We all dream and feel satisfied of living in a pure and clean environment. So, to stay healthy and fit, we need to be aware as well as to make people aware of our surroundings. Say for instance, if a passer-by sees an empty cold drink can or a plastic bag lying on the road, park or a pavement. Then, we should react accordingly. We should throw all these waste materials into the nearby dustbins to keep that place hygienic and clean.
In the same way, what would we do if we sense a foul smell coming from behind the bushes in the park or next to the public toilets? Obviously, we will wither away from that horrible smell and the place. So, a basic question arises – How do we ensure a clean sanitation along with the environment continuously and everytime? Our political analysts and environmentalists thought and debated about this critical issue and ultimately, they came out with a unique alternative – Toilets, of course, but its usage without using water.
Hence, came an invention developed by the environmentalists all over the world – the Biological Composting Toilets or simply Bio-Toilets. A composting toilet is a dry toilet that uses a predominantly aerobic processing system that treats human excreta, typically with no water or very small volumes of flush water, via composting or managed aerobic decomposition. Composting toilets may be used as an alternative to flush toilets in situations where there is no suitable water supply or sewer system and sewage treatment plant available, or to capture nutrients in human excreta as manure.
This system can be used successfully, if implemented properly in drought prone areas of sub-Saharan Africa, the Middle East, South Asia, parts of South-East Asia, along the Andes mountain ranges of South America and the tropical deserts of Australia and North America. Currently, bio-toilets are in use in many households of North America, Europe and Australia.
Composting toilets should not be confused with the pit latrine or a tree bog, all of which are forms of less controlled decomposition, and may not protect groundwater from nutrient or pathogen contamination or provide optimal nutrient recycling. They should also not be confused with urine-diverting dry toilets(UDDTs) where pathogen reduction is achieved through dehydration and the faeces collection vault is therefore kept as dry as possible. These toilets are usually set up without urine diversion but can also include urine diversion sometimes. Offering a waterless urinal in addition to the composting toilet can help keep excess amounts of urine out of the composting chamber.
Before the flush toilets became universally accepted in the late 19th century, there were inventors, scientists, and public health officials who supported the use of “dry earth closets”, a type of dry toilet with some similarities to the modern composting toilets. However, the collection vessel for the human excreta was not designed to achieve composting at the toilet level. Dry earth closets were invented by the English clergyman Henry Moule, who dedicated his life to improving public sanitation after witnessing the horrors of the cholera epidemics of 1849 and 1854 in England.
The model he made is depicted in the starting of the article. He invented what he called the ‘dry earth system’. His system was adopted in private houses, in rural districts, in military camps and in many hospitals extensively in many British-colonised countries, including India. But, it failed to gain public support and attention as the water-flushed toilet connected to a sewer system.
Composting toilets are generally built step by step with precision and care taken. It consists of four parts:-
- a reactor which is the storage or composting chamber.
- a ventilation unit to provide air to ensure aerobic conditions, to allow carbon dioxide and water to evaporate and to reduce odour.
- a leachate collection system to drain excess liquid.
- an access door for withdrawing the mature product.
They use the natural processes of decomposition and evaporation to recycle human waste. Waste entering the toilets is over 90% of water, which is evaporated and carried back to the atmosphere through the vent system. The small amount of remaining solid material is converted to useful fertilizing soil by natural decomposition. The correct balance between oxygen, moisture, heat and organic material is needed to ensure a rich environment for the aerobic bacteria that transform the waste into fertilizing soil.
This ensures odour-free operation and complete decomposition of waste. When human waste is properly composted, the end product does not contain any pathogens or viruses as these are destroyed by bacterial breakdown. This nutrient-rich fertilizer can then be used on plants or around the base of trees, as part of the natural cycling of nutrients, reducing your need for commercial fertilizers and preserving local water quality.
Human excreta and food waste do not provide optimum conditions for composting. Usually the water and nitrogen content is too high, particularly when urine is not separated and is mixed with the other material in the vault. Additives or “bulking material”, such as wood chips, bark chips, sawdust, ash and pieces of paper, are used to absorb moisture. The additives also improve the aeration of the pile and increases the carbon to nitrogen ratio by adding carbon-rich material. Bulking material also serves as cover of the fresh faeces and reduces access of flies and other insects. If sufficient bulking material is not added, the organic matter in the composting vault may get too compact and form impermeable layers, which leads to anaerobic conditions and odour.
Maintaining bio-toilets is not at all an easy task. The emptying frequency of the composting container depends on the size of the container, the amount of material added per day and the composting conditions. Frequency of emptying will depend on the speed of the decomposition process and capacity, from a few months to years. With a properly sized and managed unit, a very small volume of a humus-like material results, which can be suitable as soil amendment for agriculture, depending on local public health regulations.
Maintenance of composting toilets, whether they are in private or in public settings, is critical to ensure they operate well and without odour. Maintenance tasks include – Cleaning, checking of technical components of the composting toilet as well as safe treatment, handling and use of the compost and its waste products, if produced. Composting toilets require greater management efforts than urine-diverting dry toilets due to the need to maintain a consistent relatively high moisture content. Thus, it is quite tedious and expensive to maintain such toilets even today.
