matter present in
Wastewater.
It require less time. It require long time.

12. Thank You