Probiotics, the ‘good’ microorganisms with health benefits that are commonly found in fermented foods, are now being deployed in sewage treatment. Chennai-based Esquire Enterprise manufactures a ‘bio-augmented probiotic liquid’ as a locally made “organic and sustainable” alternative to chemical agents such as sodium hypochlorite for sewage treatment.
Launched in December 2020, the company has four plants in Tamil Nadu and Karnataka with capacity to manufacture 390 tonnes of probiotic liquid; it is currently setting up a new 600-tonne plant in Gujarat. Its CEO, Balaaji Sundararaaman, spoke with businessline on the advantages of the product and its potential uses. Edited excerpts:
A regular sewage treatment plant (STP) of 8-10 kilo litres per day (KLD) capacity costs ₹2.5-3 lakh. How economical is the probiotic-based system in comparison?
A regular STP can typically recycle only 60-80 per cent of [sewage] water. But with probiotics, this can be increased to 95 per cent. And the water we supply, which is colourless and odourless, can even go back for use in building maintenance, including toilets. Similarly, when it comes to electricity usage, the blowers in STPs often work for 24 hours a day. With probiotics, you can save six hours of electricity, which is humongous. We are making it economical by increasing the plant’s efficiency by recycling more sewage with fewer resources and in an organic way.
Imported probiotics are priced ₹1,500-2,100 per 500 gram; our product costs just one-third of this.
Moreover, though the chemical supplements are cheaper, our probiotic replacement is better in efficiency and sustainability.
Of the 72,368 million litres of sewage generated per day in India, existing plants treat 31,841 million litres. Will the probiotic system address this gap?
There has been no new technological development in STP. Now, we have the probiotic solution. Probiotic indigenous microbes are available in our country and you’re going to pay less for it, compared to imported supplies, for running an STP. We would like to educate people about the made-in-India product. It can be dispatched to any part of India within four days. So, yes, we will be able to help bridge the gap.
There is no solution, yet, for sludge management in regular STPs. How will the probiotic system address this issue?
This is an augmented liquid. It digests the faecal matter. Basically, these microbes multiply as long as there is faecal matter. And if the system is very efficient, it almost metabolises 97-98 per cent of the sewage. So, there is really no need to dispose of sludge in a river or pond. One litre of our probiotic liquid can handle 10,000 litres of faecal matter. And poured in, the microbes start eating up whatever is available and multiply within seconds.
How is the probiotic system more sustainable than the regular ones?
It uses less water, hence there is cost savings and decrease in carbon footprint. Recycling water within the facility eliminates the need for water tankers and reduces diesel consumption needed for water transportation. Additionally, probiotics help reduce the formation of excess sludge. This, in turn, reduces the need for sludge tankers to transport and disposed of it in environmentally harmful ways, and the associated fuel consumption and carbon footprint. The negative impact of liquid suspended solids (LSS) in terms of odour and toxic emissions, specifically hydrogen sulphide, which can contribute to health issues like asthma, is avoided with organic recycling.
How are you mobilising the raw material for the plant?
Our main ingredients — nearly 60 per cent — comprises cow dung and cow urine. This comes from the 6,000 cows we have across our six centres, of which 90 per cent can’t yield milk. We take care of their food and health needs round the year, collect the cow dung, and ensure it is processed well within time. The processing time for probiotics is 60 days. We’ve already produced close to 500 tonnes of probiotics. This can clean up to 5 billion litres of sewage