Introduction to soil and paint

1. SOIL
&
PAINTS
Presented by :
Miss.Jayshree Katariya
M.sc.(F.S)1st Yr

2. DEFINITION
◦Soil is a mixture of organic
matter, minerals, gases, liquids,
and organisms that together
support life.

3. Soil is the unconsolidated outer layer of the Earth’s crust.
It appears in a variety of forms
(different textures, colour, structure and nutrient content)
There are
four main ingredients (fractions) that are
consistent with all types of soil:
mineral,
organic matter, water and air.
These four
fractions fall into two categories:
solid
(mineral and organic matter) and non solid (water and air).

5. SOIL COMPONENTS
◦ 1. Mineral
The largest component of soil is the mineral portion, which makes up
approximately 45% to 49% of the volume.
◦ 2. Water
Water is the second basic component of soil. Water can make up
approximately 2% to 50% of the soil volume. Water is important for
transporting nutrients to growing plants and soil organisms and for
facilitating both biological and chemical decomposition. Soil water
availability is the capacity of a particular soil to hold water that is
available for plant use.

6. ◦ 3. Organic matter
Organic matter is the next basic component that is found in soils at levels
of approximately 1% to 5%. Organic matter is derived from dead plants
and animals and as such has a high capacity to hold onto and/or provide
the essential elements and water for plant growth
◦ 4. GASES
Gases or air is the next basic component of soil. Because air can occupy
the same spaces as water, it can make up approximately 2% to 50% of the
soil volume. Oxygen is essential for root and microbe respiration, which
helps support plant growth. Carbon dioxide and nitrogen also are important
for belowground plant functions such as for nitrogen-fixing bacteria

7. ◦ 5. Microorganisms
Microorganisms are the final basic element of soils, and they are found in
the soil in very high numbers but make up much less than 1% of the soil
volume

8. SOIL FORMATION

9. SOIL HORIZONS

10. TYPES OF SOIL

11. ◦ Sand :-
◦ Sand is gritty and consists of very small particles of rock and minerals.
...
◦ Silt :-
◦ Silt is a very fertile soil. ...
◦ Clay :-
◦ Clay is very fine grain soil with little air space.
◦ Loam :-
◦ is soil composed mostly of sand silt and a smaller amount of clay

12. SOIL ANALYSIS
Soil is the system which supplies plant with available nutrients
through the root. Physical and
◦ Chemical analysis of the soil are carried out to indicate the efficiency
of soil for supplying plants
◦ with nutrients in available forms as well as identification of the
factors affecting this efficiency in
◦ the soil. Therefore, besides perfect sampling in the field, soil samples
must be properly prepared
◦ and analyzed in order to reach the correct evaluation of the soil
nutritional status.

13. ◦ Determination Of Mositure Content
◦ Principle:
◦ Hygroscopic water of air-dry soil is determined by heating in an oven at 105o
◦ C.
◦ Apparatus:
◦ 1- Electric oven with thermostate.
◦ 2- Desiccators with siccative.
◦ Procedure:
◦ 1- Weigh 5.00 g of air-dry soil < 2 mm into a perviously dried (at 105o
◦ C) and weighed
◦ weighing-dish with lid (a labelled aluminium dish).
◦ 2- Dry in an oven at 105o
◦ C with unfitted lid over-night.
◦ 3- Remove from oven, fit lid, cool in a desiccator for at least 30 minutes and reweigh. All
◦ weighings should be recorded to 3 decimal places

14. Particle Size Distribution
◦ Apparatus
◦ Soil dispersing stirrer: A high-speed electric stirrer with a cup receptacle.
◦ Hydrometer with Bouyoucos scale in g/L (ASTM 152H).
◦ Reagents
◦ A. Dispersing Solution
◦ Dissolve 40 g sodium hexametaphosphate [(NaPO3)13], and 10 g sodium
carbonate (Na2CO3) in DI water, and bring to 1-L volume with DI water. This
◦ solution deteriorates with time and should not be kept for more than 1 to 2
◦ weeks.
◦ B. Amyl Alcohol

