Q. Write an account on the possible approaches for management of wastes and their potential to generate energy in India. [48-52 BPSC/2009] ©crackingcivilservices.com
Ans:
Waste management includes the activities and actions required to manage waste from its inception to its final disposal. This includes the collection, transport, treatment and disposal of waste, together with monitoring and regulation of the waste management process.
Waste can be solid, liquid, or gas and each type has different methods of disposal and management. Waste management deals with all types of waste, including industrial, biological and household.
Urban India generates 62 million tonnes of waste (MSW) annually, and it has been predicted that this will reach 165 million tonnes in 2030. Out of the total generated waste, less than 60% is collected and around 15% processed.
The wastes are of various types: Municipal waste (e.g. household waste, construction and demolition debris, sanitation residue, and waste from streets), Hazardous waste (e.g. industrial and hospital waste containing toxic substance), E-waste ( discarded and end-of-life electronic products like computers, equipments used in ICTetc ) etc.
The possible approaches for management of wastes:
- Open dumps:
- Open dumps refer to uncovered areas that are used to dump solid waste of all kinds. The waste is untreated, uncovered,and not segregated.
- It is the breeding ground for flies, rats, añnd other insects that spread disease. The rainwater run-off from these dumps contaminates nearby land and water thereby spreading disease.
- Treatment by open dumps is to be phased out.
- Landfills:
- Landfills are generally located in urban areas. It is a pit that is dug in the ground.
- The garbage is dumped and the pit is covered with soil everyday thus preventing the breeding of flies and rats.
- Thus, every day, garbage is dumped and sealed. After the landfill is full, the area is covered with a thick layer of mud and the site can there after be developed as a parking lot or a park.
- Problems: All types of waste are dumped in landfills and when water seeps through them it gets contaminated and in turn pollutes the surrounding area. This contamination of groundwater and soil through landfills is known as leaching.
- Sanitary landfills:
- Sanitary landfill is more hygienic and built in a methodical manner to solve the problem of leaching.
- These are lined with materials that are impermeable such as plastics and clay, and are also built over impermeable soil.
- Constructing sanitary landfills is very costly.
- Incineration plants:
- The process of burning waste in large furnaces at high temperaturs is known as incineration.
- In these plants the recyclable material is segregated and the rest of the material is burnt and ash is produced.
- Burning garbage s not a clean process as it produces tonnes of toxic ash and pollutes the air and water. A large amount of the waste that is burnt here can be recovered and recycled.
- In fact, at present, incineration is kept as the last resort and is used mainly for treating the infectious waste.
- Pyrolysis:
- It is a process of combustion in absence of oxygen or the material burnt under controlled atmosphere of oxygen. It is an alternative to incineration. The gas and liquid thus obtained can be used as fuels.
- Pyrolysis of carbonaceous wastes like firewood, coconut, palm waste, corn combs, cashew shell, rice husk paddy straw and saw dust, yields charcoal along with products like tar, methyl alcohol, acetic acid, acetone and a fuel gas.
- Composting:
- Composting is a biological process in which micro-organisms, mainly fungi and bacteria, decompose degradable organic waste into humus (excellent medium for growing plant)like substance in the presence of oxygen.
- Apart from being clean, cheap and safe, composting can significantly reduce the amount of disposable garbage.
- Vermiculture:
- It is also known as earthworm farming, In this method, Earth worms are added to the compost. These worms break the waste and the added excreta of the worms makes the compost very rich in nutrients.
- Four R’s: Refuse, reduce, reuse and recycle.
- Bioremediation:
- In this process, the micro-organisms (bacteria and fungi) are used to degrade the Hazardous wastes into less toxic forms.
- In-situ bio-remediation techniques are Bio-venting, Bio-sparging and Bio-augmentation.
- Ex-situ bio-remediation techniques are Landfarming, Bio-piles, Bio-reactors and composting.
- Hazardous wastes can be converted to non-toxic products using this natural degradation process. The limitations are that is takes a long time, and controlling the natural process of degradation can be hard.
- Plasma Gasification:
- This process of waste management utilises highly ionised or electrically charged gases called plasma within a vessel to convert carbon-based materials into fuel.
- It is an emerging technology that treats hazardous waste by converting incinerator ash or chemicals into non-hazardous slag. The high temperature and lack of oxygen prevent the formation of toxin compounds like dioxins, NOX, furans or sulphur dioxide.
- The whole processing of waste is ecologically clean, converting solid or liquid wastes into a syngas.
- Waste to Energy (WtE):
- An efficient disposal system is essential to save ourselves and the environment from non-recyclable items. The disposal technique generates heat or electricity from waste materials.
- Reducing the need for fossil fuel can help decrease carbon emission.
- Waste to wealth techniques:
- Use of plastic waste in road construction.
- Toys from Trash: e.g. Padma Shri recipient, Arvind Gupta speaks about creating toys from recycled products to help create an equal and sustainable education system
The potential to generate energy through waste in India:
- According to Ministry of New and Renewable Energy estimates:
- The solid waste generated from cities/towns in India has a potential to generate power of approximately 500 MW, which can be enhanced to 1,075 MW by 2031 and further to 2,780 MW by 2050.
- The total estimated energy generation potential from urban and Industrial organic waste in India is approximately 5,690 Megawatt. (Minister of MNRE in a written reply in Parliament)
- India has so far installed 96 waste-to-energy projects for generation of power based on urban, industrial, agricultural and municipal solid waste.
