Reports

• Incineration


  The treatment of waste material by combustion of organic substances present in the waste materials

  
• Incineration is not a preferred method of disposal because it can result in the emission of dioxins and other atmospheric pollutants, and it contributes to global warming

  
• Incineration with energy recovery


  The next best option to recycling for waste management

  
• In more modern facilities, the resulting byproducts can be recovered and used for other purposes, recycling them in effect
• Republic Act No. 8749 or the "Clean Air Act of 1999" (RA 8749)


  Section 20 prohibits incineration for treating municipal, bio-medical, and hazardous wastes if the process emits "poisonous and toxic fumes"

  
• "Poisonous and toxic fumes"


  Emissions exceeding internationally accepted standards, including those set by the World Health Organization (WHO)
• Republic Act No. 9003 or the "Ecological Solid Waste Management Act of 2000" (RA 9003)

  Promotes a systematic and comprehensive approach to solid waste management, prioritizing environmentally sound methods that maximize resource utilization and encourage waste reduction and recycling

  
• While RA 9003 doesn't explicitly address incineration, it emphasizes protecting public health and the environment, which aligns with RA 8749's restrictions

  
• Local Government Units (LGUs)

  Have primary responsibility for implementing and enforcing these national laws within their jurisdictions
• Incineration Mechanism

  1. Combustion: Waste is continuously fed into the furnace by an overhead crane

  2. Boiler/ steam turbine: The heat from the combustion is used to generate steam in the boiler

  3. Exhaust gas cleaning: The exhaust gas from the boiler is typically cleaned by advanced pollution control systems to ensure compliance with the stringent environmental standards

  
• Exhaust gas cleaning

  1. Dry or Wet scrubbers: To spray lime powder or fine atomized slurry into the hot exhaust gas to neutralize and remove the polluted acidic gases (sulphur oxides, hydrogen chloride)

  2. Activated Carbon Injection: To adsorb and remove any heavy metal and organic pollutants (e.g. dioxins) in the exhaust gas

  3. Bag house filter: To filter and remove dust and fine particulates

  4. Selective Non-Catalytic Reduction: To remove a nitrogen oxide (which is a cause of urban smog) by reacting them with ammonia or urea
• Municipal Solid Waste Incineration (MSWI) Residue

  • Bottom Ash
  • Grate Siftings
  • Boiler and Economizer Ash
  • Fly Ash
  • Air pollution control (APC) residues

  
• Bottom Ash

  Coarse noncombustible materials and unburned organic matter collected at the outlet of the combustion chamber in a cooling tank, usually combined with bottom ash

  
• Grate Siftings

  The coarse fraction of the particulate carried over by the flue gases from the combustion chamber and collected at the heat recovery section

  
• Fly Ash

  The fine particulate matter still in the flue gases downstream of the heat recovery units, is removed before any further treatment of the gaseous effluents
• Air pollution control (APC) residues

  This residue may be in a solid, liquid or sludge form, depending on whether dry, semi-dry or wet processes are adopted for air pollution control
• Types of Incinerators

  • Rotary Kiln
  • Moving Grate
  • Fluidized Bed

  
• Rotary Kiln

  Commonly used for combusting industrial and hazardous wastes, but is also used in some municipal solid waste incinerators. The principal design consists of two thermal treatment chambers: a slightly inclined primary chamber where waste is fed in (together with inlet of hot exhaust air with oxygen), rotated and thermally decomposed by the heat radiation from the secondary chamber: the re‐combustion chamber positioned at the rear of the kiln where the decomposition air and the rest waste is completely burnt with the supply of secondary air. Rotary kiln has the advantage of producing a low level of NOx and thermal destruction of hazardous chemicals.

  
• Moving Grate

  A typical combustion design of a municipal solid waste incinerator. Waste is dropped by a crane on to the descending grate, which moves into the combustion chamber and eventually moves down to drop the burnt residuals into an ash pit at the other end of the grate. The moving grate is a metallic porous bed, allowing primary combustion air to flow through from the bottom. Secondary combustion air is supplied by nozzles from above the grate, facilitating a complete combustion by the introduction of turbulence.

  
• Fluidized Bed

  Recently increased in application in municipal solid waste incinerators, although it is still mainly used for the combustion of hazardous waste. There are different types of fluidized bed combustors (bubbling, rotating and circulating fluidized bed), but the principle of the design remains the same: waste particles are suspended by the upward flow of combustion air injected from beneath so that it seems like a fluid, by which the turbulence created enhances uniform mixing and heat transfer hence an increased combustion efficiency. The advantage of fluidized bed technology is the enhanced combustion efficiency, however the pre‐condition of that is the homogenization of waste inputs in size as well as in heat value, which requires extensive pre‐treatment of waste including typically size reduction and mixing.

