Question

What is the characteristic of “domestic” wastewater?
A) Grey colour, musty odour
B) Blue colour, odourless
C) Green colour, musty odour
D) All of the above

Answer 1

Hint: Wastewater which is produced as a result of human activities in households is known as domestic waste water. It contains water from the toilets, sinks, showers, washing machines etc. The colour and the odour of the water id dependent on the waste present. The odour produced is due to the gases present in the waste.

Complete answer:
The wastewater is generated from the household, industries offices etc. This wastewater contains organic, inorganic compounds including several gases.

Domestic wastewater comprises a solid content of about 0.1%. The solid materials are the mixture of faeces, grease, soap, salts, detergent, grit, food particles, soaps etc. The solid materials can either exist in a suspended state or in a dissolved state. The physical characteristic of domestic wastewater is it is grey in colour with a musty odour. The musty odour is due to the presence of gases like hydrogen sulphide, nitrogen, ammonia, methane. These gases are released as a result of the decomposition of organic waste.

The pure water is colourless, odourless and tasteless. However, the water appears to be blue in colour due to the reflection of the blue colour. The water appears to be green with a musty odour due to the presence of algal blooms. It may contain cytotoxins that are produced as a result of industrial waste.

Therefore the correct answer is option ‘A’.

Note: Domestic wastewater is released to the water bodies like lakes, rivers, seas or oceans. The wastewater contains disease-causing agents like bacteria, protozoa etc. They cause various diseases directly and indirectly to humans, animals and also aquatic organisms.