Recycling or chemical stabilization? Greenhouse gas emissions from treatment of waste containing mercury under the Minamata Convention

Appropriate management of waste containing mercury is important. However, reducing greenhouse gases (GHGs) associated with this process is equally important, warranting research into waste management methods that emit the least amount of GHGs. We evaluated GHG emissions from recycling systems of spent fluorescent lamps and dry cell batteries discarded by households in Japan using a life cycle assessment technique. The results show significant GHG reduction from resource recovery; therefore, it is essential to ensure that resource recovery is conducted properly. Regarding the spent fluorescent lamp recycling system, the transportation process contributes a large amount of GHG emissions if the waste is not crushed. It is recommended that they be crushed before being transported to improve transportation efficiency. The larger the population of a city, the lower the per-capita collection of waste containing mercury. Due to the hazardous nature of mercury, it is necessary to encourage its separate collection. The demand for mercury will decrease in the future, and it is possible that collected mercury will be disposed of through chemical stabilization. This study clarifies no significant, less than 0.01 kg-CO(2)e/kg-waste, increase in GHG emissions associated with the transition from mercury recycling to chemical stabilization.

Automated summary

Proper waste management containing mercury is important, and reducing associated greenhouse gas emissions is equally important. The study evaluated the greenhouse gas emissions from recycling systems of fluorescent lamps and dry cell batteries and highlighted the significant reduction achieved through resource recovery. It emphasized the need for proper resource recovery and recommended crushing the waste before transportation for improved efficiency. The study also emphasized the importance of separate collection for hazardous waste containing mercury and clarified no significant increase in greenhouse gas emissions associated with the transition from mercury recycling to chemical stabilization.