As urgency grows to show results for its Clean Ganga mission, the Centre is turning to bacterial bioremediation techniques to cut down the time lag in commissioning of Sewage Treatment Plants (STP).
While STPs typically take two to three years to come up, large-scale application of bioremediation using 'sewage-eating microbes' quickens the process of improvement in the quality of river water, though only to an extent.
Under bioremediation technique, the activated microbes eat up contaminants such as oil and organic matter.
The bacteria play a vital role in treatment of sewage without causing any release of foul odour.
The process thus also reduces stench from raw sewage.
During the process of treatment, pollutants like heavy metals and toxic chemicals are reduced.
The microbial dosing under the technique is done as per requirement assessed in terms of organic pollutants (microbial food) content in sewage.
Referring to the long gestation period of STPs, bioremediation techniques are significantly less costly and require much shorter time duration of 6-8 months for commissioning and showing results. Implementing these techniques prevent degraded quality of water from flowing directly into river Ganga and its tributaries.
The cost of the NMCG's identified projects ranges from INR 7 lakh to 17 crore, depending on sewage flow into the drain.
Drains for Bioremediation- Some of the drains identified by the NMCG for application of bioremediation techniques include Golaghat, Ranighat and Budhiyaghat drains in Kanpur;
- Sasurkhaderi and Mavaiya drains in Allahabad; Nagwa and Rajghat drains in Varanasi;
- Saklichand drain in Bhagalpur and
- Ramkrishna Mullick Ghat and Telkal Ghat drains in Howrah among others.
