Deep cleansing

rainwater harvesting can also cleanse water. Storage of treated wastewater and storm runoff in underground aquifers purges it of disease-causing organisms. This allows the water to be recycled for irrigating parks, gardens, ovals and farms.

This was revealed in a study recently conducted by Australia-based Commonwealth Scientific and Industrial Research Organisation (csiro). During the study, csiro researchers found that after 40 days of storage in an underground aquifer, all bacteria and viruses are removed from water due to unfavourable conditions like temperature changes and, lack of oxygen and nutrients.

An army of naturally occurring groundwater microorganisms also kills or inactivates the disease-causing organisms. For example, during laboratory tests, researchers found that naturally occurring groundwater bugs in the aquifers eliminated the polio virus to undetectable levels in less than 40 days.

The researchers also studied the behaviour and fate of other microbes such as the protozoan cryptosporidium , and the salmonella and aeromonas bacteria. The found that these microbes too got eliminated due to the storage.

"The idea behind our technique is to harvest surplus water during the wet part of the year, store it underground for some months, then bring it to surface again for irrigation during the dry season. Such a form of rainwater harvesting or recharging of groundwater could be the best way to clean polluted water," said csiro microbiologist Simon Toze.

But there are a number of concerns, particularly pertaining to the quality of the water, that need to be addressed for the successful use of the process, admits Toze.

Subscribe to Daily Newsletter :

SUPPORT US

We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.