Bio-digester toilet technology, perfected by the DRDO (Defence Research and Development Organisation), is an eco-friendly and maintenance-free system to manage human waste. Under the Swachh Bharat Mission movement, the system is now being demonstrated in rural areas, both at schools and individual households, in Rajasthan and Uttarakhand, among others.
With the use of a combination of anaerobic bacteria, the system has been formulated and adopted to work at a temperature as low as 5°C. It converts the organic waste into methane and carbon dioxide, which inactivates pathogens responsible for water-borne diseases,” said Sanjay Banka, Managing Director, Banka BioLoo. His company, a service provider of bio-digester toilets, has installed bio-toilets in 20 States, apart from the trains.
“The system comprises of a pre-fabricated toilet shelter, a bio-digester tank, inoculum (anaerobic bacteria), and associated items such as overhead water tank, wash basin, tiles, squatting pan, urinal, etc. Installation and commissioning can be done in a day,” he said.
As far as the cost is concerned, the system costs approximately Rs. 35,000 for a household, although, the biodigester tank size would be commensurate with the number of users. The biggest advantage is that all the faecal matter is converted into liquid, which is pathogen-free, unlike the pit system which can contaminate the ground water. This water can be allowed to either seep into the ground or be collected for gardening, acting as an effective liquid fertilizer. “The odour-free effluent water contains rich nutrients and I have seen gardens using this water turn into lush greenery,” he added.
On the issue of space, a biodigester toilet would take the same amount of space as any other toilet (4X5 feet) and same space for the underground tank. The consumer only needs to ensure that the toilet is kept clean with the use of basic cleaning material.
So far, Banka BioLoo has installed over 5,000 systems effectively across the country, the most recent one being probably the first household bio-toilet in Bundi district of Rajasthan. A few months ago, the Banka BioLoo team experimented with a few households in a village close to Hyderabad, following which many families installed the system. “It is entirely doable. It is a simple procedure which a plumber can be guided to perform,” Banka said.
The system which can be used for mobile toilets is a replacement to age-old septic tanks, and can also be used in resorts, exhibition grounds, remote places, rural housing, hilly terrain, border areas, high altitude areas, islands and beaches.
The eco-friendly biodegradation technology for human waste disposal was first developed by DRDO for the armed forces that were deployed at high altitudes where the sub-zero temperature does not allow the natural biodegradation of organic matter. This used to lead to accumulation of the human waste over the years, contaminating the surrounding ice, which is the only source of drinking water and poses a great health risk. Further, melted ice contaminates the rivers and other water sources, and ultimately spreads the contamination downstream.
The system has proven to be efficient without depending on conventional energy sources, the effluent being odourless while rid of most of the pathogens. Over the years, hundreds of bio-digesters have been installed at various places all over the country.
DRDO’s biodigester technology has been extended to Indian Railways for on-board treatment of human waste and low-cost single house biodigesters have been designed for rural sector of the country. Recently developed version of this technology, named ‘BioTank’ is an excellent low cost alternative to the conventional septic tanks currently used by individual houses and communities.
Notably, the biodigester technology has received global appreciation and acclaim. It was one among 14 selected solutions to be presented at the UN Solutions Summit, during the 2015 UN General Assembly that passed the sustainable development goals (SDGs) as a part of the 2030 Agenda.