  
• Effective Utilization of By-Products During Incineration

  • Ash: The waste material is loaded from top and after undergoing incineration process the ash content is withdrawn from the ash door. The ash is in the form of solid lumps which can be effectively used for construction of both commercial and residential purposes.
  • Flue gases: Flue gas which are a mixture of many gases are obtained as the byproduct of the incineration process. These gases are released into an atmosphere which are the root cause of many diseases such as asthma, lung cancer, heart attacks which indirectly leads to early death of living beings.
  • Heat: Waste heat can be utilized by converting it into electricity. Thermoelectric generators are used to convert heat to energy by seebeck effect. Thermoelectric materials use a phenomenon of converting the temperature difference into an electric potential.
• Advantages of Incineration

  • Reusing Bottom Ash
  • Improved Odor and Noise Control
  • Destruction of Organic and Hazardous Waste
  • Smaller Land Footprint
  • Reduced Methane Generation

  
• Disadvantages of Incineration

  • Air Pollution
  • Ash and Wastewater Generation
  • High cost
  • Reliance on Foreign Technology
  • Lack of System Flexibility

  
• The Philippines currently prohibits incineration under the Clean Air Act (RA 8749)

  
• House Bill 2286, proposed in 2017, sought to amend both the Clean Air Act and the Solid Waste Management Act to allow WTE facilities
• This bill sparked controversy, with proponents arguing for its potential to address waste problems and generate energy, while opponents raised concerns about air pollution, public health risks, and potential inconsistencies with international environmental treaties like the Stockholm Convention on Persistent Organic Pollutants
• Factors to be weighed for incineration in the Philippines

  • Stringent emission control: Ensuring WTE facilities meet strict emission standards is crucial to minimize environmental and health risks.
  • Technology and expertise: The Philippines might require technology transfer and capacity building to ensure proper operation and maintenance of WTE facilities.
  • Public acceptance: Addressing public concerns and ensuring transparency in decision-making processes is essential

  
• Incineration, particularly WTE, presents a complex issue for the Philippines. While it offers potential benefits in terms of waste volume reduction and energy generation, significant environmental and economic concerns remain

  
• A comprehensive analysis considering the specific needs and context of the Philippines, alongside continued efforts to strengthen the 3Rs and explore alternative solutions, is crucial before considering WTE as a viable waste management strategy

  
• Advanced Oxidation Process (AOP)

  A set of chemical treatment procedures designed to remove organic (and sometimes inorganic) materials in water and wastewater by oxidation through reactions with hydroxyl radicals (·OH)
• Why AOP is important in water treatment and environmental remediation

  • Effective degradation of pollutants
  • Minimization of harmful byproducts
  • Versatility
  • Regulatory compliance
  • Complementary to conventional treatment methods
• Hydroxyl radical (·OH)

  The most used reactive oxygen species, as an oxidant in AOP, with a very high reduction potential (2.8 V)
• Classification of the AOP Process

  • Fenton's Process
  • Ozonation
  • Photocatalysis
• Fenton's Process

  Involves the use of hydrogen peroxide (H2O2) and ferrous iron (Fe2+) to generate hydroxyl radicals (·OH) which can oxidize organic contaminants
• Ozonation

  Utilizes ozone (O3) as the primary oxidant, which can directly oxidize organic compounds or generate hydroxyl radicals (·OH) through reactions with water
• Photocatalysis

  Employs a photocatalyst, typically a semiconductor material like titanium dioxide (TiO2), which generates hydroxyl radicals (·OH) when exposed to UV light
• Applications of AOP

  • Water and wastewater treatment
  • Air purification
  • Soil remediation
• Ozone (O3) is commonly used in AOP for its strong oxidizing properties. It can generate hydroxyl radicals (·OH) when combined with other chemicals like hydrogen peroxide or UV light, leading to the degradation of organic pollutants
• Challenges and Limitations of AOP

  • High operational cost - chemical used
  • High operational cost - specialized equipment
  • Climate change mitigation
• Ozone Generators

  Can be expensive, with a typical cost of around P 9,999.00. The cost can be further increased by the need for specialized equipment for their operation and maintenance