Cleaning water without chemicals

Dr Uday Bhawalkar graduated in chemical engineering in 1973 from IIT Bombay. Deciding to make his career in utilising waste organic resources, his first opportunity was to get involved in the design and operation of a composting project, processing 300 tonnes per day, for the city of Mumbai. This project provided Dr Bhawalkar with a good exposure to the problem of municipal solid wastes and the conventional techniques that were available.

“I concluded then that what we required was a natural, cost-effective and simple solution to tackle waste organics in a decentralised way. The solution came to my notice in the form of an article titled: The Importance Of An Earthworm in the June 1981 issue of SPAN. I was engaged in farming during this period and was already disenchanted with the use of chemical fertilisers and pesticides. I therefore started some practical experiments with earthworms and the results were impressive,” he recounts.

To develop large-scale engineering applications, Dr Bhawalkar registered for a PhD programme at the Indian Institute of Technology, Bombay, in July 1987. During this period he developed the concept of ‘Vermiculture Ecotechnology’ and tested it in several large-scale demonstrations to process solid and liquid organic residuals generated by society and in industries. These demonstrations generated resources for the users.

This technology went through continuous upgradation in view of the practical experience that was generated over the years. Eco-Logic that was developed during these years to learn from nature helped him to develop a refined form of technology in 1996. This came to be known as the Biosanitizer Ecotechnology. Dr Bhawalkar discusses his product that has been granted an American patent with OneWorld South Asia.

Here are the excerpts:

OneWorld South Asia: What is the theory behind the development of your product?

Dr Uday Bhawalkar: If we use chemicals (alum, copper sulphate, chlorine, etc) to clean water, all we are doing is spoiling the quality of water. It becomes more acidic and corrosive. A lot of this water enters our bodies when used for drinking or washing and you can imagine what it does to our digestive system. I therefore felt a need for an ecological filter that can be used to clean wastewater as an absolutely safe method. It took 20 years of research by our group at IIT Bombay’s Department of Chemical Engineering to develop the right methodology. This eco-friendly composting is such that there is no production of greenhouse gases, heat and toxic leachate. I have upgraded this technology to produce a product called Biosanitizer, which is a natural biocatalyst. A small quantity of 100 mg has the power to convert pollution into resources equivalent to 1 acre of natural forest.

OWSA: How harmful is chemically treated water?

UB: A recent study has suggested that pregnant mothers who drink or even shower in tap water, which is chlorinated, can double the risk of serious heart and brain abnormalities in their unborn babies. The findings, reported in the journal Environmental Health, links by-products of water chlorination - chemicals known as trihalomethanes or THMs - to increasing the risk of holes in the heart, cleft palate and anencephalus, which results in the absence of a major portion of the brain, skull, and scalp.

Babies born in areas where drinking water is heavily disinfected with chlorine are at double the risk of heart problems, cleft palate or major brain defects, according to a study carried out in Taiwan on nearly 400,000 infants. The disturbing finding suggests that expectant mothers can expose themselves to this higher risk by drinking chemically treated water, swimming in chlorinated water, taking a bath or shower, or even by standing close to a boiling kettle.

Even the use of soap is a chemical approach. It pollutes the water and this becomes a bigger sanitation problem for the downstream communities. Current methods that are used for sewage and water treatment cannot remove all these sanitation chemicals and the river gets full with these as it flows. Modern allopathic drugs also come into our drinking water against our wish and can have serious impact on us in the long run.

OWSA: Where can Biosanitizer be used?

UB: Biosanitizer helps produce need-based amount of active oxygen and drives ecological reactions that clean polluted surface, ground or wastewater. This oxygen-rich water also becomes a resource for eco-sanitation. It can be sprayed to sanitise soil, garbage heaps, medical waste, and animal carcasses. The spraying also controls odour, pathogens, and pests such as mosquitoes, flies, cockroaches and rats. It is a non-recurring input and can be placed in a well, bore well or a water storage tank to obtain treated water. The inorganics that actually define the sanitation challenge also get corrected and the water becomes a resource for all its intended applications in homes, farms and industries.

OWSA: Is there a traditional base to this technology?

UB: Our forefathers used cow urine, cow dung and healthy soil for achieving sanitation. Similarly, farmers have been very creative in developing ecological techniques, though the agricultural universities have been promoting the toxic chemical route for sanitation and pest control. After all, farmers are close to nature and have seen toxic methods failing and only adding to the cost. They have found that panchgavya that consists of five products of desi (holy) cow produces good results when used in homes, cowsheds and farms. Cow products have nitrates, which act as a resource for eco-sanitation.

OWSA: How does it function?

UB: Biosanitizer is a natural biocatalyst that converts any polluted, dead water into living or bio-water. Its action is based on the ecological principle of utilisation of wastes as valuable raw materials, turning them into resources, rather than separation/ concentration and disposal. Bio-water resists scaling, corrosion, algal growth, biofouling, chemical contamination and growth of pathogens/ pests. The key reaction of this product involves production of active oxygen, which can drive several resource-producing reactions. Harmful salts, for instance, become useful minerals.

In nature, coconut water is produced from seawater using a similar reaction. This reaction is used to convert saline/ brackish water into rich mineral water.

OWSA: Are there any case studies to prove the efficacy of Biosanitizer?

UB: The utility of Biosanitizer technology was well demonstrated after the July 26, 2005 deluge in Mumbai, when it rained about 1,000 mm in a day. Accumulated garbage heaps and dead carcasses of animals created sanitation hazards in Mumbai. A special bio-spray was created by combining Biosanitizer with a 100 PPM solution of calcium nitrate. This was sprayed on stinking garbage heaps and animal carcasses. The results of eco-sanitation achieved were dramatic, as seen by control of odour, pathogens and pests. This was a joint project of the Green Cross Society of Mumbai, Bombay Municipal Corporation (BMC) and Indian Express Initiative. The operation was also extended in the jurisdiction of the Vasai Municipal Council where dead buffaloes were dumped and their neglect could have created conditions suitable for plague.

Biosanitizer has been used successfully in several field-scale projects to demonstrate its efficacy. For example, it was applied in a commercial prawn farm where the production had reduced due to a viral attack. It is well understood in the aquaculture industry that management of nitrates (and other nitrogen species such as ammonia, nitrites, etc) is a key to healthy prawn/fish growth.

Increase in the nitrogen load reduces the dissolved oxygen (DO) level, particularly during the night when algal oxygen production stops. At low DO concentrations, prawns are under stress, which reduces their resistance to viruses. The virus is a wasteful mechanism of nature that uses nitrates but does not produce any resources. It is an alarm indicating that the nitrate level is high.

The nitrate overload, and hence the viral problem, was solved by the use of Biosanitizer at the rate of 1 gram per acre of pond (2-3 meters deep). Because of the oxygen produced by Biosanitizer, the food chain that converts prawn waste into prawn food also got triggered. Expenses on prawn feed thus got reduced.

This resulted in higher food conversion ratio and higher profit for the prawn farmer. The need to change the polluted water from the pond was also reduced because prawn waste was feeding the algal food chain that produced the prawn food. Thus, the waste of one process was utilised to feed another useful process. In conventional waste treatment, both organics and nitrates are destroyed to clean the water, which amounts to spending more resources to destroy wasted resources.