Developing countries have been witnessing rapid industrialization, high population growth rate, and fast urbanization that have resulted in increased levels of waste. Big cities with a population of over millions and per capita waste generation of 1 to 2 kg per person per day produce huge amount of waste. The majority of the population is concentrated in urban areas, which make it necessary for the government to initiate measures to increase recycling and Solid Waste Management (SWM) scenario in the country. Solid waste generation in the large cities exceeds 6 million tonnes per year, which indicates the enormity of the problem faced by civic bodies.
The garbage is collected from individual or community bins and, after some mechanical treatment for segregation, disposed in landfills or dumpsites. Most of the landfills are expected to reach their capacities within the next 10 years. Although they are getting increased attention, recycling and energy recovery remain at an early stage. The recycling rate, mostly manual and labour intensive, ranges from 10% to 15%; this is mainly due to the presence of informal sector that extracts paper, metals, and plastics from municipal waste.
The waste dumped at bi cities’ landfill is about 2000 tonnes/day, solid waste is collected through large bins placed all around the commercial and residential areas. The collected waste is first taken to the transfer stations and then ultimately sent to the dumping site.
Composting is gaining increased interest due to the high organic content (around 40%) of municipal solid waste (MSW). Efforts are also underway to deploy Waste-to-Value (WtV) technologies, and all activities are coordinated and financed by the government. The government is aware of the critical demand for SWM solutions, and is investing heavily in solving this problem.
Waste management includes numerous activities including collection, separation, recycling and various ways of waste disposal such as landfilling, composting, incineration and to some extent conversion to fuel and chemicals. It is noteworthy that a significant portion of greenhouse gas emissions in the world is related to the landfilling sites and incinerators in the waste management sector.
WtV projects offers the following benefits:
- Upcycling waste such as MSW to high-value chemicals, heat and power and producing revenue
- Lessening the waste landfill by nearly 60% to over 90%, depending on the waste composition and the adopted WtV technology
- Reduction of the demand for land, which is already scarce in cities, for landfilling
- Reduction of the cost of transportation of waste to faraway landfill sites
Feedstocks for the WtV technologies are summarised below:
- MSW
- Sewage sludge from sewage treatment of industrial or municipal wastewater
- Commercial and industrial waste
- Construction and demolition waste
- Scrap tyres
- Waste textiles
- Reject from manufacturing