Microbes Can Clean Polluted Water

Bioremediation uses naturally occurring bacteria, fungi or plants to degrade substances that are hazardous to human health or the environment

Can the problem of water pollution be checked by letting loose sewage-eating microbes?

The answer is yes and the technology that offers this hope—bioremediation—doesn’t cost the earth.

Indeed, authorities in India are batting for this technology, both to clean drains and to check pollution in the river Ganga, Prime Minister Narendra Modi’s dream project.

The technology has been successfully demonstrated in pilot projects by the Central Pollution Control Board. And the National Mission for Clean Ganga is now in the process of using bioremediation for cleaning up some parts of the river.

Internationally, the technology has been used in several countries.

In simple terms, bioremediation is a system of sewage treatment where microbes are used to degrade flowing sewage into carbon dioxide and water. The process also reduces the stench from raw sewage.

The microbes simply eat up contaminants such as oil and organic matter (e.g., waste food), convert them and then let off carbon dioxide and water. The process uses naturally occurring bacteria, fungi or plants to degrade substances that are hazardous to human health or the environment.

Bioremediation technology includes phytoremediation (plants) and rhizoremediation (plant and microbe interaction). At present, the process is used to check contamination in soil, groundwater and surface water. The system does not require construction or any major modification of drains or diversion of flow. It takes place in open drains without displacement of sewage. The process also does not require any additional land or power, making it a simple and easy system.

It is cheaper than conventional treatment methods, easy to handle and, importantly, does not require skilled manpower.

Under the process, bacteria are cultured in bulk and applied to the flowing sewage. Then, the microbes are activated and they multiply—with or without oxygen and food available in the form of organic matter present in sewage. Sometimes, enzymes are also added to activate the microbes.

However, bioremediation can be effective only in places where environmental conditions permit microbial growth and activity. Where the conditions are not favourable for their growth, manipulation of environmental parameters is carried out to allow microbial growth and allow degradation at a faster rate.

These microbes consume the organic mass of the waste water and utilize the nutrients from sewage for their growth, ultimately enhancing the cleaning action of waste water. The treatment can restore water quality and increases the self-cleansing capacity of the water body. The process also helps reduce biochemical oxygen demand (BOD) in sewage and reduces odour.

Waste water often contains organic materials that are decomposed by microorganisms, which use oxygen in the process, and BOD is the amount of oxygen that is used by such organisms in breaking down the waste matter.

The microorganisms that are used already exist in nature and this prevents any harm to the environment. Sometimes, they are indigenous to a contaminated area, otherwise, they need to be brought in to the targeted site.

Source: Live Mint

Read More Related Content On This Topic - Click Here

Media

Taxonomy

• Bioremediation
• Water microbiology
• Environment Protection and Pollution control