After decades of tests and trial, the first Municipal Sewage Plant based on irradiation technology is going to be operational in Ahmedabad soon. The plant is a result of collaboration between Ahmedabad Municipal Corporation and Bhabha Atomic Research Centre (BARC); and aims to achieve two-pronged objective of treating toxic sludge and creating bio-manure for farmers.
BARC has entered into a Memorandum of Understanding (MoU) with Ahmedabad Municipal Corporation to provide all technical and scientific support for setting up a Cobalt-60 Gamma Irradiation Plant at Ahmedabad. The foundation stone for the facility was laid on January 30, 2016 and it will be operational by early next year.
“We were 30 million in 1947 and now we are more than 1.2 billion. Our GDP is growing at a rate of 6-8 per cent per year. One problem with this GDP growth is that we are moving ahead while leaving waste behind. If we do not take care of it we will not be able to enjoy our growth,” Head of Radiation Technology Development Department (RTDD) at BARC, Dr Lalit Varshney told Nuclear Asia while making a case for how irradiation technologies can come to the aid of Swachh Bharat Mission.
To grasp the enormity of the situation one can take an example of a metro city like Bombay creates 2197 million litres of sludge every day. Out of this 30 per cent of sewage is given minor treatment before being drained into the sea and the rest 70 per cent is drained out without treatment. This sludge will form ‘smoking hills’ where the waste catches fire releasing toxic substances into air.
The treatment of sludge can help its recycling as it is rich source of organic carbon (20-40 per cent), which is three times more than city compost organic fertilisers. The organic carbon is important for replenish the depleting fertility of the soil. The sludge also has macro and micro nutrients like sodium, Phosphorus and Zinc among others, besides comprising of pathogens, virus, bacteria, weeds, chemical contaminants, heavy toxic metals, lead, Arsenic, Cadmium, Chromium etc. Hence, leaving the untreated sludge into water bodies can be dangerous for environment.
Ahmedabad in Gujarat is leading the way by coming up with the first facility of this kind in the country that can treat 100 tons of sludge per day. “The total cost of the project is Rs. 30 crores. The facility will be operational next month (January) when we will load radiation source,” said Dr. Varshney.
The benefits of the facility are manifold as it converts waste sludge to manure, protects health and environment, provides organic carbon to soil and saves subsidy on Urea. “Urea subsidy is 15 Rs per kg so even if this manure is given for free to farmers the government saves money,” Dr. Varshney added. The fully automatic facility creates value-added bio-fertiliser by inoculating the treated sludge with useful bacteria. The product will be marketed by Gujarat Agro Industries Corporation under a separate MoU with Ahmedabad Municipal Corporation. Apart from this, Radiation Technology makes sludge safer by killing pathogens, degrading chemicals, allowing inoculation with useful bacteria, killing weeds and reducing smell.
The RTDD has already found more seekers for the technology. A MoU has already been inked with the Municipal Corporation of Indore, Madhya Pradesh and the construction for the same may start in three months. The Surat Municipal Corporation is also in talks with the RTDD and a formal contract is expected soon. Dr. Varshney revealed that Delhi has also contacted them for facilities that can help in treatment of 300 tons of sludge per day and the Department is working on technological solutions for it. The RTDD is looking at achieving a goal of 15-20 plants across the country by 2030.
Radiation technology applications are being seen as an aid for sustainable development. Dr. Varshney said: “The money value of such benefits cannot be determined. India has an ambitious nuclear power program and as a result availability of Cobalt-60 is assured for many years through Board of Radiation and Isotope Technology (BRIT). A gamma irradiation facility of 100 tons/day capacity cost about 25-30 crore Rupees and require an area of 4,500 square metre. The sludge treatment cost per kg is less than one Rupee.”
Gamma irradiators typically installed with an energy source of radioactive cobalt-60, have been widely used globally since the early 1960s especially in the sterilisation of medical products and consumer goods. India also had a Sludge Hygienisation Research Irradiator (SHRI) that was formally commissioned in the city of Baroda in early 1992. The sludge acted as a technological demonstrator as it treats liquid sludge. Taking lessons from that the new facility treats dry sludge and is more efficient and economical.
