Physical Analysis of Water Samples

In this physical analysis of water post we have briefly explained about physical analysis of water, principle, procedure for temperature, colour, taste, smell, turbidity and solid analysis of water.

The physical analysis of water determine its quality. There is a lot of variation in these water quality indicators all throughout the world. As a result, the quality of natural water sources or waste water used for various purposes should be determined in terms of the specific water quality criteria that have the greatest impact on the water’s potential usage.


The senses of touch, sight, smell, and taste define the physical features of water (temperature, colour, taste, scent, and so on). Temperature can be felt, colour can be seen, floating debris, turbidity and suspended solids can be seen, and taste and aroma can be smelled.

Physical Analysis of Water


Thermal capacity, density, specific weight, viscosity, surface tension, specific conductivity, salinity, and solubility of dissolved gases are only a few of the essential physical analysis of water that are affected by temperature.

The pace of chemical and biological reactions increases as the temperature rises. For a 10°C increase in temperature, reaction rates are commonly estimated to double. Water temperatures in streams and rivers around the world range from 0 to 35 degrees Celsius.


Water colour is largely an aesthetic concern when it comes to water quality. Even if the water is totally safe for public consumption, coloured water gives the impression that it is unsafe to drink.

Color physical analysis of water, on the other hand, can reveal the presence of organic components like algae or humic chemicals. Color is now being employed as a quantitative indicator of the presence of potentially dangerous or poisonous organic compounds in water.

Taste and Smell

Human senses of water quality include taste and odour. Sour (hydrochloric acid), salty (sodium chloride), sweet (sucrose), and bitter are all flavours that humans perceive (caffeine).

Sour and salty flavours are produced by relatively basic chemicals. Sweet and bitter tastes, on the other hand, are formed by more complex organic molecules.

Humans detect far more odour hints than tastes. Organic items discharged directly into water, such as fallen leaves, runoff, and other organic materials, are sources of tastes and odour-producing compounds produced during biodegradation.


Turbidity physical analysis of water is a measurement of water’s light-transmitting qualities, and it is made up of suspended and colloidal matter. It is crucial for both health and appearance.

Gently stir the sample using a moderate agitator. Before pouring the sample into the cell, wait for the air bubbles to disappear. Fill the cell with a well-mixed sample and place it in an ultrasonic bath for 1 to 2 seconds to remove all bubbles, or use vacuum degassing to eliminate all bubbles. The turbidity of the water can be determined directly from the instrument display.

Calibrate continuous turbidity monitors for low turbidities using a laboratory-model nephelometer by determining the turbidity of the water flowing out of them. Alternatively, calibrate the instruments using a formazin primary standard or a suitable secondary standard, as directed by the manufacturer.


The residue left after evaporating the water and drying it to a constant weight at 103°C to 105°C is referred to as the total solids content of water.

The organic fraction (or volatile solids content) is thought to be related to the weight loss of the residue that remains after the water has evaporated and the residue has been ignited at 500°C.

At this temperature, the volatile solids will oxidise and escape as gas. The inorganic (or fixed solids) have a similar appearance to inert ash. Solids are divided into three categories: settleable, suspended, and filterable solids.

Solids physical analysis of water that settle under the effect of gravity are known as settleable materials (silt and heavy organic solids). Particle size and the retention of suspended solids on ordinary glass-fibre filters are used to classify suspended solids and filterable solids.

Further Readings