Nagaland University’s Committee for Mission LiFE organised a lecture on Solid Waste Management in hybrid mode at Lumami on October 21, highlighting the importance of waste segregation, recycling, composting and community participation in addressing environmental and public-health challenges.
Lecture on Solid Waste Management at NU.
The lecture was delivered by Prof Ligy Philip, Institute Chair Professor in the Department of Civil Engineering at IIT Madras. The physical session was held at the Conference Hall of the Department of Environmental Science (EVS), while participants also joined online. A brief introduction of the resource person was presented by Peter Ki, Public Relations Officer (PRO), Nagaland University.
n her lecture, Prof Philip emphasised that effective solid waste management was essential for protecting public health, preserving soil and water resources, and promoting sustainable development.
She explained that waste generation varies considerably between rural and urban areas. Rural communities generate approximately 0.1 to 0.4 kg of waste per capita per day, compared with 0.5 to 1.2 kg in urban areas. The higher generation rate in towns and cities is largely associated with packaged and ready-to-eat food, commercial activities, rising incomes and changing lifestyles.
In rural areas, a substantial proportion of domestic waste is biodegradable and often reused within households, including as livestock feed, meaning it does not always reach centralised waste-management facilities.
Prof. Philip cautioned that improper waste disposal, particularly open dumping, poses serious environmental and public-health risks. Rainwater passing through unsegregated waste can produce leachate containing heavy metals, organic pollutants and hazardous household substances, potentially contaminating groundwater and surface-water sources.
Plastic waste can also degrade soil structure, reduce its water-absorption capacity and affect agricultural productivity. Open dumping encourages the breeding of disease vectors such as rats and mosquitoes, releases methane from decomposing organic matter and contributes to air pollution.
She further highlighted the growing concern over microplastics, defined as plastic particles smaller than five millimetres, which can adsorb toxic pollutants and potentially contaminate soil and groundwater.
Emphasising that sustainable waste management must begin at the source, Prof. Philip advocated proper waste classification and segregation into at least three categories: organic or biodegradable waste, non-biodegradable waste and sanitary waste.
Organic waste, including kitchen and garden refuse, can be converted into compost or processed through biomethanation. Non-biodegradable waste includes plastics, paper, textiles, metals, glass and electronic waste, much of which can be recycled when kept clean and properly segregated.
Sanitary waste, including diapers, sanitary napkins, bandages, syringes and needles, requires separate handling to prevent contamination of recyclable materials and protect sanitation workers.
She outlined the preferred waste-management hierarchy, placing source reduction and reuse first, followed by recycling, composting, waste-to-energy recovery and sanitary landfilling. Carrying reusable cloth bags instead of accepting single-use bags was cited as an example of preventing waste generation at source.
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While recycling recovers valuable materials and composting converts biodegradable waste into nutrient-rich soil conditioner, Prof. Philip stressed that landfilling should be the last resort for residual waste after maximum resource recovery. She distinguished sanitary landfills from open dumps, explaining that engineered landfills use protective liners, leachate-collection systems, daily covering and other measures to prevent groundwater contamination.
Composting and community participation
Prof. Philip identified composting as one of the most practical decentralised solutions for managing biodegradable waste. She explained that effective aerobic composting requires suitable temperature, moisture and carbon-to-nitrogen balance to support decomposition and control odour.
Organic waste should reach approximately 55 to 60 degrees Celsius for three to five days under appropriate composting conditions to help destroy pathogens. Mature compost can generally be produced within 20 to 60 days, depending on the method used. Maintaining a carbon-to-nitrogen ratio of about 30:1 and moisture content of around 40 to 45 per cent is also important for effective decomposition.
She discussed various methods, including pit composting, windrow composting, vermicomposting and mechanical or in-vessel composting, which can be adopted according to operational scale, ranging from individual households to municipalities.
Highlighting the importance of community participation, Prof. Philip referred to a corporate social responsibility-supported sustainable-villages programme implemented in more than 12 villages. The initiative integrated waste segregation, collection, composting, recycling, wastewater management and community training.
In one village, improved composting practices reportedly enabled mature compost to be produced within 20 to 25 days and sold at ₹25 per kilogram. Income generated from compost and recyclable materials was reported to cover approximately one-third of the operating costs.
She said the initiative demonstrated how awareness, community involvement, appropriate infrastructure and sustained local participation could transform solid waste from an environmental burden into a valuable resource.
The lecture concluded with an interactive question-and-answer session. Dr. Latonglila Jamir, Head of the Department of Environmental Science, proposed the vote of thanks.
Faculty members, staff, research scholars, postgraduate students and members of Nagaland University’s Committee for Mission LiFE attended the programme.
