Waste to Energy (WTE): Will it work for BD?
Municipal Solid Waste (MSW) or Garbage generation is increasing faster with increasing population in developing countries. Sustainable waste management is a major challenge for both mega cities like Dhaka with 20 million people and smaller cities/rural areas. The availability of land/space for building waste management systems (landfills, composting, recycling, and/or Waste to Energy, WTE) can constrain the decision making. However, we need to pay special attention on: (1) availability of land/space and (2) applicability of technology in a specific region (based on waste characteristics). The last one works for developed countries but may not be applicable to Bangladesh.
Waste to Energy (WTE) or Incineration can provide a lucrative solution to waste management as WTE plants may address the issue of land/space in both developed and developing countries. WTE or incineration system requires less land or space and can process a large volume of waste in a single processing plant. It is an appropriate technology for waste management in developed countries (European countries, USA, Japan, South Korea) as their waste is relatively dry, and the presence of a large amount of plastics, paper, and other combustible materials make it a good source of energy.
Bangladesh Constitution was amended in 2011 to include a constitutional directive to the State to protect the environment and natural resources for current and future generations. The current decision of adopting waste management through WTE or incineration directly opposes the policy of Prime Minister Sheikh Hasina's vision and plan for a sustainable urban environment for Bangladesh. In this write up I have highlighted major issues that need in-depth feasibility studies and evaluations when considering the WTE in developing economies and Bangladesh:
1. Applicability: Waste in developing countries like Bangladesh has high amount of food waste (more than 70%), and moisture content compared to similar waste in European countries. Generating power through WTE or incineration using this low calorific (organic waste), highly wet waste is neither applicable not cost-effective. However, following the success of the WTE plant in Europe and intense lobbying from many WTE companies, many developing countries including Bangladesh are trying to use WTE technology without understanding the applicability of the WTE/Incineration technology or their serious environmental and public health consequences. WTE is not an appropriate technology for Bangladesh.
2. Cost: Very expensive operation - both initial capital investment and operating cost of the WTE. Moreover, the technology does not apply to the type of waste we are dealing with in Bangladesh and other developing countries.
3. Environment and public health concerns:
Bottom ash: Waste to energy plant generates 20% bottom ash from burning the waste. In most cases, there is no plan for managing the generated bottom ash. They end up in our water bodies polluting the nearby rivers and creating a serious problem for clean water and agricultural lands.
Air pollution: Difficulty in controlling air pollution from the toxic emission from WTE plants and, in many cases, enforcing air pollution regulations. Incinerator emissions are also a source of particulate matter (PM 2.5) -tiny particles of dust that can lead to decreased lung function, irregular heartbeat, heart attacks, and premature death. On March 23, 2019, South Delhi residents organized one of the largest open-chain rallies to protest the Okhla waste-to-energy (WTE) plant. Their complaint against the plant, which generates electricity by burning waste, is spewing toxic fumes, filling the atmosphere with stench, and making people ill.
COVID-19 and WTE: In Wuhan, China, North Italy and New York, USA death from COVID 19 are higher than any other places in the world and all three places have a high number of WTE plants. Just a coincidence? Beth Gardiner reported that researchers from Harvard University's TH Chan School of Public Health analyzed data on PM2.5 levels and COVID-19 deaths from about 3,000 US counties covering 98 per cent of the US population found that counties with just one microgram per cubic meter more PM2.5 in the air increased COVID-19 death rate by 15 percent.
These tiny particles PM2.5, emitted from incineration plants, penetrate deep inside body and promotes hypertension, heart disease, breathing trouble, and diabetes, all of which increase complications in coronavirus patients. Francesca Dominici, Harvard biostatistics professor and the study's senior author said, "If you're getting COVID, and you have been breathing polluted air, it's really putting gasoline on a fire".
4. Success in developing countries: In 1987, the old Timarpur WTE plant in Delhi, India, had to shut down just 21 days after opening due to operational failure brought upon by low calorific value of incoming waste (2.5-2.9 MJ/kg) (Shah, 2011). Since 1990, 14 WTE plants were installed in India. However, half of them has already been closed, and the remaining ones are also under scrutiny. Along with the low calorific value and high moisture content of MSW, the presence of inert materials in MSW has also failed several projects in developing nations.
The major alternative solution to WTE is to consider waste as resource and design "Sustainable Resource Management Facility (SRMF)". SRMF include maximum material recovery and diversion (through recycling, composting, cost effective locality based Anaerobic Digester (AD) before final disposal and processing of waste through perpetual landfill and/or WTE. Perpetual landfill, operated as biocell and recycles landfill space, can continue operation in same place as much as 200 years.
This addresses the issue of space availability for construction of new landfills in every 20/30 years. Moreover, collection of generated gas through AD and biocell and conversion to electricity can provide access to electricity in remote areas where electric grids are not available. The SRMF will create green jobs and become a perfect example of circular economy in developing countries. WTE can also be used for metropolitan cities if waste characteristics are suitable for the technology.
The writer is a professor, Civil Engineering at the University of Texas at Arlington, USA. He is also the director, Solid Waste Institute for Sustainability (SWIS)