Question

What are the two processes that result in natural water purification? State the difference between them. Distinguish between green water and blue water.

Short answer

Natural water purification occurs via filtration, a physical process where water seeps through layers of soil and rock, and biodegradation, a biological process using microbes to decompose organic matter. Green water is soil moisture used for plant growth, returned to the atmosphere through transpiration, whilst blue water is found in bodies of water, recharged by precipitation, and used for human needs such as drinking and irrigation.

Step-by-step solution

Understanding Natural Water Purification

Natural water purification involves two main processes: filtration and biodegradation. Filtration is the process where water is filtered through various layers of soil and rock, removing foreign particles, and harmful substances. Biodegradation, on the other hand, involves the breakdown of various substances in the water by organisms or their enzymes.

Difference Between Filtration and Biodegradation

While both processes help in purifying water, they primarily differ in the mechanisms employed. Filtration is a physical process mainly reliant on the layers of soil and rock. Biodegradation is more of a biological process where microbes decompose or consume organic material.

Understanding Green and Blue Water

Green water refers to the moisture that is used by plants and then transpired back to the atmosphere. It comes from precipitation that is stored in the root zone of the soil. Blue water, on the other hand, is the visible water in lakes, rivers, and groundwater that can be recharged by precipitation and released into the atmosphere via evaporation or utilized for human use.

Difference between Green and Blue Water

The primary difference between green and blue water lies in their forms and uses. Green water is essentially soil moisture used for plant growth and is returned to the atmosphere through transpiration, while blue water serves the needs of humans including drinking, irrigation and industrial use after being extracted from bodies of water and groundwater.