Turning Municipal Waste into Value
In a wide-ranging conversation with Senior Journalist Vasudevan Patri, environmental biotechnologist Dr. V. Renu Sarath Babu illuminated how waste, often dismissed as refuse, can become renewable resources and energy carriers — “trash can indeed be gold,” he said. His work combines environmental science, technological innovation, and sustainable policy insights to tackle the pressing challenge of municipal waste management in India.
Dr. Sarath Babu opened by contextualizing waste generation trends in Indian cities. He contrasted the common perception — that Indians generate relatively less waste per person — with recent assessments showing India among the top per-capita waste generators globally, alongside the USA, Singapore, and China. The difference, he explained, is that developed countries already practice systematic waste-to-wealth conversion, while much of India’s waste remains unmanaged or dumped with little scientific utilization.
Scientific sources confirm that India’s Solid Waste Management Rules mandate segregation of waste at source into organics, dry recyclables, and hazardous fractions, encouraging recycling and scientific processing rather than uncontrolled disposal.
Biomedical Waste: From Hazard to Resource
A disturbing trend highlighted in the interview is the mismanagement of biomedical waste — from sharps and syringes to infected bandages and fluids mixing with regular municipal waste. Dr. Sarath Babu warned that improperly treated biomedical waste can spread pathogens and antibiotic-resistant bacteria into water tables and food chains, increasing disease burdens in communities.
By law in India, biomedical waste must be segregated, treated with autoclaves or incineration systems, and only properly processed materials can be passed to recyclers. (HSPCB) Dr. Sarath Babu described how unregulated practices constitute a public health risk and are in conflict with regulatory requirements.
Pyrolysis & Syngas
Instead of sending plastics to landfills where they fragment into microplastics that contaminate soil and water, Dr. Sarath Babu argued that advanced thermal technologies like pyrolysis and plasma carbonization can extract value. In controlled environments, plastics and mixed waste can be heated in oxygen-limited conditions to produce coal-equivalents, syngas (mixture of hydrogen and carbon monoxide), and bio-oils that serve as alternative fuels.
Scientific literature confirms that pyrolysis of plastic waste yields significant quantities of liquid fuels and syngas, which may support industrial heating or power generation if emissions are carefully managed. This aligns with Dr. Sarath Babu’s description of producing “coal,” “bio-oil,” and “syngas” from city waste without harmful airborne emissions in a closed loop system.
From RDF to Waste-Derived Fuels
India’s solid waste management policy framework includes guidelines for converting municipal solid waste into Refuse-Derived Fuel (RDF) and alternative fuels for industry, including cement plants and thermal power stations. RDF is a combustible fuel produced by shredding and dehydrating combustible components such as plastics, paper, and textiles.
Recent government updates include a policy for co-firing municipal waste-derived charcoal and biomass with coal in thermal power plants to reduce emissions and support cleaner energy transitions. Such frameworks provide a regulatory opening for scalable utilization of city wastes as inputs to energy systems, cement kilns or industrial heat circuits — an agenda that Dr. Sarath Babu advocates through deployment of his technologies.
City Scale Waste Flows
Dr. Sarath Babu provided an estimate for Hyderabad’s municipal waste: approximately 7,000 tonnes per day of household solid waste from its population base, plus an additional ~3,000 tonnes from commercial sources, totalling around 10,000 tonnes daily. He described logistical costs of transporting waste to distant dumping grounds and the environmental impacts of legacy landfills that emit offensive gases and odours across wide areas.
These issues mirror national waste-to-energy planning challenges. Major cities like Delhi and Bengaluru are scaling scientific waste processing plants — Delhi with plans for new waste-to-energy facilities to process thousands of tonnes per day, and Bengaluru sending segregated waste to RDF-based plants to generate electricity.
Circular Economy & Construction Materials
Beyond fuels, Dr. Sarath Babu outlined value-added applications of processed waste. He described converting residual inert materials (sand, stone fractions) — along with carbonized outputs — into eco-bricks, paving blocks, tiles, and construction aggregates. Independent tests at technical institutes have shown such materials can meet industry strength standards, offering lower-cost alternatives to conventional bricks and paving materials, he noted.
Such applications reflect broader global efforts to integrate waste materials into construction sector value chains.
Technology, Innovation & Execution Challenges
Dr. Sarath Babu acknowledged that while robust technologies exist — including closed-loop carbonization reactors, syngas cleanup systems, and automated optical sorting — policy execution, institutional inertia, and risk aversion remain hurdles. He recounted challenges in securing approvals, long administrative processes, and the reluctance of officials to adopt novel systems despite national mandates and environmental imperatives.
This resonates with broader national observations: India’s Solid Waste Management Rules and related policies call for source segregation and scientific processing of waste, but implementation gaps persist across municipalities.
Waste as a Scientific Asset
Dr. Sarath Babu concluded with a powerful affirmation: when waste is treated scientifically, it ceases to be waste. Through thermal conversion, material recycling, and integration into industrial energy systems, refuse becomes alternative fuels, carbon products, construction materials, and economic opportunities.
His vision is not only technological but societal — a circular economy where waste streams are valorized in ways that protect public health, recapture energy value, and reduce environmental burdens.
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