Waste: a problem or a resource? by Green shells
Extraction of material and energy from waste by treating it as resource.This can be achieved by segregation of waste at source.
Worldwide municipal solid waste generation is nearly about 1.9 million tonnes(Waste atlas) which can be converted into useful materials and/or energy instead of land filling. This would help us reduce million of tonnes of CO2 emissions into environment. Here we describe a holistic approach to waste management
Waste is being created whenever a process is carried out. For example; in kitchen during cooking when skins of vegetables are removed and thrown, waste is generated. Waste is also being generated when life cycle of a product ends. For example, used batteries, electronic items, plastic items, torn clothes etc. Many of these products are generally thrown and go to landfills. All this accounts to municipal solid waste. Another waste which is termed as industrial waste is being generated whenever a process is carried out which leads to generation of by-product or co-product which is useless and hence thrown.
Now the key is to segregate the waste at source where it is being generated. Once it is segregated it can be treated properly. Mixed waste always creates a problem as the organic and inorganic materials are mixed they cannot be utilised or recycled. Municipal solid waste consists of recyclables, organic waste and some inert. Recyclables like metal, plastic and paper goes to their recycling unit. Organic waste can be made converted into compost and can be used in gardens. This can be done by individuals or communities. Further if large amount of organic waste is generated it can be converted in bio-gas and used as cooking fuel. On city level we can use this waste as resource to generate electricity. Organic solid waste will be converted into methane in a bio-reactor which can produce electricity.
Instead of ‘cradle to grave’ approach the approach should be of ‘cradle to cradle ‘. The product must be recycled, and raw material extracted form it can be used to make a product again. This can also help us save our natural resources.
Category of the action
Reducing emissions from waste management
What actions do you propose?
All the household waste generated must be segregated at the source. Recyclable waste goes to their respective recycling facility. For example; Paper waste (resource) goes to paper mills for recycling. Similarly e-waste (resource) goes to electronic recycling centre( already in existence) where the raw materials are processed and recovered. Organic food waste (resource) goes to either composting or biogas generation or can be used to generate electricity. This can be done on household level or/and community level or/and city level. Four different dustbins- food waste, recyclable waste, general waste, hazardous waste/biomedical waste to be setup on community level for segregation of waste. This segregation will help to treat each waste easily. These dustbins can be made smart dustbins accompanied with ultrasonic level sensors. Further a smart collection system is must for the collection of this waste from the bins. This system will get to know the amount of wastes filled in different areas in the city which will help to save on petrol cost and extra vehicular emissions otherwise.
This can be summarized as follows
1) Segregation of waste at source
2) Extraction of raw materials from the waste
3) Organic waste to composting and bio-gas generation
4) Waste to electricity generation via biomethanation in a bio-reactor
Source : USEPA
Who will take these actions?
Actions to be taken by/for individuals
1) Awareness to citizens
2) Educating people about sustainable practises
3) Reusing and reducing unwanted usage of resources
4) Segregation of waste at source
5) Recyclables to recycling unit
6) Organic waste to compost/ energy generation
Actions to be taken by government
1) Campaigns for awareness
2) Strict law for segregation of waste
3) Smart collection system for Collection of segregates
4) Community level different smart dustbins for wet waste, dry waste, plastic and hazardous waste /biomedical waste
5) Community level composting/ biogas
6) Organic waste to energy plant via biomethanation
7) Waste tax (already in India know as Swachh bharat cess)
8) Incentives to recycling companies
Actions to be taken by recycling companies
1) Tie-up with societies and collection of recyclable materials
Actions to be taken by organization, hospitals, universities, big institutes etc
1) They can setup their own bio-gas facility which can be used for cooking.
2) They can utilise heat generated for generation of electricity, HVAC system, etc
Actions to be taken by NGO’S
1) Awareness campaigns for waste segregation, composting, gardening etc.
Where will these actions be taken?
All over the world these actions can be carried out. But this proposal has been made by keeping India in mind.
What are other key benefits?
Almost No waste to landfills.
Clean and hygienic environment
As the waste is segregated and recycled we would be Saving our resources for our future generation. (Sustainable resource conservation)
Reduction in our carbon footprints
Waste is used as resource.
Composting would reduce the use of chemical fertilizer
Bio-gas generation can be used as cooking fuel
How much will emissions be reduced or sequestered vs. business as usual levels?
Presently landfills and incineration are carried out of mixed waste which leads to pollution. Landfills generate methane a green house gas which goes to environment if not captured. Since methane is not produced in a controlled way. According to USEPA, 36.7 million tonnes of methane was generated globally from landfills in 2000. Nearly about 10% of methane generated from landfills is captured and utilized. Remaining all the methane generated goes into environment. As we know methane has a global warming potential of 25 times more effective of a greenhouse gas than carbon dioxide over a 100-year time horizon.
Hence, instead of landfill other methods like composting, waste to energy can be employed wherein the generation of methane is regularized and controlled. Therefore we could save 36 million tonnes of methane going to environment.
It is important that we recover all the materials from the waste so that we can conserve our natural resources
What are the proposal’s costs?
Economic cost would include cost of
1) Go Green Campaings / awareness to citizen
2) Smart Dustbins with smart collection system
3) Setting up composting facility – for housing societies, schools, universities,etc
4) Setting up bio-gas plant for schools, hospitals, organization,etc.
5) Setting up city level waste to energy plants
This cost would vary depending on the amount of waste generated and also will depend on the area/location in world where this approach is to be applied.
Some of the negative side effects of the proposed action
Composting would lead to some CO2 generation during aerobic digestion. But if we reduce the use of chemical fertilizer and use organic compost, we would save emissions on the manufacturing of fertilizers
Further, during generation of electricity, via methanation, methane os burnt and converted into water and CO2. This CO2 is again a problem if it is going to environment. For solving this problem we can use carbon capture and carbon storage technology.
These actions can be carried out over the period of short term as it is the combination of the pre-existing technologies. A planning on city level is required, knowing the amount of waste generated per person, one can determine the amount of treatment facilities required for the same. Hence after a period of 8-10 years there will be no waste going to landfills. Whatever waste is generated will be used as resource to either convert it into raw materials or into energy.