15. ◦ Procedure
◦ 1. Weigh 40 g air-dry soil (2-mm) into a 600-mL beaker.
◦ 2. Add 60-mL dispersing solution.
◦ 3. Cover the beaker with a watch-glass, and leave overnight.
◦ 4. Quantitatively transfer contents of the beaker to a soil-stirring cup, and
◦ fill the cup to about three-quarters with water.
◦ 5. Stir suspension at high speed for 3 minutes using the special stirrer.
◦ Shake the suspension overnight if no stirrer is available.
◦ 6. Rinse stirring paddle into a cup, and allow to stand for 1 minute.
◦ 7. Transfer suspension quantitatively into a 1-L calibrated cylinder (hydrom
◦ eter jar), and bring to volume with water.
◦ A. Determination of Blank
◦ • Dilute 60 mL dispersing solution to 1-L hydrometer jar with water.
◦ • Mix well, and insert hydrometer, and take hydrometer reading, Rb.
◦ • The blank reading must be re-determined for temperature changes of
◦ more than 2°C from 20°C.

16. ◦B. Determination of Silt plus Clay
◦Mix suspension in the hydrometer jar, using a special
carefully,
◦withdraw the paddle, and immediately insert the

17. FORENSIC IMPORTANCE
◦ Forensic soil analysis is the use of soil science and other disciplines
(e.g. geochemistry and geology) to aid in criminal investigations.
◦ Each soil possesses unique properties that serve as identification
markers.
◦ This means investigators can trace and match soils to each other. For
example, clay embedded in the shoe treads of a criminal can be
traced back to a specific clay type found along a lake where a murder
victim was discovered.
◦ Each soil type has specific characteristics—like color, texture and
structure—that tell its history, formation and location of origin.

18. DEFINITION OF PAINTS
◦Paint is any liquid, liquefiable, or mastic composition that,
after application to a substrate in a thin layer, converts to
a solid film. It is most commonly used to protect, color, or
provide texture to objects

19. COMPOSITION

20. COMPOSITION OF PAINTS
There are four main components in a paint:
pigment, binder, liquid, and additive
BINDERS :
Is the main ingredient of paints. Binders are polymers forming a continuous film on the substrate surface.
Alkyd resins
Acrylic resins
Phenolic resins
Urethane resins
Epoxy resins

21. • SOLVENTS
• water is a medium where the binder, pigment and additives are
dispersed in molecular form or as colloidal dispersions
PIGMENT
Is a solid substance dispersed throughout the coating to impart
it a color, opacity.
Pigments may protect the substrate from UV light.
Pigments change the paint appearance

22. Additives
Are small amounts of substances modifying the Paint properties.
Examples of additives:
Dries
Uv-stabilzer
Anti-skinning agents
Texturizers

23. TYPES OF PAINTS
◦ WATER-BASED PAINTS
◦ The majority of wall paint sold today is water-based, primarily because of its ease of use.
◦ OIL-BASED PAINTS
◦ Oil-based paint can be used on almost all surfaces, and is praised for its high durability and rich finish.
◦ Matte paint:
◦ is the least reflective sheen available
◦ has a velvety texture
◦ helps hides imperfections in walls and ceilings

24. ◦ Eggshell and satin paint (satin is slightly glossier than eggshell):
◦ have some reflectivity
◦ offer improved durability
◦ are frequently used in demanding
◦ Semi-gloss and gloss paint:
◦ great for kitchens, doors, window trim, accent walls, and bathrooms
◦ are the most reflective sheens

25. ANALYSTS OF PAINTS
Paint samples can be difficult to collect from the scene of a crime.
They can be found on a variety of objects, including clothing, vehicles, and tools.
Micro-spectrophotometryin its reflectance mode will help determine the nature of the pigments
Infra red spectrometry will determine its organic components.
X-ray powder diffraction is useful for determining the identity of any microcrystalline components. Because
paint in the form of a chip is solid, a specialized technique called pyrolysis
Gas chromatography might be used to determine its composition.

26. FORENSIC IMPORTANCE
◦Paint chips or remnants can reveal a significant amount of
information during forensic investigations.
◦ Paint that is located at a crime scene is referred to as trace
evidence, because it has been transferred from a main source
to the scene of a crime. ...
◦ This is usually done by scraping or peeling off
the paint evidence.

27. THANK YOU !