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The Hidden Costs of Incinerating and Landfilling Plastics

In our modern world, the disposal of plastic waste has become a pressing issue, with incineration and landfilling being two common methods employed. However, the negative impacts of these practices are far-reaching, affecting both the environment and public health, while also presenting operational challenges for incineration companies. Let’s delve into the complexities surrounding the incineration and landfilling of plastics, exploring the detrimental effects of emissions from burning, the consequences of burying bottom ash, and the physical impact on incinerator operations.

Emissions from Incineration:

Incineration operations pose significant challenges, especially when dealing with polymers. These challenges stem from the high calorific value of plastics, which can lead to erratic energy release during incineration. The combustion of polymers often results in temperature spikes, causing damage to incinerator refractories and necessitating regular cleaning to prevent corrosion.

Furthermore, the incineration of certain plastics, such as polyvinyl chloride (PVC), can release chlorine gas and other harmful byproducts. Chlorine emissions contribute to air pollution and can lead to the formation of toxic compounds like dioxins and furans. These emissions not only pose regulatory concerns but also have adverse effects on equipment, causing corrosion and fouling.

The existence of chlorine in the gas phase can also lead to the volatilization of heavy metals, contributing to corrosion mechanisms that reduce the lifetime of equipment like superheater tubes in high-pressure steam boilers. Such corrosion issues highlight the complex interplay between polymer combustion and the release of hazardous substances.

Impacts of Burying Bottom Ash:

Beyond the emissions from burning plastics, the disposal of bottom ash presents its own set of challenges. Bottom ash is the residue left after the combustion process and consists of non-combustible materials such as metals, glass, and other inert substances. This ash can be rich in heavy metals and other pollutants. When buried in landfills, these pollutants can leach into the soil and groundwater, posing risks to human health and the environment.

Studies have shown that bottom ash from medical waste incineration contains higher levels of heavy metals compared to municipal solid waste bottom ash. Additionally, incomplete combustion during incineration can lead to the formation of persistent organic pollutants such as polychlorinated dibenzo-dioxins and furans, as well as polycyclic aromatic hydrocarbons (PAHs). These pollutants persist in the environment, posing long-term risks to human health due to their carcinogenic properties.

Operational Challenges for Incineration Companies:

In addition to environmental and public health concerns, incineration companies face operational challenges when dealing with plastics. The high calorific value of polymers can lead to temperature spikes and refractory damage, requiring frequent maintenance and repairs. Moreover, the presence of chlorine in plastics like PVC can cause corrosion and fouling of equipment, further increasing operational costs.

Furthermore, the physical impact of burning plastics can pose challenges for incinerator operations. The rapid combustion of polymers can create fly ash with sticky properties, leading to deposits on furnace walls and boiler tubes. These deposits can restrict the movement of waste on grates and require additional cleaning measures to maintain efficiency.

Why Incineration Companies Might Hesitate to Burn Plastics:

Given the operational challenges and environmental risks associated with burning plastics, some incineration companies may hesitate to incinerate these materials. The unpredictable nature of polymer combustion and the potential for equipment damage can increase operational costs and liabilities for incineration facilities. Moreover, concerns about emissions and public perception may discourage incineration companies from accepting plastics for disposal.

In conclusion, the disposal of plastics through incineration and landfilling comes with significant negative consequences for both the environment and public health, while also presenting operational challenges for incineration companies. Addressing these challenges requires a holistic approach that prioritizes waste reduction, recycling, and the development of sustainable waste management practices. Only by reducing our reliance on incineration and landfilling can we mitigate the adverse impacts of plastic waste disposal and move towards a healthier, more sustainable future.