- Current Capacity: There are five municipal Waste to Energy plants operational in India, with a total capacity to produce 66.4 MW electricity per day, of which 52 MW per day is generated in Delhi.
- Types of Technique at waste to energy:
- Incineration It uses MSW as a fuel, burning it with high volumes of air to form carbon dioxide and heat. In a waste-toenergy plant that uses incineration, these hot gases are used to make steam, which is then used to generate electricity.
- Gasification is a process that converts organic or fossil fuel based carbonaceous materials into carbon monoxide, hydrogen and carbon dioxide.
- Pyrolysis involves application of heat with no added oxygen in order to generate oils and/or syngas (as well as solid waste outputs) and requires more homogenous waste streams.
- Biomethanation is a process by which organic material is microbiologically converted under anaerobic conditions to biogas. It involves fermenting bacteria, organic acid oxidizing bacteria, and methanogenic archaea.
- Need of Waste to Energy Plants:
- Problems of unscientific Municipal Solid Waste (MSW) disposal: Only about 75- 80% of the municipal waste gets collected and out of this only 22-28 % is processed and treated and remaining is disposed of indiscriminately at dump yards. It is projected that by the year 2031 the MSW generation shall increase to 165 million tonnes and to 436 million tons by 2050.
- Harmful emission from Landfills: Organic decomposition of food waste mixed with municipal solid waste at landfill sites leads to high amounts of emissions which is also a public health issue.
- Net Greenhouse Gas Reducer: Methane is a greenhouse gas which is mostly emitted from decomposing waste in landfills. WtE facilities avoid the production of methane while producing almost ten times more electricity from each ton of waste compared to landfills.
- Resource savings and recovery greatly expanded: Metals left in the municipal solid waste stream can be extracted from the ash resulting from incineration and the metals can be recycled.
- 24*7 Electricity: WTE facilities, unlike wind and solar, are capable of providing 24*7 renewable electrical power.
- Landfill usage and expansion greatly reduced: Waste to energy facilities typically reduce waste volumes by 90%. Fewer and smaller landfills are needed to process.
- Transportation of waste long distances can be greatly reduced with a waste to energy facility in a community, resulting in less air pollution
- Challenges:
- Low Calorific Waste: Municipal waste in India is often not segregated properly. It has a very high biodegradable (wet) waste content ranging anywhere between 60 and 70 per cent of the total, compared with 30 per cent in the West. This gives our waste a high moisture content and low calorific value. In Delhi, for example, only 12 per cent of the waste can be thermally treated through incineration technologies.
- High Toxic Waste: Incinerators develop toxic ash or slag, containing heavy metals and gas pollutants which are toxic (corrosive impact) and pollute underground water.
- Expensive power: Compared to Rs 3-4 per kWh from coal and solar plants, WTE plants sell electricity at about Rs 7/kWh.
- Lack of indigenous technology, and high capital and operation and maintenance costs of waste-to-energy systems
- Lack of Finance for Urban Local Bodies (ULBs) affects institutional capacity necessary for integrated management of municipal solid waste, which requires investments for WtE projects.
- Other Challenges include irregular and inadequate quantity of supply; non-payment of agreed fee and non-marketability of waste processed projects, including power.
- Protests by locals against setting up such plants:
- Recently, residents of Okhla and surrounding areas in Delhi have been protesting against WtE plant in their vicinity.
Government Initiative:
- NITI Aayog in its Three-Year Action Agenda 2017-18 to 2019-20 has suggested that municipal solid waste be burnt to produce energy. Some proposals are:
- Composting and biogas are not sustainable since they generate by-products or residues in large quantities. Only incineration, thermal pyrolysis and plasma gasification technologies offer sustainable disposal solutions.
- Incineration is preferable to pyrolysis (which is unsuited for our municipal solid waste) and plasma technology (which is too costly).
- Setting up Waste to Energy Corporation of India, under the Ministry of Urban Development, to speed up the process of cleaning municipal solid waste.
- Program on Energy from Urban, Industrial and Agricultural Waste/Residue for creating conducive conditions and environment with fiscal and financial regime to develop, demonstrate, and disseminate utilization of wastes and residues for recovery of energy.
- Central financial assistance (CFA) in the form of capital subsidy and grants-in-aid will be provided for biogas production from industrial waste, sewage treatment plants, etc.
- Swachh Bharat Mission (SBM), 100% scientific processing and disposal of municipal solid waste is envisaged by 2019. WTE plants are key to Mission since they lead to the most scientific disposal of waste.
- Niti Aayog has, under the Swachh Bharat Mission, set a target of constructing 800 megawatt (MW) of WTE plants by 2018–19, which is ten times the capacity of all the existing WTE plants put together.
- India’s Solid Waste Management policy requires that wet and dry wastes should not be mixed so that only noncompostable and non-recyclable wastes with at least 1500 Kcal/kg should reach WtE plants.
Yes, India needs to spend a lot of money to create an effective waste management infrastructure but a clean India will be able to earn more by attracting more tourists. Moreover, new jobs will be created and people will start looking at waste as an opportunity to create wealth.
As India continues to rebuild, its citizens should ensure that they avoid reaching the dangerous levels of the average westerner in plastic consumption and waste production because waste reduction is better than any kind of waste management. And India’s traditional wisdom of “Aparigraha” (the virtue of non-possessiveness, non-grasping or non-reediness) which is very relevant even today can play a key role in achieving that. ©crackingcivilservices.com
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