Water Treatment Methods | Physical and Chemical Procedures

1. PHYSICAL AND CHEMICAL
PROCEDURES FOR WATER
TREATMENT
SUBMMITED BY
ANITA SA
REGD NO - 230705180001
SUBJECT – WATER AND SOIL QUALITY
MANAGEMENT IN AQUACULTURE
SUBJECT CODE – CUTM1443
BRANCH – M.Sc. ZOOLOGY
GUIDED BY – Dr. BIKASH RANJAN SAHU

2. CONTENTS
 INTRODUCTION
 PHYSICAL TREATMENT
 CHEMICAL TREATMENT
 REFERENCES

3. INTRODUCTION
● Industries use water that obtained from the water treatment system for a variety
of purposes, such as:
- For manufacturing goods.
- For heating.
- For cooling.
- As carrier of raw material.
- As carrier of waste matter.
- As a solvent.
● The resulting water is then classified as a wastewater.

4. ● The indiscriminate discharge of these wastewater streams into the environment can
- Render soils "sick ".
- Pollute the receiving bodies of water.
- Cause air pollution by generating obnoxious gases.
● Discharge untreated wastewater into the domestic sewer system makes the task of
treating domestic sewage, a very difficult and costly exercise.
● To prevent any health hazards caused by discharging wastewater into the
environment and protect domestic sewage , the wastewater must be treated before
discharge.
● There are 2 Primary Methods of Water Treatment :
a. Physical
b. Chemical

5. Greensand Filtration
Multimedia Filtration
Microfiltration
Ultrafiltration
Nanofiltration
Reverse Osmosis
Methods of Physical Water Filtration:
©2015

6. Consists of glauconite coated with
manganese oxide
Ideal for filtering dissolved iron,
hydrogen sulfide and manganese
Often requires pretreatment with an
oxidizing agent

7. Consists of at least 3 different layers of
filtration media
Ideal for filtering suspended solids and
particles larger than 10-25 microns
Does not remove viruses, bacteria or
small protozoans

8. Uses a barrier membrane to remove
suspended solids
Ideal for filtering particles down to
0.1-10 microns (e.g. algae, protozoans)
Does not remove dissolved
contaminants
May be used to reduce suspended
solids to protect reverse osmosis
membranes

9. Uses a barrier membrane to remove
suspended solids
Ideal for filtering particles down to 0.01
micron (e.g. bacteria and some viruses)
Does not remove dissolved contaminants
Often used as pretreatment upstream of RO
systems on water high in small suspended solids
Protects membranes by reducing the silt
density index (SDI)

10. Uses a semi-permeable membrane to
remove suspended solids and some
dissolved solids
Ideal for filtering particles down to
0.001 microns (e.g. bacteria, viruses,
divalent and trivalent ions)

11. Uses a semi-permeable membrane to
remove suspended solids
Ideal for filtering contaminants down to
0.0001 micron (e.g. dissolved ions,
bacteria, and viruses)
One of the most cost-efficient
technologies for deionization (removes
up to 98% of dissolved ions with a
single pass)

12. CHEMICAL TREATMENT
• Treatment methods in which the removal or conversion of
contaminants is brought about by the addition of chemicals or
by other chemical reactions.
• Precipitation, adsorption, and disinfection are the most common
examples used in wastewater treatment.
• Basically the treatment includes:
- Coagulation
- Neutralization
- Precipitation
- Oxidation

13. COAGULATION
In coagulation, individual particles combine together. When a
coagulant is used in water, it forms a spongy gelatinous precipitate
which absorbs fine size particles in water and binds them together.
The whole process results into bigger particles which are heavier and
easily settle able.
Properties of common coagulants
• React quickly
• Cheap
•Easy to handle and store
• React in longer range of pH
• Electrolyte ( positively charged)
• High valance ions for high efficiency
•Not detoriate

14. Coagulation & Flocculation Process

15. NEUTRALIZATION
If a waste stream is found to be hazardous due to corrosivity, neutralization is the primary treatment used.
It is used as a pretreatment system before a variety of biological, chemical, and physical treatment
processes.
It is the process of adjusting the pH of water through the addition of an acid or a base, depending on the
target pH and process requirements. Some processes such as boiler operations and drinking water
standards need neutral water at a pH of 7.
Water or wastewater is generally considered adequately neutralized if:
(1) its damage to metals, concrete, or other materials is minimal; (2) it has little effect on fish and aquatic
life; (3) it has no effect on biological matter (i.e., biological treatment systems).
PARAMETERS WHICH AFFECT NEUTRALIZATION:
-pH
-alkalinity/acidity
-Hardness
-Buffers

16. Fig: continuous neutralization tank

17. PRECIPITATION
•It is used for removing dissolved metals from waste water solution
containing toxic materials. To convert this dissolved metal into solid
particles, a precipitation reagent is added. A chemical reaction occurs
where dissolved metals form solid particles.
•Filtration can be used to remove the particles from the mixtures.
How well the process takes place depends on the types of metal
present, its concentration, and reagent used.

18. •Example : in hydroxide precipitation, calcium or sodium
hydroxide is used as a reagent to create solid metal hydroxides.
But the main difficulty being the mixture of metals in waste water
making it difficult to precipitate.

19. OXIDATION
•It is a waste water treatment which involves the use of oxidizing
agents such as ozone, hydrogen peroxide, permanganate, chloride,
chlorine, oxygen etc.
•The electrons move from the oxidant to the pollutants in waste water.
They undergo structural modification becoming less destructive
compounds.
•Alkaline chlorination uses chlorine as oxidizing agent against
cyanide. But it can lead to production of toxic chlorinated compounds
hence require further steps.

20. APPLICATIONS
•Reduce concentration of the residual organics
•Controls odors
•Remove ammonia
•Reduce microbial content
Common oxidation agents used in wastewater treatment:
-Oxygen(O2).
-Chlorine (Cl2).
-Sodium hypochlorite (NaClO).
-Calcium hypochlorite (Ca(ClO)2).
-Potassium permanganate(KMnO4).
-Hydrogen peroxide(H2O2).

21. •Authored by “Innocent L Swai, Bsc EHS ’’, Centralized water treatment. Vol 1 Page 456.
•Authored by “Joseph R.V. Flora and J. Paul Chen”, Flow equalization and neutralization.
Vol 1 Page 381.
REFERENCES