Now coming into the India’s context, bio-toilets have been implemented only in some urban areas. As mentioned before, though the first composting toilet came into being during the British Raj, it quickly withered away from India, due to its inefficiency to clean up the solid waste materials into the sewer system with lack of water, which is a necessity. Hence, it lost popular public support and instead, water-flushed toilets were put in use.
Even after installing plenty of public water-flushed toilets for the poor since independence, many of them still do not have access to it, due to non-awareness of using public toilets. Hence, about 55% of the Indian population have practised open defecation, leading to deadly epidemics, which have jolted both towns and villages of India ever since. Sanitation facilities in India continue to be inadequate, despite longstanding efforts by the various levels of government and communities at improving coverage. The level of investment in water and sanitation, albeit low by international standards, has increased in size during the 2000s. Also, access to water has also increased significantly.
For example, in the 1970s rural sanitation coverage was only a mere 0.5% that time, which reached 34% in 2014. Also, the share of Indians with access to improved sources of water has increased significantly from 67% in 1980 to 93% in 2014. At the same time, local government institutions in charge of operating and maintaining the infrastructure are seen as weak and lack the financial resources to carry out their functions. In addition, only two Indian cities- Trivandrum(Kerala) and Kota(Rajasthan) have continuous water supply and clean sanitation facilities and an estimated 45% of Indians still lack access to improved sanitation facilities.
Banka BioLoo Private Limited, a firm committed to environmental betterment and social uplift, is supporting to eradicate the malaise of open defecation. By providing eco-friendly bio-toilets, the enterprise is helping meet the Millennium Development Goals (MDG-7) and actively supporting the government’s vision of an open defecation free society. Banka’s solutions address the following needs of the end-users:-
- Meet the need for basic, easy-to-install and hygienic human waste disposal mechanism in areas with no infrastructural facilities.
- Address the need for a cheaper and easy-to-operate alternative to the traditional waste disposal system.
The bio-toilet consists of an easy to install super-structure, a multi-chambered bio-tank that holds the bacterial culture and supports the treatment of human waste. The system does not need external energy for treatment and rather gives out pathogen-free effluent water, that is apt for gardening and biogas, that could be used for cooking or heating. The system meets all regulatory and environmentally compliances and enhances the socio-environmental fabric of India.
Moreover, the bio-digester technology was initially developed by Defence Research and Development Organisation(DRDO) for the defence personnel. The enterprise is pioneering this, in an integrated approach, and taking this effective and innovative sanitation solution to the civil population with varying applications. Today, the DRDO are helping many public and social sectors and NGOs for adapting and installing bio-toilets in drought-prone areas of peninsular India.
Bio-digester is a consortium of anaerobic bacteria, which have been screened and gradually adapted to work at temperatures as low as -5 degrees Celsius. These convert the organic waste into water, methane and CO2. The anaerobic process inactivates the pathogens responsible for water-borne diseases. Bio-digesters serve as reaction vessels for bio-methanation and provide anaerobic conditions and the required temperature for the bacteria.
The waste is either treated centrally or dumped in the ground. The former consumes energy in transportation and treatment, whereas the latter contaminates the environment and ground water. Septic tank retains the human waste, and is also periodically emptied and cleaned, emits foul smell and any leakage harms the groundwater. The other major practice is of hugely built sewage treatment facilities(commonly called STPs). The human waste is transported via sewer lines to the central facility and treated using colossal amounts of energy.
Bio-toilets, in contrast, treat the human waste at source, obviating the need to transport the faecal matter, no spoiling of environment or groundwater and do not need any energy. With no heavy infrastructure required, the composting toilets eases the burden on government bodies. The system leaves pathogen-free water as effluent that can be re-used. For large bio-tanks, methane can be collected and used. These can be installed anywhere, without specification of land type, terrain, distance, etc. Many experts foresee bio-toilets as a true panacea to many of India’s sanitation woes.
With a lot of awareness generated and hardwork put in, the government’s first bio-toilet was installed in the national capital, New Delhi on June 1, 2014, near the Ram Manohar Lohia Hospital. Delhi’s first bio-digesting toilet was installed by the Delhi Urban Arts Commission(DUAC) chairman, Raj Rewal, who is better known for designing iconic spaces and structures such as the Parliament Library, Asiad Village, Metro Bhawan and Visual Institutional Arts Campus in Rohtak.
This prototype uses aluminium sandwiched honeycomb panels with stainless steel veneering for durability. The fluids discharged are treated by bacteria that converts it into water and a negligible amount of odourless non-toxic gas. It takes place in an underground chamber within a duration of three days. The water is fit for horticulture, a DUAC source explained. The unit has been manufactured at Mohan Rail Components in Kapurthala, Punjab.
The source also added that while the initial cost of a twin-toilet – one each for women and men was Rs.2.3 lakh, if mass produced, a single unit could cost Rs.1 lakh. The DUAC plans to install 200 such units all over Delhi. The chairman further added- “The NDMC(New Delhi Municipal Council) has given us two more sites. These include one at Safdarjung Hospital and one near Lady Irwin College. We are in talks with all the three municipal corporations.” Hopefully, the dream project, initiated by the Pradhan Mantri Swachh Bharat Abhiyan in October 2 last year, should be of great success. The programme aims to install 30,000 bio-toilets in selected places of India by 2018.