Bio-digester Technology

DRDO’s recently developed Bio-Digester Technology (BDT) with zero waste formulation is now being largely implemented in various sectors to solve sanitation problems.

While, BDT has been installed in railway coach toilets and general toilets on a trial basis, it is found to be an ideal option of solving excreta issues faced by the defence camps in Siachen and Ladakh. BDT effectively functions in all weather conditions, including those of the snow-clad sub-zero pockets where temperature ranges from minus 6oC to minus 50oC.

In 1994, when research scientists of the Defence Ministry went to Antarctica to study bacteria capability of degrading/breaking down excreta, it was found that psychrotrophic bacteria like Clostridium and Methanosarcina had the natural capability to survive on waste. These organisms breakdown excreta to produce re-usable water and gas through anaerobic process. To test the capability of the organisms at minus 50oC and at plus 50oC at different altitudes, a toilet was made with a tank fitted below the commode where faeces could be deposited. It was found that the tank sheets with bacteria embedded in it could not escape out of the sheet and could multiply. Thus, when human waste comes in contact with the bacteria, it gets converted into methane gas and yields water through the process of anaerobic digestion: the process of hydrolysis, acidogenesis, acetogenesis and methanogenesis.

Nicknamed ELDO (for eco-friendly loo), the BDT is an alternative to ‘Flush and Forget’ toilets. Easy to install in the mountainous slopes and terrains and involving no maintenance, ELDO eliminates pathogens and also generates odourless and inflammable clean energy: biogas. The gas can be utilized for energy/cooking and water for irrigation purposes.

Faecal matter is composed of carbohydrates, protein and fats. In the first step, they are converted into simple sugars, amino acids and fatty acids. In the next step, these break to form carbonic acid, alcohols, hydrogen and water. In the third step, acetic acid, hydrogen and carbon dioxide is formed. In the last step, methane, carbon dioxide and water are formed.

Special Features

• Anaerobic microbial inoculum

• Cold tolerant microbial consortium

• Required one time inoculum charging

• Immobilization matrix for retaining higher microbial mass for survival in adverse conditions

• Specially designed tank for efficient biodegradation

• Suitable for mobile and stationary platforms

• Permits use of toilet cleansing agents

• Tailor made in respect to number of users, materials, situation and condition

Advantages

• Wide applicability

• Maintenance free

• Effluent water recyclable

• Pathogen reduction: > 99%

• Minimizes water consumption

• Customized & easily adoptable

• Organic waste Reduction:

> 99%

• Environment-friendly & cost-effective

• Suitable for any geo-climatic condition

GOI Initiatives

FICCI in association with the Ministry of Defence and DRDO has envisaged a plan for setting up bio-digester based toilets across the identified Gram Panchayats. The Ministry of Drinking Water and Sanitation has earmarked `400 crore for this programme which will be undertaken in phases where each phase would involve an investment of `150 crore.

“Seventy per cent of the people in India reside in rural areas and are deprived of proper sanitation facilities. BDT is not just eco-friendly but is also cost effective and DRDO will try to further reduce the cost,” remarked

A K Antony, Defence Minister, Government of India.

Of the 2.4 lakh of Gram Panchayats in the country, only a few have sanitation facilities. The programme intends to create model villages that employ innovative technologies to achieve civic hygiene by converting the Panchayats into ‘Nirmal Panchayats’.”

In Odisha, six-twin Bio-Digester based toilets (male and female) have been constructed by FICCI at the five identified sites along the Jhamjhadi -Dhamra 90km stretch which leads to the Chandipur Station from where the Agni missiles are launched. He also proposed that from the MPLADS fund a fixed amount should be earmarked for the construction of Bio-Digesters.

About 130 bio-toilets are soon going to be installed in Karoti village, 110km from Mumbai. The Chennai Corporation has also decided to install 300 bio-toilets in the city.