Proper waste segregation, composting and community participation are essential to sustainable solid waste management, Prof. Ligy Philip of IIT Madras said during a lecture organised by Nagaland University’s Committee for Mission LiFE at Lumami on October 21.
Prof. Philip, Institute Chair Professor in the Department of Civil Engineering at IIT Madras, delivered the lecture in hybrid mode, with the in-person session held at the Conference Hall of the Department of Environmental Science (EVS).
She highlighted the environmental and public health risks of improper waste disposal, particularly open dumping, which can contaminate groundwater and surface water through leachate, degrade soil quality and contribute to air pollution and methane emissions. She also drew attention to the growing concern over microplastics and their potential to carry toxic pollutants into the environment.
Prof. Philip noted that urban areas generally generate more waste per capita than rural communities, largely because of packaged food, commercial activity, rising incomes and changing lifestyles. While rural households generate substantial biodegradable waste, much of it is reused for feeding livestock and does not necessarily reach central waste-management facilities.
Emphasising segregation at source, she said waste should be separated into biodegradable, non-biodegradable and sanitary categories. Kitchen and garden waste can be converted into compost or processed through biomethanation, while recyclable materials such as paper, plastics, metals and glass should be kept clean and segregated. Sanitary waste, including diapers, sanitary napkins and medical sharps, requires separate handling to prevent contamination and protect sanitation workers.
She outlined the waste-management hierarchy, which prioritises waste reduction and reuse, followed by recycling, composting, waste-to-energy recovery and sanitary landfilling. She stressed that reducing waste generation in the first place was preferable to disposal and clarified that sanitary landfills, unlike open dumps, are engineered facilities designed to minimise environmental contamination.
Prof. Philip identified composting as a practical, decentralised method of managing biodegradable waste. Depending on the method used, mature compost can generally be produced within 20 to 60 days. She said appropriate temperature, moisture and carbon-to-nitrogen balance were important for effective decomposition and odour control. Methods such as pit composting, windrow composting, vermicomposting and mechanical composting can be adopted at household and municipal levels.
Highlighting the importance of community participation, she cited a corporate social responsibility-supported sustainable-villages programme implemented in more than 12 villages, integrating waste segregation, collection, composting, recycling, wastewater management and community training. In one village, improved composting practices reportedly produced mature compost within 20 to 25 days, which was sold at Rs 25 per kg. Revenue from compost and recyclable materials was said to cover approximately one-third of the operating costs.
The programme, she said, demonstrated how awareness, suitable infrastructure and sustained community involvement could help turn waste into a resource and support local waste-management efforts.
Peter Ki, PRO, Nagaland University, introduced the resource person. The lecture concluded with a question-and-answer session, followed by a vote of thanks proposed by Dr. Latonglila Jamir, Head of the Department of EVS. Faculty members, staff, research scholars, postgraduate students and members of the university’s Committee for Mission LiFE attended the programme.